Ball Breeder

Genetics can be a very daunting subject.  A breeder needs to know the basics, before he/she can determine what ball pythons to buy and what they will get in return. The genetics of a ball python are much more complicated than what is explained below.  This description, however, should be enough to get a breeder started.

 

To start out, you have Dominant, Co dominant, and Recessive traits.

 

A dominant trait would be something like Brown Hair, on a person.  At the location or loci of the alleles (two genes - one from the mother and one from the father) that control hair color, if one allele is brown and the other is blonde, the phenotype (appearance) of the person will be brown hair.  Brown is dominant, so it will always show up if it is present.

 

A co dominant trait would be something like pastel in snakes.  If one allele is normal and the other is pastel, the snake will be light colored.  In the ball python world, it would be called Pastel.  If both alleles were pastel, it would be Super Pastel, very light colored.  Co dominance is essentially an allele that works with the other present allele and combines its traits.  Kind of like how blue and yellow makes green.

 

A recessive trait would only be visible if both alleles are recessive.  Albino is a recessive trait. Only if both alleles are albino, would the snake appear albino. 

 

The next step is to figure out what your snake’s offspring will look like and what genes they will pass on.  Remember, the look or appearance of a snake is its phenotype, and what genes it carries are its genotype. 

 

If you’re not confused already, it gets kind of rough after this.  My suggestion would be to get a pencil and some paper and experiment with symbols for different traits.  Read all the way through once, and then re-read jotting notes down and experimenting as you go. 

 

Ok.  Let xx represent Axanthic (a recessive trait for a black, white and brown snake (lacks red and yellow pigment).  Lowercase letters would be the recessive form.  Uppercase would be normal.  So if you have a Normal looking snake but it carries one Axanthic allele and one Normal allele, it would be represented by Xx.   X=Normal x=Axanthic.

 

Ok. Let Pp represent Pastel (a co dominant trait for Pastel).  So this snake would have one Normal allele = P and one Pastel allele = p

So for plotting purposes, the Axanthic snake would be labeled xxPP and the pastel would be labeled XXPp

 

So you are looking for all of the possible genotypes (what genes the offspring will carry) and phenotypes (what the offspring will look like) To do this, set up a punnett square.  Down the left side, you place one parent and across the top you place the other parent.  Because we are dealing with four alleles, there will be four spaces x, x, P, P.   Match up the first set of alleles one at a time with the next set and plot them from top to bottom.  Axanthic:  xP, xP, xP, xP.  Then for the Pastel snake: X, X, P, p.    shown as     XP, Xp, XP, Xp.

 

        XP  Xp  XP  Xp

xP   

xP   

xP   

xP   

 

Then match them up in the corresponding squares:

       XP      Xp       XP      Xp

xP   XxPP  XxPp  XxPP  XxPp

xP   XxPP  XxPp  XxPP  XxPp

xP   XxPP  XxPp  XxPP  XxPp

xP   XxPP  XxPp  XxPP  XxPp

 

Now you can analyze:  Phenotype:  50% of the offspring will look Pastel

                                                      50% will look normal. 

                                     Genotype:  50% of the offspring will be Pastel Het Axanthic (Het is short for Heterozygous which means it carries a gene. In this case, it carries one Axanthic gene or you can say one allele is axanthic, so it is Het for Axanthic). 

100% of the offspring will be Het Axanthic.