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Temporal variation of allele frequencies in four population samples of Akodon montensis (Rodentia, Cricetidae)

Tania Tassinari Rieger1^I; Tania de Azevedo Weimer^I; Alfredo Langguth^II; Luiz Flamarion Barbosa Oliveira^III

^IDepartamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Prédio 43323, Caixa Postal 15053, 91501-970 Porto Alegre, RS, Brasil. Send correspondence to T.A.W.
^IIDepartamento de Sistemática e Ecologia, CCEN, Campus Universitário, UFPb, 58059-900 João Pessoa, PB, Brasil
^IIIMuseu Nacional, Mastozoologia, Quinta da Boa Vista, 20940-040 Rio de Janeiro, RJ, Brasil

ABSTRACT

Protein variation at 22 loci was studied in four population samples of Akodon montensis investigated at different times in Torres, RS, Brazil, (29^o20'S; 49^o45'W). Fourteen loci were monomorphic and the other eight showed polymorphism in at least one sample. Differences between samples in allele frequencies were found at all polymorphic loci and occurred in two general patterns: the first was a wide variation in allele frequencies as well as the appearance or disappearance of alleles in some samples (Aat, Alb, Glo, Pgi, Pgm-1, Pgm-2, Pgm-3, Sod-1), and the second involved a shift from one predominant allele to another (Glo, Pgi, Pgm-2, Pgm-3). There was also a decline in the degree of polymorphism and mean heterozygosity from the first to the last sample. Gene frequency fluctuations may be due to reproductive variation in terms of population density, genetic drift, selection and migration or recolonization. We obtained indications that recolonization is a very important factor in gene frequency fluctuations.

Keywords: Temporal variation; allele frequencies; Akodon montensis.

REFERENCES

Apfelbaum, L.I. and Blanco, A. (1985). Temporal variation of allele frequencies in populations of Akodon dolores (Rodentia, Cricetidae). Theor. Appl. Genet. 70: 569-572.

Bowman, B.H. and Beam, A.G. (1965). The presence of subunits in inherited group-specific protein of human serum. Proc. Natl. Acad. Sci. 53: 722-729.

Fonseca, G.A.B. and Kierulff, M.C.M. (1989). Biology and natural history of Brazilian Atlantic Forest small mammals. Bull. Florida State Mus. Biol. Sci. 34: 99-152.

Gaines, M.S. and Krebs, C.J. (1971). Genetic changes in fluctuating vole populations. Evolution 25: 702-723.

Harris, H. and Hopkinson, D.A. (1976). Handbook of Enzyme Electrophoresis in Human Genetics. North-Holland, Amsterdam, pp. 352.

Nei, M. (1978). Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89: 583-589.

Parr, C.W., Bagster, J.A. and Welch, S.G. (1977). Human red cell glyoxalase I polymorphism. Biochem. Genet. 15: 109-113.

Selender, R.K., Smith, M.H., Yang, S.Y., Johnson, W.E. and Gentry, J.B. (1971). Biochemical polymorphism and systematics in the genus Peromyscus. I. Variation in the old-field mouse (Peromyscus polionotus). Univ. Texas Publ. 7103: 49-90.

Semeonoff, R. and Robertson, F.W. (1968). A biochemical and ecological study of plasma esterase polymorphism in natural populations of the field vole, Microtus agrestis L. Biochem. Genet. 1: 205-227.

Spencer, N., Hopkinson, D.A. and Harris, H. (1964). Phosphoglucomutase in man. Nature 201: 299-300.

Swofford, D.L. and Selender, R.B. (1981). BIOSYS-1: a FORTRAN program for the comprehensive analysis of electrophoretic data in population genetics and systematics. J. Hered. 72: 281-285.

Tamarin, R.H. and Krebs, C.J. (1969). Microtus population biology. II. Genetic changes at the transferrin locus in fluctuating populations of two vole species. Evolution 23: 183-211.

Zimmerman, E.G. (1988). Temporal genetic variation in a population of the pocket gopher, Geomys bursarius. Genetica 76: 153-159.