Postdoctoral Research Fellowship in Molecular Evolution

植物的自交不亲和性（SI）一直被认为是被子植物的祖先，但现在知道是从一个预先存在的多基因家族反复进化而来的。 本研究的目的是确定茄科植物中SI的起源时间。 在茄科的几个物种的S和非S等位基因的氨基酸序列将被确定和基于S和非S RNA酶的序列分歧的系统发育树将被构建，以获得它们的相对进化速率的估计。 该项目应导致在茄科内的SI系统的年龄的估计，序列的非S-RNases，也可以被其他研究人员使用，和选择作用于非S RNases的性质的指示。 茄科包括许多重要的植物物种，包括番茄、马铃薯和烟草。 了解SI系统的多样性对作物育种具有重要意义。

Self-incompatibility (SI) in plants had long been assumed to be ancestral to the angiosperms, but is now known to have evolved repeatedly from a pre-existing multigene family. The objective of this work is to determine the time of origin of SI within the Solanaceae. Amino acid sequences of both S and non-S alleles of several species in the Solanaceae will be determined and phylogenetic trees based on sequence divergence of both S and non-S RNases will be constructed to obtain an estimate of their relative rates of evolution. This project should result in an estimation of the age of the SI system within the Solanaceae, sequences for non S-RNases that also can be used by other researchers, and an indication of the nature of selection acting on the non-S RNases. The Solanaceae include a number of commerically important plant species, including tomatoes, potatoes, and tobacco. An understanding of the diversity of SI systems has important implications for crop breeding.