Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China.
College of Life Sciences, Northwest University, Xi'an, China.
BMC Genomics. 2019 Sep 9;20(1):702. doi: 10.1186/s12864-019-6037-y.
The reproductive plasticity of termite workers provides colonies with tremendous flexibility to respond to environmental changes, which is the basis for evolutionary and ecological success. Although it is known that all colony members share the same genetic background and that differences in castes are caused by differences in gene expression, the pattern of the specific expression of genes involved in the differentiation of workers into reproductives remains unclear. In this study, the isolated workers of Reticulitermes labralis developed into reproductives, and then comparative transcriptomes were used for the first time to reveal the molecular mechanisms underlying the reproductive plasticity of workers.
We identified 38,070 differentially expressed genes and found a pattern of gene expression involved in the differentiation of the workers into reproductives. 12, 543 genes were specifically upregulated in the isolated workers. Twenty-five signal transduction pathways classified into environmental information processing were related to the differentiation of workers into reproductives. Ras functions as a signalling switch regulates the reproductive plasticity of workers. The catalase gene which is related to longevity was up-regulated in reproductives.
We demonstrate that workers leaving the natal colony can induce the expression of stage-specific genes in the workers, which leads to the differentiation of workers into reproductives and suggests that the signal transduction along the Ras-MAPK pathway crucially controls the reproductive plasticity of the workers. This study also provides an important model for revealing the molecular mechanism of longevity changes.
白蚁工蚁具有很强的生殖可塑性，能够根据环境变化灵活应对，这是其进化和生态成功的基础。虽然已知所有蚁群成员都具有相同的遗传背景，而且蚁群的分化是由于基因表达的差异引起的，但参与工蚁向生殖蚁分化的基因特异性表达模式仍不清楚。本研究首次利用分离的台湾乳白蚁工蚁发育成生殖蚁的方法，结合比较转录组学技术，揭示了工蚁生殖可塑性的分子机制。
我们鉴定了 38070 个差异表达基因，并发现了一个与工蚁向生殖蚁分化相关的基因表达模式。在分离的工蚁中，有 12543 个基因特异性上调。25 条信号转导途径被归类为环境信息处理，与工蚁向生殖蚁分化有关。Ras 作为信号开关调节工蚁的生殖可塑性。与寿命有关的过氧化氢酶基因在生殖蚁中上调。
我们证明了离开蚁巢的工蚁可以诱导工蚁中特定阶段基因的表达，从而导致工蚁向生殖蚁分化，并表明 Ras-MAPK 信号通路的信号转导对工蚁的生殖可塑性起着关键的控制作用。本研究还为揭示长寿变化的分子机制提供了一个重要模型。
