Leopard Gecko Genetics

Leopard Gecko Genetics:

There are dozens, if not hundreds of different color and pattern combinations now seen in leopard geckos.  Up until the 1990s, normals (wild-type) and high yellows (similar to wild-type, but with brighter yellow) were the only types of leopard geckos found in captivity.  Most of these were imported, but a few people were producing captive bred geckos.  During the 1990s, many new color and pattern varieties were produced as a result of selective-breeding.  Hypomelanistic, jungle, stripe, and patternless (leucistic) were among the first "morphs" produced.  A morph is a basically a color or pattern variety different from the normal type.  Towards the end of the 1990s, the first albinos became available.  By combining some of these traits, new morphs were produced.  We produced the world's first of the following morphs:

Las Vegas Blazing Blizzard (Las Vegas Albino + Blizzard)  2002

Ember (Raptor + Tremper Patternless Albino)  2007

Mack Snow Diablo Blanco (Mack Snow, + Raptor + Blizzard)  2009

Mack Super Snow Diablo Blanco (Mack Super Snow + Raptor + Blizzard)  2010

Every year, new combinations are added together to produce new morphs.  Keeping up with all of them can be very difficult, even for someone who does it full-time!  It is extremely important to understand the genetics behind these morphs, in order to figure out how to combine them to reproduce them, or to produce new ones.  The information below is a very  brief overview of leopard gecko genetics:

Terminology:
Heterozygous (het)- A gecko that is listed as a "het" means it is carrying a recessive gene, but not actually showing it.  When bred to other geckos showing or carrying the same recessive gene, the visible morph can be produced.

The Normal (wild-type) leopard gecko is the dominant type.

Normal x Normal = all Normals

Simple-recessive
Example:  Albino
Albino x Albino = all Albino
Albino x Het Albino = 1/2 Albinos and 1/2 Het Albinos
Albino x Normal = all Het Albinos
Het Albino x Het Albino = 1/4 Albinos, 1/4 Normals, and 1/2 Het Albinos.  3 out of 4 babies will come out looking normal, and 2 out of those 3 should come out Hets, so all normal-looking babies would be considered 66% Possible Hets.

Double Recessive:
Combining 2 different recessive genes. 
Example:  Albino and Blizzard
Albino x Blizzard = all normals that are Het Albino and Het Blizzard- considered Double Het Albino Blizzard (marketed name for this is Blazing Blizzard)  You have to breed these double hets to each other to produce an actual Blazing Blizzard.
Double Het Blazing Blizzard x Double Het Blazing Blizzard will produce normals, albinos, and blizzards.  Each egg has a 1 in 16 chance of producing a Blazing Blizzard

Dominant:
Example:  Enigma
Enigma x Normal = 1/2 Enigmas and 1/2 Normals
Enigma x Enigma = all Enigmas

Dominant x Recessive:
Dominant Example:  Enigma
Recessive Example:  Albino
Enigma x Albino = 1/2 Enigma Het Albino and 1/2 Normal Het Albinos

To produce Albino Enigmas, you have to breed the following:
Enigma Het Albino x Albino = 1/4 Enigma Het Albinos, 1/4 Normal Het Albinos, 1/4 Albinos, and 1/4 Albino Engimas

Co-dominant (incompete-dominant):
This type is dominant to the normal, meaning you can breed it to normals and produce some geckos showing the morph.  There is also a super form of co-dominant morphs.
Example:  Mack Snow
Mack Snow x Normal = 1/2 Mack Snows and 1/2 Normals
Mack Snow x Mack Snow = 1/4 Normals, 1/2 Mack Snows, and 1/4 Mack Super Snows
Mack Super Snow x Normal = all Mack Snows
Mack Super Snow x Mack Snow = 1/2 Mack Snows and 1/2 Mack Super Snows
Mack Super Snow x Mack Super Snow = all Mack Super Snows

Co-Dominant x Recessive:
Co-Dominant Example:  Mack Snow
Recessive Example:  Albino
Mack Snow x Albino = 1/2 Mack Snows and 1/2 Normals, all of which are Het Albino.

To produce a gecko showing both the Mack Snow AND albino, one of the Mack Snow Het Albinos would have to be bred back to an Albino, Het Albino, or Mack Snow Albino.

Mack Snow Het Albino x Albino = 1/4 Normal Het Albinos, 1/4 Mack Snow Het Albinos, 1/4 Albinos, and 1/4 Mack Snow Albinos

Mack Snow Het Albino x Mack Snow Het Albino = Normals , Albinos, Super Snows, and Albino Super Snows.  All non-albinos in this combination would be considered 66% possible het albino.

