Zhu Chenxu, Zhou Lijun, Chen Dongbin, Yang Xu, Zhu Lu, Qian Lansa, Xu Xiaomiao, Fang Gangqi, Andongma Awawing A, Dong Yongcheng, He Lin, Huang Yongping, Wang Yaohui
Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China; Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China; School of Life Science, East China Normal University, 200241, Shanghai, China.
Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China.
Insect Biochem Mol Biol. 2025 Feb;177:104245. doi: 10.1016/j.ibmb.2024.104245. Epub 2024 Dec 5.
Spermatogenesis is a key process for the sexual reproduction species. In lepidopteran insects, spermatogenesis produces two different types of sperms, in which eupyrene sperm carry genomic DNA and fertilize eggs, whereas apyrene sperm are necessary for eupyrene sperm to enter eggs. However, functional genetic studies of spermatogenesis in Plutella xylostella remain a longstanding puzzle even though the phenomenon in lepidoptera has been widely documented more than a century. In this study, we particularly focus on the gene Nap1 which belongs to the Nucleosome assembly protein family. Our findings revealed that Nap1 was highly expressed in the testes, and the disruption of PxNap1 induced male sterility in P. xylostella, while the fertility of mutant females was comparable to wild-type females. Additionally, through immunofluorescence staining analysis, we found that the eupyrene sperm bundles presented diffusedly scattered nuclei in PxNap1 mutant males, while the nuclei in the wild-type were clustered together presented as needle shape. We also found that PxNap1 deficiency hinders the transfer of eupyrene sperm to the bursa copulatrix and spermatheca of females. However, the apyrene spermatogenesis was not affected in the PxNap1 mutant. RNA-seq analyses indicated that the defects of eupyrene sperm in PxNap1 mutants were related to energy metabolic such as pentose and glucuronate interconversions, biosynthesis of amino acids, and pentose phosphate pathway. Our study demonstrates that PxNap1 plays crucial function in eupyrene spermatogenesis and eupyrene sperm migration. Our research provides valuable insights for the genetic factors underlying reproductive processes in Lepidopteran insects.
精子发生是有性生殖物种的关键过程。在鳞翅目昆虫中，精子发生产生两种不同类型的精子，其中有核精子携带基因组DNA并使卵子受精，而无核精子是有核精子进入卵子所必需的。然而，尽管鳞翅目昆虫的这一现象在一个多世纪前就已被广泛记载，但小菜蛾精子发生的功能遗传学研究仍然是一个长期存在的难题。在本研究中，我们特别关注属于核小体组装蛋白家族的Nap1基因。我们的研究结果表明，Nap1在睾丸中高度表达，PxNap1的破坏导致小菜蛾雄性不育，而突变雌性的生育能力与野生型雌性相当。此外，通过免疫荧光染色分析，我们发现PxNap1突变雄性的有核精子束呈现出分散的细胞核，而野生型的细胞核聚集在一起呈针状。我们还发现，PxNap1的缺陷阻碍了有核精子向雌性交配囊和受精囊的转移。然而，PxNap1突变体中的无核精子发生不受影响。RNA测序分析表明，PxNap1突变体中有核精子的缺陷与能量代谢有关，如戊糖和葡萄糖醛酸相互转化、氨基酸生物合成和磷酸戊糖途径。我们的研究表明，PxNap1在有核精子发生和有核精子迁移中起关键作用。我们的研究为鳞翅目昆虫生殖过程的遗传因素提供了有价值的见解。
