Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Pestic Biochem Physiol. 2022 Jun;184:105087. doi: 10.1016/j.pestbp.2022.105087. Epub 2022 Mar 28.
Sex-lethal (Sxl) encodes an RNA-binding protein that acts as the switch of sex determination in Drosophila and influences the genitalia formation and gonadal development. However, its sex-determination roles are not conserved in all insects and its role in the gonadal development of Lepidoptera is not well documented. In this study, three splicing variants of Sxl mRNA were identified in Spodoptera litura and they highly expressed in gonads, particularly in the testis. The mRNA levels of SlSxl exhibited higher expression in the spermatid than the testis sheaths, and gradually increased with the spermiogenesis. Sex-lethal protein (SlSXL) is mainly distributed in the cytoplasm of spermatocytes and the head of spermatid. Knockout of SlSxl resulted in fewer eupyrene sperm bundles and apyrene sperm bundles in the testes of moth and a large number of undeveloped spermatocysts retained in the moth of mutant testis, and leading to the reduction of oviposition and hatch rate in the offsprings after mating with female. These results suggest that SlSxl is a critical player in the spermiogenesis of S. litura.
性致死（Sex-lethal，Sxl）基因编码一种 RNA 结合蛋白，作为果蝇性别决定的开关，影响生殖器形成和性腺发育。然而，其在所有昆虫中的性别决定作用并不保守，其在鳞翅目昆虫性腺发育中的作用也没有得到很好的记录。在本研究中，在斜纹夜蛾中鉴定出了 Sxl mRNA 的三种剪接变体，它们在性腺中高度表达，特别是在睾丸中。SlSxl 的 mRNA 水平在精细胞中比在睾丸鞘中表达更高，并且随着精子发生逐渐增加。性致死蛋白（Sex-lethal protein，SlSXL）主要分布在精母细胞的细胞质和精细胞的头部。斜纹夜蛾 SlSxl 的敲除导致精囊中正常精囊的数量减少，畸形精囊的数量增加，以及大量未发育的精囊细胞在突变体睾丸的雄蛾中保留，导致与雌蛾交配后的后代产卵率和孵化率降低。这些结果表明 SlSxl 是斜纹夜蛾精子发生的关键因子。
