Miyagawa Y, Lee J M, Maeda T, Koga K, Kawaguchi Y, Kusakabe T
Laboratory of Silkworm Sciences, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
Insect Mol Biol. 2005 Jun;14(3):245-53. doi: 10.1111/j.1365-2583.2005.00553.x.
The AHA1 (activator of Hsp90 ATPase) family of proteins were exclusively conserved from yeast to humans, but little is known about their tissue distribution or biological function. In this study, a cDNA for a Bombyx mori AHA1 homologue, BmAHA1, was isolated from the testes of larvae on day 3 of the fifth instar using an mRNA differential display method. This cDNA encodes a protein with 341 amino acid residues. Gene expression studies revealed that BmAHA1 mRNA occurred prominently in the testes. In situ hybridization and immunostaining showed that the BmAHA1 mRNA signals were strongly detected in spermatogonial cells and primary spermatocytes at the fifth larval instar stage, whereas the BmAha1 protein was abundant in round and elongated spermatids at the pupal stage. The localization pattern of the accumulated protein in the elongated spermatids was reminiscent of that reported previously for microtubules, but the BmAha1 protein showed a decrease in apparent concentration during maturation process. The stage- and cell-specific expression indicated that BmAha1 might play a role in silkworm spermatogenesis, especially in postmeiotic differentiation.
AHA1（热休克蛋白90 ATP酶激活剂）蛋白家族在从酵母到人类的生物中都有保守存在，但对其组织分布或生物学功能却知之甚少。在本研究中，使用mRNA差异显示方法从五龄幼虫第3天的睾丸中分离出家蚕AHA1同源物BmAHA1的cDNA。该cDNA编码一个含有341个氨基酸残基的蛋白质。基因表达研究表明，BmAHA1 mRNA主要在睾丸中出现。原位杂交和免疫染色显示，在五龄幼虫阶段，精原细胞和初级精母细胞中能强烈检测到BmAHA1 mRNA信号，而在蛹期，圆形和伸长的精子细胞中BmAha1蛋白含量丰富。伸长精子细胞中积累蛋白的定位模式让人联想到先前报道的微管的定位模式，但BmAha1蛋白在成熟过程中表观浓度有所下降。阶段和细胞特异性表达表明，BmAha1可能在家蚕精子发生中发挥作用，尤其是在减数分裂后分化过程中。
