CLOSELY LINKED ALPHA‐CHAIN HEMOGLOBIN LOCI IN
            <i>PEROMYSCUS</i>
            AND OTHER ANIMALS: SPECULATIONS ON THE EVOLUTION OF DUPLICATE LOCI

Snyder, Lee R. G.

doi:10.1111/j.1558-5646.1980.tb04049.x

Cited by 16 publications

(12 citation statements)

References 60 publications

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“…A different expression of the duplicated a-globin genes has been shown in horse (Clegg, 1970;Clegg et aL, 1984) and in caprine breeds (Vestri et aL, 1983(Vestri et aL, , 1987Braend and Tucker, 1988), as well as in a wide range of mammalian and avian species (Snyder, 1980). Liebhaber et al (1986) have shown in great detail that the two linked human ~-globin genes produce mRNA at a ratio of approximately 2.6:1, the 5'-located gene having a dominant role in ~-globin expression.…”

Section: Discussionmentioning

confidence: 97%

Electrophoretic and chromatographic evidence for allelic polymorphisms in the river buffalo α-globin gene complex

Luccia

Iannibelli

Ferranti³

et al. 1991

Biochem Genet

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Isoelectric focusing in the ultranarrow immobilized (7.1-7.5) pH gradient (IPG) of hemoglobin and high-performances liquid chromatography (HPLC) of globin chains were used to investigate Hb polymorphism in Italian river buffalo. Six different phenotypes, each characterized by two or four different Hbs, were detected by IPG, whereas two different II alpha-globin chains were separated from two different I alpha-chains by HPLC. Two alpha-chains (I alpha 1 and II alpha 3), and Hbs with similar mobilities (Hb1 and Hb3), were associated with the AA Hb phenotype: two alpha-chains (I alpha 2 and II alpha 4), and Hbs with different mobilities (Hb2 and Hb4), were associated with the BB phenotype: two sets of doublet Hbs were associated with the AB phenotype, thus suggesting allelic polymorphisms at the two alpha loci. An allele at the beta locus is responsible for increasing to as many as eight the number of different Hbs, thus further complicating the notable Hb polymorphism of the river buffalo.

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Section: Discussionmentioning

confidence: 97%

Electrophoretic and chromatographic evidence for allelic polymorphisms in the river buffalo α-globin gene complex

Luccia

Iannibelli

Ferranti³

et al. 1991

Biochem Genet

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“…The species inhabits one of the broadest altitudinal ranges of any North American mammal, from sea level to above 4300 m. At 4300 m, the partial pressure of oxygen (Po2) is only 55% of the sea-level value, and that may severely limit aerobic metabolism. Deer mice also exhibit one of the most complex and extensive polymorphisms for hemoglobin of any mammal (13)(14)(15). In most individuals, the adult a-chains of hemoglobin are encoded by two tightly linked loci, Hba and Hbc (15).…”

Section: Aibstractmentioning

confidence: 99%

“…Deer mice also exhibit one of the most complex and extensive polymorphisms for hemoglobin of any mammal (13)(14)(15). In most individuals, the adult a-chains of hemoglobin are encoded by two tightly linked loci, Hba and Hbc (15). At both loci, the multiple structural alleles can be classified into two groups (a0 versus a' and co versus c') on the basis of similarity of isoelectric points.…”

Section: Aibstractmentioning

confidence: 99%

Biochemical and physiological correlates of deer mouse alpha-chain hemoglobin polymorphisms.

Chappell¹,

Snyder²

1984

Proc. Natl. Acad. Sci. U.S.A.

