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Abstract – The reproductive biology of three species of rainbowfish (Melanotaeniidae) in northeastern Australian rainforest streams was investigated. Two species, Melanotaenia eachamensis and Cairnsichthys rhombosomoides are endemic to the area, whereas the third, M. splendida splendida, is more widespread. The species were all highly fecund, producing many hundreds of eggs between 1.10 and 1.24 mm in diameter. Melanotaenia eachamensis was the most fecund, produced the largest eggs of the three species, and consequently exhibited the greatest maternal investment (as measured by gonadosomatic index). The majority of reproductive effort occurred during the dry season, although reproductively active fish were present year-round for each of the species, but particularly so for M. s. splendida and C. rhombosomoides. No evidence for a role by temperature or photoperiod as environmental cues for reproduction was found, and it was suggested that gonad development was strongly tied to somatic growth. The concentration of reproduction to the dry season ensures that larvae are produced during a period of relatively stable and benign physical conditions. Comparison of temporal changes in gonadosomatic index values suggest that the spawning season of M. eachamensis , which occurs in high-elevation streams, is more restricted and commences about 1 month earlier than either other species. A similar phenology was observed for the M. s. splendida population found at high elevation and highlights the potential for spatial differences in stream productivity to influence life history. Note 相似文献
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Bird SJ 《Science (New York, N.Y.)》1984,224(4649):595-596
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AIM: To examine the expression of human endostatin in E.coli, produce its fusion protein antibody and observe its biological activity. METHODS: Endostatin gene was amplified by polymerase chain reaction,recombined with plasmid vector pGEX-2T and induced expression with IPTG.The protein activity was tested by endothelial cell proliferation inhibitory assay.Inclusion body crudely purified was used to generate polyclonal antibody to detect its expression at mouse's liver and kidney etc. RESULTS: The protein expressed was 20kD after digestion by thrombin,it appeared the anti-angiogenesis activity and Western blotting indicated the expression of endostatin in liver and kidney of mouse. CONCLUSION: The successful expression of human endostatin and the preparation of polycolonal antibody indicated its potential application in anti-angiogenesis therapy and diagnosis tumors. 相似文献
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五种鬼伞过氧化物酶和酯酶的同工酶研究 总被引:2,自引:0,他引:2
应用垂直板聚丙烯酰胺凝胶电泳对五种野生鬼伞 (Coprinus)真菌进行了过氧化物酶 (POD)和酯酶(EST)的同工酶分析 ,结果表明 :五种鬼伞的POD和EST同工酶酶谱比较稳定清晰 ,且分别有一条共同的酶带 ,可能是鬼伞属的POD和EST同工酶特征酶带 ;POD和EST同工酶酶谱均表明 ,家园鬼伞 (C .domesticus)和瓦鳞鬼伞 (C .clavatus)间有较近的亲缘关系 ;不同种鬼伞的POD和EST同工酶之间既有共同的特征 ,又各自有本物种的特有特征 ,POD和EST同工酶酶谱可以作为鬼伞属种类鉴定、亲缘关系比较的重要依据。 相似文献
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DU Yi-mei TANG Ming LIU Chang-jin HONG Zhi-gang KE Qin-mei DI Jiu-fang LUO Hong-yan HU Mou-xian HU Xin-wu XI Jiao-ya TANG Bi Jurgen Hescheler 《园艺学报》2004,20(9):1537-1541
AIM: To determine the role of Kv1.2, Kv1.5, Kv2.1 in the hypoxia pulmonary vasoconstriction (HPV). METHODS: Male Wistar rats were divided into two groups: normoxic group and hypoxic group. The single smooth muscle cell was obtained from pulmonary artery of Wistar rats with acute enzymatic digestion method. The conventional whole-cell patch clamp technique was used to record the resting membrane potential (Em) and the potassium currents of voltage-gated potassium channel (IKv) in rat pulmonary arterial smooth muscle cells (PASMC). Intracellular application of Kv1.2/Kv1.5/Kv2.1 antibodies (1∶125) was conducted through the whole-cell patch clamp system. RESULTS: ① Em of PASMC was depolarized after 24 h hypoxia compared with that of control cells . IKv of PASMC was decreased after 24 h hypoxia, . ② The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies depolarized Em and inhibited IKv in PASMC from normoxic rat, whereas the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on them. ③ The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies and the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on IKv and Em from rats hypoxic for 24 h. CONCLUSION: Kv1.2, Kv1.5, Kv2.1 might be oxygen sensitive potassium channels which mediated HPV. 相似文献
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In vitro studies of Norwegian Red bovine semen immobilized and cryopreserved in alginate solid gel network 下载免费PDF全文
AH Alm‐Kristiansen ER Gaustad G Bai FB Standerholen G Klinkenberg E Kommisrud KE Waterhouse 《Reproduction in domestic animals》2018,53(2):365-370
Development of new semen cryopreservation techniques improving sperm survival and ensuring availability of viable spermatozoa for a prolonged time‐period after AI is promising tools to reduce sensitivity of timing of AI and enhance overall fertility. The SpermVital® technology utilizes immobilization of bull spermatozoa in a solid network of alginate gel prior to freezing, which will provide a gradual release of spermatozoa after AI. The objective of this study was to compare post‐thaw sperm quality and in vitro sperm survival over time of Norwegian Red bull semen processed by the SpermVital® (SV) technology, the first commercialized production line of SpermVital® (C) and by conventional procedure applying Biladyl® extender (B). Post‐thaw sperm motility was not significantly different between SV, C and B semen (p > .05). However, sperm viability and acrosome intactness were higher for SV than C and B semen (p < .05). Small differences in DNA quality were observed (p < .05). Sperm viability after storage in uterus ex vivo was higher for SV than for C semen (p < .05). Furthermore, sperm survival in vitro over time at physiological temperature was significantly higher for SV semen than C semen as well as B semen during the incubation period of 48 hr (p < .05). In conclusion, the SpermVital® technology is improved and is more efficient in conserving post‐thaw sperm quality and results in higher sperm viability over time in vitro for SV than for C and B semen. 相似文献
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