SDS-PAGE pattern polymorphism of X-chromosomal glue proteins in natural populations of two Drosophila nasuta subgroup species.

For the first time, the glue protein pattern polymorphism in natural populations of D. n. nasuta and D. s. neonasuta has been analyzed by SDS-PAGE. The study involving 200 and 185 isofemale lines comprising 2028 and 1900 individuals of D. n. nasuta and D. s. neonasuta, respectively, revealed the occurrence of eight variant glue protein phenotypes in D. n. nasuta and seven in D. s. neonasuta. The number and frequency of variant phenotypes in different populations of both species were found to vary. Analysis of glue protein patterns in the F1 progeny of crosses involving parents with variant glue protein phenotypes revealed that the polymorphic fractions are produced by co-dominant genes located on the X chromosome. More than 87% of the naturally inseminated adult females were found to produce polymorphic progeny. The heterozygous female larvae were found to exceed the homozygotes in the isofemale line progeny of most of the populations.