A 1.1 Mb duplication CNV on chromosome 17 contributes to skeletal muscle development in Boer goats.

The Boer goat is one of the top meat breeds in modern animal husbandry and has attracted widespread attention for its unique growth performance. However, the genetic basis of muscle development in the Boer goat remains obscure. In this study, we identified specific structural variants in the Boer goat based on genome-wide selection signals and analyzed the basis of the molecular heredity of related candidate genes in muscle development. A total of 9 959 autosomal copy number variations (CNVs) were identified through selection signal analysis in 127 goat genomes. Specifically, we confirmed that the highest signal CNV (HSV) was a chromosomal arrangement containing an approximately 1.11 Mb (CHIR17: 60062304-61171840 bp) duplicated fragment inserted in reverse orientation and a 5 362 bp deleted region (CHIR17:60145940-60151302 bp) with overlapping genes (e.g., ARHGAP10, NR3C2, EDNRA, PRMT9, and TMEM184C). The homozygous duplicated HSV genotype (+/+) was found in 96% of Boer goats but was not detected in Eurasian goats and was only detected in 4% of indigenous African goats. The expression network of three candidate genes ( ARHGAP10, NR3C2, and EDNRA) regulating dose transcription was constructed by RNA sequencing. Results indicated that these genes were involved in the proliferation and differentiation of skeletal muscle satellite cells (SMSCs) and their overexpression significantly increased the expression of SAA3. The HSV of the Boer goat contributed to superior skeletal muscle growth via the dose effects of overlapping genes.

Identification of differentially expressed long non-coding RNAs and messenger RNAs involved with muscle development in Dazu black goats through RNA sequencing.

This study aimed to explore the genetic basis of muscle development in goats. The transcriptome dataset for differentially expressed lncRNAs (DELs) and differentially expressed genes (DEGs) of goat muscle at different developmental stages were obtained using RNA-Seq. A total of 447,806,481 and 587,559,465 clean reads in the longissimus dorsi muscle of Dazu black goats between 75d embryonic stage and 1d after birth were generated through Illumina paired-end sequencing, and their mapping rates were 89.82 and 90.99%, respectively. Moreover, 4517 DEGs and 648 DELs were identified, and 4784 lncRNA-mRNA targeting relationships were predicted. Gene function annotation results showed that 4101 DEGs were significantly enriched to 1098 GO terms, and 2014 DEGs were significantly enriched to 40 KEGG pathways, including many GO terms and pathways related to muscle development, such as cell differentiation and Wnt signaling pathway. Then, 10 DELs and 20 DEGs were randomly selected for RT-qPCR verification, and the agreement rate between the verification and RNA-Seq results was 90%, indicating the high reliability of the RNA-Seq data analysis. In conclusion, this study obtained several mRNAs and lncRNAs related to the muscle development of Dazu black goats and identified several targeted regulatory pairs of lncRNA-mRNA. This study may serve as a reference to understand the genetic basis and molecular mechanism of muscle development in goats.

Comparative analysis of the genetic diversity of the neutral microsatellite loci and second exon of the goat MHC-DQB1 gene.

This study compared and analyzed the genetic diversity and population structure of exon 2 of the DQB1 gene and 13 autosomal neutral microsatellite markers from 14 Chinese goat breeds to explore the potential evolutionary mechanism of the major histocompatibility complex (MHC). A total of 287 haplotypes were constructed from MHC-DQB1 exon 2 from 14 populations, and 82 nucleotide polymorphic sites (SNPs, 31.78%) and 172 heterozygous individuals (79.12%) were identified. The FST values of the microsatellites and MHC-DQB ranged between 0.01831-0.26907 and 0.00892-0.38871, respectively. Furthermore, 14 goat populations showed rich genetic diversity in the microsatellite loci and MHC-DQB1 exon 2. However, the population structure and phylogenetic relationship represented by the two markers were different. Positive selection and Tajima's D test results showed the occurrence of a diversified selection mechanism, which was primarily based on a positive and balancing selection in goat DQB. This study also found that the DQB sequences of bovines exhibited trans-species polymorphism (TSP) among species and families. In brief, this study indicated that positive and balancing selection played a major role in maintaining the genetic diversity of DQB, and TSP of MHC in bovines was common, which enhanced the understanding of the MHC evolution.

A nonsynonymous SNP within the AMH gene is associated with litter size in Dazu black goats.

