Gerbil Genetics – Definitions and Glossary
Gerbil genetics can be a daunting thing – so hopefully even if our own articles trying to explain it seem confusing and use words you need to clarify – hopefully this extensive List of Definitions will help explain a few things.
Below is a continually growing list of definitions of words used in my Gerbil Genetics and How to Breed Gerbils clusters.
They are in alphabetical order as best we can, but will be repeated throughout if they have lots of definitions or ways of being described – just to make sure you find what you are looking for.
Right, here goes…
* the way of showing that you don’t know a particular gene in your genetic notations. Some people use -, + or ^ instead for the same thing in other small animal genetic guides
a the way of writing the recessive version of the Agouti gene (A)
aa the way of writing that a gerbil does not carry the dominant Agouti gene at all – it has two identical recessive genes
A the way of writing the dominant version of the Agouti gene
AA the way of writing that a gerbil carries two identical dominant genes at the Agouti locus and therefore cannot have first generation non-agouti pups in any of their litters
Aa the way of writing that you know for sure that the gerbil carries one dominant and one recessive version of the Agouti gene
A* the way of writing that you do not know for sure whether this specific agouti-based gerbil carries either the dominant or the recessive version of the Agouti gene on their second (unseen) gene.
Agouti (Golden Agouti)
the color of a gerbil who has the original look of a wild gerbil – it has a golden-brown ticked coat, with dark eyes and a white belly. It is the most common color form of Mongolian Gerbils as it is created by all the dominant genes currently available to gerbils
agouti-based
the way to describe all the gerbil coat colors which carry the dominant Agouti gene. They will all have either AA or Aa starting their genetic notation – and it means that they all have white bellies as standard
Agouti Gene
this gene is the gene which determines whether gerbils have a ticked coat and white belly as adults. They need to be carrying at least one Agouti gene for these color traits to be seen on the gerbil itself
Algerian Fox (A* ee)
this name is an old name for a Dark-Eyed Honey
Apricot
this gerbil color describes a genetically REH gerbil that also has two versions of the underwhite dense gene – so A*eeppuwᵈuwᵈ
Argente (A* pp)
this name is given to an Agouti gerbil who also carries two versions of the pink eye gene – so A*pp. There are three versions of this color (which we call ‘the gingers’) from really dark ginger to really pale ginger depending on which colorpoint genes they carry. These colors are called Argente Golden, Argente Fawn and Argente Cream. They are genetically made in the same way as, and are the color partners of what we call, ‘the silvers’ (Lilac, Sapphire and Dove)
Argente Cream
this gerbil color describes an Argente gerbil who carries one single cʰ colourpoint gene – so A* Ccʰ pp. This is the palest color of the three Argente shades as it has the strongest colorpoint dilution. Its color partner is the Dove (aa Ccʰ pp)
Argente Fawn (Topaz)
this gerbil color describes an Argente gerbil who carries one single cᶜʰᵐ colorpoint gene – so A* Ccᶜʰᵐ pp. This is the middle color of the three Argente shades as it has only a mild colorpoint dilution. Its color partner is the Sapphire (aa Ccᶜʰᵐ pp)
Argente Golden
this gerbil color describes an Argente gerbil who carries no recessive colorpoint genes – so A*CCpp. This is the darkest of the three Argente shades as it has no colorpoint dilution. Its color partner is the Lilac (aaCCpp)
Argente Nutmeg
this name is an old name for a Saffron (aa ee)
Azure Slate (color)
this gerbil color describes a genetically Slate gerbil BUT which has only one version of the underwhite dense gene plus one version of the underwhite standard gene – so aauwᵈuw.
Black-Eyed White
this gerbil color describes a genetically ee colorpoint gerbil of either A* or aa that also have two colorpoint genes (not cʰcʰ – see Dark-Tailed White below). These normally ginger gerbils lose all their color with the effect of the colorpoint genes, and all you are left with are bits of grey speckling. Adding uwᵈuwᵈ to the mix bleaches out much of that speckling as will a single cʰ gene. Add Dominant Spotting to your gene pool and the effect can be beautiful
Blue (color)
this gerbil color describes a genetically Black gerbil that has two versions of the dilute gene known – so aa dd
Blue Fox
this name is an old name for a Silver Nutmeg (A*ee uwᵈuwᵈ)
Burmese (aka Colorpoint Black)
this gerbil color describes a genetically Black gerbil that has two versions of the colorpoint gene known as cᶜʰᵐ or c[chm] – so aacᶜʰᵐcᶜʰᵐ
c
this recessive version of the colorpoint gene is not found (yet) in Mongolian Gerbils. It represents ‘albino’ in many other rodent fancies, but this gene has yet to be formalised in gerbil coat colors and may not even exist. It can also be used a shorthand for a gerbil having an unknown recessive colorpoint gene.
