We used genetic crosses with the mixed brown stock to create ST and SR flies that were genetically similar except for the X-chromosome (electronic supplementary material, figure S2). Myself and SRNy) and four wild-type stocks (MI, Ny1, Nyc2, PEI). Males used in the experiment carry an ST or SR X-chromosome from the tester stock, and females are heterozygous at the X-chromosome, with one b X-chromosome and the other from the tester ST or SR stock (electronic supplementary material, figure S2). Flies were collected as virgins and stored 10 flies vial ?1 on regular culture food. At one week of age, flies were transferred to vials containing a blended senior friend finder mushroom-agar food. Survival was assayed every 1–2 days, and the flies were transferred to fresh food every 4 days. Survival analyses used a Cox proportional hazard model with P roc P hreg in SAS v. 9.3 (SAS Institutes), with SR carrier status and line nested within SR carrier status as fixed effect variables, and the vial as a random effect variable. Analyses were completed separately for females and males.
(d) Ladies mate discrimination
We tested for virgin female discrimination against mating with SR males using both no-choice and choice assays. First, we conducted no-choice trials with SRMe and ST males. Using a series of genetic crosses, we created morphologically indistinguishable males that were either SRMe personally or ST with an otherwise similar genetic background (electronic supplementary material, figure S3). Mate trials of a female from the mixed wild-type stock with either a single SRMe or ST male were observed for 2 h, with mating latency noted. After the trial, males were genotyped as SRMe personally or ST as described above. Analyses used Fisher’s exact tests (FET) and non-parametric Wilcoxon rank-sum tests.
Second, we used a mass mating cage experiment to test whether females discriminate against mating with male SR carriers under high male–male competition conditions. Each cage included 40 females from the dark mixed stock, 40 ST males from the dark mixed stock, and 40 tester males that were wild-type for eye colour and carried ST, SRMe personally or SRNY. Females were placed in the cage first, and after 5 min, all the males were added; copulating pairs were removed by aspiration and each male was scored for eye colour. Each cage was observed until half of the females mated. A total of 35 cage experiments were carried out, which included 16 with SRMe personally males, 14 with SRNY males and five controls with wild-type ST males from the mixed stock. We used a Cochran–Mantel–Haenszel test within each male type to test for a deviation from 50 : 50 random mating.
(e) Spunk race assay
We used cage assays to examine the rate of female remating and whether SR males suffer reduced fertility in conditions of potentially high sperm competition. We used small cages (10 cm diameter ? 15 cm tall) that contained instant Drosophila food and a mushroom cap. In each cage, we placed 20 dark females, 20 dark ST males, and 20 of either wild-type ST males from the mixed stock or SRMyself males. All flies were 7-day-old virgins when placed in the cage. Each cage was left for 1, 2, 3, 4, 6 or 10 days, after which the flies were removed and females were placed individually in culture vials for 10 days, after which they were discarded. The offspring of each female were scored for eye colour to determine paternity. Between 4 and 10 cages were set up for each day and male SR status (n = 65 cages total).
Female one to put both black and you can insane-method of children was in fact inferred to possess mated with each other brand of guys. Ladies one to produced simply ebony otherwise crazy-variety of young children possess mated having one men, numerous guys of the identical phenotype, otherwise boys of different phenotypes but then simply used the sperm of just one sort of male. Thus, which try out cannot disentangle pre- and you can post-mating girls discrimination against SR males; our very own purpose was to guess if or not lady mate multiply, and if inside standards out-of each other companion battle and lady selection, if SR boys sire fewer children than just ST males.