Genetic diversity and population genetic structure analysis of Apis mellifera subspecies in Algeria and Europe based on complementary sex determiner (CSD) gene

International audienceIn honeybees, the mechanism of sex determination depends on genetic variation at the complementary sex determiner ( CSD ) locus, which has a large allelic diversity. In this study, we examined the population genetic structure and genetic diversity within the highly variable region ( HVR ) of CSD in five Apis mellifera subspecies, in addition to Buckfast and unknown mixed ancestry bees. We sequenced CSD in 329 drones, 146 from Algeria ( A. m. intermissa and A. m. sahariensis subspecies) and 183 from Europe ( A. m. ligustica , A. m. carnica , A. m. mellifera subspecies, Buckfast samples, and individuals of unknown mixed ancestry). A total of 119 nucleotide haplotypes were detected. These corresponded to 119 protein haplotypes, of which 81 were new. The analysis of these haplotypes showed that HVR diversity levels were comparable with those in other populations of honeybee worldwide. Paradoxically, this high level of diversity at the locus did not allow for a separation of the samples according to their subspecies origin, which suggested either an evolutionary convergence or a conservation of alleles across subspecies, and an absence of genetic drift. Our results can be used to provide more information about the CSD diversity to include in breeding programs of honeybee populations

Caractéristiques morpho-biométriques et systèmes d’élevage des poules locales en Algérie occidentale (Oranie)

Des enquêtes ont été menées dans 48 élevages répartis sur les 9 wilayas de la région de l’Oranie afin de caractériser les populations de poules locales et leur mode d’élevage. Ces enquêtes ont porté sur les caractéristiques des élevages (état socio-économique de l’éleveur, mode d’élevage, reproduction et destination des produits d’élevage) et sur la description phénotypique de 334 poules locales. Les résultats montrent que les femmes sont les principales responsables des élevages avicoles et qu’elles utilisent le revenu modeste de ce type d’exploitations pour répondre à certaines charges domestiques. Les poules sont élevées dans des conditions médiocres et leur productivité est faible. Les mensurations corporelles considérées (poids corporel, longueur des pattes et des barbillons, diamètre des pattes et hauteur des crêtes) confirment le dimorphisme sexuel connu dans cette espèce, avec des valeurs de poids corporel significativement plus élevées chez le mâle (1 817 ± 297 g) que chez la femelle (1 335 ± 227 g). Cette étude sera complétée par une caractérisation génétique et moléculaire. Ainsi, l’association de l’information phénotypique et génétique et l’amélioration des conditions d’élevage pourront aider les éleveurs à améliorer les performances de cette activité

Genetic diversity and relationships among six local cattle populations in semi-arid areas assessed by a bovine medium-density single nucleotide polymorphism data

International audienceThe local cattle populations belonging to the‘ Brune de l’Atlas’ cattle in Algeria and Morocco are potential resources in terms of genetic diversity and socioeconomic prevalence and their characterization is an essential step in any program designed to conserve genetic diversity. Our objectives were to assess the genetic diversity, the population structure and relationships among four Algerian cattle breeds, the Biskra, Cheurfa, Chelifienne and Guelmoise and of two Moroccan, the Oulmès-Zaër and Tidili by genotyping 50 309 single nucleotide polymorphism in 203 unrelated animals. A low population structure was observed across breeds with pairwise FST values ranging from 0.008 to 0.043, suggesting a high level of geneflow. These data were combined with the available data on cattle populations representative of Europe (EUT), West African taurine (WAT) and zebu (ZEB). Principle Components Analysis was carried out which revealed that the Maghrebin populations are closer to the EUT/ZEB population than to the WAT. Structure analysis confirmed this mixed origin of the Maghrebin cattle populations. We also detected the influence of zebu breeds in Cheurfa and Guelmoise populations. This study provides the first information about genetic diversity within and between Algerian and Moroccan cattle populations and gives a detailed description of their genetic structure and relationships according to their historical origins. This study revealed that several combined effects contributed to shape the genetic diversity of the six Maghrebin populations studied: (i) gene flow among local breeds, (ii) the recent introgression of European breeds in local Algerian breeds and (iii) the traditional management systems. The results of this study will primarily assist policy makers and livestock keepers to make useful decisions for improvement of genetic resources while ensuring the preservation and conservation of local breeds in Algeria and Morocco