Fate of a redundant gamma-globin gene in the atelid clade of New World monkeys: implications concerning fetal globin gene expression.
Conclusive evidence was provided that gamma 1, the upstream of the two linked simian gamma-globin loci (5'-gamma 1-gamma 2-3'), is a pseudogene in a major group of New World monkeys. Sequence analysis of PCR-amplified genomic fragments of predicted sizes revealed that all extant genera of the platyrrhine family Atelidae [Lagothrix (woolly monkeys), Brachyteles (woolly spider monkeys), Ateles (spider monkeys), and Alouatta (howler monkeys)] share a large deletion that removed most of exon 2, all of intron 2 and exon 3, and much of the 3' flanking sequence of gamma 1. The fact that two functional gamma-globin genes were not present in early ancestors of the Atelidae (and that gamma 1 was the dispensible gene) suggests that for much or even all of their evolution, platyrrhines have had gamma 2 as the primary fetally expressed gamma-globin gene, in contrast to catarrhines (e.g., humans and chimpanzees) that have gamma 1 as the primary fetally expressed gamma-globin gene. Results from promoter sequences further suggest that all three platyrrhine families (Atelidae, Cebidae, and Pitheciidae) have gamma 2 rather than gamma 1 as their primary fetally expressed gamma-globin gene. The implications of this suggestion were explored in terms of how gene redundancy, regulatory mutations, and distance of each gamma-globin gene from the locus control region were possibly involved in the acquisition and maintenance of fetal, rather than embryonic, expression.
Meireles
C M
CM
Departamento de Genetica, Universidade Federal do Para, Belem, Brazil.
Schneider
M P
MP
Sampaio
M I
MI
Schneider
H
H
Slightom
J L
JL
Chiu
C H
CH
Neiswanger
K
K
Gumucio
D L
DL
Czelusniak
J
J
Goodman
M
M
D000508:Alouatta / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002427:Cebidae / Q000235:genetics*; D017931:DNA Primers; D005091:Exons; D005319:Fetal Hemoglobin / Q000096:biosynthesis*; D005333:Fetus; D015870:Gene Expression; D008040:Genetic Linkage; D005914:Globins / Q000235:genetics*; D015186:Hominidae / Q000235:genetics; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011544:Pseudogenes; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D005914:Globins; D005319:Fetal Hemoglobin