【摘要】 本文首次报道了制备家蚕,五龄初期幼虫后部丝腺线粒体DNA的结果。后丝腺匀浆后,以600g和15,000g差速离心,得到完整离体线粒体。在高渗条件下,以牛胰 DNase Ⅱ处理污染的核DNA。碱性SDS裂解线粒体后,经RNase处理,并通过Sepharose 2B凝胶柱分部,便得到可供电镜分析与限制性内切酶消化的线粒体DNA制品。初步结果表明,家蚕后丝腺mtDNA为环状分子。分子量较大,约为11×10⁶d的2倍、3倍和4倍。每条丝腺约含0.5微克。每个线粒体约含3×10^-3微克,大概有2—4个拷贝。更多还原

【Abstract】 We will first report the results about the preparation and properties of mtDNA in the posteria silk gland at the beginning of the fifth laval stage Bonibyx mori.The intact mitochondria were obtained via 600 g and 15000 g differential centrifugation.The contaminated nucleic DNAs were digested by DNase II in a hypertonic solution.After lys’s treatment by using alkaline SDS solution,ENase digestion and Sepharose 2B gel filtration were successively carried out,then a purifed mtDNA was prepared.In agarose gel electrophoresis,the preparation of mtDNA showed a clear band,whose position was resemble to those of lamda DNA which suggested its high molecular weight.Electron microscopic examination of the mtDNA showed that mtDNA was circular.The molecular weight was about twice or three times or four times heavier as 11×104 d.Each posteria silk gland contained around 0.5 microgram of mtDNA,every mitochondrion possessed 3×10-5 microgram or so.The copy number was probably 2 to 4.更多还原