生物各種性狀之演化和新性狀的產生，往往必須與其他性狀相輔相成，本研究計畫主 要就功能相關但是功能機制相異的性狀探討其遺傳相關性之遺傳基礎。東方黃果蠅種群 (Oriental Drosophila melanogaster species)內雄性專一性的黑色翅斑(wing spot)之演化常常 伴隨著展翅行為 (wing display)的發生，有翅斑的物種往往在求偶的時候具有展翅行為， 經由牽牛花果蠅(D. elegans)和高山果蠅 (D. gunungcola)的種間雜交和QTL mapping 分 析已知這兩種性狀具有遺傳相關性，但此現象的分子遺傳機制未知。為進一步了解功能相 關但功能機制相異的性狀如何演化出其遺傳相關性，我們計畫先利用SMRT sequencing 分 析解碼兩種果蠅的基因組，再進行RNA-seq 的實驗，利用分析wing transcriptome 和brain transcriptome 來尋找參與調控兩性狀發育和表現的基因。藉由以上實驗與1)性聯遺傳和2) 性別專一調控兩條件，期望能找到位於X 性染色體上，主要調控翅斑和展翅行為的遺傳因 子，進而探討這兩種性狀的演化遺傳機制。 ;The genetic correlation of two male-specific functionally-related traits, wing spot (as a morphological trait) and wing display (as a behavioral trait), has been reported from QTL analysis in the hybrid backcross progeny of two sibling species. Given that many genes participate in more than one biological function and are involved in multiple developmental time points, the evolutionary theory predicts that genetic correlation among different types of phenotypic traits is plausibly common. As the first stage of studying underlying genetic mechanisms for the co-option of these two functionallyrelated traits, we plan to identify genes involved in the development of these two traits. In order to acquire complete annotation and facilitate the analysis of genetic architecture in D. elegans and its sibling species, we will obtain the genomic sequencing by taking advantage of two NGS technologies with complementary merits. Then, we propose to identify genes important to wing spot development and behavior initiation by studying gene expression in wings and brains under the framework of interspecific, sex-specific, and development-serial comparative transcriptome. Finally, we will confirm the results from our large-scale transcriptome analysis in several conventional methods, including quantitative RT-PCR, in situ hybridization, in silico analysis for the divergence of causal DNA sequence, and mutant phenotype assays. We expect to identify the major genetic factors on X-linked genes with sex-specific expression because 1) the overlapping QTL for both traits is on X chromosome according to the previous study and 2) the traits of our interest are sex-specific.
