DISSERTATION RESEARCH: Examination of Expression Profile Differences in Candidate Loci Underlying Female Hybrid Sterility in Drosophila

拟果蝇（Drosophila simulans）、D.黑腹果蝇和它们的雌性杂种在基因组水平上使用微阵列进行了比较。杂种中一个亲本物种的表达水平相对于另一个亲本物种的优势是决定其总体育性的重要因素，因为发现最能育的杂种以父本模式表达更多的基因，即使大多数基因最初在发育期间以母本模式表达。在杂交后代中的一个基因子集已被选定，以进一步探索这种开关在基因表达的发育时间。此外，杂种的表达模式将从D。黑腹果蝇和另外两个密切相关的物种，寻找基因表达进化的一般趋势。这项工作将有助于提高我们对物种形成的理解，通过基因表达差异参与杂种雌性不育的进化。 虽然杂种不育性通常出现在物种形成过程中，但对不育效应背后的基因表达的实际变化知之甚少。更普遍地了解基因表达调控如何演变也将有助于我们了解其他情况下基因表达的变化，例如人类癌症的发展。

Gene expression levels in Drosophila simulans, D. melanogaster, and their female hybrids were compared at the genomic level using microarrays. Dominance of expression levels of one parental species over the other in hybrids is an important factor in determining their overall fertility in that the most fertile hybrids were found to express more of their genes in a paternal pattern even though most genes are initially expressed in a maternal pattern during development. A subset of genes in the hybrids has been selected to explore further the developmental timing of this switch in gene expression. Additionally, expression patterns of hybrids will be examined from crosses between D. melanogaster and two other closely related species to look for general trends in gene expression evolution.This work will help improve our understanding of speciation through the evolution of gene expression differences involved in hybrid female sterility. Although hybrid sterility commonly arises during speciation, little is know about the actual changes in gene expression that underlie the sterility effect. Understanding more generally how gene expression regulation evolves will also help us understand changes in gene expression in other contexts, such as with cancer development in humans.