The Different Mechanisms of Hypoxic Acclimatization and Adaptation in Lizard Phrynocephalus vlangalii Living on Qinghai‐Tibet Plateau

Abstract

Phrynocephalus vlangalii is a species of lizard endemic in China, which lives on Qinghai-Tibet Plateau ranging from 2000 to 4600 m above sea level. In this study, P. vlangalii were collected from low altitude (2750 m) and high altitude (4564 m). The lizards from low altitude were acclimatized in simulated hypoxic chamber (equivalent to 4600 m) for 7, 15, and 30 days. The hematological parameters, heart weight, myocardial capillary density, and myocardial enzyme activities were examined. The results showed that acclimatization to hypoxia significantly increased hemoglobin concentration ([Hb]), hematocrit (Hct), heart weight (HW), heart weight to body mass (HW/BM), lactate dehydrogenase (LDH) activity, but markedly decreased mean corpuscular hemoglobin concentration (MCHC) and succinate dehydrogenase (SDH) activity. Red blood cell (RBC) count, body mass (BM), myocardial capillary density did not change markedly during hypoxic acclimatization. On the other hand, [Hb], Hct, MCHC, HW/BM, myocardium capillary density, and SDH activity of P. vlangalii from high altitude were remarkably higher than those from low-altitude; however, LDH activity of high-altitude P. vlangalii was lower than that of low-altitude lizards. There was no significant difference in HW or BM between populations of high-altitude and low-altitude. Based on the present data, we suggest that P. vlangalii has special anatomical, physiological, and biochemical accommodate mechanisms to live in hypoxic environment, and the regulative mechanisms are different between hypoxic acclimatization and adaptation.

Changes in intestinal microbiota across an altitudinal gradient in the lizard Phrynocephalus vlangalii

“…), blood oxygen affinity (He, Xiu, Tang, Yue, et al. ; Lu et al., ), lung and/or heart mass (Han et al., ; He, Xiu, Tang, Yue, et al. ) as well as by decreasing aerobic respiration (Tang et al., ).…”

“…P. vlangalii has been an ideal organism for evolutionary and ecological studies (Han et al., ; He, Xiu, Tang, Yue, et al. ; Jin & Liu, ; Jin et al., ; Li et al., ; Li, Liang, et al. ; Yang, Qi, & Fu, ).…”

“…Through millions of years of evolution, P. vlangalii has evolved many highland‐adaptive traits in molecular biology (Yang et al., ), physiology (Han et al., ; He, Xiu, Tang, Yue, et al. ; Li, Liang, et al. ), and life history (Jin & Liu, ; Jin et al., ; Li et al., ).…”

“…On the other hand, highland ectotherms also increase their energy production. At low temperature and under hypoxic conditions, highland ectotherms can provide a steady flow of energy for life by increasing their heart rate ), blood oxygen affinity (He, Xiu, Tang, Yue, et al 2013;Lu et al, 2015), lung and/or heart mass (Han et al, 2016;He, Xiu, Tang, Yue, et al 2013) as well as by decreasing aerobic respiration .…”

Metabolic Characteristics and Response to High Altitude in Phrynocephalus erythrurus (Lacertilia: Agamidae), a Lizard Dwell at Altitudes Higher Than Any Other Living Lizards in the World

“…So far, studies on the mechanisms of high altitude adaptation in reptilian species have mainly been conducted using acute or chronic treatments (from several days to months) of low temperature and/or low PO 2 [18,19]. These treatments generally only induce adjustments at the level of mitochondria and enzymes; however, the adaptation characteristics of native reptilian species at high altitude are considered to be the result of long-term evolution at high altitude and may be strongly heritable.…”