Genetic variation in the land snail Isognomostoma isognomostoma (Gastropoda : Pulmonata : Helicidae)

Citation
P. Van Riel et al., Genetic variation in the land snail Isognomostoma isognomostoma (Gastropoda : Pulmonata : Helicidae), MALACOLOGIA, 43(1-2), 2001, pp. 1-11
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
MALACOLOGIA
ISSN journal
0076-2997 → ACNP
Volume
43
Issue
1-2
Year of publication
2001
Pages
1 - 11
Database
ISI
SICI code
0076-2997(2001)43:1-2<1:GVITLS>2.0.ZU;2-L
Abstract
Genetic and phenotypic variation in 13 populations of Isognomostoma isognom ostoma (Schroter, 1784) from central and peripheral areas of its distributi on range in central Europe was estimated by means of allozyme electrophores is at 11 loci and a morphometric analysis of six shell and 12 genital tract measurements. Because of the effects of genetic drift and inbreeding, which may lead to r apid genetic differentiation, peripheral isolates may play an important rol e in diversification and speciation. Besides this, these populations may al so be vulnerable to extinction because of the genetic impoverishment result ing from the same population genetic processes. Population differentiation as evidenced by allozyme electrophoresis was ver y high (mean F-ST: 0.550) and genetic variation was found to be partitioned among regions (mean F-RT : 0.480), rather than between populations within regions (mean F-SR : 0.152). Only low allozyme variation could be detected within local populations (mean F-IS: 0.373; mean number of alleles per locu s: 1.27; mean expected heterozygosity: 0.062). Although morphological diffe rentiation was less pronounced among populations and/or regions, it reveale d mainly the same pattern of variation. No genetic variation, or the loss o f it, could be attributed to the position of populations near the periphery of the distribution range.