c*
this genetic notation may be used to signify that a gerbil has a recessive gene at the C locus, but that we don’t know exactly which one it is. It won’t be just c alone as this gene hasn’t yet been proved as found in gerbils, it will either be cᶜʰᵐ or cʰ
C
the way of writing the dominant version of the Colorpoint gene (meaning that a gerbil ISN’T colorpoint in appearance)
carries (i.e. carries a gene)
to carry a gene means that that specific gene is one of the two genes at a particular locus that each gerbil is ‘allowed’ to have – you may or may not know what this gene is. Often, when this is used to refer to the second or unused gene – it is often called a ‘hidden gene’
cᵇ or c[b]
the old way of writing that a gerbil carries the gene for chinchilla medium (see next entry below) – the ᵇ was to stand for ‘burmese’ as that was the color it produced on a self black gerbil
cᶜʰᵐ or c[chm]
the way of writing that a gerbil carries the gene for chinchilla medium – a version which bleaches out a tiny bit of the original color from the main body of the gerbil in all colors when found singly – but when found as a homozygous pair lightens the coat further but leaves the ‘points’ almost their original color
cʰ or c[h]
the way of writing that a gerbil carries the gene for Himalayan – a version which bleaches out quite a bit of the original color from the main body of the gerbil in all colors when found singly. When found as a homozygous pair it is so powerful that it bleaches the coat completely white – devoid of all color regardless of all the other dominant genes present
Champagne
this gerbil color describes a genetically Schimmel gerbil that also has the dominant spotting gene – so eᶠeᶠ Sp+
Chinchilla
this word is not used within the gerbil fancy to describe a coat color of gerbil – even if they are carrying the chinchilla medium gene. Some people call Grey Agoutis and Colorpoint Agoutis ‘chinchilla’ as they superficially look like what is known as chinchilla in other fancies
Chinchilla Medium
the way of describing one of the two common colorpoint genes found in the gerbil fancy – the weaker of the two currently found in gerbils (2020). It can be written in a number of ways including cᶜʰᵐ and c[chm]
Cinnamon
this name is an older/alternate name for an Argente Golden (A* CC pp)
Clan (singular)
this is the name given to a group of two or more gerbils living together in the same tank or set-up. A gerbil clan has a dominant gerbil and then all the others fall into a sort of pecking order downwards. Clans are very sensitive to change – and they don’t mix together
Clan (plural)
this is the name given sometimes to a whole collection of gerbils held by a breeder (usually called a kennel). Breeders are able to choose a Clan Name (a show or kennel name) that they can attach to their individual gerbil names to show where they came from and to distinguish them in show circles – for example RodentZone Twinkling Pumpkin (where RodentZone is the clan name and Twinkling Pumpkin is the gerbils name (where Twinkling shows the line he was from and Pumpkin is his pet name)) NB: you can follow any naming pattern you want – and you don’t need to be a registered breeder or regular show attendee to use them
Coat Color
coat color genes affect the color of the coat itself (ACDEP and Uw) but other gerbil genes like Spotting (Sp) and Rexoid (Re) actually affect the growth of the hairs that form that coat – they are in ADDITION to the color. They do not change the genetics of that color – although they can change the appearance of that color – so when discussing only the colors of gerbils or pup colors you are expecting, you do not need to add these to your notation as if your gerbil is black – they’re black.
Coat Type
coat type describes the effects that can be laid over the top of the coat color to give it a different appearance – including Rexoid and Wavy coats. The coat color may look slightly different with these coat type changes as the hairs are not growing in the same way as a non-affected gerbil
Co-Dominant
this describes the effect of genes on each other and the order that they affect the coat. A Dominant Gene isn’t always completely in control – take C for example: If you have a Red-Eyed Black gerbil (say a Lilac) and give it CC – and you still have a Red-Eyed Black gerbil; however give it Ccᶜʰᵐ and it becomes a Sapphire; or give it Ccʰ and it becomes a Dove
Color Linkage
this describes the effect where two gene loci are found close together and are sometimes, as a result, inherited together. This often happens with the colorpoint gene and the pink eye gene and so results in a slightly swayed percentage of PEW pups in certain breeding pairs
Colorpoint Black (aka Burmese)
this gerbil color describes a genetically Black gerbil that has two versions of the colorpoint gene known as cᶜʰᵐ or c[chm] – so aacᶜʰᵐcᶜʰᵐ
Colorpoint Gene
this describes the 3 versions of the gene that can make your gerbils have colored ‘points’ or not have colored points. These genes are all denoted with different versions of the letter c to tell them apart: and are C (displaying the wild colour); cᶜʰᵐ (chinchilla medium); and cʰ (himalayan)
Colorpoint Gerbil
this gerbil color describes a gerbil that has colored ‘points’ (nose, ears, feet and tail) where the body of the gerbil will be lighter than the points – with the points most like the color of the gerbil that this is a pointed version of. For example a Burmese gerbil usually has Black points (as it is a Black Colorpoint Gerbil)
Colorpoint Slate (aka Dark Burmese)
this gerbil color describes a genetically Slate gerbil that has two identical versions of the colorpoint gene known as cᶜʰᵐ or c[chm] – so aacᶜʰᵐcᶜʰᵐuwᵈuwᵈ. This color is often confused with normal Burmese, but it is MUCH darker and without such clear points
CP (or sometimes CPT)
this is shorthand for Colorpoint and means that the gerbil has two recessive colorpoint genes – but they can be any of those genes and is often used for any colorpoint gerbil – whatever the combination of recessive genes. However genetically, it means specifically that the gerbil is homozygous for two of the same recessive colorpoint genes as opposed to being a LCP (Light Colorpoint) which usually indicates that the gerbil had one of each – so cᶜʰᵐ + cʰ
Cream Fox
this name is an old name for a Red-Eyed Polar Fox (A* pp uwᵈuwᵈ)
c-separator
this alternate name for a Red-Eyed Silver Nutmeg was used to define a gerbil that was used for breeding purposes to find out all of a gerbils hidden genes – to separate them out. All of the genes that a c-separator has (except the colorpoint genes) are double recessives – aaeeppuwᵈuwᵈ and so used in breeding such a gerbil can help ‘pull out’ all the hidden genes from other gerbils without adding in any colors of its own. Many different versions can be used today for your breeding
d
the way of writing the recessive version of the Dilute Gene (D). A homozygous aa dd gerbil is called a ‘Blue’
D
the way of writing the dominant version of the Dilute Gene – which means the gerbil keeps full color
Dark-Eyed Honey
this gerbil color describes a genetically Agouti gerbil that also has two versions of the extension of yellow gene – so A* ee. It is dark ginger in color with an obvious white tummy and eye rings
Dark-Eyed White (Funky White)
this gerbil color describes a genetically Underwhite Cream gerbil that also has two versions extension of yellow gene – so ee uwuw
Dark-Patched Pied (also see Spun)
