Phylogeography and Genetic Structure of the South African Population of Raja miraletus (L., 1758) and Leucoraja wallacei (H., 1970).
Nome Cognome
Samira Vinjau
Contatto
scienze.biologiamarina-info@unibo.it
Relatore/Correlatore
Prof. Fausto Tinti
Dott.ssa Alessia Cariani
Dott. Alessandro Velonà
Dott. Rob Leslie
Ente e Laboratorio di Ricerca
Laboratorio di GenMAP
Asbtract
In this thesis the phylogeography and the genetic structure of the two batydemersal rajidaes species Raja miraletus (Linneaus, 1758) and Leucoraja wallacei (Hulley, 1790) were analyzed, using both mitochondrial DNA and microsatellite loci. For the Raja miraletus two mitochondrial loci (COI and ND2) and seven microsatellite loci (LERI24, LERI26, LERI27, LERI34, LERI40, LERI50 and LERI63) were used, while for Leucoraja wallacei the mitochondrial COI and six microsatellite loci (LERI24, LERI27, LERI34, LERI40, LERI50 and LERI63) were applied. Specimens were collected in three different geographic area of Africa (Senegal, Angola and South Africa) for Raja miraletus, while for Leucoraja wallacei three populations from South Africa (West Coast, South Coast 2006 and South Coast 2011) were sampled. The aim of the work was to detect the genetic differentiation among the populations of these two species both at the mitochondrial and nuclear genome. To reach this purposes different statistical analyses (haplotype and nucleotide diversity, Median-Joining networks, observed and expected heterozygosity, Hardy-Weinberg equilibrium analysis, population structure analysis) were performed. In Raja miraletus the mitochondrial analysis, performed on the COI and ND2 mitochondrial genes, clearly evidenced the separations of the three Western Africa populations analyzed (Senegal, Angola and South Africa). According to these results, the nuclear analyses, performed on seven microsatellite loci, evidenced Senegal and South Africa as clearly structured populations, while the Angola one resulted totally mixed. In Leucoraja wallacei, the three population of South Africa analyzed (West Coast, South Coast 2006 and South Coast 2011) resulted not to much separated using the COI gene, while the nuclear data evidenced a total mixing of these populations, as probable consequence of high actual gene flow. The results obtained were discussed on the light of the biology of the species and of the hydrogeology of the sampling areas.
