Maintenance of polymorphism by potentially injurious genes in eight natural populations of the platyfish,xiphophorus maculatus

Genetic Linkage and Color Polymorphism in the Southern Platyfish (Xiphophorus maculatus): A Model System for Studies of Color Pattern Evolution

“…Interestingly, complete crescent (Cc) was at a frequency of 0.18 in males and 0.21 in females. (Gordon and Gordon 27 did not find C in the Belize River, but they did find Cc.) One explanation for the difference in frequencies of the similar patterns, C and Cc, is that both patterns equally improve the likelihood of survival (avoid detection by predators), but random genetic drift could have driven one pattern to lower frequencies while alternate alleles at the same locus were driven to higher frequencies.…”

“…Studies of pigment cells in platyfish have established that a number of types of coloration are expressed, including black melanins, red, orange, and yellow carotenoids, and yellow, orange, red, and reddish brown pterins. 20,24,[26][27][28]34 These studies have also characterized the genetic basis of at least 42 different color patterns (Table 1). (The adult expression of these patterns and the pertinent references are given in the Appendix.)…”

“…23 Several attributes of this system have made it ideal for both laboratory and field research, including a short generation time, high fecundity, ease of rearing and collecting, and the extensive background information that has steadily been generated on its natural history and a variety of measurable traits. In the past 60 years, platyfish have been used in genetic research focusing on sex determining mechanisms, age and size at sexual maturation, 20,24 melanin expression and melanoma formation, [25][26][27][28][29][30][31][32] and sex ratio evolution. 33 From this extensive body of work, the genetic basis of a surprising number of color patterns has been characterized.…”

Genetics of plate morphology in an unusual population of threespine sticklebacks (Gasterosteus aculeatus)

“…A long series of studies by Gordon and associates on the platyfish, Xiphophorus maculalus (see Gordon & Gordon, 1957;Gordon & Smith, 1938;Gordon, 1947) provides evidence for genetic coadaptation in fishes. Development of patterns of melanophores within platyfish populations was shown to be controlled by different alleles of a particular genetic locus.…”

Mechanism of a case of genetic coadaptation in populations of Drosophila melanogaster.

“…In Avena, one constellation of alleles seems to be favored in xeric habitats, another in mesic habitats.-A highly nonrandom linkage association observed between four tightly linked esterase loci in Drosophila montana is also suggestive of selection, but no environmental correlations have yet been discerned (7,8). In Mexican populations of the platyfish Xiphophorus maculatus, certain black body markings are evidently regulated during development by a coadapted complex of alleles which differs from population to population, the regulation breaking down in interpopulational crosses (2,9).…”