Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil.
Sci Rep. 2021 Jan 21;11(1):1918. doi: 10.1038/s41598-021-81387-1.
Rhodnius prolixus is a Triatominae insect species and a primary vector of Chagas disease. The genome of R. prolixus has been recently sequenced and partially assembled, but few transcriptome analyses have been performed to date. In this study, we describe the stage-specific transcriptomes obtained from previtellogenic stages of oogenesis and from mature eggs. By analyzing ~ 228 million paired-end RNA-Seq reads, we significantly improved the current genome annotations for 9206 genes. We provide extended 5' and 3' UTRs, complete Open Reading Frames, and alternative transcript variants. Strikingly, using a combination of genome-guided and de novo transcriptome assembly we found more than two thousand novel genes, thus increasing the number of genes in R. prolixus from 15,738 to 17,864. We used the improved transcriptome to investigate stage-specific gene expression profiles during R. prolixus oogenesis. Our data reveal that 11,127 genes are expressed in the early previtellogenic stage of oogenesis and their transcripts are deposited in the developing egg including key factors regulating germline development, genome integrity, and the maternal-zygotic transition. In addition, GO term analyses show that transcripts encoding components of the steroid hormone receptor pathway, cytoskeleton, and intracellular signaling are abundant in the mature eggs, where they likely control early embryonic development upon fertilization. Our results significantly improve the R. prolixus genome and transcriptome and provide novel insight into oogenesis and early embryogenesis in this medically relevant insect.
丽蝇科的长角血蜱是恰加斯病的主要传播媒介。长角血蜱的基因组最近已经测序并部分组装，但迄今为止，很少有转录组分析。在这项研究中，我们描述了卵发生的前卵期和成熟卵中获得的阶段特异性转录组。通过分析大约 2.28 亿对配对末端 RNA-Seq reads，我们显著改进了当前对 9206 个基因的注释。我们提供了扩展的 5'和 3'UTR、完整的开放阅读框和替代转录变体。引人注目的是，我们使用基因组指导和从头转录组组装的组合发现了两千多个新基因，从而将长角血蜱的基因数量从 15738 个增加到 17864 个。我们使用改进的转录组来研究长角血蜱卵发生过程中的阶段特异性基因表达谱。我们的数据表明，11127 个基因在卵发生的早期前卵期表达，它们的转录本被沉积在发育中的卵中，包括调节生殖细胞发育、基因组完整性和母-合子过渡的关键因素。此外，GO 术语分析表明，编码类固醇激素受体途径、细胞骨架和细胞内信号转导成分的转录本在成熟卵中丰富，它们可能在受精后控制早期胚胎发育。我们的结果显著提高了长角血蜱的基因组和转录组，并为该医学相关昆虫的卵发生和早期胚胎发生提供了新的见解。
