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result(s) for
"Tarekegn, Getinet Mekuriaw"
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Genome‑wide insights of Ethiopian indigenous sheep populations reveal the population structure related to tail morphology and phylogeography
by
Tarekegn, Getinet
,
Nasser, Yao
,
Hanotte, Olivier
in
Adaptation
,
Animal and Dairy Science
,
Animal Genetics and Genomics
2020
Background Ethiopian sheep living in diferent climatic zones and having contrasting morphologies are a most promising subject of molecular-genetic research. Elucidating their genetic diversity and genetic structure is critical for designing appropriate breeding and conservation strategies. Objective The study was aimed to investigate genome-wide genetic diversity and population structure of eight Ethiopian sheep populations.
Journal Article
Quantifying morphometric and adaptive characteristics of indigenous cattle genetic resources in northwest Ethiopia
by
Tarekegn, Getinet Mekuriaw
,
Taye, Mengistie
,
Kebede, Damitie
in
Agroecology
,
Animal genetics
,
Animal populations
2023
Ethiopia is the gateway of livestock genetic resources to Africa and has a wide range of altitude. It is endowed with huge diverse cattle genetic resources. The aim of this research was to determine the morphometric and potentioally adaptive characteristics of cattle populations. Multi-stage purposive and random sampling methods were employed to select the study areas, households and animals. A total of 1200 adult cattle were sampled and characterized for 14 qualitative and eight morphometric variables. The comparison of marginal means, chi-square tests, canonical discriminant analysis, and clustering analysis were employed using SAS and SPSS statistical software. The sex of the animal, location and agro-ecology were fitted as fixed effects in the model and had highly significant (p<0.001) effects for most body measurements. The chi-square test values of all categorical variables were significantly different (p<0.001) and potentioally adaptive characteristics such as coat colour type, navel flap, and tail length had higher association (> 0.45) values. White with red, light red, black and dark red were the most predominant coat colour types of cattle. The maximum hit rates were recorded in Enebsie and Sinan cattle. From five extracted canonical variate, (can1 and can2) accounted 75.4% and 78.8% in the female and male cattle populations, respectively. The canonical class has separated cattle populations of Sinan from Banja at can1 and Mecha from Sinan populations at can2. The square Mahalanobis distances between sites were significant (p<0.001) and the largest distance was found between Banja and Sinan locations. Cluster analysis result classified the study populations into four major cattle groups. The cumulative analysis results showed that the cattle populations of the study area can be categorized into four breed types as Jawi Sanga, Gojjam Zenga, Banja cattle, and Sinan cattle. However, this morphology based grouping need to be confirmed by molecular data.
Journal Article
The mosaic genome of indigenous African cattle as a unique genetic resource for African pastoralism
2020
Cattle pastoralism plays a central role in human livelihood in Africa. However, the genetic history of its success remains unknown. Here, through whole-genome sequence analysis of 172 indigenous African cattle from 16 breeds representative of the main cattle groups, we identify a major taurine × indicine cattle admixture event dated to circa 750–1,050 yr ago, which has shaped the genome of today’s cattle in the Horn of Africa. We identify 16 loci linked to African environmental adaptations across crossbred animals showing an excess of taurine or indicine ancestry. These include immune-, heat-tolerance- and reproduction-related genes. Moreover, we identify one highly divergent locus in African taurine cattle, which is putatively linked to trypanotolerance and present in crossbred cattle living in trypanosomosis-infested areas. Our findings indicate that a combination of past taurine and recent indicine admixture-derived genetic resources is at the root of the present success of African pastoralism.
Whole-genome sequence analysis of 172 indigenous African cattle from 16 breeds identifies 16 loci linked to environmental adaptations among crossbred animals, including a highly divergent locus in African taurine cattle putatively linked to trypanotolerance.
Journal Article
Whole-genome sequencing of copy number variation analysis in Ethiopian cattle reveals adaptations to diverse environments
by
Van Damme, Renaud
,
Liang, Chunnian
,
Ayalew, Wondossen
in
Adaptability
,
Adaptation
,
Adaptation (Physiology)
2024
Background
Genomic structural variations (GSVs), notably copy number variations (CNVs), significantly shape genetic diversity and facilitate adaptation in cattle populations. Despite their importance, the genome-wide characterization of CNVs in indigenous Ethiopian cattle breeds—Abigar, Fellata, and Gojjam-Highland remains largely unexplored. In this study, we applied a read-depth approach to whole genome sequencing (WGS) data to conduct the first comprehensive analysis of CNVs in these populations.