127

133

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AIBSTRACTThe a-hemoglobin chains in adult deer mice are usually encoded by two tightly linked loci. Because of strong linkage disequilibrium, almost all a-globin haplotypes fall into just two classes. The a0co class predominates in highaltitude populations, whereas the aYcl class is generally fixed in low-altitude populations. Here we show that the a-globin genotype has effects at both the biochemical level [on blood oxygen affinity (P50)] and at the level of whole-anmal physiol- The deer mouse Peromyscus maniculatus provides an opportunity to assess the effects of a specific selective force (high-altitude hypoxia) on discrete genetic elements (a-chain hemoglobin haplotypes). The species inhabits one of the broadest altitudinal ranges of any North American mammal, from sea level to above 4300 m. At 4300 m, the partial pressure of oxygen (Po2) is only 55% of the sea-level value, and that may severely limit aerobic metabolism. Deer mice also exhibit one of the most complex and extensive polymorphisms for hemoglobin of any mammal (13-15). In most individuals, the adult a-chains of hemoglobin are encoded by two tightly linked loci, Hba and Hbc (15). At both loci, the multiple structural alleles can be classified into two groups (a0 versus a' and co versus c') on the basis of similarity of isoelectric points. There is very strong linkage disequilibrium between the two loci, such that a-globin haplotypes are almost always composed of alleles of like superscript (ref.16; un-published data). "Recombinant" haplotypes (i.e., either a c or a'co) are quite rare; their average population frequency is estimated at 0.015. In populations in western North America, there is a highly significant negative correlation between o'c' haplotype frequency and the altitude of the collection site (ref. 17; unpublished data). That distribution provides circumstantial evidence for evolutionary adaptation of a-globin polymorphisms to altitude, but other interpretations not involving natural selection-e.g., stochastic biogeographical processes-cannot be ruled out. To resolve those two possibilities, independent criteria are needed to assess whether the haplotype classes are in fact differentially adapted to altitude.Here we examine the effects of the common a-globin genotypes on the oxygen affinity (P50) of whole blood and also on an important parameter of whole-animal physiology, maximum rate of oxygen consumption (Vo2max), during both cold exposure and exercise. MATERIALS AND METHODSGenetic Strains and Population Samples. Strains of deer mice were developed that carried distinct a-globin haplotypes in identical-by-descent (IBD) condition, arrayed against contrasting a-globin haplotypes chosen at random from their original wild population. To develop an IBD strain for an aYc1 haplotype, a single alc'l/a'c heterozygote was mated to several unrelated aoco/aoco mice from the source population. Progeny carrying the alcl haplotype (all copies of which are identical, barring mutation) were mated to unrelated aoc0/aoc0 mice. After one or more genera...

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“…maniculatus has the broadest altitudinal range of any North American mammal, as the species is continuously distributed from sea-level environments to alpine environments at elevations above 4,300 m. At 4,300 m, the partial pressure of oxygen (P o 2 ) is approximately 55% of the sea-level value, and the resultant hypoxia imposes severe constraints on aerobic metabolism. Experimental evidence indicates that adaptive variation in blood biochemistry among mice from different elevations is associated with a complex hemoglobin polymorphism [8–11]. Specifically, experimental crosses involving wild-derived strains of P.…”

Section: Introductionmentioning

confidence: 99%

The Molecular Basis of High-Altitude Adaptation in Deer Mice

et al. 2007

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Elucidating genetic mechanisms of adaptation is a goal of central importance in evolutionary biology, yet few empirical studies have succeeded in documenting causal links between molecular variation and organismal fitness in natural populations. Here we report a population genetic analysis of a two-locus α-globin polymorphism that underlies physiological adaptation to high-altitude hypoxia in natural populations of deer mice, Peromyscus maniculatus. This system provides a rare opportunity to examine the molecular underpinnings of fitness-related variation in protein function that can be related to a well-defined selection pressure. We surveyed DNA sequence variation in the duplicated α-globin genes of P. maniculatus from high- and low-altitude localities (i) to identify the specific mutations that may be responsible for the divergent fine-tuning of hemoglobin function and (ii) to test whether the genes exhibit the expected signature of diversifying selection between populations that inhabit different elevational zones. Results demonstrate that functionally distinct protein alleles are maintained as a long-term balanced polymorphism and that adaptive modifications of hemoglobin function are produced by the independent or joint effects of five amino acid mutations that modulate oxygen-binding affinity.

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CLOSELY LINKED ALPHA‐CHAIN HEMOGLOBIN LOCI IN PEROMYSCUS AND OTHER ANIMALS: SPECULATIONS ON THE EVOLUTION OF DUPLICATE LOCI

Cited by 16 publications

References 60 publications

Electrophoretic and chromatographic evidence for allelic polymorphisms in the river buffalo α-globin gene complex

Electrophoretic and chromatographic evidence for allelic polymorphisms in the river buffalo α-globin gene complex

Biochemical and physiological correlates of deer mouse alpha-chain hemoglobin polymorphisms.

The Molecular Basis of High-Altitude Adaptation in Deer Mice

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