Tag: chimera

sixpenceee:

The following is a rare half male and half female butterfly. The butterfly was determined to be a Lexias pardalis, and its condition is called bilateral gynandromorphy. Gynandromorphism is most frequently noticed in bird and butterfly species where the two sexes have very different coloration. (Source)

Gynandromorphs are chimeras, i.e. two different sets of genetics in one animal. They usually happen when a set of non-identical twins, or members of a larger litter, fuse in the womb. It happens in egg-born animals when two fertilized egg cells end up encased in the same egg and fuse due to the lack of space. They’re probably more common than we think, but chimeras are impossible to detect without testing every inch of a creature’s body for DNA, inside and out. Gynandromorphs like this one are often more obvious, but, in animals (say, fish) with minimal sexual dimorphism, often go unnoticed. Chicken gynandromorphs are particularly neat to see, they have the fluffy rooster hackles on just one side, and a thick leg and spur on that side.

ainawgsd:

Chimera and Mosaic Insects Part 1-Assorted Insects

A chimera (also spelled chimaera) (from the creature Chimera in Greek mythology) is a single organism composed of cells from different zygotes. This can result in male and female organs, two blood types, or subtle variations in form. Animal chimeras are produced by the merger of multiple fertilized eggs.  If the different cells have emerged from the same zygote, the organism is called a mosaic. Chimeras are formed from at least four parent cells (two fertilised eggs or early embryos fused together). Each population of cells keeps its own character and the resulting organism is a mixture of tissues. Chimeras can often breed, but the fertility and type of offspring depends on which cell line gave rise to the ovaries or testes; varying degrees of intersex differences may result if one set of cells is genetically female and another genetically male. A gynandromorph is an organism that contains both male and female characteristics, authorities say. The term gynandromorph, from Greek “gyne” female and “andro” male, is mainly used in the field of entomology, though it has also been observed in arthropods and birds as well. Another way that chimærism can occur in animals is by organ transplantation, giving one individual tissues that developed from two genomes. For example, a bone marrow transplant can change someone’s blood type. Normally, chimærism is not visible on casual inspection; however, it has been detected in the course of proving parentage and may be more common than was believed before the advent of DNA testing.