Effect of the singed locus on the egg production curve of Drosophila melanogaster.

Egg production curves of virgin and mated females of several genotypes at the singed locus of Drosophila melanogaster have been studied. Fitz-Earle's theorectical model (1971) for characterizing daily egg production has been used. In general, the model gave good fit to the experimental data. A clear effect of the female genotype is detected on the following parameters and derivations of the model: alpha, rate of decrease in egg production; tq, day of cessation of egg-laying, N(tmax), maximum egg production; and T(t0,Tq), total lifetime egg production. Homozygous snqr females present higher values of alpha and lower values of tq, N(tmax), and T(t0,tq) than heterozygous and wild-type homozygous females. Egg-to-larva viability along female lifetime related with the different physiological stages of the egg-laying curve (increasing, maximum, and decreasing parts) has been also studied. Homozygous snqr females show low viability and decreasing with age compared to wildtype females. In some cases, different physiological stages of the egg production curve show characteristic egg-to-larva viability values.