Abstract：
The molecular mechanism of sex determination has long been considered conserved in insects. However, recent studies of hemimetabolous insects have challenged this notion. One notable example is termites. In Reticulitermes speratus, a homolog of sex determination gene, Doublesex (RsDsx), exhibits characteristics that are distinct from those of other insects, including sister-group cockroaches. It comprises a single exon, contains only doublesex/mab-3 DNA-binding domain (DM) but lacks a conserved oligomerization domain (OD), and exhibits transcriptional activity only in males. To investigate whether these characteristics are widespread within the termite lineage, we identified Dsx homologs in three different families. The absence of the conserved OD sequences was observed in all termite species examined, whereas the number of exons and expression patterns between sexes varied among families. Particularly, distinctive differences in Dsx were found in species from the Archotermopsidae and Kalotermitidae, both of which have a linear caste developmental pathway. Our findings indicate that diversification of Dsx structure and expression patterns may have contributed to ecological diversification, such as caste developmental pathways, within the termite lineage.
摘要：
性别决定的分子机制在昆虫中一直被认为是保守的。然而,最近对半代谢昆虫的研究对这一概念提出了挑战。一个值得注意的例子是白蚁。在精子细胞中，性别决定基因的同源物,双人间(RsDsx),表现出与其他昆虫不同的特征，包括姐妹组的蟑螂.它包含一个外显子，仅包含doublesex/mab-3DNA结合域（DM），但缺乏保守的寡聚化结构域（OD），并且仅在男性中表现出转录活性。为了调查这些特征是否在白蚁谱系中广泛存在，我们在三个不同的家族中鉴定了Dsx同源物。在检查的所有白蚁物种中观察到不存在保守的OD序列，而外显子的数量和性别之间的表达模式在家庭中有所不同。特别是,在Archotermopsidae和Kalotermitidae的物种中发现了Dsx的独特差异，两者都有一个线性的种姓发展途径。我们的发现表明，Dsx结构和表达模式的多样化可能有助于生态多样化，比如种姓发展途径，在白蚁谱系内。
