The Genetics of Artemia Salina. Ii. White Eye, a Sex-Linked Mutation

This paper describes the first sex-linked gene discovered among the Crustacea. The experimental results can be accounted for by the following hypotheses: (1) the mutant gene w, which determines white eyes, is recessive to its wild allele W. (2) Female brine shrimp are heterogametic. The chromosome constitution of the female will be represented as XY; the males are XX. (3) The white locus is partially sex-linked. Because it lies on the homologous segments of the sex chromosomes, both males and females may have the genotype of WW, Ww, or ww.2. In matings of Ww females to ww males, crossing over between the white locus and the sex locus may be detected. In the #9 stock, females have the genotype XW YW and the frequency of crossing over is low (1/1625 or 0.06%). This results in a "mother-to-daughter" inheritance of the W gene in the #9 stock.