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HEMOGLOBIN POLYMORPHISMS IN DEER MICE ( PEROMYSCUS MANICULATUS ): PHYSIOLOGY OF BETA‐GLOBIN VARIANTS AND ALPHA‐GLOBIN RECOMBINANTS
Author(s) -
Chappell Mark A.,
Hayes Jack P.,
Snyder Lee R. G.
Publication year - 1988
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1988.tb02486.x
Subject(s) - biology , peromyscus , globin , haplotype , hemoglobin , genetics , deer mouse , genotype , linkage disequilibrium , heterozygote advantage , population , altitude (triangle) , microbiology and biotechnology , gene , zoology , biochemistry , demography , geometry , mathematics , sociology
Wild populations of deer mice ( Peromyscus maniculatus ) contain hemoglobin polymorphisms at both alpha‐globin ( Hba, Hbc ) and beta‐globin ( Hbd ) loci. Population gene frequencies of beta‐globin variants ( d 0 and d 1 haplotypes) are not correlated with altitude, whereas a 1 c 1 alpha‐globin haplotypes are fixed in low‐altitude populations, and a 0 c 0 haplotypes reach near fixation at high altitudes. We examined the effects of alpha‐ and beta‐globin variants on blood oxygen affinity and on aerobic performance, measured as maximum oxygen consumption ( V ˙ O 2 max ). Exercise and cold exposure were used to elicitV ˙ O 2 max . Experiments were performed at low (340 m) and high (3,800 m) altitude to include the range of oxygen partial pressures encountered by wild deer mice. Beta‐globin variants had little effect on blood oxygen affinity orV ˙ O 2 max . Oxygen‐dissociation curves from a 0 c 0 and a 1 c 1 homozygotes and heterozygotes had similar shapes, but the P 50 of a 0 c 0 homozygotes was significantly lower than that of other genotypes. Mice carrying a 1 c 1 /a 1 c 1 genotypes had the highestV ˙ O 2 max at low altitude, but mice with a 0 c 0 /a 0 c 0 genotypes had the highestV ˙ O 2 max at high altitude. Mice carrying rare recombinant alpha‐globin haplotypes ( a 0 c 1 ) had lowerV ˙ O 2 max than nonrecombinant genotypes as a whole but in most cases were not significantly different from nonrecombinant heterozygotes ( a 0 c 0 /a 1 c 1 ). We conclude that genetic adaptation to different altitudes was important in the evolution of deer mouse alpha‐globin polymorphisms and in the maintenance of linkage disequilibrium in the alpha‐globin loci but was not a significant factor in the evolution of beta‐globin polymorphisms.