The male accessory glands (MAGs) in insects are pair(s) of internal reproductive organs that produce and secrete the plasma component of seminal fluid. In various insects, MAG size is important for male reproductive success because the fluid provides physiologically active substances and/or nutrients to females to control sperm as well as female reproductive behaviors. Although the MAG epithelial cells in most insect species are standard mononucleate cells, those in some insect taxa are binucleate due to incomplete cytokinesis (e.g., Drosophila [Fallén] [Diptera: Drosophilidae]) or cell fusion (e.g., Cimex [Linnaeus] [Hemiptera: Cimicidae]). In the case of Drosophila, the apicobasal position of the two nuclei relative to the epithelial plane changes from vertical to horizontal after nutrient intake, which allows the volume of the MAG cavity to expand effectively. On the other hand, in the case of Cimex, the positions of the two nuclei do not change apicobasally in response to feeding, but their position relative to the proximodistal axis varies depending on the tubular/spherical organ morphology. Here, we report that the MAG of the benthic water bug Aphelocheirus vittatus (Matsumura) (Hemiptera: Aphelochiridae) shows binucleation in all epithelial cells. Despite the phylogenetically close relationship between Aphelocheirus and Cimex, the MAG cells in Aphelocheirus showed a Drosophila-like apicobasal change in the position of the two nuclei in response to feeding. Furthermore, the cytological processes during binucleation are more similar to those in Drosophila (incomplete cytokinesis) than to those in Cimex (cell fusion). These results indicate that the physiological role and mechanism of binucleation in MAG cells changed during the evolution of Hemiptera.

中文翻译：

---

底栖水Bug，Aphhelocheirus vittatus（Hemiptera：Aphelochiridae）中雄性辅助性腺细胞双核化的形态和发育特征。

昆虫中的雄性副腺（MAG）是一对内部生殖器官，它们产生并分泌精液的血浆成分。在各种昆虫中，MAG的大小对于雄性生殖的成功很重要，因为这种液体可以为雌性提供生理活性物质和/或营养，以控制精子以及雌性的生殖行为。尽管大多数昆虫种类的MAG上皮细胞是标准的单核细胞，但由于细胞分裂（例如果蝇[Fallén] [Diptera：Drosophilidae]）或细胞融合（例如Cimex [Linnaeus] [Hemiptera ]），某些昆虫类群的MAG上皮细胞是双核的。：Cimicidae]）。果蝇的情况，养分摄入后，两个核相对于上皮平面的顶突位置从垂直变为水平，这使得MAG腔的容积有效地扩展。另一方面，在Cimex的情况下，两个原子核的位置不会因进食而近顶面改变，但是它们相对于近前轴的位置会根据管状/球形器官的形态而变化。在这里，我们报道了底栖水生臭虫Aphhelocheirus vittatus（Matsumura）（半翅目：Aphelochiridae）的MAG在所有上皮细胞中均显示出双核化。尽管之间的系统发育关系密切Aphelocheirus和臭虫，在MAG细胞Aphelocheirus结果显示，果蝇样果蝇的两核位置发生变化，以响应进食。此外，双核化过程中的细胞学过程与果蝇（不完全胞质分裂）中的细胞学过程比Cimex（细胞融合）中的细胞学过程更为相似。这些结果表明在半翅目进化过程中，MAG细胞中双核的生理作用和机制发生了变化。