macmanmatty

This not really a savannah breeding question but my current litter of kittens got me thinking about this. My current litter of kittens have four different species of cats in them domestic, serval, jungle cat, and asian leopard cat. They have the following TWIG's for their wild cat parents I calculated using pedigrees and a few assumptions. Jungle cat 19.5% Asian leopard cat 13.185% serval 7.35% That gives them a total TWIG of 40.035 or 40% wild blood. Now, Intend to keep one male and possibly one from another kitten of this mating which will be repeated. Now, I bet your thinking I must be mad, keeping a male with a TWIG of 40% and expecting to be fertile and make kittens. But here is where you mat be wrong. Haldane's rule which governs the sterility of hybrid male cats states "When in the F1 offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterozygous sex " Which in mammals is the male. For years this was though to be the case for all hybrids of heterozygous sex but have proven to be untrue through numerous studies of backcrossing one the parent species to its self IE The savannah f4 and are lower males because the domestic parent is back crossed to itself to at lest 4 times. Actually f3 could be fertile and even f2's because the haploid sex cells of the f1 female due to recombination of DNA during meiosis are either mainly serval gemes with varying amounts of domestic genes or domestic with varying amounts of serval genes. When you add more domestic to the mix the f2's become either serval with varying amounts domestic domestic with varying amounts domestic or pure domestic. and so on and so forth. In many studies done on this it was found that when 70% of the autosomes are of one single species then the heterozygous sex is fertile over that number leads to the sterility of the heterozygous sex. So Based on what Just said the keeping hasn't any chance of making kittens. But That only deals with crossing two species to each other my cats have four in them or possibly more as in the early days of the bengal margay and fishing cat hybrids were sometimes used in the program after they realized that those hybrids when they reached the SBT level wouldn't look that different from a bengal. Now here is my question would it not be possible through breeding to take these 4 species of cat or possibly more level them all out at around 25% and then have a new species because the males are fertile? A species is defined as a group of organisms capable of interbreeding and producing fertile offspring which my new cats would able to do. They would also have less than 98% similar gene sequences which is another new requirement for a species and the reason the savannah cat is not classified as a new species. If this will work I think I have new breeding goal. Let me know what you think?? Here is good artical on Haldane's Rule http://post.queensu.ca/~forsdyke/haldane1.htm

no one knows anything? any ideas of who to contact that would?

Hello My friend and I are cross breeding a female geoffrey's cat to a male f4 bengal (domestic cat at this point). The problem is that geoffrey's cat has a different number of chromosomes than the domestic bengal. The geoffrey's has 36 while the domestic has 38. This should give the resulting hybrid 37 right? Now this cross has been done the other way numerous times to make what is called the safari cat. In this cross a male geoffrey's is mated to a female domestic. It produces very large kittens and resemble the wild parent geoffrey's cat alot. The geoffrey's cat is completely missing f series of chromosomes (which are some of the more pronounced chromosomes in the domestic cat species so I have read) and also has an extra c chromosome i believe. Would this make the cat larger than normal or cause any fertility problems in females (with other cross there have been fertile females produced and when mated with domestics have gone to produce f2 cats with varying numbers of chromosomes) also what the effect be on meiosis in the embryos with this combo? With mother having the lower number of chromosomes what would be the effect on the embryos? In reality I just want know wether these will be large cats and wether the females will have chance at fertility. I would also like to know if selecting cats that only have 36 chromsomes in the f2 and later generations would produce a more wilder looking cat or have any other effect on personality ect, as I do not know what genetic information is carried on these chromosomes. Thanks Jesse