this word describes a gerbil who has Dominant Spotting present but has also got a noticeable and clearly-edged patch of darker (original color) somewhere on its body – or in multiple places (see feature image of pup). So, a phenotypical Sapphire Spotted gerbil will have a Lilac-looking patch. Dark Patched Pied (DPP) should not be confused with the irregular patches of original color seen in heavily mottled individuals where the color looks lighter in places due to the sheer volume of white hairs
Dark-Tailed White (aka Himalayan)
this gerbil color describes a genetically homozygous colorpoint gerbil for the gene cʰ. It doesn’t matter what any of the other genes are that the gerbil has – as with these two genes everything else is void. The gerbil will always be a Dark-Tailed White which will have ruby eyes even though it has the genes for dark eyes (P*). (If it had the genes for pink-eyes (pp) it would be a Pink-Eyed White)
DEH
this is shorthand for Dark-Eyed Honey (A* ee)
DEW
this is shorthand for Dark-Eyed White (any combinations of ee and cʰcʰ)
Diluted
this word describes any color coat that isn’t as strong as the standard due to the effect of any number of recessive genes in the genotype of a gerbil. This can be through the subtle effects of any single recessive genes present including but not restricted to the Dilute Gene
Dilute Gene (D)
this gene is the gene which determines whether gerbils have a slightly diluted coat from the standard. This gene is easier to see in the self colors (aa) but generally just fades the original color slightly
Domestic Animal
this describes animals that have been bred over time from a wild animal into one that is more suited to living with humans. They are totally different to their wild counterparts and usually cannot survive on their own as a result. Many exotic pets (usually still only found in their ‘wild’ color coat and not to be confused with ‘exotic pets’ which are from different countries and have specific temperature/humidity/UV or other specialised requirements) are not completely domesticated yet and so are slightly harder (more specialised) to keep as a pet and require more specific habitats and foods
Dominant
the word used to describe a version of a gene that always shows itself in the color or appearance of a gerbil if it is present. You cannot carry a dominant gene – it can’t be ‘hidden’
Dominant Spotted
this refers to the most common spotting gene in the gerbil fancy and it acts in a dominant fashion genetically. You only need one Dominant Spotting Gene (Sp) to have a spotted coat. When this gene is found homozygously (SpSp) in a fertilised cell, it self destructs (pre-natal lethal) so no pups are ever born ‘Double Dominant Spotted’
Double Rex
this is a gerbil who has double the Rex gene – ReRe – and as a result of all the damaged hairs this causes – they are usually almost or totally hairless. They may also suffer with other health issues including a lower life expectancy, increase dietary needs/thermoregulation issues and very often eye issues both internal (including cataracts) and external (involving the eyelashes)
Dove
this gerbil color describes a self Argente gerbil who carries one single cʰ colorpoint gene – so aa Ccʰ pp. This is the palest color of the three ‘silver’ shades as it has the strongest colourpoint dilution.
DREX
this phrase is another way to describe a double-rex gerbil – a homozygous Rex – that is, a gerbil with 2 dominant Rex genes – ReRe
DPP
this is shorthand for Dark Patched Pied (no genetic notation as this isn’t a color)
DTW (cʰcʰ)
this is shorthand for Dark-Tailed White (aka Himalayan)
e
the way of writing the common recessive version of the Extension of Yellow Gene (E). This gene version when homozygous makes Honeys, Foxes and Nutmegs, etc.
eᶠ
the way of writing the less common recessive version of the Extension of Yellow Gene (E) known as ‘fading’. This gene causes a loss of color to the orange coat – fading it entirely to white when found homozygously. This gene version makes schimmel gerbil colors
E
the way of writing the dominant version of the Extension of Yellow Gene. This gene version keeps the wild coat color
EW
the shorthand notation for an Extreme White gerbil – however a gerbil who carries the ability to make an Extreme White gerbil is called a White Paws (WP); and finally the gene for both WP and EW is written as Sls (confusing, eh?)
Exotic Animals
this word is used to describe one of three things: 1) species of animals that have been pets for a long time but are still quite unusual in the world of mainstream pets (for example snakes and chipmunks); then 2) species of animals that haven’t been pets for very long and so are closer to their wild counterparts. As a result there is less know about their diets, behaviour and breeding as well as their medical care and other needs (for example Great Gerbils and Prairie Dogs); and 3) species of animals that have to have specialist care based on their original habitat and who usually can’t survive without it (for example tree frogs and salt-water fish). Some vets even call gerbils exotic pets…
Extension of Yellow Gene (E)
this gene is the gene which determines whether gerbils have any agouti or black in their coats by removing these colours to varying degrees in conjunction with other gene combinations
Extreme White (EW – or Sls)
this refers to the less common spotting gene in the gerbil fancy that can’t work on its own to create the spotting – it has to be present with the Dominant Spotting Gene. It allows for very much more white to be apparent on a gerbil coat – basically it blanks out almost all of the colour from a gerbils standard coat and creates variegated and what are called ‘extreme white’ coats (where more than 85% of a gerbil’s colour is lost). This extreme piebalding carries the risk of many health issues including loss of sight and hearing
Fancy
a word used to describe the love of a certain domestic animal to the point where people are breeding them for pets and for show
First Generation
this is used to describe all the pups from two single parents – regardless of how many pups they have together. All their pups only have the genes given to them from these same parents. It is usually shown as F1, where the F stands for ‘filial’
Foxes (any ee)
this describes specifically the Polar Fox and its partner color the Apricot (or Red-Eyed Fox) but can be used to describe the whole family of colors which depend on the Extension of Yellow Gene. In the US – the REH is called Yellow Fox and the Saffron is called a Red Fox – however, the DEH used to be called an Algerian Fox and the Silver Nutmeg was then a Blue Fox). The Fox colours found in other animals – including mice (pictures of Fox mice) – acts in a totally different way to that which we have called Fox in gerbils. It was decided (by the gerbil fancies in many countries) that there may be the chance of the mouse Fox coloring (the Tan gene – at) appearing in gerbils at some point (which would be super cool) and then it would all be rather confusing for everyone involved if we already HAD so many foxes – so they began to come up with new names for all of the gerbil foxes
Fox Gene (actually the Tan gene (at) along with c^c^)
this (tan) gene is not yet found in gerbils. The Tan Gene (which also creates the Fox appearance in mice and otters in guinea pigs amongst other things) is where the coloured belly of a normally self critter is replaced by ginger fur – or with white fur when double colorpoint genes are present too (for example a Black Fox is a Black mouse with a full white belly). The Tan gene itself is actually a recessive gene on the Agouti Locus (at ) and interacts strangely with the colorpoint genes – cancelling all the hair color completely. Therefore all Fox mice are genetically colorpoint – but do not show this in their coats – Very confusing, eh?