AMH, KISS1R and GDF9 genes play a vital role in human and animal reproduction and might be used as the genetic markers for the reproduction traits selection. The aim of this study was to screen the single nucleotide polymorphisms (SNPs) within the AMH, KISS1R and GDF9 genes and to determine the correlations between these SNPs and the litter size in goats. Nine single SNPs within these genes were used for genotyping of the 190 Dazu black goat populations by SNaPshot technique. The polymorphisms of nine SNPs within these genes were detected in Dazu black goats. The significant correlation was observed between one SNP (g.89172108A > C) within the AMH gene and the litter size of second born in Dazu black goats (p < 0.05). The SNP was located in exon 4 (XM_018050765.1) of the AMH gene and was one nonsynonymous substitution, which resulted in a change of an amino acid from Glutamine to Proline (Gln38Pro). These results suggested that the nonsynonymous SNP g.89172108A > C of AMH gene could be used as a potential genetic marker for Marker-assisted selection (MAS) in goats breeding programs.

Genome-wide selective detection of Mile red-bone goat using next-generation sequencing technology.

The ecotype population of goats (Capra hircus) was created by long-term artificial selection and natural adaptation. Mile red-bone goat is an indigenous breed with visible red bones, and its special bone structure has received extensive attention. This study aimed to identify genetic variants and candidate genes associated with specific bone phenotypes using next-generation sequencing technology (NGS). The results revealed that 31,828,206 single nucleotide polymorphisms (SNPs) were obtained from 72 goats (20 Mile red-bone goats and 52 common goats) by NGS. A total of 100 candidate genes were identified on the basis top 1% window interaction from nucleotide diversity (π), π ratio (π A/π B), and pairwise fixation index (F ST). Exactly 77 known signaling pathways were enriched. Specifically, three coding genes (NMNAT2, LOC102172983, and PNLIP) were annotated in the vitamin metabolism signaling pathways, and NCF2 was annotated to the osteoclast (OC) differentiation pathway. Furthermore, 5862 reliable copy number variations (CNVs) were obtained, and 14 and 24 genes were annotated with the top 1‰ CNV based on F ST (>0.490) and V ST (>0.527), respectively. Several pathways related to bone development and metabolism of exogenous substances in vivo, including calcium signaling pathway, OC differentiation, and glycerophospholipid metabolism, were annotated. Specifically, six genes from 19 candidate CNVs, which were obtained by interaction of the top 1‰ CNVs with F ST and V ST, were annotated to mucin-type O-glycan biosynthesis and metabolic pathways. Briefly, the results implied that pseudopurpurin and specific genetic variants work together to contribute to the red-bone color and specific bone structure of Mile red-bone goat. This study is helpful to understanding the genetic basis of the unique bone phenotype of Mile red-bone goats.

Three SNPs within exons of INHA and ACVR2B genes are significantly associated with litter size in Dazu black goats.

The aim of this study was to analyse the association between single-nucleotide polymorphisms within INHA and ACVR2B and litter size in Dazu black goats. In total, twenty-two SNPs were genotyped in 190 individuals by SNaPshot and resequencing. The results showed that three SNPs (SNP_1, SNP_12 and SNP_13 in this study) were detected to have significant additive genetic effect on the recorded goat litter size (p < .05). The SNP_1 (NC_030809.1), a non-synonymous substitution of G for T at chr2-g. 28314990 in the exon 2 of INHA gene (NM_001285606.1), resulted in homozygote 2 (HOM2) contributed 0.25 and heterozygote (HET) contributed 0.12 larger litter than homozygote 1 (HOM1). Meanwhile, SNP_12 (Chr22-g. 11721225 A > T) and SNP_13 (Chr22-g. 11721227 A > C) (NC_030829.1) simultaneously mutated at the first and third position of a triplet AAA (lysine, K) in the exon 4 of ACVR2B gene (XM_018066623.1) had estimated genetic effects of HOM1 (0.00) and HOM2 (0.03) larger than HET (-0.12). In conclusion, one SNPs (chr2-g. 28314990 T > G) within the exon 2 of INHA and two SNPs (Chr22-g. 11721225 A > T and Chr22-g. 11721227 A > C) in the exon 4 of ACVR2B gene were highly recommended as candidate markers of litter size in Dazu black goats. A large-scale association study to assess the impact of these variants on litter size is still necessary.

