木薯蚕五龄至化蛹蚕蛋白质代谢的研究

本文报道木薯蚕南一品种,从五龄起蚕至化蛹第一天血液蛋白质含量的动态变化。五龄起蚕血液蛋白质含量为30.4mg/ml,摄食木薯叶一天后,反而略有下降,为29.2mg/ml,第三天后回升,第五天开始急剧直线上升,吐丝时达最高量96.4mg/ml,为起蚕时含量的三倍多,预蛹期逐渐下降,化蛹第一天下降幅度最大。电子显微镜观察五龄第四天脂肪体细胞,细胞质内只见脂肪球,未见蛋白质颗粒。证明五龄期脂肪体合成蛋白质后释放到血液中,化蛹期血液蛋白质又转输入脂肪体,脂肪体由合成蛋白质部位转变为蛋白质贮藏部位,符合昆虫变态与蛋白质代谢的规律。

THE PROTEIN METABOLISM OF CASSAVA-SILKWORM (PHILOSAMIA CYNTHIA RICINA)FROM FIFTH INSTAR TO PUPATION

The content of protein in blood has a dynamic change from first day of fifth instar to first day of pupation on cassava-silkworm(the Nanning No. 1 race). The content of protein in blood was 30.4mg/ml on the first day of fifth instar and 29.2mg/ml after one day for eating cassava leaves. The protein increased on the third day and went up sharply from the fifth day. And the content was 96.4mg/ml, the highest on the spinning time, three times of the first day of fifth instar. It decreeasd gradually during the pre- pupal period, and dropped sharply on the first day of pupation. Fat globules in the cytoplasm was seen only and protein granule was not observed when the fat cell examined with electron microscope on the fourth day of fifth instar. But protein granule was seen on the first day of pupation. It proved that protein was synthesized by fat body and released into blood. The protein in blood transport into fat body during pupation stage, the fat body as a site for protein synthesis turned to the storage place of protein. It accorded with the regularity of insect metamorphosis and protein metabolism.