Funky White (Dark-Eyed White)
this gerbil color describes a genetically Underwhite Cream gerbil that also has two versions extension of yellow gene – so eeuwuw
Gene
the word used when describing the thing that will (or won’t) affect your gerbils color, hair type (or anything else that makes your gerbil a gerbil) – like the ‘Agouti gene’ or the ‘Spotting gene’
Gene Linkage
this describes the effect where two gene loci are found close together and are sometimes, as a result, inherited together. This often happens with the colorpoint gene and the pink eye gene and so result in a slightly sway percentage of PEW (pink-eyed white) pups in certain breeding pairs
Gene Pool
this describes the genes available within a collection of gerbils. It can mean just within your clan – the genes you can use over and over to create the colors you need; or it can mean all the genes in all the gerbils of the world
Genetic Notation
the way you show the genes you know that a gerbil has. It can be either; 1) all the known genes of that gerbil (Nutmeg: aaC*DDeeP*UwUw) or; 2) it can be only the ones you need to show a certain color or certain recessives (Nutmeg: aaee) – whichever suits your needs. This is also known as the genotype
Genotype
this word describes the genes that are present in your gerbil whether you can see them or not (basically it is your genetic notation)
gerbilforum.proboards.com
this is a great place to find out more about gerbils and to find out more info on all things gerbil. From housing to feeding, behaviour and breeding – it’s all here…
Golden Agouti (just Agouti)
the color of a gerbil who has the original look of a wild gerbil – it has a golden brown ticked coat, with dark eyes and a white belly. It is the most common color form of Mongolian Gerbils as it is created by all the dominant genes available to gerbils
Grey Agouti
this gerbil color describes a genetically Agouti gerbil that also has two versions of the underwhite dense gene – so A* uwᵈuwᵈ. It is a lovely dark speckled grey color with a strong white belly. It also has ruby eye-shine when using flash photography
Heterozygous
the describes when two gene versions at one locus are different – either A a or e ef – it doesn’t matter which versions or genes they are – as long as they are different and in the same place. Homozygous is the opposite of this
Hidden Gene
the word used to describe a gene that you cannot physically see is present on an individual gerbil based only on their color or appearance. It would usually be the second gene of a pair and would be represented by a symbol such as *. In gerbils such as PEWs – all the genes will be hidden – the only genes you know for sure by looking at it would be c[*] c[*] pp – or in full: ** c[*]c[*] ** ** pp **
Himalayan (color)
the gerbil color describes any gerbil with two cʰ (or Himalayan) genes together. It doesn’t matter what any of the other genes are or whether its genotype is homozygous dominant at all other points (AAcʰcʰDDEEPPUwUw) – the combination of the two cʰ genes will strip virtually all its color away – including from the eyes. These gerbils can get some color back in their tail as they age and the gene gets ‘weaker’ – and in self versions – it can really get very dark indeed – hence this colors alternate name: Dark-Tailed White
Himalayan Gene
the way of describing one of the two common colorpoint genes found in the gerbil fancy – the stronger of the two currently found in gerbils. It can be written in a number of ways including cʰ and c[h]
Homozygous
the describes when two gene versions at one locus are the same – either AA or aa – it doesn’t matter which versions or genes they are – as long as they are identical and in the same place. Heterozygous is the opposite
Honeys (ee)
this describes specifically the Dark-Eyed Honey (DEH) and Red-Eyed Honey (REH), but can be used to describe the whole family of colors which depend on the Extension of Yellow Gene
Honey Cream (aa ee)
this gerbil color describes specifically either a Dark-Eyed Honey (DEH) or a Red-Eyed Honey (REH) that also has the dominant spotting gene – as the combination of A*ee and pp play around with the distribution of color. These pups are born around 80% white with only tiny bits of ginger coloring around the ears, spine and rump. Gradually over the next few moults they become more and more ginger and less and less white
Inbreeding
this term usually describes the action of indiscriminate breeding of close family members together – like mothers to sons and uncles to nieces, etc. It is usually looked on in a negative way in the fancy – as breeding with closely related individuals over and over again in a small population can ‘bring out’ or inflate the likelihood of negative traits such as ‘fixed wrist’ and other inherited illnesses and behavioural problems. It can also be used carefully to bring out a favourable trait in a small population where it is known as Line Breeding
Ivory Cream
this gerbil color describes a genetically Argente gerbil which has two versions of the underwhite dense gene – so A* pp uwᵈuwᵈ
LCP
this is shorthand for Light Colorpoint (a heterozygous colorpoint gerbil – so a gerbil having cᶜʰᵐ + cʰ). It is the cʰ that makes it ‘Light’
Lethal Gene
this describes the lethal effect of a certain gene and is usually found when the gene is homozygous. These can be prenatal lethal (the fertilised egg is destroyed or prevented from developing as with the Dominant Spotting Gene) or postnatal lethal (a pup is born alive but will not survive very long beyond that as with Semi-Dominant Lethal Spotting Gene)
Light Colorpoint Slate
this gerbil color describes a genetically Slate gerbil that has two different versions of the colorpoint gene – one cᶜʰᵐ or c[chm] and one cʰ or c[h] (the latter himalayan gene makes it ‘light’) – so aa cᶜʰᵐcʰ uwᵈuwᵈ. It looks very similar to a Burmese-coloured gerbil
Lilac
this gerbil color describes a self Argente Golden that carries no recessive colorpoint genes – so aa CC pp. This is the darkest of the three ‘silver’ shades as it has no colorpoint dilution
Line Breeding
this term usually describes a concerted effect to breed in and increase the likelihood of a specific trait appearing in a population – for example; a longer tail, a new color or coat type, or to eliminate an undesirable gene from a small population. It involves breeding close relatives together (known as a ‘line’) and is carefully planned and executed over a period of time for the safest results
Locus
the name given to the place in a gerbils chromosomes (their DNA) where the space for a gene is found. Each different gerbil color gene is in a different place and acts separately. There is one point of color linkage found so far between the colorpoint and pink eye genes – but they still most often act independently
Meiosis
this describes the biological action of gene sorting and cell division. An egg or sperm cell has only half the information of a whole cell. This happens because you need two halves to make a whole new cell (a baby) Anyway, to get these half cells, a normal whole cell has to divide into two – but before it divides in half – it mixes up all the information inside and lays it out slightly differently. This re-shuffling process produces individuals and is the reason why you don’t look exactly that same as your brothers, sisters or your nan
Meriones Sp.
