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，但现在已知是从一个先前存在的多基因家族反复进化而来的。这项工作的目的是确定茄科植物中SI的起源时间。我们将测定茄科植物中几个种的S和非S等位基因的氨基酸序列，并根据S和非S核糖核酸酶的序列差异构建系统发育树，以估计它们的相对进化速度。这个项目应该会导致对茄科植物中SI系统的年龄的估计，也可以被其他研究人员使用的非S核糖核酸酶的序列，以及对非S核糖核酸酶的选择性质的指示。茄科包括一些重要的商业植物种类，包括西红柿、土豆和烟草。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.