兰州北山三种蜥蜴春季食性分析

兰州地区密点麻蜥、丽斑麻蜥和草原沙蜥的春季食物均为动物食物。无论在栖息地重叠地区还是非重叠地区,三种蜥蜴的食物种类在种间均无显著差异（Ｆ＝０．８６１,ｄｆＴ＝２,ｄｆＥ＝３６,Ｐ〉０．０５）。种内不同性别和年龄食性无显著差异。     

密点麻蜥几种组织SDH和LDH活性对温度的适应

研究了密点麻蜥肝脏、骨骼肌、大脑组织中琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)活性对温度的依赖关系.结果表明:密点麻蜥3种组织中SDH在5～35℃范围内随温度的升高而升高,在35℃时达到峰值后随着温度的升高而下降,35℃可能为SDH的最适温度;3种组织的LDH活性随温度的升高而升高;大脑中的SDH和LDH活性最高.这表明SDH和LDH的活性与动物组织的能量代谢相适应.     

MHC Class I Exon 4 in the Multiocellated Racerunners （Eremias multiocellata）： Polymorphism,Duplication and Selection

The major histocompatibility complex （MHC） is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- death evolution, gene conversion, and concerted evolution. Studies investigating the evolution of MHC class I genes have been biased toward a few particular taxa and model species. However, the investigation of this region in nonavian reptiles is still in its infancy. We present the first characterization of MHC class I genes in a species from the family Lacertidae. We assessed genetic diversity and a role of selection in shaping the diversity of MHC class I exon 4 among 37 individuals of Eremias multiocellata from a population in Lanzhou, China. We generated 67 distinct DNA sequences using cloning and sequencing methods, and identified 36 putative functional variants as well as two putative pseudogene-variants. We found the number of variants within an individual varying between two and seven, indicating that there are at least four MHC class I loci in this species. Gene duplication plays a role in increasing copy numbers of MHC genes and allelic diversity in this species. The class I exon 4 sequences are characteristic of low nucleotide diversity. No signal of recombination is detected, but purifying selection is detected in β2-microglobulin interaction sites and some other silent sites outside of the function-constraint regions. Certain identical alleles are shared by Eremias multiocellata and E. przewalskii and E. brenchleyi, suggesting trans-species polymorphism. The data are compatible with a birth-and-death model of evolution.     

Food restriction affects maternal investment but not neonate phenotypes in a viviparous lizard

Food availability significantly affects an animal's energy metabolism,and thus its phenotype,survival,and reproduction.Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species.In this study,we conducted food manipulation experiments in field enclosures to identify the effect of food restriction on female reproductive traits and postpartum body condition,as well as on hatchling phenotypes,in a lacertid viviparous lizard from the Inner Mongolian desert steppe of China.Females under low-food availability treatment (LFT) had poorer immune function and body condition compared with those under high-food availability treatment (HFT).The food availability treatments significantly affected the litter size and litter mass of the females,but not their gestation period in captivity or brood success,or the body size,sprint speed,and sex ratio of the neonates.Females from the LFT group had smaller litter sizes and,therefore,lower litter mass than those from the HFT group.These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance,and incur a cost in the form of poor postpartum body condition and immune function.The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.     

温度对南疆沙蜥和密点麻蜥消化酶活性的影响

为探究不同温度对南疆沙蜥Phrynocephalus forsythii和密点麻蜥Eremias multiocellata消化酶活性的影响,本研究测定了不同温度下南疆沙蜥和密点麻蜥的肝脏、胃及十二指肠的消化酶——淀粉酶(碘-淀粉比色法)、脂肪酶(比浊法)及胰蛋白酶(紫外线吸收法)的活性。结果显示,南疆沙蜥和密点麻蜥消化酶活性在4～45℃随着温度升高呈现先上升、后下降的趋势;40℃驯化的南疆沙蜥、35℃驯化的密点麻蜥肝脏、胃及十二指肠的淀粉酶、脂肪酶及胰蛋白酶活性最高。南疆沙蜥和密点麻蜥消化酶活性具有温度依赖性,这与机体在不同温度下的生理机能是密切相关的。同时,2种蜥蜴的消化酶活性最大时的驯化温度明显不同,这与它们偏好的环境温度密切相关。     

