State Key Laboratory of Ecological Pest Control for Fujian/Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China.
Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, China.
Pest Manag Sci. 2024 Jul;80(7):3194-3206. doi: 10.1002/ps.8022. Epub 2024 Feb 29.
Oogenesis is a complex pathway necessary for proper female reproduction in insects. Ovary-serine protease (Osp) is a homologous gene of serine protease Nudel (SpNudel) and plays an essential role in the oogenesis and ovary development of Drosophila melanogaster. However, the function of Osp is not determined in Plutella xylostella, a highly destructive pest of cruciferous crops.
The PxOsp gene comprises a 5883-bp open-reading frame that encodes a protein consisting of 1994 amino acids, which contain four conserved domains. PxOsp exhibited a high relative expression in adult females with a specific expression in the ovary. Through the utilization of CRISPR/Cas9 technology, homozygous mutants of PxOsp were generated. These homozygous mutant females produced fewer eggs (average of 56 eggs/female) than wild-type (WT) females (average of 97 eggs/female) when crossed with WT males, and these eggs failed to hatch. Conversely, mutant males produced normal progeny when crossed with WT females. The ovarioles in homozygous mutant females were significantly shorter (5.02 mm in length) and contained fewer eggs (average of 3 eggs/ovariole) than WT ovarioles (8.09 mm in length with an average of 8 eggs/ovariole). Moreover, eggs laid by homozygous mutant females were fragile, with irregular shapes, and were unable to maintain structural integrity due to eggshell ruptures. However, no significant differences were observed between WT and mutant individuals regarding developmental duration, pupal weight, and mating behavior.
Our study suggesteds that PxOsp plays a vital role in female reproduction, particularly in ovary and egg development. Disrupting PxOsp results in recessive female sterility while leaving the male reproductive capability unaffected. This report represents the first study of a haplosufficient gene responsible for female fertility in lepidopteran insects. Additionally, these findings emphasize PxOsp as a potential target for genetically-based pest management of P. xylostella. © 2024 Society of Chemical Industry.
卵子发生是昆虫正常繁殖所必需的复杂途径。卵巢丝氨酸蛋白酶（Osp）是丝氨酸蛋白酶 Nudel（SpNudel）的同源基因，在黑腹果蝇的卵子发生和卵巢发育中发挥重要作用。然而，在十字花科作物的高度破坏性害虫小菜蛾中，Osp 的功能尚未确定。
PxOsp 基因包含一个 5883 个碱基对的开放阅读框，编码一个由 1994 个氨基酸组成的蛋白质，其中包含四个保守结构域。PxOsp 在成年雌性中表现出高相对表达，在卵巢中有特异性表达。通过利用 CRISPR/Cas9 技术，产生了 PxOsp 的纯合突变体。这些纯合突变体雌性与野生型（WT）雄性交配时产卵量较少（平均每只雌性 56 个卵），而这些卵未能孵化。相反，突变雄性与 WT 雌性交配时产生正常后代。纯合突变体雌性的卵巢小管明显缩短（长度为 5.02mm），含有的卵较少（平均每个卵巢小管 3 个卵），而 WT 卵巢小管的长度为 8.09mm，平均每个卵巢小管有 8 个卵。此外，纯合突变体雌性产下的卵脆弱，形状不规则，由于蛋壳破裂，无法保持结构完整性。然而，WT 和突变个体在发育持续时间、蛹重和交配行为方面没有观察到显著差异。
我们的研究表明 PxOsp 在雌性生殖中起着至关重要的作用，特别是在卵巢和卵子发育中。破坏 PxOsp 导致隐性雌性不育，而雄性生殖能力不受影响。本报告代表了首例研究小菜蛾中负责雌性育性的单倍体充足基因。此外，这些发现强调了 PxOsp 作为小菜蛾遗传防治的潜在靶标。 © 2024 化学工业协会。
