Louisiana State University Agricultural Center, Department of Entomology, Baton Rouge, LA 70803, USA.
Comp Biochem Physiol Part D Genomics Proteomics. 2012 Mar;7(1):14-27. doi: 10.1016/j.cbd.2011.10.002. Epub 2011 Oct 20.
Termites are known to have an extraordinary reproductive plasticity and capacity, but the underlying genetic patterns of termite reproductive biology are relatively understudied. The goal of this study was to identify genes for which expression levels differ between dealated precopulatory females (virgins) and egg-laying queens of the Formosan subterranean termite, Coptotermes formosanus Shiraki. We constructed a normalized polyphenic expressed sequence tag (EST) library that represents genomic material from most of the castes and life stages of the Formosan subterranean termite. Microarrays were designed using probes from this EST library and public genomic resources. Virgin females and queens were competitively hybridized to these microarrays and differentially expressed candidate genes were identified. Differential expression of eight genes was subsequently confirmed via reverse transcriptase quantitative PCR (RT-QPCR). When compared to virgins, queens had higher expression of genes coding for proteins related to immunity (gram negative binding protein), nutrition (e.g., termite-derived endo-beta-1,4-glucanase), protein storage, regulation of caste differentiation and reproduction (hexamerin, juvenile hormone binding protein). Queens also had higher transcript levels for genes involved in metabolism of xenobiotics, fat, and juvenile hormone (glutathione-S-transferase-like proteins, and cytochrome P450), among others. In particular, hexamerin, juvenile hormone binding protein, and a cytochrome P450 from the 4C subfamily are likely to be involved in initiating the inactive period during the reproductive cycle of the queen. Vice versa, virgins had higher expression than queens of genes related to respiration, probably due to recent flight activity, and several genes of unknown function.
白蚁以具有非凡的生殖可塑性和能力而闻名，但白蚁生殖生物学的潜在遗传模式相对研究较少。本研究的目的是鉴定出在有翅前预交配雌蚁（处女蚁）和产卵蚁后之间表达水平存在差异的基因，这些白蚁为台湾乳白蚁，Coptotermes formosanus Shiraki。我们构建了一个标准化的多态性表达序列标签（EST）文库，该文库代表了台湾乳白蚁的大多数形态和生活阶段的基因组物质。使用来自该 EST 文库和公共基因组资源的探针设计了微阵列。将处女蚁和蚁后竞争性地杂交到这些微阵列上，并鉴定出差异表达的候选基因。随后通过逆转录定量 PCR（RT-QPCR）验证了 8 个基因的差异表达。与处女蚁相比，蚁后具有更高表达水平的与免疫（革兰氏阴性结合蛋白）、营养（例如，白蚁衍生的内-β-1,4-葡聚糖酶）、蛋白质储存、等级分化和生殖调节（六聚体、保幼激素结合蛋白）相关的基因。蚁后还具有更高转录水平的与代谢外来物质、脂肪和保幼激素（谷胱甘肽 S-转移酶样蛋白和细胞色素 P450）相关的基因，等等。特别是，六聚体、保幼激素结合蛋白和来自 4C 亚家族的细胞色素 P450 可能参与启动蚁后生殖周期的不活跃期。反之，处女蚁比蚁后具有更高表达水平的与呼吸相关的基因，可能是由于最近的飞行活动，以及几个未知功能的基因。