Results
We identified 3,893 CNV regions (CNVRs) covering 19.15 Mb (0.71% of the cattle genome). These CNVRs ranged from 1.60 kb to 488.0 kb, with an average size of 4.92 kb. These CNVRs included deletions (1713), duplications (1929), and mixed events (251) showing notable differences in distribution among the breeds. Four out of five randomly selected CNVRs were successfully validated using real time polymerase chain reaction (qPCR). Further analyses identified candidate genes associated with high-altitude adaptation (
GBE1
and
SOD1
), heat stress adaptation (
HSPA13
,
DNAJC18
, and
DNAJC8
) and resistance to tick infestations (
BoLA
and
KRT33A
). In addition, variance stabilizing transformation (
V
ST
)
statistics highlighted population-specific CNVRs, emphasizing the unique genetic signatures of high-altitude adaptation in the Gojjam-Highland cattle breed. Among the detected CNVRs, 4.93% (192 out of 3,893) overlapped with 520 quantitative traits loci (QTLs) associated with six economically important trait categories suggesting that these CNVRs may significantly contribute to the genetic variation underlying these traits.
Conclusions
Our comprehensive analysis reveals significant CNVRs associated with key adaptive traits in Ethiopian cattle breeds highlighting their genetic diversity and resilience. These findings offer valuable insights into the genetic basis of adaptability and can inform sustainable breeding practices and conservation efforts. Future research should prioritize the functional validation of these CNVRs and their integration into breeding programs to enhance traits such as disease resistance and environmental adaptability.
Journal Article
Typology and characteristics of indigenous goats and production systems in different agro-ecological zones of Tanzania
by
Kyallo Martina
,
Zabron, Nziku
,
Chenyambuga Sebastian
in
Animal populations
,
Animals
,
Castration
2022
Tanzania has a goat population of about 24.8 million most of which belong to the Small East African breed distributed in almost all agro-ecological zones. The different goat populations and the production system in which they are raised are not well characterized depriving animal breeders useful information in designing and running improvement and conservation programs. Therefore, the study was conducted in all agro-ecological zones in Tanzania to characterize the indigenous goats and the production system in which they are raised. Data on animals were collected from 688 randomly selected adult female goats and for production system description; 220 households were interviewed. Analysis of variance and discriminant analysis were used on quantitative data, while frequency analysis was used on qualitative data. Income generation and meat production were the primary goat rearing objectives. More than 55% of respondents grazed their animals freely in communal lands where natural pasture was the chief feed resource. Mating was mainly uncontrolled with apron and castration being used by goat keepers as mating control methods. Common diseases were contagious caprine pleural pneumonia and helminthiasis. Feed shortage, prevalence of diseases, and water scarcity were the major goat production constraints. There were morphological variations between and within these goat populations, and based on quantitative data, the goats were categorized into two groups. High twinning was observed in Ujiji and Lindi goats and low for Sukuma. The dominant coat color was plain white in Pare, Gogo, Maasai, and Tanga. Other coat color patterns were mixed black and white for Sukuma, reddish-brown for Lindi, black and reddish-brown for Ujiji, and white and reddish-brown for Pwani and Maasai. High within population variation is observed which is important as it can be used as a basis for genetic improvement through selection.
