Y. Manjeli

Molecular typing of the major histocompatibility complex B microsatellite haplotypes in Cameroon chicken

The chicken major histocompatibility complex B (MHC-B) – a cluster of genes associated with natural disease resistance or susceptibility – has been investigated in experimental and inbred lines by serological typing. However, that method showed some weaknesses for its use on out breeds. This study aims to explore the genetic diversity of the MHC-B of Cameroon indigenous chicken through molecular typing with LEI0258 and MCW0371 microsatellite markers. MHC-B haplotypes of 290 chickens from four agro-ecological zones were identified and compared with published haplotypes. Alleles were analysed for genetic diversity and relationship among Cameroon chicken populations. Hypothetically new LEI0258 alleles and haplotypes were detected. Overall, polymorphism parameters were relatively high in the Cameroon western highlands. The analysis of molecular variance revealed great variability (80.00 percent) between individuals than among and within ecotypes. The inbreeding coefficients of overall populations (FIT), among population (FST) and within population (FIS) were 0.26, 0.04 and 0.22, respectively, and all were highly significant (P < 0.001). A UPGMA tree based on Nei’s DA genetic distances showed a clear distinction between Cameroon and out-groups and a structuring of within-country populations into three clusters. There is a great genetic diversity of the MHC-B in Cameroon native chicken and also a need of sequencing of the identified alleles for an accurate identification prior to their assessment for natural disease resistance and responsiveness to vaccination

Caractérisation morphobiométrique de la poule locale en Centrafrique

Mots-cles: caracterisation phenotypique, diversite, morphobiometrie, poule locale, Republique centrafrique Summary The survey, which had for its main objective, the morphobiometrical characterization of the local chicken was carried out from December 2010 to March 2011 in 20 villages in Lobaye Division in the Central African Republic. It was carried out on 474 adult females and 183 adult males. The main results show that the morphological features are very heterogeneous. Indeed, five main types of feathering were observed: normal feathering (75.8%), crested type (10.4%), naked neck (7.0%), feathered tarsus (5.9%) and frizzle type (2.3%). The colouration of feathers is heterogeneous, with a predominance of the white (18.0%), wild (13.4%) and mahogany (11.1%) colours. The single comb is more frequent (95.8%), and is generally red (33.8%) or pink in colour (55.1%). Earlobes are red (24.7%), white (24.0%), white centred (18.1%), yellow (16.1%) or pink (14.6%). The wattles are mainly red (55.4%) or pink (35.2%). The tarsi are mainly yellow (40.6%) or white (37.9%). With regard to the biometric characteristics, the average weight of the local chicken of Lobaye is 1176 ± 206 g for females and 1514 ± 296 g for males. The live weight and most body measurements vary according to the sex and the feathering type. The live weight and the body measurements are significantly (P < 0.01) higher in the males. In the same way, the animals with feathered tarsi are heavier and bigger than the other phenotypes.

Genetic diversity and structure of domestic cavy (Cavia porcellus) populations from smallholder farms in southern Cameroon

Although domestic cavies are widely used in sub-Saharan Africa as a source of meat and income, there are only a few studies of their population structure and genetic relatedness. This seminal study was designed with the main objective to assess the genetic diversity and determine the population structure of cavy populations from Cameroon to guide the development of a cavy improvement program. Sixteen microsatellite markers were used to genotype 109 individuals from five cavy populations (Wouri, Moungo and Nkongsamba in the Littoral region, and Mémé and Fako in the Southwest region of Cameroon). Twelve markers worked in the five populations with a total of 17 alleles identified, with a range of 2.9 to 4.0 alleles per locus. Observed heterozygosity (from 0.022 to 0.277) among populations was lower than expected heterozygosity (from 0.42 to 0.54). Inbreeding rates between individuals of the populations and between individuals in each population were 59.3% and 57.2%, respectively, against a moderate differentiation rate of 4.9%. All the tested loci deviated from Hardy-Weinberg equilibrium, except for locus 3. Genetic distances between populations were small (from 0.008 to 0.277), with a high rate of variability among individuals within each population (54.4%). Three distinct genetic groups were structured. This study has shown that microsatellites are useful for the genetic characterization of cavy populations in Cameroon and that the populations investigated have sufficient genetic diversity that can be used to be deployed as a basis for weight, prolificacy and disease resistance improvement. The genetic of diversity in Southern Cameroon is wide and constitute an opportunity for cavy breeding program.