Reptile & Amphibian Forums

Hi, I don't know whether this is the right forum but what does "DH" means? Example DH albino genetic stripe. Thanks

Quick Answer: DH = Double Het = heterozygous for 2 traits.

In snakes like in humans 2 copies exist for each gene. If one gene is messed up, sometimes the second will be enough for the gene to function normally. In albinos, if both genes that control the same function along the pathway to make melanin are not functioning, the snake appears albino (amelanistic). If one gene doesn't function , but the other copy does, then the animal appears normal, but since it has one normal copy and one messed up copy of one gene, it is said to be heterozygous. In recessive mutations (typically), heterozygotes look like the normal or wild type animals. The stripe gene seems to work this way too so a double het for albino and stripe has one normal gene and one aberrant gene at sites that control melanin and pattern respectively. The normal gene is enough to allow normal function so the animal looks normal, but it carries the genes for albino and stripe. When gametes (eggs or sperm) are made, some of the offspring can inherit the trait from the parent. If the offspring get two aberrant copies (one from each parent), then they show the mutation. So double hets carry mutant genes, but only one copy is mutated (heterozygote). To show the trait on a recessive mutation, the animal needs two copies of the messed up gene (homozygous). I'm tired and I'm typing quickly so if anything doesn't make sense let me know and I'll try to explain it better.