昆蟲的體色變異影響著昆蟲擬態、求偶等各種適應行為，而控制體色生成與分子遺傳機制的研究則對於了解這類性狀的演化非常重要，已知參與體色調控的基因大多在黑腹果蠅(Drosophila melanogaster)研究發現的，但是仍有一些在此模式物種中發現影響體色的突變尚未被研究分析。其中帶有sable基因突變的果蠅，不但包含體色變深且胸部背板三叉戟黑紋的性狀。為了定位並分析sable基因，本研究利用既有的P-element基因轉殖染色體和兩個已知突變基因作為染色體位置的標定，利用基因重組方法計算 sable與標定突變基因的重組率及相對距離，以推測sable基因座的範圍。此外，我們也使用互補測驗方法，藉由FRT/FLP system，製造5個精準的小片段缺失染色體，並與帶有sable突變的染色體進行互補測試，藉由性狀確認sable基因的位置。我們同時也發現sable突變會導致果蠅的爬行能力下降，另外，為了檢測sable與其他體色相關基因的交互作用，我們將sable突變基因置入影響體色基因的突變背景以觀測該果蠅個體性狀的表現。實驗的結果我們精確地將sable基因縮短至88.0kb，並藉由在該基因突變使爬行能力降低，推斷可能與神經或肌肉發育的Neto基因等位基因突變相似，且sable基因調控果蠅體色的遺傳機制推測位於在yellow基因及ebony基因的上游，且在double mutant的基因型果蠅株，發現有sexual dimorphism的性狀。;Insect body color variation affects various adaptive traits, such as insect mimicry and courtship. Research on the molecular genetic mechanisms controlling body color is very important to understand the evolution of such traits. Most of the genes known to participate in body color regulation in fruit fly, Drosophila melanogaster, have been identified, but some classic body color mutants are yet studied and analyzed. In the sable mutant gene, not only the body color becomes darker but also the black tridents appear on the notum. In order to identify the sable locus, we used six P-element transgenic chromosomes and two known mutant genes as markers to narrow down its position by calculating recombination frequencies. In addition, we also performed complementary tests with 6 precise deletions made by the FRT/FLP system. As a result, the range of the sable gene has been narrowed down from 151.7 kb to 88.0kb, which includes 6 genes. Furthermore, we found the climbing ability of the sable mutant flies is greatly reduced, suggesting similar to Neto gene mutant allele. Also only yellow and ebony mutant phenotypes are exhibited in the double-mutant experiments with sable. This suggests sable may regulate the pigmentation through the genetic mechanism at the upstream of yellow and ebony. sable1 is very likely a Neto mutant allele, because its phenotype of climbing ability is very similar to Neto mutant.
