Reptile & Amphibian Forums

Hi all,
Is it ok to breed brother and sister cresteds together?

Justin

first of all, if at all possible, i would suggest never inbreeding. it simply reduces diversity in the gene pool in the long run. not to mention, it increases the chances of homozygosity, which increases the chances of your offspring developing genetic diseases and such.

heres a little genetics lesson on how it works. in the most basic manner, a single gene codes for a single trait. this is not always the case, there are some genes that interact, some genes that fill a sort of 'genetic gap', etc. but im just gonna use the simplest way to explain it. say theres a gene for trait 'B'. there is the dominant allele, B, and the recessive allele, b. each individual carries two copies of a single allele to make a trait. one allele is passed on from each parent to the offspring. there are three combinations of the alleles possible, XX, Xx, and xx. XX is homozygous dominant, Xx is heterozygous, and xx is homozygous recessive. in the simplest fashion, if an individual carries at least one copy of the X allele, no matter if it is homozygous or heterozygous, it will show the trait linked to the X allele. say X is for large-bodied and x is for small-bodied. XX will give a large, Xx will give a large, and xx will be the only combination to give a small. these alleles can also code for genetic disease. most often, a genetic disease will be recessive, for if it were dominant it would likely lead to extinction if it were always being passed on and expressed in each individual. now if you have two parents that are heterozygous, this means they show the dominant trait, but could still be carriers of genetic disease. if both parents are Xx (heterozygous) and lets say that xx leads to some genetic disease, then there is a 1/4 chance for every single offspring to develop the genetic disease (xx). lets say that one parent is a carrier, and one parent is homozygous dominant. this means there is no chance that their offspring will develop disease (in this simplest case). but but the offspring still have a chance of turning out Xx (carriers of the genetic disease). since you wont know the exact genetics unless you actually take them in to get tested, you never know, but you could end up mating two carriers and then they have a 1/4 chance for that one single gene to lead to disease. now remember, there are thousands of genes for living organisms (most, at least), and there are chances for genetic disease in many of those genes.

so the moral of the story is, inbreeding leads to homozygosity in genes, which leads to much greater chances of genetic disease. the results of inbreeding may not be immediately noticeable, but in the long run it can lead to problems if people are buying your babies and breeding them too. now if you're looking to make a few babies and pass them on to your lil nieces and nephews, its still not advisable, but not as destructive to the crested breeding community.

hope this makes at least a little sense!
do yourself and all cresteds a favor and buy or trade for an unrelated mate!

as far as i know, selective breeding is, in part, inbreeding. for the same idea as genetic diseases, say cc leads to pinstripe, Cc partial pin, and CC no pinstripes. now this isnt actually how it is, but by increasing chances of homozygosity, you can increase your chances for better genetic combinations. but its still always got the increased chances of disease.