LauraFrog
Fish Gatherer
In most animals there are a few genes that, if homozygous will kill, but if heterozygous (split) will look very good... the manx cat is an example. As far as I know the genes for manx (M) and normal tail (T) are codominant. So a Manx cat is heterozygous, or split: MT - it has a stub of a tail. But a cat that inherits both (MM) is stillborn. The gene is fatal.
The true albino gene in horses is fatal also, the 'albino' horses with wall eyes (blue) and a seemingly white coat are actually the standard base colours (chestnut, bay and black) but inherit two dilution genes, resulting in a double dilute, we call them cremello, perlino and smokey cream respectively.
I'm pretty sure there are a few of these fatal combinations operating in bettas as well. There's one somewhere on the melano gene, the true melano and not the dark formation of blue. As far as I know, a percentage of a double melanistic brood will begin gastrulation and then die, so the eggs never hatch.
I also heard that there is a fatal gene on doubletails, and that breeding two doubletails together means no fry. This is why you hear about double-veil, double-HM, double-crown because you can't breed 2 DTs together.
Does anybody know what genes are in operation here and whether they are outright-dominant or codominant? Obviously if they display at all they can't be recessive because the idea of a fatal gene is that the homozygous combination is fatal.
Also what is the reason behind 'never cross FT/FT, RT/RT or RT/FT'? Is it just that the fish struggle with their excessive finnage or is there something more to it?
Thanks to anybody who can shed some light on this...
The true albino gene in horses is fatal also, the 'albino' horses with wall eyes (blue) and a seemingly white coat are actually the standard base colours (chestnut, bay and black) but inherit two dilution genes, resulting in a double dilute, we call them cremello, perlino and smokey cream respectively.
I'm pretty sure there are a few of these fatal combinations operating in bettas as well. There's one somewhere on the melano gene, the true melano and not the dark formation of blue. As far as I know, a percentage of a double melanistic brood will begin gastrulation and then die, so the eggs never hatch.
I also heard that there is a fatal gene on doubletails, and that breeding two doubletails together means no fry. This is why you hear about double-veil, double-HM, double-crown because you can't breed 2 DTs together.
Does anybody know what genes are in operation here and whether they are outright-dominant or codominant? Obviously if they display at all they can't be recessive because the idea of a fatal gene is that the homozygous combination is fatal.
Also what is the reason behind 'never cross FT/FT, RT/RT or RT/FT'? Is it just that the fish struggle with their excessive finnage or is there something more to it?
Thanks to anybody who can shed some light on this...
