Genetic diversity of Saudi native chicken breeds segregating for naked neck and frizzle genes using microsatellite markers

Aim: To assess genetic diversity of two chicken ecotypes from Egypt and Saudi Arabia and compare these ecotypes to six local Egyptian and two exotic pure chicken breeds using 14 microsatellite markers. Methodology: Dataset consisted of two subsets. First subset represented two ecotypes from Saudi Arabia and Egypt. Second dataset consisted birds six Egyptian native chicken strains: Fayoumi (FAY), Dandarawy (DAN), Baladi (BAL), Sinai (Sini), El-Salam (Els) and Golden Montazah (GG), and two commercial strains: White Leghorn (WL) and Rhode Island Red (RIR). fourteen microsatellites markers were utilized to assess DNA polymorphism. Data analyses of the results were carried out using R statistical environment. Results: The obtained results indicated that number of alleles per locus averaged 11.4 ± 5.0. Polymorphic information content was informative (> 50%) for the local breeds, but not for two ecotypes. The observed and expected heterozygosity averaged 0.46 and 0.75, both ecotypes had the lowest estimates. All breeds showed significant deviation from Hardy–Weinberg equilibrium expectation. The average population differentiation index (FST) was 0.143, overall heterozygosity deficiency (FIT) was 0.156, and global inbreeding of individuals within breeds (FIS) was 0.319. Interpretation: This study revealed that both Egyptian and Saudi ecotypes have an endangered status. Lower genetic distances and lower FST values were reported for the Egyptian indigenous breeds. Phylogenetic and principle components showed that both ecotypes were genetically closer to each other when compared with other breeds. It also showed that the Dandarawy native Egyptian chicken breed was genetically the closest breed to both the Egyptian and Saudi ecotypes. Key words: Chicken, Ecotypes, Genetic diversity, Microsatellites, Phylogenetics

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High Genetic Diversity but Absence of Population Structure in Local Chickens of Sri Lanka Inferred by Microsatellite Markers

Frontiers in Genetics ◽

10.3389/fgene.2021.723706 ◽

2021 ◽

Vol 12 ◽

Author(s):

Amali Malshani Samaraweera ◽

Ranga Liyanage ◽

Mohamed Nawaz Ibrahim ◽

Ally Mwai Okeyo ◽

Jianlin Han ◽

...

Keyword(s):

Genetic Diversity ◽

Sri Lanka ◽

Microsatellite Markers ◽

Allelic Diversity ◽

Genetic Distances ◽

Population Substructure ◽

High Genetic Diversity ◽

Naked Neck ◽

Local Chicken ◽

Local Chickens

Local chicken populations belonging to five villages in two geographically separated provinces of Sri Lanka were analyzed using 20 microsatellite markers to determine the genetic diversity of local chickens. Population genetic parameters were estimated separately for five populations based on geographic locations and for eight populations based on phenotypes, such as naked neck, long legged, crested or crown, frizzle feathered, Giriraj, commercial layer, crossbreds, and non-descript chicken. The analysis revealed that there was a high genetic diversity among local chickens with high number of unique alleles, mean number of alleles per locus (MNA), and total number of alleles per locus per population. A total of 185 microsatellite alleles were detected in 192 samples, indicating a high allelic diversity. The MNA ranged from 8.10 (non-descript village chicken) to 3.50 (Giriraj) among phenotypes and from 7.30 (Tabbowa) to 6.50 (Labunoruwa) among village populations. In phenotypic groups, positive inbreeding coefficient (FIS) values indicated the existence of population substructure with evidence of inbreeding. In commercial layers, a high expected heterozygosity He = 0.640 ± 0.042) and a negative FIS were observed. The positive FIS and high He estimates observed in village populations were due to the heterogeneity of samples, owing to free mating facilitated by communal feeding patterns. Highly admixed nature of phenotypes was explained as a result of rearing many phenotypes by households (58%) and interactions of chickens among neighboring households (53%). A weak substructure was evident due to the mating system, which disregarded the phenotypes. Based on genetic distances, crown chickens had the highest distance to other phenotypes, while the highest similarity was observed between non-descript village chickens and naked neck birds. The finding confirms the genetic wealth conserved within the populations as a result of the breeding system commonly practiced by chicken owners. Thus, the existing local chicken populations should be considered as a harbor of gene pool, which can be readily utilized in developing locally adapted and improved chicken breeds in the future.

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