SNP of AHSA2 gene in three cattle breeds using snapshot technology.

Droughtmaster is a tropical breed of beef cattle that can survive in hot climates and easily adapt to torrid environments. These traits are important in livestock breeding. In this study, we genotyped five single-nucleotide polymorphisms (SNPs) of the AHSA2 gene from 190 cattle belonging to three different breeds (Droughtmaster, Angus and Simmental) by using snapshot technology. This work aimed to identify the valuable molecular marker of heat resistance in cattle. Results showed that Droughtmaster exhibited higher expected heterozygosity and polymorphic information content compared with the two other breeds. The AHSA2-1 locus deviated from the Hardy-Weinberg equilibrium in the Droughtmaster breed (P < 0.05). Two SNPs in Droughtmaster diverged significantly from Angus and Simmental. The SNPs were identified as AHSA2-3 and AHSA2-4, which were closely linked to the three breeds based on pair-wise FST. AHSA2-4 involved a missense mutation. In summary, the GG genotypes in AHSA2-3 and AHSA2-4 may be candidate genotypes associated with heat resistance traits and may serve as valuable genetic markers for breeding of heat-tolerant beef cattle in the future.

Evolutionary relationship and population structure of domestic Bovidae animals based on MHC-linked and neutral autosomal microsatellite markers.

Major histocompatibility complex (MHC) genes are critical for disease resistance or susceptibility responsible for host-pathogen interactions determined mainly by extensive polymorphisms in the MHC genes. Here, we examined the diversity and phylogenetic pattern of MHC haplotypes reconstructed using three MHC-linked microsatellite markers in 55 populations of five Bovidae species and compared them with those based on neutral autosomal microsatellite markers (NAMs). Three-hundred-and-forty MHC haplotypes were identified in 1453 Bovidae individuals, suggesting significantly higher polymorphism and heterozygosity compared with those based on NAMs. The ambitious boundaries in population differentiation (phylogenetic network, pairwise FST and STRUCTURE analyses) within and between species assessed using the MHC haplotypes were different from those revealed by NAMs associated closely with speciation, geographical distribution, domestication and management histories. In addition, the mean FST was significantly correlated negatively with the number of observed alleles (NA), observed (HO) and expected (HE) heterozygosity and polymorphism information content (PIC) (P < 0.05) in the MHC haplotype dataset while there was no correction of the mean FST estimates (P> 0.05) between the MHC haplotype and NAMs datasets. Analysis of molecular variance (AMOVA) revealed a lower percentage of total variance (PTV) between species/groups based on the MHC-linked microsatellites than NAMs. Therefore, it was inferred that individuals within populations accumulated as many MHC variants as possible to increase their heterozygosity and thus the survival rate of their affiliated populations and species, which eventually reduced population differentiation and thereby complicated their classification and phylogenetic relationship inference. In summary, host-pathogen coevolution and heterozygote advantage, rather than demographic history, act as key driving forces shaping the MHC diversity within the populations and determining the interspecific MHC diversity.

Identification of a Goat Intersexuality-Associated Novel Variant Through Genome-Wide Resequencing and Hi-C.

Background: Polled intersex syndrome (PIS) leads to reproductive disorders in goats and exerts a heavy influence on goat breeding. Since 2001, the core variant of an 11.7 kb deletion at ~129 Mb on chromosome 1 (CHI1) has been widely used as a genetic diagnostic criterion. In 2020, a ~0.48 Mb insertion within the PIS deletion was identified by sequencing in XX intersex goats. However, the suitability of this variation for the diagnosis of intersex goats worldwide and its further molecular genetic mechanism need to be clarified. Results: The whole-genome selective sweep of intersex goats from China was performed with whole-genome next-generation sequencing technology for large sample populations and a case-control study on interbreeds. A series of candidate genes related to the goat intersexuality phenotype were found. We further confirmed that a ~0.48 Mb duplicated fragment (including ERG and KCNJ15) downstream of the ~20 Mb PIS region was reversely inserted into the PIS locus in intersex Chinese goats and was consistent with that in European Saanen and Valais black-necked goats. High-throughput chromosome conformation capture (Hi-C) technology was then used to compare the 3D structures of the PIS variant neighborhood in CHI1 between intersex and non-intersex goats. A newly found structure was validated as an intrachromosomal rearrangement. This inserted duplication changed the original spatial structure of goat CHI1 and caused the appearance of several specific loop structures in the adjacent ~20 kb downstream region of FOXL2. Conclusions: Results suggested that the novel complex PIS variant genome was sufficient as a broad-spectrum clinical diagnostic marker of XX intersexuality in goats from Europe and China. A series of private dense loop structures caused by segment insertion into the PIS deletion might affect the expression of FOXL2 or other neighboring novel candidate genes. However, these structures require further in-depth molecular biological experimental verification. In general, this study provided new insights for future research on the molecular genetic mechanism underlying female-to-male sex reversal in goats.

