Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, 214081, People's Republic of China,
Dev Genes Evol. 2014 Mar;224(2):97-105. doi: 10.1007/s00427-014-0467-y. Epub 2014 Feb 19.
Sex-lethal (Sxl) plays an important role in sex determination in insects. In this study, the full-length complementary DNA (cDNA) of Sxl of the Chinese mitten crab Eriocheir sinensis (EsSxl) was cloned. EsSxl is expressed during different developmental stages of embryos, and its expression level in the cleavage stage is lower than that in other stages of embryonic development, such as the original zoea stage when it reaches the highest level. The expression level of EsSxl in eight different tissues was investigated. EsSxl was expressed in seven examined tissues, excluding eyestalk, and the highest expression levels were observed in testis and hepatopancreas. EsSxl expression in testis was 13-fold higher than that in ovary. After induction by eyestalk ablation, changes in EsSxl expression were also tissue-specific, with EsSxl expression increasing by 2.6-fold and 11.5-fold in ovary and muscle, respectively, between 0 and 7 days after eyestalk ablation and decreasing by 2.0-fold in testis between 0 and 3 days after eyestalk ablation and by 265-fold in hepatopancreas between 0 and 7 days after eyestalk ablation. Two splice variants of EsSxl were identified, and the only difference between them was a 77-bp alternatively spliced intron that is transcripted in EsSxl1 and skipped in EsSxl2. Both variants were expressed in males and females, demonstrating the lack of a sex-specific expression pattern for Sxl in Chinese mitten crab.
性致死（Sex-lethal，Sxl）在昆虫性别决定中起着重要作用。本研究克隆了中华绒螯蟹（Eriocheir sinensis）Sxl 的全长 cDNA。EsSxl 在胚胎的不同发育阶段表达，其在卵裂期的表达水平低于原溞状幼体等其他胚胎发育阶段，在原溞状幼体时达到最高水平。研究了 EsSxl 在 8 种不同组织中的表达情况。EsSxl 在 7 种检测组织中表达，除眼柄外，在睾丸和肝胰腺中表达水平最高。EsSxl 在睾丸中的表达水平比卵巢高 13 倍。在眼柄切除诱导后，EsSxl 的表达变化也是组织特异性的，眼柄切除 0 至 7 天，卵巢和肌肉中的 EsSxl 表达分别增加了 2.6 倍和 11.5 倍，眼柄切除 0 至 3 天，睾丸中的 EsSxl 表达减少了 2.0 倍，眼柄切除 0 至 7 天，肝胰腺中的 EsSxl 表达减少了 265 倍。鉴定出两种 EsSxl 的剪接变体，它们之间的唯一区别是在 EsSxl1 中转录而在 EsSxl2 中跳过的 77bp 选择性剪接内含子。这两种变体均在雄性和雌性中表达，表明 Sxl 在中华绒螯蟹中不存在性别特异性表达模式。
