Research for Chamomile Chimera:: The occurrence of this Chimera cat is similar to non-identical twins, but it does not become two different individuals but becomes one individual with different characteristics in one individual,” explained Prof. The resulting gender depends on the embryo that is joined so that theoretically, this Chimera cat is male with two sets of sex chromosomes (XY + XY) or fertile female cats (XX + XX) and cats with sterile intersex gender (XX + XY). Curly Fur:: Curly coat is an unusual genetic variation which occurs in many mammals including cats, dogs, horses, rabbits and rats. Rex mutations cause changes in the structure of groups of hairs and in the cross-sections of individual hairs, which subsequently leads to the curly appearance of the fur. A curly coat is scientifically referred to as rexed coat. Rexed mutations are not frequent, but they can occur spontaneously in a variety of genes, thus creating various types of curly coats. In cats, several different rexed mutations have been identified and selected for, including the following: r (found in Cornish Rex), gr (found in German Rex), re (found in Devon Rex), ro (found in Oregon Rex), Se (found in Selkirk Rex) and Lp (found in LaPerm). Each genetic variant leading to rexed coat can influence the formation of distinctly unique types of curls, which is why rexed cats can vary considerably in appearance.