| Literature DB >> 32545749 |
Rabiul Islam1,2, Zhangfa Liu3, Yefang Li1, Lin Jiang1, Yuehui Ma1.
Abstract
Conservation of genetic resources is of great concern globally to maintain genetic diversity for sustainable food security. Comprehensive identification of the breed composition, estimation of inbreeding and effective population size are essential for the effective management of farm animal genetic resources and to prevent the animals from genetic erosion. The Zhongwei male (ZWM), Arbas Cashmere male (ACM) and Jining Grey male (JGM) goats are conserved in three different state goat farms in China but their family information, level of inbreeding and effective population size are unknown. We investigated the genomic relationship, inbreeding coefficient and effective population size in these three breeds from three state goat farms using the Illumina goat SNP50 BeadChip. Genomic relationships and phylogenetic analysis revealed that the breeds are clearly separated and formed separate clusters based on their genetic relationship. We obtained a high proportion of informative SNPs, ranging from 91.8% in the Arbas Cashmere male to 96.2% in the Jining Grey male goat breeds with an average mean of 96.8%. Inbreeding, as measured by FROH, ranged from 1.79% in ZWM to 8.62% in ACM goat populations. High FROH values, elevated genomic coverage of very long ROH (>30 Mb) and severe decline in effective population size were recorded in ACM goat farm. The existence of a high correlation between FHOM and FROH indicates that FROH can be used as an alternative to inbreeding estimates in the absence of pedigree records. The Ne estimates 13 generations ago were 166, 69 and 79 for ZWM, ACM and JGM goat farm, respectively indicating that these goat breeds were strongly affected by selection pressure or genetic drift. This study provides insight into the genomic relationship, levels of inbreeding and effective population size in the studied goat populations conserved in the state goat farms which will be valuable in prioritizing populations for conservation and for developing suitable management practices for further genetic improvement of these Chinese male goats.Entities:
Keywords: Ne; SNP; genome coverage; inbreeding coefficient; runs of homozygosity
Year: 2020 PMID: 32545749 PMCID: PMC7349881 DOI: 10.3390/genes11060652
Source DB: PubMed Journal: Genes (Basel) ISSN: 2073-4425 Impact factor: 4.096
Breed name, sample size, location, utility and demography, breeding practices, agro-ecology and raising methods of studied goat populations.
| Breed | Sample Size | Location | Utility, Demography and Breeding Practices | Agro-Ecology and Raising Methods | Pop. Trend |
|---|---|---|---|---|---|
| Zhongwei male (ZWM) | 48 | Zhongwei City, Ningxia Hui Autonomous Region | The Chinese Zhongwei goat is used primarily for the production of kid pelts. Total population was 30,000 in 2006. It is an excellent local variety after natural and artificial selection. | Av. Altitude 1200 m. Semi-pasture land, semi-dry land, mainly stall-feeding reared. | Negative |
| Jining Grey male (JGM) | 20 | Jining City, Shandong Province, China | They are fast maturing and very prolific, with an average kidding rate of 283%. Total population was 430,000 in 2006. Bred in the local natural environment, after many years of selection their adaptability is high, high fecundity rate. | Av. Altitude 45 m. Agricultural land, wetland, grazing in mountain area in summer and stall feeding in winter | Stable |
| Arbas Cashmere male (ACM) | 30 | Erdos City, Inner Mongolia Autonomous Region, China | It is well known for its excellent quality cashmere fiber. Total population was 4.3 million in 2006. After long-term natural and artificial selection under difficult ecological conditions, the cashmere and meat varieties are adapted to the local conditions. | Av. Altitude 1500 m. Semi-pasture land, semi-dry land. Mainly grazing practices. | Positive |
Single nucleotide polymorphisms (SNPs) filtration result.
| Parameters | Excluded SNPs | SNP Remained |
|---|---|---|
| Total number of SNPs | 53,347 | |
| SNPs removed due to unrecognized position | 2773 | 50,574 |
| SNP Call frequency (call rate) (<0.95) | 1956 | 48,618 |
| Minor allele frequency (<0.05) | 3425 | 45,193 |
| Hardy-Weinberg equilibrium ( | 152 | 45,041 |
| Total SNPs | 8306 | 45,041 |
Figure 1Visualization results of G-matrix analysis. Each small square represents the genetic relationship between two samples. Samples, closer to the red color grid, the larger the value, indicates the closer genetic relationship between two individuals. ACM, Arbas Cashmere male; JGM, Jining Grey male; ZWM, Zhongwei male.
Figure 2Neighbor-joining (NJ) tree showing different clusters of the studied goat populations. Samples with the same color label are estimated to be samples of the same family in cluster analysis.
Figure 3(a) Principle component analysis (PCA), (b) cross-validation error, (c) population structure plot of three goat breeds at K = 3.
Breed name, sample size (n), proportion of polymorphic SNPs (P), inbreeding coefficient based on ROH (F) and based on observed and expected heterozygosity differences (F), correlation between F and F. ACM, Arbas Cashmere male; JGM, Jining grey male; ZWM, Zhongwei male.
| Breed |
| % |
|
|
|
| |
|---|---|---|---|---|---|---|---|
| ZWM | 48 | 95.2 | 0.385 ± 0.20 | 0.386 ± 0.19 | 0.017 | 0.021 | 0.92 |
| ACM | 30 | 91.8 | 0.367 ± 0.19 | 0.384 ± 0.20 | 0.086 | 0.074 | 0.99 |
| JGM | 20 | 96.2 | 0.401 ± 0.20 | 0.391 ± 0.20 | 0.028 | −0.010 | 0.96 |
| Overall | 98 | 96.8 | 0.385 ± 0.19 | 0.397 ± 0.20 | 0.040 | 0.032 | 0.92 |
Figure 4Distribution of F across breeds.
Average percentage genomic inbreeding coefficient (F) for different length categories of ROH across three goat populations.
| Breed | 0–5 Mb | 5–15 Mb | 15–30 Mb | >30 Mb | Total |
|---|---|---|---|---|---|
| ZWM | 0.92 | 0.59 | 0.25 | 0.03 | 1.79 |
| ACM | 1.67 | 4.03 | 2.13 | 0.79 | 8.62 |
| JGM | 0.47 | 0.83 | 0.83 | 0.53 | 2.66 |
Figure 5Distribution of inbreeding coefficients (F) based on runs of homozygosity (ROH) for each chromosome across breeds.
Figure 6The average sum of runs of homozygosity (ROH) of each breed in different ROH length classes.
Figure 7Estimated effective population sizes (N) in three Chinese goat populations over the past 1000 generations.