Robert Summarizes

Drewell RA, Lo N, et. al. (2012) “Kin conflict in insect societies: a new epigenetic perspective.” TREE

Review paper that suggests that imprinting may play a role in conflict between paternal and maternal interests in social insects (i.e. ants, bees, wasps). Since it would be in the paternal interests for workers to produce offspring but this is not in the interests of the queen genes that regulate fertility in workers may be under strong conflict. Since fathers are more related to their own offspring than to a random worker from the (1/2 vs ⅜-0 depending on the matings the queen has), there also may be conflict amongst workers since relatedness is not equal between all workers. However, there seems to be much less methylation in ants than in mammals (3 orders of magnitude less), which indicates that methylation may not play a large role in imprinting, it is mediated by a different mechanism, or that methylation is used much more sparingly. They suggest that there are many candidate genes (primarily developmental and those that control sterility) that are good candidates for imprinting. However, some evidence from behavior of crosses between European honey bees and Africanized bees does indicate that direction of cross affects phenotype.

Doing reciprocal crosses here would be very interesting, but because most queen multiply mate it may complicate matters (or at least make results somewhat not biologically relevant if queens are forced to mate only once). I want to think about this one some more...

Glémin S, Bazin E, and Charlesworth D. (2006) “Impact of mating systems on patterns of sequence polymorphism in flowering plants.” Proc R Soc B

They gathered available sequence data from many plant species and families. They analyzed polymorphism (Watterson’s theta and pi) in synonymous, nonsynonymous, and some non-coding (intronic) sites. They performed ANOVAs to test whether mating system contributed more to diversity levels than other life history traits. Mating system did contribute significantly more than any other trait. They also showed that selfing species have less GC content (possibly due to less biased gene conversion because of low heterozygosity). Additionally they showed tentative evidence that selfers have less effective selection than outcrossers.