嗜盐菌中的类视紫红质蛋白

在嗜盐菌中发现了4种含视黄醛的膜蛋白: 细菌视紫红质、氯视紫红质、感觉视紫红质-I(M 慢视紫红质)和感觉视紫红质-Ⅱ(憎光视紫红质)。文中着重介绍了上述4中膜蛋白的结构、 功能及其相似性等方面的研究进展。图6参20

主分量分析(PCA)在动物分类学中的运用

就主量分析(PCA)的基本原理、 运用发展过程及在动物分类学上的应用作了 阐明。并以亚洲疣猴类5个属为例, 利用其面颅和颅骨的6项变量进行分析, 且 叙述了PCA的主要计算过程。 结果表明, 在分类过程中, 主要是面颅的凸度和宽 度结构起贡献作用。图5参21

湖南尖吻吻蝮蛇毒两个出血毒素的纯化和理化性质

经Sephadex G-75凝胶过滤, QAE-Sephadex A-50和CM-Sephadex C-25离子交换层析, 从尖吻蝮蛇毒中纯化出两个出血毒素(DaHT-1和DaHT-2)。SDS-PAGE测得分子量均为23.5kD,IEF-PAGE测得等电点分别为5.6和5.2, DaHT-1和DaHT-2的最小出血剂量分别为0.5#mu#g和0.8#mu#g。都具蛋白水解酶活性, DaHT-1和DaHT-2的最适温度分别为35℃和40℃, 最 适pH为6-9, 对热均不稳定, 温度高于60℃活性完全丧失。图7表1参13

The reproductive strategies of an endemic Tibetan fish, Gymnocypris selincuoensis

The reproductive traits of Gymnocypris selincuoensis from Selincuo Lake and its tributaries were investigated in 1997 and 1998. The youngest mature male was age 7 with a standard length (SL) of 172.0 mm, and the youngest mature female was age 8 with a SL of 194.0 mm. The L(50)s Of SL and age at first maturity were respectively 250.32 mm and age 9 for males and 224.71 mm and age 8 for females. The gonadosomatic index (GSI) significantly changed with seasons for mature individuals but not for immature individuals. GSIs of mature females at stages IV and V of ovary development increased with SL and reached a maximum value at the SL range from 370 mm to 390 mm; the GSIs of mature males were negatively correlated with SL. The breeding season lasted from early April to early August. Egg size did not significantly change with SL but increased with the delay of spawning. The individual absolute fecundity varied from 1,341 to 28,002 eggs (mean 12,607+/-7,349), and the individual relative fecundity varied from 6.4 to 42.0 eggs.g(-1) (mean 25.5+/-9.7). The individual fecundity increased with total body weight; it also increased with SL for those of SL less than 370 mm. There was a rest of spawning for mature individuals.