Gemma gemma is a small ovoviviparous bivalve distributed in shallow sand flats along the North American Atlantic and Gulf of Mexico coasts. Genetic variation in G. gemma was analysed by means of Inter-Simple Sequence Repeats (ISSRs) at the following levels: (i) between localities (Maine and Virginia), (ii) among 10-mw-diameter patches within localities, and (iii) within patches. Thirty individuals/patch and three patches/locality were analysed. Individuals were genotyped for 67 ISSR polymorphic loci from five primers. The portion of the genetic variation found between localities (2%) was small compared to that found either among patches within localities (37%) or within patches (61%). ISSRs in Q gemma allowed the detection of significant differentiation at individual and patch levels. By contrast. a low degree of genetic variability was found between localities. The small-scale genetic heterogeneity does not follow a simple. consistent pattern. Our results contrast with the generally accepted rule that aplanic species are locally homogeneous and globally heterogeneous and teleplanic species are the inverse.
|Autori:||Casu, M; Maltagliati, Ferruccio; P., Cossu; T., Lai; M., CURINI GALLETTI; Castelli, Alberto; J. A., Commito|
|Titolo:||Fine-grained spazial genetic structure in the bivalve Gemma gemma from Maine and Virginia (USA), as revealed by Inter-Simple Sequence Repeat markers|
|Anno del prodotto:||2005|
|Digital Object Identifier (DOI):||10.1016/j.jembe.2005.04.020|
|Appare nelle tipologie:||1.1 Articolo in rivista|