Molecular cloning and evolutionary analysis of hemoglobin alpha-chain genes in bats.
Bats are the only mammals with the capacity for powered flight. When flying, they need abundant energy and oxygen. According to previous works, the hemoglobin (Hb) oxygen loading function of bats is insensitive to variations in body temperature, although different bat species have different heat sensitivity. We cloned Hb alpha-chain sequences from eight bat species to investigate whether they have different characteristics. We found that Hb in the bat lineages is under purifying selection, which accords with the importance of its function in bats. Three turn regions in bat Hb, however, have distinct evolutionary rates compared with those of other mammals, and the codons in these regions have an accelerated rate of evolution. These codons are under divergent selection in bats. These changes in Hb may have occurred in response to the physiological requirements of the species concerned, as adaptations to different lifestyles.
Liu
Yang
Y
School of Life Science, East China Normal University, Shanghai, People's Republic of China.
Dong
Dong
D
Han
Nai-Jian
NJ
Zhao
Hua-Bin
HB
Zhang
Jin-Shuo
JS
Li
Gang
G
Racey
Paul A
PA
Zhang
Shu-Yi
SY
D000818:Animals; D001483:Base Sequence; D002685:Chiroptera / Q000235:genetics*; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D055542:alpha-Globins / Q000235:genetics*
D055542:alpha-Globins