South Haplotypes Research Articles

Phylogenetic Relationships among Populations of the Vineyard SnailCernuella virgata(Da Costa, 1778)

Cernuella virgata(Da Costa, 1778) (Mollusca: Hygromiidae), commonly known as the “vineyard snail,” is endemic species in Mediterranean and Western Europe including the British Isles, but in the Eastern USA and Australia it represents an introduced invasive species. The present work examines the genetic variability and phylogenetic relationships among the four populations of this land snail sampled along the east Adriatic region of Croatia using mitochondrial markers (partial 16S rDNA and COI gene) in addition to traditional methods of shell’s shape analysis. All the three molecular-phylogenetic approaches (median joining haplotype network analysis and Bayesian analysis, as well as maximum likelihood analysis) revealed two-three major subnetworks for both 16S rDNA and COI, with a clear distinction between south Adriatic haplotypes (Pisak) and north Adriatic haplotypes (Krk and Cres). The population from Karlobag was comprised of both north and south haplotypes, thus representing a putative contact zone between these two groups. The morphometric analysis showed that individuals from Cres island population were statistically significantly wider and higher than individuals from Pisak population. Analysis of the SW/SH ratio and the relationship between shell width and shell height showed no differences in shell growth between the two examined populations, indicating equal shell growth and shape, which gives the possibility that differences in size of individuals between those two populations could be influenced by biotic (physiological) or abiotic (environmental) factors. This study represents the first analysis of genetic variability and relatedness among native populations ofC. virgata.

Beta‐globin gene cluster haplotypes in Afro‐Uruguayans from two geographical regions (South and North)

The beta-globin gene cluster haplotypes were identified in 52 and 40 chromosomes from two Afro-Uruguayan populations located in the South and North of the country, respectively. In both regions, the 5' haplotype 2 (+ - - - -), characteristic of non-African populations, was the most frequent, reflecting a strong process of admixture in Afro-Uruguayans (0.355 and 0.262, respectively). The haplotypes 3 (- - - - +) and 4 (- + - - +), characteristics of African sub-Saharan populations, present inverse frequencies in North and South: whereas in the South haplotype 3 is the second most frequent (0.232), and haplotype 4 presents a low frequency (0.019), in the North haplotype 4 is the third most frequent (0.140), and haplotype 3 only reaches an intermediate frequency (0.088). The pairwise F(ST) and the exact test of differentiation show genetic heterogeneity between both regions. Nei's genetic distance show that South and North present affinities with Bantu groups, although the North present the smallest genetic distance with the Mandenka, a Senegalese population. With respect to 3' haplotypes, haplotype I was the most frequent in both populations, followed by haplotype II, characteristic of sub-Saharan Africans. The high frequencies of haplotype III-Asian could indicate admixture with Native American populations. The differences observed between both Uruguayan regions could be explained by microevolutionary events as genetic drift, founder effects, differential admixture, and/or distinct origin of the African slaves introduced in those regions.