this is the genus name of the wider group of animals we know as gerbils or jirds. Common members of this group are: Meriones (M.) unguiculatus – our lovely gerbils; M. persicus – Persian Jirds and M. Shawi – Shaw’s jirds… (genus and species names are always written in italics – and once you know the genus name, you can shorten it to the first letter henceforth!)
Mongolian Gerbil
this is the full name of the small animals we know as ‘gerbils’ and they are from the species: Meriones unguiculatus. They are also known as the Clawed Jird, but their species name is the same. There are many other gerbils and jirds across the world – but only one Mongolian Gerbil
Morphological Features
this word describes the shape, size and structure of an organism. It can be different within the same species depending on what those different animals do (for example dog breeds are all morphologically different) but on a smaller scale if can mean for example, that wild gerbils may have a shorter tail to stop it getting caught by predators – but domesticated gerbils have had their tail lengthened over time through selective breeding
Non-Agouti
the way to describe all the gerbil coat colors which do not carry a dominant Agouti gene. They will all be aa only at the start of their genetic notation – and it means that they do not have white bellies as standard
Nutmeg (aa ee)
this gerbil color describes genetically a self DEH gerbil – so aa ee. It is bright ginger as a pup, but gets darker black speckles as it ages
Nutmegs (ee)
this phrase describes specifically the Nutmeg itself and its partner color Red Fox/Saffron, as well as the Silver Nutmeg and its partner color the Red-Eyed Silver Nutmeg (or c-separator) but can be used to describe the whole family of colors which depend on the Extension of Yellow Gene
Orange Mold (Orange Siam)
this name is an older/alternate name for a standard Schimmel (** eᶠeᶠ)
p
the way of writing the recessive version of the Pink Eye Gene (P)
P
the way of writing the dominant version of the Pink Eye Gene (which leaves the gerbil with dark eyes)
Pearl
this name is an old name for a Colorpoint Grey Agouti (A* cᶜʰᵐcᶜʰᵐ uwᵈuwᵈ)
PEW
this is shorthand for Pink-Eyed White (** c^c^ pp)
Phenotype
this word describes the appearance of your gerbil only. It doesn’t take into account any hidden genes or homozygous genes, it just describes what you can see with your own eyes
Piebalding
this describes the increasing amount of white fur on an animal, from one spot to a virtually white creature. The white patches are actually where the body has stopped the effects of the cells from working – basically it turns the ability to make color completely off. Low levels of piebalding can make calmer animals (this is why most domestic animals have a small amount of white markings on them) however, too much piebalding can affect their health, temperament, and can cause blindness and deafness (as the same genes that make color also make eyes and ears work)
Pink Eye Gene (P)
this gene is the gene which determines whether gerbils have pink eyes or not. This gene has a bleaching effect on the standard coat also and usually strips out any strong brown or black colors, for example an agouti plus pink eyes becomes an Argente, and a Slate plus pink eyes becomes a cream (a Ruby-Eyed White (REW))
Polar Fox
this gerbil color describes a genetically DEH gerbil that also has two versions of the underwhite dense gene – so A* ee P* uwᵈuwᵈ. It is creamy as a pup, but gets darker grey speckles as it ages
Population
this describes the gerbils – and the genes within those gerbils – that are contactable and able to breed with each other as required. It could mean just your own clan, your clan plus neighbouring breeders, or your clan and your whole country. Basically, the population of a species, biologically speaking, is those individuals which can meet and produce more young
Post-Natal Lethal
this describes the lethal effect of a certain gene on a developing pup. It is where a pup is actually born – but is unable to survive due the effects of the gene
Pre-Natal Lethal
this describes the lethal effect of a certain gene on a developing embryo. It is where a pup isn’t actually born – it is unable to survive past basic cell division due to the effects of the gene
Probability
this describes the likelihood of getting certain color pups in a litter. You may have the genes for 8 colors with your breeding pair – all equally probable in terms of genetics: but if you only have a litter of 3 pups – you won’t see all of them. The probability of getting certain colors can only be based on the genes that are available to make those colors – it is not an actual prediction of what colors you will physically get. Using Punnet Squares you can see patterns occurring for the probabilities of certain colors – as dominant and recessive genes work in a predictable way – but the actual colors you get depends on the very fickle biological process of meiosis – which is totally random in its actions (basically that is it’s job otherwise all human brothers and sisters would look identical)
Punnet Square (Calculation)
this method of calculating probability of offspring is common in the gerbil fancy. It forms a simple table where all the possible gene combinations of two parents can be calculated – showing all the possible offspring. It only shows the offspring that are statistically possible from that pair – it doesn’t mean that they will ever produce pups which are those colors – it just means that they could (if all the genes fell into the right places during meiosis)
Pure White
this gerbil color describes a genetically SlsSls Sp+ gerbil that is produced when breeding together the Dominant Spotting Gene and the Semi-Lethal Spotting gene. This combination of genes is post-natal lethal, just like the Rumpback genotype (SlsSls)
Rainbow Litter
this is the name given to a group of pups that contain a wide variety of colors – or the parents at least have the potential for a wide variety of colors – and have perhaps been chosen for breeding together for that exact reason. A Rainbow Litter would best be achieved by breeding together Agouti and Black parents who are both heterozygous at every loci – as this would give you the most potential colors