Genome-wide selection signatures analysis of litter size in Dazu black goats using single-nucleotide polymorphism.

Litter size is considered to be the most important index for estimating domestic animal productivity. The number of indigenous goats in China with higher litter sizes than those of commercial breeds in other countries may be helpful for accelerating genetic improvements in goat breeding. We performed a genome-wide selective sweep analysis of 31 Dazu black goats with extreme standard deviation in litter size within the third fetus to identify significant genomic regions and candidate genes through different analyses. The analysis identified a total of 33,917,703 variants, including 32,262,179 SNPs and 1,655,524 indels. In addition, two novel candidate genes (LRP1B and GLRB), which are related to litter size, were obtained with π, Tajima's D, πA/πB, and F ST at the individual level with a 95% threshold for each parameter. These two genes were annotated in five GO terms (localization, binding, macromolecular complex, membrane part, and membrane) and two pathways (long-term depression and neuroactive ligand-receptor interaction pathway). Regarding the result of linkage disequilibrium (LD) analysis, in LRP1B and GRID2, the high-yield Dazu black goats exhibit significantly different LD patterns from low-yield goats. Litter size variability has low heritability and is related to multiple complex factors found in domestic animals. Obtaining a clear explanation and significant signal by genome-wide selective sweep analysis with a small sample size is difficult. However, we investigated some candidate genes, particularly LRP1B and GLRB, which may provide useful information for further research.

Selection signatures of litter size in Dazu black goats based on a whole genome sequencing mixed pools strategy.

Litter size is considered to be the most important index for estimating domestic animal productivity. Due to its complexity, the molecular mechanism of litter size has not been elucidated, and it has restricted the use of marker-assisted selection to create high-yield populations in goats. A genome-wide selective sweep analysis was performed with 31 Dazu black goats to identify significant genomic regions and candidate genes related to litter size by a mixed pools strategy. A total of 96 candidate genes were identified, including NR6A1, STK3, IGF2BP2, AR, HMGA2, NPTX1, ANKRD17, DPYD, CLRB, PPP3CA, PLCB1, STK3 and HMGA2, using mixed pool analysis with ZHp and FST. We classified these candidate genes based on the functional classification and annotation of signaling pathways. According to the GO and KEGG analysis results, a total of 43 GO terms and 108 pathways were annotated from these genes. In particular, some novel candidate genes were enriched in reproduction-related pathways, such as the estrogen signaling pathway and oocyte meiosis. These findings provide insight into the influences of coding genes on the fecundity traits of goats.

Genetic diversity estimation of Yunnan indigenous goat breeds using microsatellite markers.

BACKGROUND: To assess the genetic diversity of seven Yunnan indigenous goat populations (Fengqing hornless goat, Mile red-bone goat, Longling goat, Ninglang black goat, Black-bone goat, Yunling black goat, and Zhaotong goat), their population structures were investigated using 20 microsatellite markers. RESULTS: The results indicated that the genetic diversity of these goats was rich. The observed heterozygosity ranged from 0.4667 ± 0.0243 to 0.5793 ± 0.0230, and the mean number of alleles ranged from 4.80 ± 1.61 and 4.80 ± 1.64 to 6.20 ± 2.93. The population structure analysis showed that these seven goat populations were separated into two clusters, consistent with the results from phylogenetic networks, pairwise differences, and STRUCTURE analyses. We speculate that this may have been caused by natural geographical isolation, human migration and economic and cultural exchanges. We suggest removing CSRD247 and ILSTS005, two loci identified to be under positive selection in the present study, from the microsatellite evaluation system of goats. CONCLUSIONS: The present study may provide a scientific basis for the conservation and utilization of Yunnan indigenous goats.

Genome-wide analysis of Chongqing native intersexual goats using next-generation sequencing.