Journal Article
Breeding objectives and selection criteria of farmers keeping indigenous cattle populations in north-west Ethiopia
by
Tarekegn, Getinet Mekuriaw
,
Taye, Mengistie
,
Kebede, Damitie
in
Animal sciences
,
Body size
,
Breeding
2023
This study was conducted to identify farmers' breeding objectives and trait preferences for indigenous cattle in north-west Ethiopia. Multistage purposive and random sampling techniques were used to select study districts, and smallholder farmers. The required data were collected through structured questionnaires from 320 households, personal observations, and focus group discussions. The chi-square (χ2) test, least squares mean, and ranking index were statistical methods used for data analysis. The least squares mean analysis showed a difference (p < 0.001) and the mean herd size was 10.9 heads. Based on ranking index results, milk production (0.35) and draught power (0.25) were the main cattle production purpose/objectives of farmers. The chi-square (χ2) test results of mating practices showed a significant difference (p < 0.001) and 63.8% of farmers used controlled mating. According to the ranking index result, large body size (0.35), colour (0.26), and good traction (0.18) were considered the most important traits in selecting a breeding bull. High milk yield (0.4), colour (0.19), large body size (0.16), and calf growth (0.13) were the preferred traits/criterias for cow selection. Prioritizing farmer trait preference and breeding objectives in this study was critical for the design and implementation of breeding programmes.
Trait preferences of farmer were based on several traits
Farmers in the area kept their bulls mainly for draft service
milk production was the first purpose of cattle keeping
Journal Article
Mitochondrial DNA D‐loop sequence analysis reveals high variation and multiple maternal origins of indigenous Tanzanian goat populations
by
Nguluma, Athumani
,
Kyallo, Martina
,
Chenyambuga, Sebastian
in
Animal populations
,
Animals
,
demographic history
2021
The Small East African (SEA) goat are widely distributed in different agro‐ecological zones of Tanzania. We report the genetic diversity, maternal origin, and phylogenetic relationship among the 12 Tanzanian indigenous goat populations, namely Fipa, Songwe, Tanga, Pwani, Iringa, Newala, Lindi, Gogo, Pare, Maasai, Sukuma, and Ujiji, based on the mitochondrial DNA (mtDNA) D‐loop. High haplotype (Hd = 0.9619–0.9945) and nucleotide (π = 0.0120–0.0162) diversities were observed from a total of 389 haplotypes. The majority of the haplotypes (n = 334) belonged to Haplogroup A which was consistent with the global scenario on the genetic pattern of maternal origin of all goat breeds in the world. Haplogroup G comprised of 45 haplotypes drawn from all populations except the Ujiji goat population while Haplogroup B with 10 haplotypes was dominated by Ujiji goats (41%). Tanzanian goats shared four haplotypes with the Kenyan goats and two with goats from South Africa, Namibia, and Mozambique. There was no sharing of haplotypes observed between individuals from Tanzanian goat populations with individuals from North or West Africa. The indigenous goats in Tanzania have high genetic diversity defined by 389 haplotypes and multiple maternal origins of haplogroup A, B, and G. There is a lot of intermixing and high genetic variation within populations which represent an abundant resource for selective breeding in the different agro‐ecological regions of the country. The indigenous goats in Tanzania belong to Small East African (SEA) goat breed widely distributed in different agro‐ecological zones. This study examines their origin, phylogenetic relationship among the different populations and the demographic history. The goats have high maternal genetic diversity defined by 389 haplotypes and multiple maternal origins of haplogroups A, B, and G. There is a lot of intermixing and high genetic variation within populations which represent an abundant resource for selective breeding in the different agro‐ecological regions of the country.
Journal Article
Whole-Genome Resequencing Reveals Selection Signatures of Abigar Cattle for Local Adaptation
by
Van Damme, Renaud
,
Ayalew, Wondossen
,
Naboulsi, Rakan
in
Abigar cattle
,
Adaptation
,
Agricultural and Veterinary Sciences
2023
Over time, indigenous cattle breeds have developed disease resistance, heat tolerance, and adaptability to harsh environments. Deciphering the genetic mechanisms underlying adaptive traits is crucial for their improvement and sustainable utilization. For the first time, we performed whole-genome sequencing to unveil the genomic diversity, population structure, and selection signatures of Abigar cattle living in a tropical environment. The population structure analysis revealed that Abigar cattle exhibit high nucleotide diversity and heterozygosity, with low runs of homozygosity and linkage disequilibrium, suggesting a genetic landscape less constrained by inbreeding and enriched by diversity. Using nucleotide diversity (Pi) and population differentiation (FST) selection scan methods, we identified 83 shared genes that are likely associated with tropical adaption. The functional annotation analysis revealed that some of these genes are potentially linked to heat tolerance (HOXC13, DNAJC18, and RXFP2), immune response (IRAK3, MZB1, and STING1), and oxidative stress response (SLC23A1). Given the wider spreading impacts of climate change on cattle production, understanding the genetic mechanisms of adaptation of local breeds becomes crucial to better respond to climate and environmental changes. In this context, our finding establishes a foundation for further research into the mechanisms underpinning cattle adaptation to tropical environments.
