DNA fingerprinting to determine paternity in laboratory rat sperm competition experiments

Abstract

DNA fingerprinting to determine paternity in laboratory rat sperm competition experimentsPrior to this study a significant amount of research had been undertaken in the field of sperm competition in mammals. However, males of different strains have been required in each of these studies to enable paternity assignment through gene expression, which has consequently resulted in problems with differential fertilising capacity being encountered. In this study paternity assignment of progeny from sperm competition experiments with Sprague Dawley rats was achieved by multilocus DNA fingerprinting using band locus matching of individual specific banding patterns between progeny and parents. Trials with 4 restriction enzymes and 5 digoxygenin labelled probes (4 oligonucleotide and 1 cloned) achieved the highest levels of DNA fingerprint heterozygosity using AluI(CAC)' and HinfI (CAC)' combinations; however, paternity could not be determined in all offspring, due to a higher than expected degree of inbreeding within the rat population used in this study. This was demonstrated in subsequent comparisons of genetic diversity of three laboratory rat breeding populations from two different animal breeding facilities. Data from the rat mating study showed that, under conditions of direct sperm competition, second males given access to a mated oestrus female either 0.5 or 6.0 h after the first mating consistently required less time than the first to ejaculate: 7.6 min vs. 19.5 min (0.5 h delay); 7.8 min vs. 19.5 min (6.0 h delay). A second male siring advantage was identified using DNA fingerprinting in both delay groups for those offspring on which paternity could be determined: 0.5 h delay, 1st = 39%, 2nd = 61%; 6 h delay, 1st = 34%, 2nd = 66%.

Social status does not predict responses to Seoul virus infection or reproductive success among male Norway rats

“…After the first few ejaculations, however, the dominant male advantage is lost and successful mating attempts can be achieved by subordinate males (Barfield and Thomas, 1986). In multi-male mating tests, the second male that copulates with a female typically has a siring advantage based on DNA fingerprinting analyses (Shimmin et al, 1995). Thus, reproductive success may be determined by the outcome of sperm competition in the reproductive tract of the female.…”

Sperm competition and genetic diversity in the agile antechinus (Dasyuridae: Antechinus agilis)

“…Females were held for 2 weeks post-partum (until good yields of DNA from the offspring could be assured) at which time all offspring and mothers were killed, with Lethabarb, for DNA extraction. Paternity analysis was conducted on family groups (mother, offspring and both males given mating access) using multilocus DNA pro®ling techniques (Shimmin, Sofronidis et al, 1995) that conclusively show paternity by inclusion whilst population or sub-population genetic diversity was indicated by the degree of band sharing.…”

“…Initially male siring success was the focus of much of this research with factors such as mating time relative to ovulation, delay between matings and order of mating access identi®ed as signi®cantly affecting the outcome of sperm competition events (Dewsbury, 1984(Dewsbury, , 1993Huck, Quinn & Lisk, 1985;Ginsberg & Huck, 1989;Shimmin, Sofronidis et al, 1995). Initially male siring success was the focus of much of this research with factors such as mating time relative to ovulation, delay between matings and order of mating access identi®ed as signi®cantly affecting the outcome of sperm competition events (Dewsbury, 1984(Dewsbury, , 1993Huck, Quinn & Lisk, 1985;Ginsberg & Huck, 1989;Shimmin, Sofronidis et al, 1995).…”

“…Sperm competition arises when more than one male mates successfully with a female during a single oestrus. Initially male siring success was the focus of much of this research with factors such as mating time relative to ovulation, delay between matings and order of mating access identi®ed as signi®cantly affecting the outcome of sperm competition events (Dewsbury, 1984(Dewsbury, , 1993Huck, Quinn & Lisk, 1985;Ginsberg & Huck, 1989;Shimmin, Sofronidis et al, 1995). Current sperm competition models, however, assess sperm competition in relation to the advantages it provides in reproductive ®tness for both sexes, particularly females.…”

Mating behaviour in the agile antechinus Antechinus agilis (Marsupialia: Dasyuridae)

“…Sperm competition arises when two or more males mate with a female within a single reproductive cycle (Parker, 1970), with success best measured by the number of offspring sired by each male. Siring success of males following competitive matings often differs between species, with ®rst male, second male and no male advantage being reported in various studies (Parker, 1970;Gwynne, 1984;Dewsbury, 1993;Shimmin, Sofronidis et al, 1995). Furthermore male and female mating behaviour may depend on the mating history of the female and also the timing of mating relative to ovulation (Dewsbury, 1979(Dewsbury, , 1985(Dewsbury, , 1993Shimmin, Sofronidis et al, 1995).…”