Sex reversal has been studied extensively in vertebrate species, particularly in domestic goats, because polled intersex syndrome (PIS) has seriously affected their production efficiency. In the present study, we used histopathologically diagnosed cases of PIS to identify correlated genomic regions and variants using representative selection signatures and performed GWAS using Restriction-Site Associated Resequencing DNA. We identified 171 single-nucleotide polymorphisms (SNPs) that may have contributed to this phenotype, and 53 SNPs were determined to be located in coding regions using a general linear model. The transcriptome data sets of differentially expressed genes (DEGs) in the pituitary tissues of intersexual and nonintersexual goats were examined using high-throughput technology. A total of 10,063 DEGs and 337 long noncoding RNAs were identified. The DEGs were clustered into 56 GO categories and determined to be significantly enriched in 53 signaling pathways by KEGG analysis. In addition, according to qPCR results, PSPO2 and FSH were significantly more highly expressed in sexually mature pituitary tissues of intersexual goats compared to healthy controls (nonintersexual). These results demonstrate that certain novel potential genomic regions may be responsible for intersexual goats, and the transcriptome data indicate that the regulation of various physiological systems is involved in intersexual goat development. Therefore, these results provide helpful data for understanding the molecular mechanisms of intersex syndrome in goats.

Current genetic diversity in eight local Chinese sheep populations.

China has numerous local domestic sheep breeds. In this study, the genetic diversity of eight sheep populations was estimated using 17 microsatellites. Knowledge of such diversity provides novel insight into the degree of breed protection needed and the prediction of hybrid advantage. In total, 17 microsatellites were genotyped in 186 individuals from eight populations. The mean number of alleles (± SD) ranged from 3.71 ± 1.36 in Zhaotong sheep to 11.94 ± 3.58 in small-tailed Han sheep. The observed heterozygote frequency (± SD) within a population ranged from 0.482 ± 0.025 in Zhaotong sheep to 0.664 ± 0.023 in Tibetan sheep. In addition, using pairwise difference (FST) analysis, the highest within-population diversity was observed in Tibetan sheep (πX = 12.8098) and small-tailed Han (πX = 12.67873), and the lowest diversity was observed in Zhaotong sheep (πX = 7.90337). The results for genetic divergence between populations indicated that the populations were significantly different (P < 0.05) based on the average number of pairwise differences between populations (πXY) and the corrected average pairwise differences. Both phylogenetic networks and structure analysis showed that these eight populations were separated into three clusters in accordance with their geographical habitat, except Tibetan and Hu sheep. In short, we genotyped eight local Chinese sheep populations using 17 microsatellites, and the results indicated that their current genetic diversity is decreasing and that new conservation strategies are needed. In addition, significant genetic differences between populations could be used in cross breeding.

Genetic diversity of the Chinese goat in the littoral zone of the Yangtze River as assessed by microsatellite and mtDNA.

The objective of this study was to assess the genetic diversity and population structure of goats in the Yangtze River region using microsatellite and mtDNA to better understand the current status of those goat genetic diversity and the effects of natural landscape in fashion of domestic animal genetic diversity. The genetic variability of 16 goat populations in the littoral zone of the Yangtze River was estimated using 21 autosomal microsatellites, which revealed high diversity and genetic population clustering with a dispersed geographical distribution. A phylogenetic analysis of the mitochondrial D-loop region (482 bp) was conducted in 494 goats from the Yangtze River region. In total, 117 SNPs were reconstructed, and 173 haplotypes were identified, 94.5% of which belonged to lineages A and B. Lineages C, D, and G had lower frequencies (5.2%), and lineage F haplotypes were undetected. Several high-frequency haplotypes were shared by different ecogeographically distributed populations, and the close phylogenetic relationships among certain low-frequency haplotypes indicated the historical exchange of genetic material among these populations. In particular, the lineage G haplotype suggests that some west Asian goat genetic material may have been transferred to China via Muslim migration.

Sheep mitochondrial heteroplasmy arises from tandem motifs and unspecific PCR amplification.