Journal Article
Genome-wide association study for the level of prolificacy in Cameroon's native goat
by
Nandolo, Wilson
,
Wouobeng, Patrick
,
Pelle, Roger
in
Agricultural and Veterinary Sciences
,
Agricultural Biotechnology
,
Animal and Dairy Science
2024
Income from goats highly depends on prolificacy, which is difficult to improve by traditional breeding methods. The study aimed to identify SNP markers for prolificacy, using a case-control genome-wide association study (GWAS) on 111 genotyped Cameroon native goat (CNG) does, based on the 50 K single nucleotide polymorphism (SNP) chip panel. None of the top SNPs reached the significant p-value of 5 × 10
−8
. The highest p-value was 0.0009. Despite the number of cases being about a quarter of the number of controls, the highest allele frequency of some of the top 20 variants in the cases was indicative of their potential role in the trait. These top variants included the following 15: rs268285661, rs268235169, rs268236449, rs268235135, rs268240394 in Sphingosine-1-phosphate phosphatase 2 (SGPP2) gene, rs268283635 in Solute carrier family 24 member 2 (SLC24A2) gene, rs268251678 in Androgen-induced gene 1 (AIG1) gene, rs268267018, rs268239617, rs268281364, rs268273029, rs268286941, rs268236144, rs268233233 in CEP126 gene and rs268278159, respectively. Our findings indicate that GWAS enable the identification of some loci within genes, with known biological functions and pathways in human being and mice animal model but far-ranging to what was previously hypothesized and tested in goat.
Journal Article
Genome-wide diversity and demographic dynamics of Cameroon goats and their divergence from east African, north African, and Asian conspecifics
by
Mwai, Okeyo Ally
,
Tesfaye, Kassahun
,
Osama, Sarah
in
Admixtures
,
Africa, Eastern
,
Africa, Northern
2019
Indigenous goats make significant contributions to Cameroon's national and local economy, but little effort has been devoted to identifying the populations. Here, we assessed the genetic diversity and demographic dynamics of Cameroon goat populations using mitochondrial DNA (two populations) and autosomal markers (four populations) generated with the Caprine 50K SNP chip. To infer genetic relationships at continental and global level, genotype data on six goat populations from Ethiopia and one population each from Egypt, Morocco, Iran, and China were included in the analysis. The mtDNA analysis revealed 83 haplotypes, all belonging to haplogroup A, in Cameroon goats. Four haplotypes were shared between goats found in Cameroon, Mozambique, Namibia, Zimbabwe, Kenya, and Ethiopia. Analysis of autosomal SNPs in Cameroon goats revealed the lowest HO (0.335±0.13) and HE (0.352±0.15) in the North-west Highland and Central Highland populations, respectively. Overall, the highest HO (0.401±0.12) and HE (0.422±0.12) were found for Barki and Iranian goats, respectively. Barki goats had the highest average MAF, while Central Highland Cameroon goats had the lowest. Overall, Cameroon goats demonstrated high FIS. AMOVA revealed that 13.29% of the variation was explained by genetic differences between the six population groups. Low average FST (0.01) suggests intermixing among Cameroon goats. All measures indicated that Cameroon goats are closer to Moroccan goats than to other goat populations. PCA and STRUCTURE analyses poorly differentiated the Cameroon goats, as did genetic distance, Neighbor-Net network, and neighbor-joining tree analyses. The haplotype analysis of mtDNA showed the initial dispersion of goats to Cameroon and central Africa from north-east Africa following the Nile Delta. Whereas, the approximate Bayesian computation indicated Cameroon goats were separated from Moroccan goats after 506 generations in later times (~1518 YA), as supported by the phylogenetic net-work and admixture outputs. Overall, indigenous goats in Cameroon show weak phylogenetic structure, suggesting either extensive intermixing.
Journal Article