【摘要】 蚕在4龄期开始的48小时连续取食抗-20,4眠家蚕被诱导成3眠蚕并吐丝结茧。根据对α-鹅膏蕈碱的敏感性,放线菌素D的抑制作用,DNA需要以及[~3H]-UMP掺入酸不可溶物,测定了蚕后丝腺的RNA聚合酶Ⅰ和Ⅱ活力。观察到随着抗-20处理后天数的增加,RNA聚合酶在热变性小牛胸腺DNA和内源DNA上转录活性迅速升高,并伴随着RNA合成的迅速增加;而对照组蚕的酶活力和RNA含量仍保持在相当稳定的低水平。更多还原

【Abstract】 Trimolter larvae were efficiently indnced from a tetramolter strain of Bombyx meri by feeding "Kang-20" to the larvae during the first 48 hours of the 4th instar and could spin smaller cocoons.RNA polymerase Ⅰ and Ⅱ activiries in the posterior sikgland ere determined on the basis of α-Amanitin sensitity,Actinomycin D inhibition,DNA requirement and [3H] UMP incorporation into acid-insoluble material.It was observed that after "Kang-20" treatment classⅠ and Ⅱ polymerase activities transcribed on hot-denatured calf thymus DNA and endogenous DNA rised rapidly with duration of the 4th instar and reached a maximum level on the 4th day of the instar.The enzyme stimulation was in good gareement with the increase of RNA contents in the posterior silkgland.But in the control the enzyme activity and RNA.content remained at a rather low and stable level.These results indicate that increased rranscriptional activity in the posterior silkgland cells is at least partly due to de novo synthesis of RNA polymerase and enhanced nuclei template-capacity by "Kang-20" treatment.更多还原