title: Differences in Hematological Traits between High- and Low-Altitude Lizards (Genus Phrynocephalus).
abstract: Phrynocephalus erythrurus (Lacertilia: Agamidae) is considered to be the highest living reptile in the world (about 4500-5000 m above sea level), whereas Phrynocephalus przewalskii inhabits low altitudes (about 1000-1500 m above sea level). Here, we report the differences in hematological traits between these two different Phrynocephalus species. Compared with P. przewalskii, the results indicated that P. erythrurus own higher oxygen carrying capacity by increasing red blood cell count (RBC), hemoglobin concentration ([Hb]) and hematocrit (Hct) and these elevations could promote oxygen carrying capacity without disadvantage of high viscosity. The lower partial pressure of oxygen in arterial blood (PaO2) of P. erythrurus did not cause the secondary alkalosis, which may be attributed to an efficient pulmonary system for oxygen (O2) loading. The elevated blood-O2 affinity in P. erythrurus may be achieved by increasing intrinsic O2 affinity of isoHbs and balancing the independent effects of potential heterotropic ligands. We detected one α-globin gene and three β-globin genes with 1 and 33 amino acid substitutions between these two species, respectively. Molecular dynamics simulation results showed that amino acids substitutions in β-globin chains could lead to the elimination of hydrogen bonds in T-state Hb models of P. erythrurus. Based on the present data, we suggest that P. erythrurus have evolved an efficient oxygen transport system under the unremitting hypobaric hypoxia.
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Songsong
authors.initials: S
authors.lastname: Lu
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Tang
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yue
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000255:Adenosine Triphosphate / Q000097:blood; D000531:Altitude; D000595:Amino Acid Sequence; D000818:Animals; D001158:Arteries / Q000502:physiology; D001784:Blood Gas Analysis; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004912:Erythrocytes / Q000378:metabolism; D006439:Hemodynamics; D006860:Hydrogen Bonding; D008116:Lizards / Q000097:blood*; D008969:Molecular Sequence Data; D010100:Oxygen / Q000097:blood; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D055542:alpha-Globins / Q000737:chemistry / Q000378:metabolism; D055544:beta-Globins / Q000737:chemistry / Q000378:metabolism
chemical_list: D021122:Protein Subunits; D055542:alpha-Globins; D055544:beta-Globins; D000255:Adenosine Triphosphate; D010100:Oxygen