Duplication and divergence of opsins and chemoreceptors

基因复制事件和单个核苷酸替换一样常见。因此，在同一物种的个体之间，基因数量在很大程度上是不同的。我的研究计划的目标是表征基因复制对分子和表型多样性的贡献。复制后基因丢失的模式可能对物种形成具有重要意义（Taylor et al., 2001, Trends Genet, 17:9 9），然而，保留的复制是我目前研究的主题。我专注于感觉受体，因为这是分子和表型创新之间联系最明显的地方。项目一：我实验室最近的研究表明，孔雀鱼比其他任何脊椎动物都有更多的长波敏感视蛋白基因。我们将通过qPCR、原位杂交以及与Kelber博士（隆德大学）合作进行的辨色测试来验证这些“额外”视蛋白改善色觉的假设。孔雀鱼是五颜六色的鱼，我们的实验将告诉我们它们是否也有特别好的色彩视觉。项目2：我们是最早在紫海胆基因组中发现化学感觉基因的团队之一（Burke et al., 2006, Devel Biol, 300:434）。我们将开展基于pcr的cDNA调查，以鉴定化学感觉器官（海胆“鼻子”）和原位杂交鉴定化学感觉细胞。通过在细胞系（如人类胚胎肾细胞）中表达化学受体，我们还将通过测量次级信使（如cAMP、IP3或钙）水平的变化来研究不同化学受体对配体刺激的反应。项目3：研究秀丽隐杆线虫（Caenorhabditis elegans）化学受体基因上游的重复非编码序列。化学感受器基因是该物种中最大的基因家族之一（约2000个基因），但大多数基因仅在32个化学感觉神经元中的一个或多个中表达。由于许多基因在相同的神经元中表达，预计它们在调节基因表达的非编码DNA方面具有相似性。我们将使用生物信息学、转基因蠕虫和荧光显微镜来表征化学受体基因调控模块。

Gene duplication events are as common as individual nucleotide substitutions. Consequently, gene number differs to a large extent among individuals of the same species. The goal of my research program is to characterize the contribution of gene duplication to molecular and phenotypic diversity. The pattern of gene loss after duplication might have important implications for speciation (Taylor et al., 2001, Trends Genet, 17:299), however, the duplicates that are retained are the subjects of my current research. I focus on sensory receptors because this is where the link between molecular and phenotypic innovation is most clear. Project 1: Recent research in my lab shows that guppies have more Long Wavelength Sensitive opsin genes than any other vertebrate. We will test the hypothesis these 'extra' opsins improve colour vision using qPCR, in situ hybridization and, in collaboration with Dr. Kelber (University of Lund), colour discrimination tests. Guppies are colourful fish and our experiments will tell us if they also have especially good colour vision. Project 2: We were among the first to identify chemosensory genes in the purple sea urchin genome (Burke et al., 2006, Devel Biol, 300:434). We will carry out a PCR-based survey of cDNA to identify chemosensory organs (the sea urchin "nose") and in-situ hybridization to identify chemosensory cells. By expressing chemoreceptors in a cell line such as human embryonic kidney cells we will also study the responses of different chemoreceeptors to ligand stimulation by measuring changes in the levels of secondary messengers such as cAMP, IP3, or calcium. Project 3: We will study duplicated non-coding sequences upstream of chemoreceptor genes in Caenorhabditis elegans. Chemoreceptor genes make up one of the largest gene families in this species (~2000 genes), yet most are expressed in one or more of only 32 chemosensory neurons. As many genes are expressed in the same neurons, they are expected to have similarities in the non-coding DNA that regulates gene expression. We will use bioinformatics, transgenic worms, and fluorescence microscopy to characterize chemoreceptor gene regulatory modules.