家蚕幼虫表皮一般含有大量的尿酸盐结晶，使其表皮呈现白色或者不透明。有些品种由于表皮细胞中尿酸盐的含量不足或者没有，整个体壁看起来半透明或透明，如同一层油纸，称为油蚕。油蚕突变体是由于尿酸代谢异常引起的，至今已发现有30多种油蚕。由于其特殊的生理特征和丰富的突变资源，开展油蚕突变基因定位克隆及相关信号传导通路研究，对于揭示尿酸盐代谢机制，以及寻找尿酸盐代谢疾病的药物靶标具有重要的参考价值。本研究拟根据家蚕定位克隆配置材料的通用策略，配置Obs与野生型品种p50T的回交群体，将其和亲本作为连锁分析样本；筛选PCR差异多肽和SNP markers；建立Obs连锁区域；分离克隆Obs并对其进行功能研究；另外对Obs进行转录组测序，分析Obs的突变对其他基因表达的影响，探明该基因在尿酸代谢、体型决定和色素形成机制中的作用。

The larval skin of the silkworm, Bombyx mori is generally white and non-translucent because of the deposition of uric acid crystals in epidermal cells. In some strains, the larval integuments accumulate little uric acid because of genetic defects and appear transparent. Because they resemble oiled paper, they have been named “oily” silkworms. More than 30 oily mutants of the silkworm have been reported. Because of the special physiological characteristics and rich resources, the cloning and researches about related signal transduction pathway of oily genes would help us understand uric acid metabolism in the silkworm and other organisms, and provide new ideas to treat diseases related to uric acid metabolism. In this study, we will isolate and identify the responsible gene for the Obs mutant “Dominant obese translucent”, a dominant oily mutant by positional cloning and the Bombyx draft genome sequence. The Obs mutant not only exhibits an abnormally reduce accumulation of uric acid but also shows an abnormal body shape, and pigmentation. Although some studies on uric acid metabolism, body shape determination, and pigment formation in insects have been reported, the association between these three systems is unknown. Therefore, the analysis of the Obs mutant will shed light on mechanisms of uric acid accumulation, body shape determination, and pigment formation in insects.