INVESTIGADORES
CHIAPPERO Marina Beatriz
artículos
Título:
Oligoryzomys flavescens (Rodentia, Muridae): gene flow among populations from central-eastern Argentina
Autor/es:
CHIAPPERO, M.B.; CALDERÓN, G.E.; GARDENAL, C.N.
Revista:
GENETICA
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 1997 vol. 101 p. 105 - 113
ISSN:
0016-6707
Resumen:
In species acting as hosts of infectious agents, the extent of gene flow
between populations is of particular interest because the expansion of
different infectious diseases is usually related to the dispersal of the
host. We have estimated levels of gene flow among populations of the
sigmodontine rodent Oligoryzomys flavescens, in which high titers of
antibodies have been detected for a Hantavirus in Argentina that
produces a severe pulmonary syndrome. Enzyme polymorphism was studied by
means of starch gel electrophoresis in 10 populations from the area
where human cases of Hantavirus have occurred. Genetic differentiation
between populations was calculated from FST values with the equation Nm = [(1/FST−1]/4.
To assess the relative importance of current gene flow and historical
associations between populations, the relationship of population
pairwise log Nm and log geographic distance was examined. Low FST
(mean = 0.038) and high Nm (15.27) values suggest high levels of gene
flow among populations. The lack of an isolation by distance pattern
would indicate that this species has recently colonized the area. The
northernmost population, located on the margin of a great river, shows
very high levels of gene flow with the downstream populations despite
the large geographic distances. Passive transport of animals down the
river by floating plants would promote unidirectional gene flow. This
fact and the highest mean heterozygosity of that northernmost population
suggest it is a center of dispersal within the species' range.