Genetic variation and population structure of two species of neo-tropical mud-mussels (Mytella spp)
Genet. mol. res. (Online)
;
4(2): 197-202, 30 jun. 2005. mapas, tab
Article
Dans Anglais
| LILACS
| ID: lil-445292
ABSTRACT
Mytella guyanensis Lamarck (1819) and Mytella charruana d'Orbigny (1846) are widespread euryhaline bivalves that have become commercially important in Brazil. Despite their importance, however, no genetic information that would be useful to orient governmental policies is available for these species. We analyzed, through allozyme electrophoresis, populations of M. guyanensis and M. charruana along 3,500 km of Brazilian coast. Pairwise comparisons among gene frequencies in M. guyanensis resulted in high levels of pairwise gene identity (I = 0.976 to 0.998). Conversely, significant levels of population structure were found in both M. guyanensis (FST = 0.089) and M. charruana (FST = 0.102). Heterozygosity levels for both species were high (H(e) = 0.090 to 0.134 in M. guyanensis and H(e) = 0.191 to 0.228 in M. charruana). The larger population size of M. charruana could explain, at least partially, the higher levels of genetic variability for this species. These levels of genetic variability yield an effective population size estimate of about 300,000 for M. guyanensis, and 540,000 for M. charruana, based on neutralist expectations. Remarkably, these numbers are much smaller than the estimated actual population sizes. This distortion might be explained by unstable population sizes and it suggests that long-term genetic variability studies are crucial to prevent artifactual viability analysis data for these commercially exploited species.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Variation génétique
/
Mytilidae
Limites du sujet:
Animaux
Pays comme sujet:
Amérique du Sud
/
Brésil
langue:
Anglais
Texte intégral:
Genet. mol. res. (Online)
Thème du journal:
Biologie moléculaire
/
Génétique
Année:
2005
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Universidade Federal do Rio de Janeiro/BR
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