兰州大学机构库 >生命科学学院
不同海拔两种沙蜥低温耐受能力及其机制的研究
Alternative TitleA study on cold hardiness and its mechanism of two toad-headed lizards living at different altitude
李相涛
Thesis Advisor陈强
2017-03-30
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword红尾沙蜥 荒漠沙蜥 低温 过冷能力 接种结冰 抗冻保护剂
Abstract

低温、低氧、强紫外线是生活在青藏高原上的物种面临的三大挑战。经过长期的进化,世居青藏高原的动物具备了一系列适应高原环境的生理和行为特征。红尾沙蜥(Phrynocephalus erythrurus)分布在西藏北部的羌塘高原地区,是世界上垂直分布最高的蜥蜴。本研究的目的是为了探究红尾沙蜥低温耐受能力及其机制。本次研究采集了青海省格尔木市唐古拉山镇(4600 m)的红尾沙蜥,并且以甘肃省民勤县(1480 m)的荒漠沙蜥(Phrynocephalus przewalskii)作为参照,比较高低海拔两种沙蜥冬眠前后的生理生化指标,包括过冷能力、接种结冰抵抗能力、血红蛋白浓度、血细胞比容、四种可能作为抗冻保护剂的有机渗透物质(葡萄糖、尿素、乳酸和甘油)等。结果表明,不同海拔的两种沙蜥过冷耐受能力没有显著差异,但是冬眠前红尾沙蜥对接种结冰的抵抗能力显著低于荒漠沙蜥,冬眠后红尾沙蜥对接种结冰的抵抗能力显著高于荒漠沙蜥;同一种沙蜥冬眠前后过冷耐受能力没有显著差异,冬眠后红尾沙蜥对接种结冰抵抗能力显著增加,而荒漠沙蜥对接种结冰抵抗能力显著降低;冬眠后,在4°C和0°C急性低温条件下红尾沙蜥的适应能力比荒漠沙蜥强;冬眠前后,同一海拔沙蜥四种渗透物质没有呈现出有规律的变化。为了更好的探究冬眠对红尾沙蜥低温耐受能力的影响,我们在实验室条件下将冬眠前期的红尾沙蜥置于2~4°C的低温条件下驯化7~8周来模拟冬眠。结果表明,与冬眠前相比,驯化后的红尾沙蜥过冷能力和对接种结冰抵抗能力都显著提高,其在4°C和0°C低温条件下的心率和呼吸频率也显著提高,而且其体内发生了一系列适应性的生理变化(如,血红蛋白含量和血细胞比容显著升高),但是四种渗透物质并没有呈现出有规律的变化。这些结果表明,低温驯化对于这两种沙蜥低温适应以及低温耐受能力的提高有显著作用;两种沙蜥都是部分耐受结冰的物种,在接种结冰的条件下蜥蜴的存活率较高;同时,这两种沙蜥在越冬时是否利用抗冻保护剂来提高存活率还需要进一步的确定。

Other Abstract

Cold, hypoxia and intense UV radiation are three major environmental challenges of organisms living at high altitudes. However, lifelong exposure to high altitude could generate certain adaptability which makes them tolerant to these environments. Phrynocephalus erythrurus inhabits the Qiangtang Plateau in northern Tibet, and is believed to be the world's highest lizard. The aim of the present study was to investigate survival strategies under low temperature and the possible mechanism of Phrynocephalus erythrurus. We collected the Phrynocephalus erythrurus living at Tanggula town of Golmud city of Qinghai Province and choose the Phrynocephalus przewalskii living at Minqin County of Gansu Province as the reference. To compare the physiological and biochemical indexes of two altitude lizards before and after hibernation, include supercooling ability, the abilty to resist incolutive freezing, the concentration of hemoglobin and hematocrit, four organic osmolytes (such as glucose,urea, lactate and glycerol) that may acted as cryoprotectants etc. The results showed that there has no difference of supercooling ability of two species. But the ability to resist incolutive freezing of Phrynocephalus erythrurus was significant lower than Phrynocephalus przewalskii before hibernation, and the result was opposite after hibernation. Compared with pre-hibernation, there were no difference of supercooling ability of same species, but after hibernation,  the abilty to resist incolutive freezing of Phrynocephalus erythrurus has significantly improved, the abilty to resist incolutive freezing of Phrynocephalus przewalskii has significantly decreased. After hibernation, Phrynocephalus erythrurus has a better adaptive ability at 4°C and 0°C than Phrynocephalus przewalskii. There were no regular difference of four organic osmolytes that may acted as cryoprotectants of same species before and after hibernation. In order to better explore hibernation for Phrynocephalus erythrurus,we put Phrynocephalus erythrurus selected before hibernation at 2~4°C for 7~8 weeks to acclimatization. The results showed that compared with pre-hibernation, the ability of supercooling and resist incolutive freezing of Phrynocephalus erythrurus has significantly improved; its heart rate and breathing rate at 4°C and 0°C have markedly improved; there have a series of physiological changes in adaptability (such as the concentration of hemoglobin and hematocrit has significantly improved); but four organic osmolytes did not show regular changes. These results suggest that low temperature acclimatization can raise the adaption ability and cold hardiness of lizards, the two species of lizards are partly freeze-tolerant and incolutive freezing is benefical for lizards survival. We speculate Phrynocephalus erythrurus may hibernate below soil freezing depth and use supercooling as the way to survive in the winter. The lizards whether use the cryoprotectant and cryoprotectant types need to be further determined.   

URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/221699
Collection生命科学学院
Recommended Citation
GB/T 7714
李相涛. 不同海拔两种沙蜥低温耐受能力及其机制的研究[D]. 兰州. 兰州大学,2017.
Files in This Item:
There are no files associated with this item.
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Altmetrics Score
Google Scholar
Similar articles in Google Scholar
[李相涛]'s Articles
Baidu academic
Similar articles in Baidu academic
[李相涛]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[李相涛]'s Articles
Terms of Use
No data!
Social Bookmark/Share
No comment.
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.