Diversidade e estruturação genética em populações africanas e brasileiras de garça-vaqueira (Bubulcus ibis, Linnaeus,1758) determinadas por microssatélites
Resumen
Bubulcus ibis (cattle egret) is an ardeid whose original distribution included the
countries of Africa, southern Europe and Western Asia. At the end of the 19th
century, the species was first recorded in northern South America and by 1970
already spread across the continent. One of the hypotheses of the entry of this bird
on the continent assumes transoceanic crossings from Center-West of the African
continent to the regions of Suriname and Guyana, an from this area they had
dispersed. The objective of this work was to study the process of colonization of
Brazil by means of microsatellite markers. We analyzed 14 microsatellite DNA loci
extracted from 300 blood samples (N = 134 Africans and N = 166 Brazilians) of
twenty-two populations. Similar levels of genetic diversity were found in the African
and Brazilian populations, but a greater diversity was observed in African
populations. By Fst and AMOVA tests, significant differentiation was found between
all individual and by the pairwise Fst analysis was evident that this differentiation is
due more to differences between the Brazilian and African populations. Bayesian
analysis of genetic groupings revealed a clear structuring between populations of the
native and colonized area. The result of the Bayesian analysis indicates that the birds
would leave the West African region, without indicating which region and they arrived
mainly in the Brazilian Northeast / North regions (Pará, Pernambuco and Fernando
de Noronha). Similar levels of genetic diversity among African and Brazilian
populations and the absence of inbreeding in the Brazilian populations are consistent
with the assumption that the colonization occurred with several inputs (propagules)
and with a reasonable number of individuals. The low degree of structuring discards
the occurrence of gene flow, previously assumed with mitochondrial data.
Colecciones
El ítem tiene asociados los siguientes ficheros de licencia: