Vacuolar H⁺-ATPase (V-ATPase) is very important for eukaryotes and consists of a conserved V₁ domain and slightly variable Vo domain. However, the Vo domain has not been systematically identified in the silkworm Bombyx mori. In this study, 11 Vo domain subunit members were identified throughout the genome of B. mori, including four isoforms of subunit a (BmVoa1–4), two isoforms of subunit e (BmVoe1–2), one each of subunit c″ (BmVob), subunit c (BmVoc), and subunit d (BmVod), and two accessory subunits (BmVoap1 and BmVoap2). Further analysis revealed BmVoa3 and BmVoa4 were located on the same chromosome and had similar molecular weights and isoelectric points, but separated to different small branches on the phylogenetic tree. Reverse transcription polymerase chain reaction results indicated that most Vo domain subunits were expressed during all silkworm developmental stages. Quantitative polymerase chain rection (qPCR) showed BmVoa1 was hemocyte-specific and BmVoe1 was testis-specific. BmVoa2 was not expressed in the midgut, while the other members were specifically or highly expressed in the midgut and Malpighian tubules. Further qPCR analysis indicated BmVoa4 in the midgut and BmVoa3 in BmE cells were significantly induced by B. mori nucleopolyhedrovirus (BmNPV), suggesting that these two genes may be involved in BmNPV infection.

液泡H ⁺ -ATPase（V-ATPase）对真核生物非常重要，由保守的V ₁结构域和稍微可变的Vo结构域组成。但是，家蚕Bombyx mori中尚未系统地识别Vo域。在这项研究中，在整个B. mori基因组中鉴定出11个Vo域亚基成员，包括亚基a的四种亚型（BmVoa1-4），e亚基的两种亚型（BmVoe1-2），每个c''亚基（BmVob）），亚基c（BmVoc）和亚基d（BmVod），以及两个辅助亚基（BmVoap1和BmVoap2）。进一步分析显示BmVoa3和BmVoa4位于同一条染色体上，具有相似的分子量和等电点，但在系统发育树上分隔为不同的小分支。逆转录聚合酶链反应结果表明，大多数Vo域亚基在所有家蚕发育阶段均表达。定量聚合酶链反应（qPCR）显示BmVoa1是血细胞特异性的，而BmVoe1是睾丸特异性的。BmVoa2在中肠中不表达，而其他成员在中肠和Malpighian小管中特异性或高度表达。此外qPCR分析表明BmVoa4中肠和BmVoa3桑蚕核多角体病毒（BmNPV）明显诱导了BmE细胞中的BmNPV感染，提示这两个基因可能与BmNPV感染有关。