Mack Snow Albino x Mack Snow Het Albino = 1/4 Mack Snows, 1/4 Mack Snow Albinos, 1/4 Mack Super Snows, and  1/4 Mack Super Snow Albinos

Mack Super Snow Albino x Mack Snow Albino = 1/2 Mack Super Snow Albino and 1/2 Mack Snow Albinos

Mack Super Snow Albino x Mack Super Snow Het Albino = 1/ Mack Super Snow Albinos and 1/2 Mack Super Snows.

Mack Super Snow Albino x Mack Super Snow Albino = all Mack Super Snow Albinos


Keep in mind that these statistics are "on average".  There can be variations within any given clutch of eggs.  The more clutches that are produced, the more likely the ratios are likely to come out correct.

There are more complicated scenarios with double or triple recessives crossed with double or triple co-dominants.  Every generation where new combinations are bred together,  the genetics can get more and more complicated!

Line-Breeding:
Some leopard gecko morphs are produced from breeding geckos with similar traits to each other.  For example,  today's super hypo tangerine carrottail baldies started a couple decades ago with a few geckos that had nice yellow colors and less than average spotting.  Each generation of breeding geckos with fewer and fewer spots and brighter colors, produced nicer geckos than the previous generation.  After several years, geckos with no black spotting on their backs were produced.  Several generations later, the nicest of these geckos developed no spotting on their heads or backs, along with brilliant tangerine coloration on their bodies and tails.  Now, geckos that are solid orange from the tip of their nose to the tip of their tail have been produced.

Line-bred morphs such as hypo have also  been crossed into recessive morphs such as albinos.  The resulting babies show both the line-bred hypo trait combined with the recessive albino trait, producing a morph called Sunglow.

Other genetic information about leopard geckos:

Albino Bloodlines:

There are 3 different lines of albinos:  Tremper, Las Vegas (sometimes called Rainwater) and Bell.  These originated in 3 different collections in the US in the 1990s.  They are genetically incompatible.  That means, if you breed geckos from 2 different lines together, normal babies will hatch, not albinos.  These normal would be considered double hets for both lines of albinos.

Eye Colors:

Over the past few years, more attention has been paid to leopard gecko eye colors.  There are several types seen in leopard geckos:

Normal- typical wild-type gecko eyes

Albino-  Eye coloration in albinos is dependent on what line of albino is used, but most albino eyes are much lighter than a normal gecko's eyes.  Las Vegas Albino eyes have black pupils, while most Trempers and all Bells have red pupils.

Eclipse- Solid black eyes.  This occurs in several morphs of leopard geckos.  Mack Super Snows also have solid black eyes.

Red- Solid red eyes.  These are mostly seen in Raptors.  Raptor stands for Red eye Patternless Tremper Orange.  An Aptor is a Raptor without the red eyes.    Super Snow Albinos also have solid red eyes.

Snake Eyes- This term is used when a gecko has either partial red and partial normal eyes, or partial black or partial normal eyes.  The amount of red or black  can vary from gecko to gecko.

"Enigma Spins":

This term refers to a trait common in all enigma morph leopard geckos.  When enigmas get excited or frightened, they will sometimes run/spin in circles, sometimes tilting their head in an unusual position.  The degree that this happens can vary from one enigma to another, but it seems like they all have it, or at least are capable of carrying the trait on.  Our original enigma didn't show any signs of this, but some of his offspring and descendents do.  In all but the most severe cases, it doesn't negatively-impact the life of the gecko.  Nearly all enigmas will live completely normal lives and have productive breeding. 

Leopard gecko genetics can be very confusing an intimidating at first.  There are so many different morphs out there now, that even full-time breeders have a difficult time keeping up.  The key is to keep learning.  Nobody is expected to know all this from the start.  I was lucky enough to be involved in breeding leopard geckos when the very first morphs started coming out, so my knowledge was able to grow at the same rate as new morphs were introduced.  Starting out today, trying to keep the genetics of all these morphs, is a big job.  The most important thing is to know how each genetic type (simple-recessive, co-dominant, and dominant) works.  Once you know the genetic type of a particular morph, it is easy to plug it into the formulas above to figure out the probable outcomes.  Leopard gecko genetics are extremely fun and challenging to work with.  Enjoy!


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