三种荒漠蜥蜴空间和营养生态位研究

同一荒漠蜥蜴群落中,荒漠沙蜥（Ｐｈｒｙｎｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉ）和虫纹麻蜥（Ｅｒｅｍｉａｓｖｅｒｍｉｃｕｌａｔａ）,密点麻蜥（Ｅｒｅｍｉａｓｍｕｌｔｉｏｃｅｌｌａｔａ）占不有同的空间生态位,其间几乎不存在竞争。两个近缘种虽然占有相同空间生态位,但个体大的密点麻蜥食物种类特化,个体小的虫纹麻蜥偏重于利用较小的食物资源。占有相同空间生态位的近缘种,营养生态位向不同方向特化,利用不同的食物资源,从而在竞争中共存,保持群落结构的稳定性。     

温度对蜥蜴腓肠肌ATP酶活性影响的研究

本文研究了荒漠沙蜥（ｐｈｒｙｎｏｃｅｐｈａｌｕｓ Ｐｒｚｅｗａｌｓｋｉｉ Ｓｔｒａｕｃｈ）和密点麻蜥（Ｅｒｅｍｉａｓ　ｍｕｌｔｉｏｃｅｌｌａｔａＧｕｅｎｔｈｅｒ）腓肠肌肌球蛋白钙激活ＡＴＰ酶活性对温度的依赖关系。结果表明，荒漠沙蜥腓肠肌ＡＴＰ酶的最适温度为３７℃，密点麻蜥腓肠肌ＡＴＰ酶的最适温度为３５℃。两种蜥蜴ＡＴＰ酶最适温度的不同与它们所喜好的温度有很好的相关性。ＡＴＰ酶活性在同种个体大小之间也存在差异。ＡＴＰ酶的生化调节可能在蜥蜴对温度适应上起重要作用。     

密点麻蜥的两性异形和雌性繁殖

蜥蜴繁殖成功率与其形态特征有密切的关系。作者在内蒙古乌拉特后旗采集密点麻蜥(Eremias multio-cellata) ,定量研究该种形态特征的两性异形和雌体繁殖特征,检验与成体形态特征相关的两性繁殖成功率差异是否能促进两性异形的进化。密点麻蜥成体个体大小无显著的两性差异,但头部大小两性差异显著;雄性个体的头长和头宽均大于体长相同的雌性成体。繁殖雌体于五、六月份排卵;在实验室条件下,雌体在六月下旬至七月下旬之间产仔。该种雌体年产单窝仔,每窝2 -4仔。窝仔重与雌体体长呈正相关,但雌体体长仅能解释很少一部分(约19 %)窝仔重的变异。窝仔数和幼仔重均与雌体体长无关。幼仔重与相对生育力(相对于雌体体长的窝仔数)呈显著的负相关,表明该种蜥蜴存在后代数量-大小之间的权衡。密点麻蜥雄体和雌体向较大体型方向进化的选择压力均相对较弱,与成体头部大小相关的两性繁殖成功率的差异是导致该种蜥蜴头部大小两性异形进化的主要原因[动物学报52 (2) : 250 -255 , 2006]。     

密点麻蜥的食性及摄食的季节性变化

分析甘肃民勤２０９只成体和４３只幼体密点麻蜥胃含物表明,密点麻蜥是以动物性食物为主的杂食性动物,主要以甲虫和白刺果为食．成体出蛰后即开始强烈摄自,摄食率均在８３％以上．食性季节性变化显著,春季仅以动物为食,夏季动物性和植物性食物各半,秋季植物性食物占１／３．食物种类多样性和营养生态位宽度随体形增大而增加．