セミナー情報

Recurrent evolution of self-fertilization (selfing) from outcrossing has been regarded as one of the most prevalent transitions in angiosperms. In outcrossing species of the Brassicaceae, selfing is primarily prevented by the self-incompatibility (SI) system, which consists of male and female specificity genes at the S-locus, and genes involved in the downstream signaling pathway. In recent decades, much attention has been paid to clarifying which genes of the SI system degraded first, thereby leading to the loss of SI and the evolution of selfing. In this seminar, I present our recent studies demonstrating that the loss of SI was driven by the degradation of the male component of SI in multiple wild Brassicaceae species, including Arabidopsis thaliana and A. kamchatica. Our compilation of recent extensive studies in Brassicaceae species demonstrated that, in wild populations, the loss of SI is often derived from mutations in the male component, unlike in cultivated populations of Brassica, where several gene-disruptive mutations in the female components are also reported to be causal for the loss of SI. These results are consistent with theoretical predictions that mutations disabling male specificity are expected to be favored by natural selection more strongly than mutations disabling female specificity, or the female downstream signaling pathway.

参考文献
Tsuchimatsu, T. & Shimizu, K.K. Journal of Evolutionary Biology, in press.
Tsuchimatsu, T., Kaiser, P., Yew C.-L. et al. PLoS Genetics 8: e1002838. (2012)
Tsuchimatsu, T., Suwabe, K., Shimizu-Inatsugi, R. et al. Nature, 464: 1342-1346. (2010)