Ishizaki H, Suzuki A
Department of Biology, School of Science, Nagoya University, Japan.
Int J Dev Biol. 1994 Jun;38(2):301-10.
Progress made toward the elucidation of molecular features of the prothoracicotropic hormone (PTTH) of the silkmoth Bombyx mori is reviewed. PTTH stimulates the prothoracic glands to synthesize and release ecdysone, and is therefore a key hormone for the regulation of insect moulting and metamorphosis. Bombyx PTTH is a 30 kDa homodimeric glycoprotein, whose carbohydrate moiety is not essential for the biological function. The Bombyx genome contains a single copy of the PTTH gene. PTTH is produced by four dorsolateral neurosecretory cells of brain. Another Bombyx brain peptide exerting prothoracicotropic activity to a heterologous moth Samia cynthia ricini but no activity to Bombyx has been identified and termed bombyxin. Bombyxin is a 5 kDa heterodimeric peptide that shows a high similarity to insulin in the amino acid sequence. The bombyxin gene structure also shows a high similarity with the insulin gene structure. The Bombyx genome contains more than 30 copies of the bombyxin gene. Bombyxin is synthesized by eight dorsomedial neurosecretory cells of brain.
本文综述了家蚕促前胸腺激素（PTTH）分子特征研究的进展。PTTH刺激前胸腺合成并释放蜕皮激素，因此是调节昆虫蜕皮和变态的关键激素。家蚕PTTH是一种30 kDa的同型二聚体糖蛋白，其糖基部分对生物学功能并非必需。家蚕基因组中PTTH基因只有一个拷贝。PTTH由脑的四个背外侧神经分泌细胞产生。另一种家蚕脑肽对异种蛾蓖麻蚕具有促前胸腺活性，但对家蚕无活性，已被鉴定并命名为家蚕素。家蚕素是一种5 kDa的异型二聚体肽，其氨基酸序列与胰岛素高度相似。家蚕素基因结构也与胰岛素基因结构高度相似。家蚕基因组中家蚕素基因有30多个拷贝。家蚕素由脑的八个背内侧神经分泌细胞合成。
