Gynandromorphism

Gynandromorphism has been noted in Lepidoptera (butterflies and moths) since the 1700s. It has also been observed in crustaceans, such as lobsters and crabs, in spiders, ticks, flies, locusts, crickets, dragonflies, ants, termites, bees, lizards, snakes, rodents, and birds. Although it can be seen in a variety of species, gynandromorphism is notably uncommon. Reporting depends on ease of detecting the phenomenon (whether a species displays noticeable sexual dimorphism) and how well-studied a region or organism is. For example, up until 2023 gynandromorphism had been reported in more than 40 bird species, but the vast majority of these are from the Palearctic and Nearctic; meanwhile, incidents in species from other regions may go underreported due to lack of data collection. == Pattern of distribution of male and female tissues in a single organism ==

Several patterns of tissue distribution occur amongst observed gynandromorphs. Patch-like patterns may arise, but commonly the phenotype presents in a symmetrical pattern, of which there are three main types: bilateral, oblique, and transverse. Papilioandrogeusfemale.jpg|Normal female of Papilio androgeus Papilioandrogeusgynandromorph.jpg|Mosaic gynandromorph of Papilio androgeus Papilioandrogeosmale.jpg|Normal male of Papilio androgeus == Causes ==

The exact cause for gynandromorphism is unknown, and appears to vary by species. This is then followed with fertilization by two Z-bearing sperm cells which creates cells in the embryo containing both ZZ and ZW chromosomes. The same phenomenon can be seen in other species, such as Drosophila melanogaster, and creates a genetic mosaic which gives rise to the mixed phenotype. == As a research tool ==

Gynandromorphs occasionally afford a powerful tool in genetic, developmental, and behavioral analyses. In Drosophila melanogaster, for instance, they provided evidence that male courtship behavior originates in the brain, that males can distinguish conspecific females from males by the scent or some other characteristic of the posterior, dorsal, integument of females, that the germ cells originate in the posterior-most region of the blastoderm, and that somatic components of the gonads originate in the mesodermal region of the fourth and fifth abdominal segment. ==See also==