The mitochondrial DNA control region (D-loop) is a widely used molecular marker in evolutionary and phylogeographic research. However, the occurrence of heteroplasmy of the D-loop region within individuals has rarely been investigated. In this study, a total of 85 Chinese sheep were used to amplify a partial D-loop region, and 15 heteroplasmic animals (17.64%) were identified. A comparative analysis of the PCR amplification and cloning of the D-loop sequences from the heteroplasmic samples revealed most of the sequencing profile from the heteroplasmic regions started at the beginning of a 75-bp random repeat motif. In addition, a total of 22 nonsyngeneic sequences with a D-loop were found in 61 of the clones obtained from the 4 random heteroplasmic and 3 homozygote animals, and their genomic locations were compared for homology. In summary, the D-Loop sequencing profiles appear to be heteroplasmic and could arise from tandem repeat motifs and unspecific replication during PCR amplification; however, they are not likely due to the presence of multiple mitochondrial genomes within an individual.

Reversibility and safety of KISS1 metastasis suppressor gene vaccine in immunocastration of ram lambs.

OBJECTIVE: The aim of this study was to investigate the reversibility and safety of KISS1 metastasis suppressor (KISS1) gene vaccine in immunocastration. METHODS: Six eight-week old ram lambs were randomly divided into vaccinated and control groups. The vaccine (1 mg/ram lamb) was injected at weeks 0, 3, and 6 of the study. Blood samples were collected from the jugular vein before primary immunization and at weeks 2, 4, 6, 10, 14, 22, and 30 after primary immunization. All ram lambs were slaughtered at 38 weeks of age, and samples were collected. RESULTS: The specific anti-KISS1 antibody titers in vaccinated animals were significantly higher and the serum testosterone level was significantly lower than those in the control groups from week 4 to 14 after primary immunization (p<0.05). No significant difference was observed at weeks 22 and 30 after the primary immunization. Similar results were also found for scrotal circumference, testicular weight, length, breadth, and spermatogenesis in seminiferous tubules in week 30 after primary immunization. KS (KISS1-hepatitis B surface antigen S) fusion fragment of KISS1 gene vaccine was not detected in host cell genomic DNA of 9 tissues of the vaccinated ram lambs by polymerase chain reaction. CONCLUSION: The effects of KISS1 gene vaccine in immunocastration were reversible and no integration events were recorded.

Conservation genetics in Chinese sheep: diversity of fourteen indigenous sheep (Ovis aries) using microsatellite markers.

The domestic sheep (Ovis aries) has been an economically and culturally important farm animal species since its domestication around the world. A wide array of sheep breeds with abundant phenotypic diversity exists including domestication and selection as well as the indigenous breeds may harbor specific features as a result of adaptation to their environment. The objective of this study was to investigate the population structure of indigenous sheep in a large geographic location of the Chinese mainland. Six microsatellites were genotyped for 611 individuals from 14 populations. The mean number of alleles (±SD) ranged from 7.00 ± 3.69 in Gangba sheep to 10.50 ± 4.23 in Tibetan sheep. The observed heterozygote frequency (±SD) within a population ranged from 0.58 ± 0.03 in Gangba sheep to 0.71 ± 0.03 in Zazakh sheep and Minxian black fur sheep. In addition, there was a low pairwise difference among the Minxian black fur sheep, Mongolian sheep, Gansu alpine merino, and Lanzhou fat-tailed sheep. Bayesian analysis with the program STRUCTURE showed support for 3 clusters, revealing a vague genetic clustering pattern with geographic location. The results of the current study inferred high genetic diversity within these native sheep in the Chinese mainland.

A complete mitochondrial genome of Youzhou black-skin goat.

The Youzhou black-skin goat (Capra hircus), an indigenous breed of Chinese southwest. Here, we describe the complete mitochondrial genome sequence of Hechuan white goat. The mitogenome is 16,640 nt in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes and a control region. As in other mammals, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes, which are encoded on the light strand. Its overall base composition is A: 33.5%, T: 27.3%, C: 26.1% and G: 13.1%. The complete mitogenome of the local subspecies of Hechuan white goat could provide an important data to further breed improvement and animal genetics resource conservation in China.

Complete mitochondrial genome of the a rare subspecies of genus Bos, Tianzhu white yak from Tibetan area in China.

The population of domestic yak, Tianzhu white yak, from Tibetan area in China is considered as a rare Bos grunniens species. We first determined and annotated its complete mitochondrial genome. The mitogenome is 16,319 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes and a control region. As in other mammals, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes, which are encoded on the light strand. Its overall base composition is A: 33.7%, T: 27.2%, C: 25.8% and G: 13.2%. The complete mitogenome of the new subspecies of Bos grunniens could provide an important data to further explore the taxonomic status of the subspecies.