Recessive
the word used to describe a version of a gene that when alone doesn’t clearly show in the color or appearance of the gerbil. Unless your gerbil has two of them – two identical recessive genes – you won’t see the full actions of this gene on the coat color of your gerbil (its phenotype). Some recessive genes can cause standard colors to be paler and are referred to a diluting or dilution effects
Red-Eyed Honey (UK)
this gerbil color describes a genetically DEH gerbil which also has two versions of the pink eye gene – so A* ee pp. It is bright ginger in color with an obvious white tummy and eye rings. (US – Yellow Fox)
Red-Eyed Schimmel
this gerbil color describes a genetically Schimmel gerbil that also has the pink eye gene – so eᶠeᶠ pp
Red-Eyed Silver Nutmeg
this gerbil color describes a genetically Silver Nutmeg gerbil which also has two versions of the pink eye gene – so aa ee pp uwᵈuwᵈ. It is a creamy color with no ginger speckles
Red-Eyed White
this name is an alternate show name for a Ruby Eyed White (aa ee uwᵈuwᵈ)
Red Fox (US)
this gerbil color describes a genetically Nutmeg gerbil that also has two versions of the Pink Eye gene – so aa ee pp. It is basically bright ginger in color all over with red eyes. (UK – Saffron)
REH
this is shorthand for Red-Eyed Honey (A* ee pp)
RESN
this is shorthand for Red-Eyed Silver Nutmeg (aa ee pp uwᵈuwᵈ)
REW
this is shorthand for Ruby-Eyed White (aa ee uwᵈuwᵈ)
Rex/Rexoid (Re/re)
this describes a coat type in gerbils. It is dominant and represented by the notation Re, so you only need one of these genes to have a gerbil showing a Rexoid coat and as a result a Rexoid gerbil will always have 50% Rexoid young. If you breed two Rexoid gerbils together you can get a Double Rex coat (ReRe) which is a more pronounced version and can cause hair loss and other issues if not done carefully
Ruby Eyes
this describes the deep red or pink color of a gerbils eyes that have been made non-black by a variety of gene combinations but which are not completely pink (like in a PEW)
Ruby-Eyed White
this gerbil color describes a genetically Slate gerbil but that also has two versions of the pink eye gene – so aa pp uwᵈuwᵈ. It is a creamy color with dark ruby eyes (not bright pink like a PEW)
Ruby Eye-Shine
this describes a effect where the flash of a camera can actually show a black-eyed gerbil to have dark ruby eyes – used sometimes as a way to determine colorpoint or underwhite dense genes in an otherwise unknown gerbil color. NEVER FLASH A CAMERA FLASH DIRECTLY INTO A GERBILS EYES
Rumplebacks
this describes the live young born with SlsSls (Semi-Dominant Lethal Spotting) who are white all over with a black rump (or totally white if combined with the dominant spotting gene). This gene – when homozygous – is post-natal lethal at the point of weaning or thereabouts. These pups are born with the genes to cause megacolon – a faulty digestive system that cannot process solid food – so they can digest mum’s milk just fine. However, when they progress onto eating solid food (which they can do just as a normal pup would) they often can’t actually digest any nutrients from it or void it from their system. As a result (unfortunately) they die very quickly of internal poisoning
Saffron (UK)
this gerbil color describes a genetically Nutmeg gerbil that also has two versions of the Pink Eye gene – so aa ee pp. It is basically bright ginger in color all over with red eyes (US – Red Fox)
Sapphire
this gerbil color describes a self Argente gerbil who carries one single cᶜʰᵐ colorpoint gene – so aa Ccᶜʰᵐ pp. This is the middle color of the three ‘silver’ shades as it has only a mild colorpoint dilution
Satin (color)
this name is an alternate name for an Underwhite Cream (uwuw) – not to be confused with the Satin Coat Gene
Satin Coat Gene (S)
this coat type is not currently found in gerbils. In other fancies – like the hamster – this coat type gives a very soft and slightly glossy coat
Second Gene
this describes the second written gene in your genetic notation – for example the A in AA – which usually doesn’t have an effect on the color or appearance of a gerbil (unless both genes are recessive genes or where homozygous dominant genes cause a health issue)
Selective Breeding
this word describes the process by humans or changing or controlling the appearance or health of an animal over time to improve, enhance or remove a feature or series of features that are either desirable or undesirable. For example; wild gerbils may have a shorter tail to stop them getting caught by predators – but domesticated gerbils don’t need to worry about that. So, over time, by selecting the gerbils with the longest tails (and the best health) breeders can gradually extend the ‘natural’ length of the tail by the accumulation of that effect. A more simple use of the term will be where breeders who want to show Burmese gerbils only will select only those gerbils with the genes needed to make more Burmese gerbils. They will select against all the other genes as they will reduce the chances of them getting more Burmese in each litter
Self Color
this word describes any gerbil who has aa at the beginning of their genetic notation. These gerbils are all self-colored in the sense that they are the same color all over – they do not have a white tummy or different colors in their hair (a non-self gerbil (like an Agouti) has three different colors making up each single hair (brown, grey and black) – whereas a Black gerbil has only the color black along all its hairs)
Self Color Gerbil (show class)
this is the name given to the show classes in the gerbil fancy that judge the basic self coat colors without any dilution – usually just Black, Slate, Lilac and Dove
Self Cream
this gerbil color describes a genetically Silver Nutmeg gerbil which also has two versions of the pink eye gene – so aa ee pp uwᵈuwᵈ
Semi-Dominant Lethal Spotting Gene (Sls)
