不同海拔两种沙蜥低温耐受性的比较

摘要

Environment has a significant impact on physiological and genetic characteristics of animals,and low temperature is one of the main characteristics of high altitude environment.However,until now,there are few studies on cold hardiness of lizards.In this study,Phrynocephalus erythrurus from Hoh Xil,Qinghai province and P.przewalskii from Minqin county,Gansu province were selected to investigate the cold hardiness of lizards living at different altitudes.The supercooling capacity,the ability to resist inoculative freezing,the heart rate and breathing rate at 4 ℃ and the concentration of organic osmolytes (such as glucose,urea etc.) were measured.The results showed that the supercooling capacity of the 2 species had no significant difference;while P.erythrurus had a stronger ability to resist inoculative freezing than P.przewalskii.At 4 ℃,the heart rate and breathing rate of P.erythrurus were higher than those of P.przewalskii.None of the 4 potential organic osmolytes that might be as cryoprotectants in these species.%环境条件会对动物的生理和遗传特征产生重要的影响.然而,目前关于蜥蜴低温耐受的研究较少.为探究不同海拔沙蜥的低温耐受性,选取了青海省可可西里地区的红尾沙蜥Phrynocephalus erythrurus和甘肃省民勤县的荒漠沙蜥P.przewalskii作为研究对象.分别测定了2种沙蜥的过冷能力、对于接种结冰的抵抗能力、急性低温(4℃)条件下的心率和呼吸频率,以及体内一些可能作为抗冻物质存在的小分子渗透物质(如葡萄糖,尿素等).结果表明:不同海拔2种沙蜥的过冷能力差异无统计学意义;而红尾沙蜥抵抗接种结冰能力明显优于荒漠沙蜥;在4℃条件下,红尾沙蜥的适应能力比荒漠沙蜥更强,其有更高的心率和呼吸频率;然而在4种可能作为抗冻保护剂存在的小分子渗透物质方面,2个物种之间并没有呈现出有规律的差异.