Orphan genes are genes with no sequence homologues in other species. Here, we identified two orphan genes, namely, Tssor-3 and Tssor-4, in Plutella xylostella. Both genes contained a signal peptide sequence, suggesting their functions as secreted proteins. Expression pattern analysis based on real-time quantitative PCR(qPCR) showed that both orphan genes were specifically expressed in all male gonads except the testes. The expression of both the orphan genes peaked at the male adult stage. Immunofluorescence assays suggested that the two proteins were seminal proteins, indicating their potential roles in male reproductive regulation. To further explain their functions, we knocked down the expression of these two genes by RNA interference(RNAi). The results showed that the expression of Tssor-3 and Tssor-4 was significantly downregulated at 24 h after injection compared to that of the controls. Biological assays showed that the number of laid eggs and the hatching rate of offspring eggs were significantly reduced when the expression of Tssor-3 and Tssor-4 was reduced, suggesting that the two orphan genes played a role in male fertility in P. xylostella. Our results provide evidence that orphan genes are involved in male reproductive regulation, which is important for male fitness during evolution.
LI Tian-puZHANG Li-wenLI Ya-qingYOU Min-shengZHAO Qian
遗传防控技术作为传统有害生物防控方式的替代策略,自20世纪50年代以来在世界各国受到广泛的关注,被认为是一类有利于人类健康、食品安全和农业可持续发展的害虫种群防控技术,同时也为日益严峻的生物入侵问题提供了解决方案.本文综述了不育昆虫技术(sterile insect technique,SIT)、释放携带显性致死基因昆虫技术(release of insects carrying a dominant lethal,RIDL)和基因驱动技术(gene drive)的基本原理及部分应用案例,比较了不同技术的优势与限制因素,并介绍了相关研究中常见的几种基因整合策略,以期进一步改进害虫综合治理的基础研究和技术研发.
The diamondback moth,Plutella xylostella (L.),uses sulfatases (SULF)to counteract the glucosinolate-myrosinase defensive system that cruciferous plants have evolved to deter insect feeding.Sulfatase activity is regulated by post-translational modi- fication of a cysteine residue by sulfatase modifying factor 1(SUMF1).We identified 12 SULF genes (PxylSulfs)and two SUMF1 genes (PxylSumfls)in the P.xylostella genome. Phylogenetic analysis of SULFs and SUMFs from P.xylostella,Bombyx mori,Manduca sexta,Heliconius melpomene,Danaus plexippus,Drosophila melanogaster,Tetranychus urticae and Homo sapiens showed that the SULFs were clustered into five groups,and the SUMFs could be divided into two groups.Profiling of the expression of PxylSulfs and Pxyl Sumfs by RNA-seq and by quantitative real-time polymerase chain reaction showed that two glucosinolate sulfatase genes (GSS),PxylSulf2and PxylSulf3,were primarily expressed in the midgut of 3rd-and 4th-instar larvae.Moreover,expression of sulfatases PxylSulf2, PxylSulf3 and PxylSulf4 were correlated with expression of the sulfatases modifying fac tor PxylSumfla.The findings from this study provide new insights into the structure and expression of SUMF1and PxylSulf genes that are considered to be key factors for the evolutionary success ofP.xylostella as a specialist herbivore of cruciferous plants.