this gene describes a commonly found but not commonly seen spotting gene in gerbils that can expand or increase the amount of white expressed on a Dominant Spotted gerbil. Alone, the gene is barely noticable – only in perhaps the odd white toenail or white foot in a self gerbil – but when combined singularly with a dominant spotted gene it causes excess white – and the gerbil color is often called an ‘extreme white’. When homozygous it is mostly pre-natal lethal, but can be post-natal lethal in a few cases with young known as rumplebacks who only usually live a few weeks
Schimmel
this gerbil color describes any genetically ee gerbil – either A* or aa – that has two versions of the extension of yellow ‘fading’ gene rather than just the plain old extension of yellow gene – so **eᶠeᶠ
Siamese (aka Light Colorpoint Black)
this gerbil color describes a genetically Black gerbil that has two different versions of the colorpoint gene – one cᶜʰᵐ or c[chm] and one cʰ or c[h] (the latter himalayan gene makes it ‘light’) – so aa cᶜʰᵐcʰ
Silver
this name is an older/alternate name for a Dove (aa Ccʰ)
Silver Pearl
this name is an older/alternate name for a Colorpoint Grey Agouti (A* cᶜʰᵐcᶜʰᵐ uwᵈuwᵈ)
Silver Schimmel
this gerbil color describes a genetically Schimmel gerbil that also has the underwhite dense gene – so eᶠeᶠ uwᵈuwᵈ
Sl
the genetic notation given to the new Steel gene – a type of spotting gene – which is shown as Sl+ (where the + represents the non-steel equivalent). It is still unclear whether you can have a SlSl gerbil (bearing in mind the other three spotting genes are all homozygous lethal) but it is also unclear as to whether you can have an un-steel gerbil from a Steel parent – apparently (from 2013 data) no pup born to a Steel parent was proved to be non-Steel. Research is still ongoing
Slate
this gerbil color describes a genetically Black gerbil that also has two versions of the underwhite dense gene – so aa uwᵈuwᵈ. It is almost identical to a Black gerbil in appearance, but is slightly duller and has ruby eye-shine when using flash photography
Sls
the genetic notation given to the Extreme White Gene using its alternate description of Semi-dominant Lethal Spotting (Sls or Sls+ where the + represents the non-spotted equivalent). You shouldn’t use the notation ++ for your gerbils not having this gene as it is the same notation used for not having the Dominant Spotting Gene, and as having neither spotting gene doesn’t actually affect your gerbils standard colors it isn’t important to know that it isn’t there – only when it is
Smoke (new color)
this gerbil color now describes a genetically Slate gerbil that also has two versions of the recessive dilute gene – so aa dd uwᵈuwᵈ
Smoke (old color)
this name is an older version of the name used to describe a Colorpoint Grey Agouti (A* cᶜʰᵐcᶜʰᵐ uwᵈuwᵈ) made with the underwhite dilute gene on the agouti side – not to be confused with the new Smoke (made with the dilute gene on the self side). Confused?
Sooty Fawn
this name is an older/alternate name for a Dark-Eyed Honey (A* ee)
Sp
the genetic notation given to a Dominant Spotted Gerbil – sometimes shown as Sp+ (where the + represents the non-spotted equivalent). In wild gerbils – they aren’t spotted – and so there was never a gene notation to show ‘no spotting’ so a + was used to fill the gap. You can never have a SpSp gerbil (see Dominant Spotting Gene) and you shouldn’t really use the notation ++ for not having one
Spun (provisional notation)
the (provisional) genetic notation given to a Dark-Patch Pied Gerbil – after years of research into how these gerbils are ‘created’ and how the inheritance of the pattern can be traced. This is ground-breaking (October 2020) and is yet to be formalised as the colouring is so variable in both its appearance and therefore in its visible inheritance. As with all the other spotting genes ins gerbils it is almost vertainly homozygous lethel.
Spotting Gene aka the Dominant Spotting Gene (Sp)
this is used to describe the variably acting gene that causes patches of white on gerbils of all colors – mainly on the nose, forehead and nape of the neck (tri spot). It also makes the tip of the tail white and can add white to the belly of a gerbil which doesn’t have a white tummy as standard
Spotting Gene aka the Extreme White Gene (Sls)
this is used to describe the action of the extreme loss of color of a standard gerbil and can create such pale colors that you can’t always tell what they were originally. However, extreme piebalding can be very detrimental to mammals. This gene thankfully, can’t work alone, and needs the Dominant Spotting Gene to produce such extreme effects. If found homozygously, it produces totally white pups with dark patches on their rump (known as rumplebacks) who unfortunately die from megacolon at a very young age
Standard Coat Color
this is used to describe a gerbils genetic coat color regardless of any other genes acting on it. A Black gerbil for example is solid black all over – but when the Dominant Spotting Gene is added on top of this – the Black gerbil will still genetically be Black – but will have a full or partially formed white tummy – usually only found in agouti-based gerbils
Steel Gene (Sl)
this gene is a new gene which seems to be grouped with the other two spotting genes (Sp and Sls) and has similar effects on lethality. It causes the coat to be more speckly and somewhat duller than usual on a non-dominant-spotted standard adult (only clearly seen in Black gerbils to date) and can cause small amounts of white patching on the rear feet of gerbils. However, when added to the Dominant Spotting gene in individuals, these bring out more spotting patterns, extending the white outside of the standard areas including up onto the face from the chin or down onto the eyes from a blaze – it also creates lop-sided mottling on some individuals. These lines were being test bred in the US
Tan Gene (at)
the Tan gene is not yet found in gerbils. The Tan Gene (which also creates the Fox appearance in mice and the Otters in guinea pigs amongst other things) is where the coloured belly of a normally self critter is replaced with ginger fur where an agouti is white. The Tan gene itself is actually a recessive gene on the Agouti Locus (at ) and it also interacts strangely with the colorpoint genes – where this gene cancels out the ginger. Therefore all colorpoint Tan mice are called Foxes/Otters and have white tummies!
