Assessment of genetic diversity among native Algerian rabbit populations using microsatellite markers

Having higher adaptability against abiotic stress, which is characterized in rural areas in developing countries, local farm animal genetic resources (FAGRs) are increasingly precarious for random and unsystematic crossing with exotic breeds. In this study, 85 microsatellite loci were utilized to assess genetic diversity among native Algerian rabbits (NARs) sampled from an area of 753 km (from north to south) and 919 km (from east to west). Those distances covered 25 significant geographical points in seven rural areas (El Taref, Mostaganem, Sidi Bel Abbès, M'Sila, Dar Chioukh, Faidh El Botma, and Laghouat). A total of 558 alleles were observed in this study. The highest genetic diversity was registered in the southern direction among NAR populations. The mean number of alleles per locus (MNa) and the inbreeding coefficient (F IS ) were highest in Laghouat (4.482 and 0.232), while they were lowest in El Taref (4.000 and 0.149). In the current study, the number of private alleles (Pa) ranged from 9 to 23. In addition, the average of observed heterozygosity (0.427) was lower than the expected value (0.524) due to high levels of inbreeding. The discriminant analysis of principal components (DAPC), the neighbor-joining tree (NJ), and the analysis of STRUCTURE software confirmed the classification of populations according to geographical zones into four main groups (east, west, south, and middle). The results of the current study are useful for breeding improvement and conservation plan research in relation to local animal genetic resources in Algeria.

Origin, Genetic Diversity, and Population Structure of Rabbits (Oryctolagus cuniculus) in Kenya

To evaluate the origin, genetic diversity, and population structure of domesticated rabbits in Kenya, a 263-base pair region of mtDNA D-loop region of 111 rabbits sampled from Kakamega, Vihiga, and Bungoma counties in the western region, Laikipia and Nyandarua counties in the central region, and Kitui, Machakos, and Makueni in the eastern region of the country were analyzed. The average haplotype (0.40702) and nucleotide (0.01494) diversities observed were low, indicating low genetic diversity of domesticated rabbits in Kenya. This study resolved 5 unique haplotypes in the mtDNA D-loop region. A population genetic structure distinguishing Europe grouping and domesticated rabbits in Kenya was obtained on incorporating 32 known haplotypes. Domesticated rabbits in Kenya clustered together with rabbits from other geographic regions, suggesting common origin. The results suggested that the Kenyan domesticated rabbits may have originated from Europe. Integration of exotic breeds into breeding programmes could have contributed to the low genetic diversity. These results provide useful information for breeding and conservation decisions by the relevant stakeholders in the agriculture industry in Kenya.

Genetic and phenotypic characterization of the native rabbits in Middle Egypt

Aim:

Native rabbits in smallholder system are considered as important genetic resources, and the present study was aimed to study the genetic and phenotypic characterization and detection of the maternal origin of the native rabbit populations located at the Middle of Egypt.

Materials and Methods:

A survey of native rabbit populations was conducted in three governorates (Fayum [FY], Beni Suef [BN], and El Menia [MN]). The phenotypic characterization of rabbits included the profile body of the head, ears, eyes, neck, and legs and the coat colors. The blood samples were collected for genetic characterization based on mitochondrial (cytochrome b) and the microsatellite markers.

Results:

The phenotypic characterization of the body parts in the three populations was almost similar. The body weight of the mature rabbits in MN Government was significantly heaviest, and the measurements for the main body parts (body length, chest circumference, and abdominal girth) were the highest compared to the two populations. The results of mitochondrial (cytochrome b) analysis revealed that the rabbits from the three governments belonged to lineage A except one animal was recorded as lineage G from MN’s rabbit population. The results of the microsatellite markers revealed that the genetic diversity between the three populations showed genetic interferences; however, a closer genetic relationship was observed between BN and MN than FY. The majority of the genetic diversity was the individual variability.

