In order to elucidate the biochemical mechanism of sperm capaeitation, the relationship between plasmalemma Na, K-ATPase, capacitation and acrosome reaction was investigated.Plasmalemma of guinea pig spermatozoa was i...In order to elucidate the biochemical mechanism of sperm capaeitation, the relationship between plasmalemma Na, K-ATPase, capacitation and acrosome reaction was investigated.Plasmalemma of guinea pig spermatozoa was isolated by sucrose gradient centrifugation for the determination of Na, K-ATPase activity. As far as the authors are aware, the Na, K-ATPase activity in plasmalemma of the guinea pig has never been detected. By treating sperm plasmalemma with 0.05% DOC (deoxycholate), enzyme activity could be quantitatively measured. After spermatozoa were incubated in capacitation medium for 8 h, Na, K-ATPase activity was found to be decreased to 35.6% as compared with that before incubation. The spermatozoa incubated for 10.5h in capacitationmedium containing 1 and 5μmol/L ouabain showed 46.5% and 64.4% acrosome reactions respectively, while the acrosome reaction of the control group was only 27.4%. The above results suggest that the decrease in the Na, K-ATPase activity of guinea pig spermatozoa may展开更多
基金supported by grants from The Ministry of Health of The People's Republic of China(2013ZX10003006-001-001)The National Laboratory of Biomacromolecules(2013kf01)The Ministry of Science and Technology of People's Republic of China(2011YQ03013404)~~
基金supported by grants from The National Natural Science Foundation of China(Y4JM061001,Y5JY011001,81072093)The Natural Science Foundation of Hebei Province(C2012401039)~~
基金supported by grants from The "973" Program(2011CBA00906)The National Special Projects for Key Scientific Instruments and Equipment Development of Ministry of Science and Technology(2011YQ03013404)The State Key Laboratory for Microbial Resources,Institute of Microbiology,Chinese Academy of Sciences(SKLMR-20130605)~~
文摘自然界中所有的蓝藻都能产生烷烃,但这些烷烃都比汽油（C5~C12）的链长更长。两个源于蓝藻的产烃基因已经在大肠杆菌细胞中成功表达。迄今为止,从头合成的最短烷烃为C9。本研究在大肠杆菌细胞中设计了一个人工进化系统,该系统能生产短链烷烃,并可以提高烷烃的产量。该进化系统由两大部分元件组成：产烃基因和胞内烷烃响应系统。烷烃是报道基因氯霉素抗性基因（Cm R）和16S r DNA的一种主要诱导物。携带有Cm R的细胞能在含有氯霉素（Cm）的培养基中存活下来,而烷烃诱导产生更多的16S RNA,能加快细胞的生长和繁殖。将这些基因组装在一种易突变的大肠杆菌菌株中,并成功地筛选出了具有生长优势和高产烷烃能力的细菌。最后,用这些细菌实现了辛烷（C8）的生产——在不加入产烃底物的情况下,创造了在人工生物系统中产生最短链长烷烃的记录。以上结果说明,在大肠杆菌中生产比C9更短的烷烃不存在机理方面的限制。
文摘In order to elucidate the biochemical mechanism of sperm capaeitation, the relationship between plasmalemma Na, K-ATPase, capacitation and acrosome reaction was investigated.Plasmalemma of guinea pig spermatozoa was isolated by sucrose gradient centrifugation for the determination of Na, K-ATPase activity. As far as the authors are aware, the Na, K-ATPase activity in plasmalemma of the guinea pig has never been detected. By treating sperm plasmalemma with 0.05% DOC (deoxycholate), enzyme activity could be quantitatively measured. After spermatozoa were incubated in capacitation medium for 8 h, Na, K-ATPase activity was found to be decreased to 35.6% as compared with that before incubation. The spermatozoa incubated for 10.5h in capacitationmedium containing 1 and 5μmol/L ouabain showed 46.5% and 64.4% acrosome reactions respectively, while the acrosome reaction of the control group was only 27.4%. The above results suggest that the decrease in the Na, K-ATPase activity of guinea pig spermatozoa may
