Cytogenetical anchoring of sheep linkage map and syntenic groups using a sheep BAC library

In order to simultaneously integrate linkage and syntenic groups to the ovine chromosomal map, a sheep bacterial artificial chromosome (BAC) library was screened with previously assigned microsatellites using a sheep-hamster hybrid panel and genetic linkage. Thirty-three BACs were obtained, fluorescently labelled and hybridised on sheep-goat hybrid metaphases (2n = 57). This study allowed us, (i), to anchor all linkage groups on sheep chromosomes, (ii), to give information on the probable position of the centromere on the linkage map for the centromeric chromosomes, (iii), to contradict the previous orientation of the ovine × linkage group by the mapping of BMS1008 on OARXq38. Concerning our somatic cell hybrid panel, this study resulted in the assignment of all the previously unassigned groups to ovine chromosomes and a complete characterisation of the hybrid panel. In addition, since hybridisations were performed on a sheep-goat hybrid, new marker/anchoring points were added to the caprine cytogenetic map

Lack of association between genetic variants in the 19q13.32 region and CHD risk in the Algerian population: a population-based nested case-control study

Background: Coronary Heart Disease (CHD) is a major cause of morbidity and mortality over the world; intermediate traits associated with CHD commonly studied can be influenced by a combination of genetic and environmental factors. Objective: We found previously significant association between three genetic polymorphisms, and the lipid profile variations in the Algerian population. Considering these findings, we therefore decided to assess the relationships between these polymorphisms and CHD risk, Methods: We performed a population-based, cross-sectional study, of 787 individuals recruited in the city of Oran, in which, a nested case-control study for MetS, T2D, HBP, obesity and CHD were performed. Subjects were genotyped for four SNP rs7412, rs429358 rs4420638 and rs439401 located in the 19q13.32 region. Results: The T allele of rs439401 confers a high risk of hypertension with an odds ratio (OR) of 1.46 (95% CI [1.12-1.9], p = 0.006) and the G allele of rs4420638 was significantly associated with a decreased risk of obesity, OR 0.48 (95% CI [0.29-0.81], p = 0.004). No associations were found for MetS, T2D and CHD. Conclusion: Although the studied genetic variants were not associated with the risk of CHD, the 19q13.32 locus was associated with some of the cardiometabolic disorders in Algerian subjects

Diagnosis of Xeroderma Pigmentosum Groups A and C by Detection of Two Prevalent Mutations in West Algerian Population: A Rapid Genotyping Tool for the Frequent XPC Mutation c.1643_1644delTG

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder. Considering that XP patients have a defect of the nucleotide excision repair (NER) pathway which enables them to repair DNA damage caused by UV light, they have an increased risk of developing skin and eyes cancers. In the present study, we investigated the involvement of the prevalent XPA and XPC genes mutations—nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643_1644delTG or p.Val548Ala fsX25), respectively—in 19 index cases from 19 unrelated families in the West of Algeria. For the genetic diagnosis of XPA gene, we proceeded to PCR-RFLP. For the XPC gene, we validated a routine analysis which includes a specific amplification of a short region surrounding the 2 bp deletion using a fluorescent primer and fragment sizing (GeneScan size) on a sequencing gel. Among the 19 index cases, there were 17 homozygous patients for the 2 bp deletion in the XPC gene and 2 homozygous patients carrying the nonsense XPA mutation. Finally, XPC appears to be the major disease-causing gene concerning xeroderma pigmentosum in North Africa. The use of fragment sizing is the simplest method to analyze this 2 bp deletion for the DNA samples coming from countries where the mutation c.1643_1644delTG of XPC gene is prevalent

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

Cytogenetical anchoring of sheep linkage map and syntenic groups using a sheep BAC library

In order to simultaneously integrate linkage and syntenic groups to the ovine chromosomal map, a sheep bacterial artificial chromosome (BAC) library was screened with previously assigned microsatellites using a sheep-hamster hybrid panel and genetic linkage. Thirty-three BACs were obtained, fluorescently labelled and hybridised on sheep-goat hybrid metaphases ($2{\rm n} = 57$). This study allowed us, (i), to anchor all linkage groups on sheep chromosomes, (ii), to give information on the probable position of the centromere on the linkage map for the centromeric chromosomes, (iii), to contradict the previous orientation of the ovine X linkage group by the mapping of BMS1008 on OARXq38. Concerning our somatic cell hybrid panel, this study resulted in the assignment of all the previously unassigned groups to ovine chromosomes and a complete characterisation of the hybrid panel. In addition, since hybridisations were performed on a sheep-goat hybrid, new marker/anchoring points were added to the caprine cytogenetic map.Ancrage cytogénétique de la carte de liaison et des groupes de synténie par utilisation d'une banque de BAC ovine. Afin d'intégrer, la carte génétique et les groupes de synténies à la carte chromosomique ovine, nous avons criblé, à l'aide de microsatellites, une banque ovine de chromosomes artificiels de bactéries (BAC). Les microsatellites utilisés font partie de la carte de liaison ovine et ont été localisés précédemment dans notre panel d'hybrides somatiques hamster-mouton. Nous avons isolé 33 clones BAC, marqués en fluorescence et hybridés sur métaphase d'un hybride chèvre-mouton ($2{\rm n} = 57$). Les résultats de cette étude ont apporté plusieurs informations. Au niveau de la carte génétique, ces localisations ont permis l'ancrage des groupes de liaison sur les chromosomes ovins et de donner la position la plus probable du centromère sur les groupes de liaison correspondant aux chromosomes métacentriques. De plus, pour le chromosome X, la localisation du microsatellite BMS1008 a permis de corriger l'orientation du groupe de liaison. Au niveau de notre panel d'hybrides somatiques hamster-mouton, ces résultats ont permis d'assigner cytogénétiquement tous les groupes de synténies à un chromosome ovin, aboutissant à une caractérisation approfondie du panel. Enfin, en utilisant des métaphases d'hybride chèvre-mouton pour les hybridations in situ, nous avons pu ajouter de nouveaux marqueurs et points d'ancrages sur la carte chromosomique caprine

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