Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
Department of Life Sciences, Imperial College London, London, UK.
Commun Biol. 2023 Aug 15;6(1):850. doi: 10.1038/s42003-023-05224-z.
Understanding development and genetic regulation in the Anopheles gambiae germline is essential to engineer effective genetic control strategies targeting this malaria mosquito vector. These include targeting the germline to induce sterility or using regulatory sequences to drive transgene expression for applications such as gene drive. However, only very few germline-specific regulatory elements have been characterised with the majority showing leaky expression. This has been shown to considerably reduce the efficiency of current genetic control strategies, which rely on regulatory elements with more tightly restricted spatial and/or temporal expression. Meiotic silencing of the sex chromosomes limits the flexibility of transgene expression to develop effective sex-linked genetic control strategies. Here, we build on our previous study, dissecting gametogenesis into four distinct cell populations, using single-cell RNA sequencing to define eight distinct cell clusters and associated germline cell-types using available marker genes. We reveal overexpression of X-linked genes in a distinct cluster of pre-meiotic cells and document the onset of meiotic silencing of the X chromosome in a subcluster of cells in the latter stages of spermatogenesis. This study provides a comprehensive dataset, characterising the expression of distinct cell types through spermatogenesis and widening the toolkit for genetic control of malaria mosquitoes.
理解冈比亚按蚊生殖系的发育和遗传调控对于设计针对这种疟疾蚊子传播媒介的有效遗传控制策略至关重要。这些策略包括针对生殖系以诱导不育或使用调节序列来驱动转基因表达，例如基因驱动。然而，只有极少数生殖系特异性调节元件已被表征，其中大多数表现出渗漏表达。这大大降低了当前遗传控制策略的效率，这些策略依赖于具有更严格的空间和/或时间表达限制的调节元件。性染色体的减数分裂沉默限制了转基因表达的灵活性，从而开发有效的性连锁遗传控制策略。在这里，我们在前一篇研究的基础上，通过单细胞 RNA 测序将配子发生分为四个不同的细胞群，使用单细胞 RNA 测序来定义八个不同的细胞簇和相关的生殖细胞类型，并使用可用的标记基因。我们揭示了在一个特定的减数分裂前细胞簇中 X 连锁基因的过表达，并记录了在精子发生的后期阶段，X 染色体在一个细胞亚簇中发生减数分裂沉默的开始。这项研究提供了一个全面的数据集，描述了生殖细胞通过精子发生的不同细胞类型的表达，并为疟疾蚊子的遗传控制扩大了工具包。
