Paternity assessment in free-ranging wild boar (Sus scrofa) – Are littermates full-sibs?

Abstract

Multiple paternity within litters occurs in various groups of mammals exhibiting different mating systems. Using seven genetic markers (i.e., microsatellites), we investigated the paternity of littermates in free-ranging wild boar (Sus scrofa) in a Mediterranean habitat. Using the software CERVUS 2.0 we estimated the probability of detecting multiple paternity across all loci (D), the probability of paternity (W) and a statistic D that allows the assignment of paternity to the most likely male with strict and relaxed levels of confidence. Multiple paternity was inferred for one of the nine analysed litters at the 80% confidence level. This suggests that a single male may control the access to receptive adult females and it shows that multiple paternity is not very common in the studied free-ranging wild boar population. Despite the possible occurrence of sperm competition and/or female cryptic choice, mate guarding seems to play a significant role in sexual selection. To better understand the wild boar's mating strategies further studies analysing the reproductive success of both sexes and under different environmental conditions should be conducted.

Multiple paternity in domestic pigs under equally probable natural matings – a case study in the endangered Gochu Asturcelta pig breed

“…The higher paternity success observed for the adult boar B 66 can be explained by its higher probabilities of success in malemale competition for accessing reproduction. Mate guarding has been reported to play a significant role in sexual selection in wild boar (Delgado et al, 2008). By contrast with previous reports (Aguilera-Reyes et al, 2006), our data were obtained without copulatory restrictions and, particularly in the case of the full sibs forming the analysed group A, no differences in hybrid vigour.…”

“…Our results can also be useful to further understand the mating system of the wild boar (Costa et al, 2012). There is extensive evidence of multiply sired litters in wild board that are likely to be due to ethological rather than to biological factors (Aguilera-Reyes et al, 2006;Delgado et al, 2008;Poteaux et al, 2009).…”

“…Whatever the cause (male copulatory competition, postcopulatory competition or differences in semen quantity and quality), multiple paternity in wild boar has been widely reported (see Delgado et al, 2008, for a review). However, this issue has not been fully addressed with regard to domestic pigs.…”

Microsatellite markers for identification and parentage analysis in the European wild boar (Sus scrofa)

“…The microsatellite loci here reported were especially selected to overcome those technical limitations, providing diversity levels which are comparable to the molecular tools reported in previous works concerning parentage analysis [5,8]. …”

Determination of the minimum number of microsatellite markers for individual genotyping in wild boar (Sus scrofa) using a test with close relatives

“…We tested 12 commonly used wild boar microsatellite markers (Delgado et al 2008;Poteaux et al 2009;Vernesi et al 2003) for species specificity and calculated PCR and genotyping success as well as P ID sib to define a minimum marker set suited for population size estimation using noninvasive sampling. We verified our results by transferring the determined minimum marker set onto three disconnected wild boar populations and by using a novel test with closely related individuals.…”