Progeny: sperm ratios and non-functional sperm inDrosophila melanogaster

Assortative fertilization in Drosophila

“…Equal mixing, however, is more likely in species that transfer fewer sperm when matings are close together (24). Nonrandom recovery of sperm following multiple mating, if it depends only upon the properties of the multiple competing ejaculates, and even in some cases where it is dependent upon female genotype (25,26), differs from assortative fertilization as defined above, although some mechanisms may be the same.…”

Chiasmata have no effect on fertility

“…Sufficiently aged males of Drosophila are reported to transfer several thousand sperm at their first mating, exceeding the total egg production of the female, but transfer progressively fewer at each successive mating to virgin females. This involves a tenfold decrease in sperm counts, while the sperm redundancy estimate falls to l3-25 depending on female genotype (Peacock and Erickson, 1965;Zimmering and Fowler, 1968). If this situation occurs in locusts, their sperm redundancy should fall at or below 100-which would nullify the regression calculated from the present insect data (table 3).…”

The wild side of life

“…Therefore the relative contributions of these variables, as well as phylogenetic constraints, to the measures made in the present study remain unknown. Nonetheless, and more importantly, these populations represent the natural milieu in which reproductive processes occur and thus provide the contexts of natural and sexual selection that have shaped the [27,[29][30][31][32][33] D. hydei 28.5 ± 4.8 (24) 20.5 ± 1.9 (13) 126 [26] D. arizonae 98.5 ± 10.6 (50) 57.6 ± 4.0 (8) 101 [10] eggs. Females having oviposited were transferred to new food vials.…”