The Gingers
this collective name is given (by me) to an Agouti gerbil who also carries two versions of the pink eye gene – so A*pp. There are three versions of this color (which are more commonly called Argente). These colors are called Argente Golden, Argente Fawn and Argente Cream. They are genetically made in the same way as, and are the color partners of what we call, ‘the silvers’ (Lilac, Sapphire and Dove)
The Silvers
this name is given (by us) to a Black gerbil who also carries two versions of the pink eye gene – so aa* pp. There are three versions of this color. These colors are called Lilac, Sapphire and Dove. They are genetically made in the same way as, and are the color partners of what we call, ‘the gingers’ (Argente Golden, Argente Fawn and Argente Cream)
Ticked Coat
this phrase is used to describe the appearance of an agouti-based gerbils’ coat – and is created by the individual hairs being three different colors throughout its length. If you part most agouti-based gerbils’ fur, it will appear a different color underneath
Topaz or Topas (Argente Cream)
this gerbil color describes an Argente gerbil who carries one single cᶜʰᵐ colorpoint gene – so A* Ccᶜʰᵐ pp. This is the middle color of the three Argente shades as it has only a mild colorpoint dilution. Its color partner is the Sapphire (aa Ccᶜʰᵐ pp)
Trait
this describes a known and possibly standard marking or coloring pattern always found on a gerbil of a certain color, for example: a trait of all Agouti gerbils is to have a white tummy; and, a trait of all Dominant Spotted gerbils is to have a white tip on the end of their tail
Unused Gene
this describes the second written gene in your genetic notation – for example the A in AA – which usually doesn’t have an effect on the color or appearance of a gerbil (unless both genes are recessive genes or homozygous dominant genes cause a health issue)
Underwhite Gene (Uw)
this gene is the gene which determines whether gerbils have a faded or creamy appearance. This gene has a variable fading effect on the standard coat (as there are two versions of this gene) and both will strip out any strong brown colors, for example with the homozygous uwᵈ version an Agouti loses all its brown and becomes a Grey Agouti – but a Black gerbil hardly loses any color and just becomes a Slate. However, with homozygous uwuw the effect bleaches out most color and you are left with various cream-colored gerbils with ruby looking eyes (even when P*)
Underwhite Cream (color)
this gerbil color describes a genetically Black gerbil that also has two versions of the underwhite gene – so aa uwuw. It is basically cream in color all over with ruby eyes
uw
the way of writing the recessive version of the Underwhite Gene (Uw) known as underwhite (a cream gene) – which is so strong when homozygous that it acts almost like cʰ. This gene creates a variety of creamy-colored gerbils with ruby eyes but is a relatively new gene and so there may be more to come from this gene in the future (2019+)
Uw
the way of writing the dominant version of the Underwhite Gene
uwᵈ
the way of writing the recessive version of the Underwhite Gene (Uw) known as underwhite dilute (sometimes written uwd, uw(d) or uw[d]). This gene creates Slates, Grey Agoutis, Polar Foxes and Silver Nutmegs
Wavy Gene
this gene is a recessive gene and causes a slight wave in the standard gerbil coat. It is not very common and so can remain hidden for many generations in stock
White-Bellied Cream (color)
this gerbil color describes a genetically Argente gerbil that also has two versions of the underwhite dilute gene – so A* pp uwᵈuwᵈ. Also called Cream or Ivory Cream
White Bellied Gerbil (or White Belly Class)
this is the name given to the show classes in the gerbil fancy that judge the basic agouti coat colors without any dilutions – usually just Golden Agouti, Grey Agouti and DEH
White-Bellied Golden Agouti
this is the name given to the show class in the gerbil fancy which judges the standard Golden Agouti coat color
White-Bellied Grey Agouti
this is the name given to the show class in the gerbil fancy which judges the standard Grey Agouti coat color
White Paws
this describes a gerbil who carries the Semi-dominant Lethal Spotting Gene that can create Extreme White gerbils. These gerbils often have different colored toe nails on the same foot and a white bib and nose – but are often very hard to identify. Two White Paws (WP) gerbils shouldn’t be bred together due to its lethal effect on the dominant homozygous young
Wild Gerbil Look
this describes a gerbil which (in color) looks externally identical to those gerbils still living in the wild around the world. It has the standard Agouti-like appearance of most wild rodents (brown speckled back and white tummy) and is visually created by the animal having at least one of all the dominant color genes available (in gerbils this is currently 6 – ACDEP and Uw). These gerbils may well have different morphological features more suited to wild living rather than the slightly modified versions living in captivity
Yellow Fox (US)
this gerbil color describes a genetically DEH gerbil which also has two versions of the pink eye gene – so A* ee pp. It is bright ginger in color with an obvious white tummy and eye rings. (UK – Red-Eyed Honey)