Conclusion:

The mitochondrial lineage A is the major lineage in rabbit populations in the area of the Middle Egypt understudy. The genetic populations’ structure is the interferences among the three populations. A large-scale survey should be done on native rabbit populations for the sustainable management and conservation of the local breeds’ genetic resources.

Population structure and phylogenetic analysis of laboratory rabbits in Taiwan based on microsatellite markers

Laboratory rabbits used in Taiwan are primarily supplied by the Livestock Research Institute (LRI) and the Animal Drugs Inspection Branch (ADIB) of the Animal Health Research Institute. An analysis of the genetic characteristics and structure of these populations would thus be a fundamental step in building a long-term management programme for maintaining stable animal quality and preserving the genetic variation among the populations. In this study, DNA samples were isolated from founders of 5 populations: New Zealand White rabbits (NZW) and Japanese White rabbits (JPN) from the ADIB, NZW and Rex rabbits (REX) from the LRI, and NZW from a private rabbit breeding farm in Ban Ciao (BC). A set of microsatellite markers, 18 in total, was designed for genetic analysis. The average values for the allele number (Na), effective number of alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (H_E), and Wright’s fixation index (F_IS) were 5.50, 2.437, 0.442, 0.568 and 0.232, respectively. These results revealed that this set of microsatellite markers has high diversity and that the major local populations have a tendency toward inbreeding. At the same time, analysis of molecular variance results showed that the laboratory rabbits used in Taiwan have maintained a high level of within-population genetic differentiation (83%). The genetic differentiation among clusters was moderate (F_ST=0.18), and Bayesian cluster analysis showed that the most likely number of groups was 4 (K=4). Principal component analysis (PCA) also showed 4 divergent clusters. The LRI and BC NZW populations were not separated when K=4 was used in a Structure software analysis and were also hard to split until principal component 3 in PCA. The individual unrooted phylogenetic tree showed that the 5 populations were separated, except that some individuals from the LRI NZW population overlapped with the ADIB NZW and BC NZW populations. As such, in order to counteract the reduced F_IS (0.232) and maximise heterozygosity, the 3 NZW populations could be interbred or have new genes introduced into them. The set of microsatellite markers used herein was useful for studying the relationships and genetic diversities among these rabbit populations of Taiwan. Based on the resulting data, rabbit farms in Taiwan could select parental stocks for planned mating in the future as part of strategies to preserve and restore the rational breeding of laboratory rabbits.

Diversity assessment among native Middle Egypt rabbit populations in North Upper-Egypt province by microsatellite polymorphism

<p>Safeguarding biodiversity is an important goal for animal production in developed countries. This study investigated genetic diversity among native Middle-Egypt rabbit (NMER) populations in North Upper-Egypt province by using microsatellite polymorphism. Nineteen microsatellite loci were used in the study and an area of 231 km was surveyed, as native rabbits covered 14 points belonging to four Northern Upper Egypt governorates (South Giza, Fayoum, Beni Suef and Minya). Standard statistical parameters of genetic variability within and between populations confirmed that the highest genetic diversity was found towards the south. Among NMER populations, the mean number of alleles per locus was lowest in South Giza (5.32), while it was highest in Minya (6.00). This study found that NMER featured a high number of private alleles ranging between 7 and 11 (mean value was 10.5). Results also showed a high genetic diversity in NMER populations and that heterozygosity ranged between 0.384 and 0.445, strongly indicating extensive genetic variation in the NMER populations. The mean values of observed and expected heterozygosity were 0.405 and 0.612, respectively. Factorial correspondence analysis and neighbour joining trees (NJ) showed 2 main NMER rabbit groups: the Northern group (South Giza and Fayoum) and the Southern group (Beni Suef and Minya). All populations showed a high percentage of assignment in this study (0.913 to 0.946). The structure analysis showed that each population existed in separate clusters. This research provides an overview of genetic diversity of NMER populations in the Northern Upper Egypt province for the first time. In conclusion, results of this study could be used to designate priorities for conservation of NMER populations.</p>