Whole-genome sequencing reveals genomic diversity and selection signatures in Xia'nan cattle.

BACKGROUND: The crossbreeding of specialized beef cattle breeds with Chinese indigenous cattle is a common method of genetic improvement. Xia'nan cattle, a crossbreed of Charolais and Nanyang cattle, is China's first specialized beef cattle breed with independent intellectual property rights. After more than two decades of selective breeding, Xia'nan cattle exhibit a robust physique, good environmental adaptability, good tolerance to coarse feed, and high meat production rates. This study analyzed the population genetic structure, genetic diversity, and genomic variations of Xia'nan cattle using whole-genome sequencing data from 30 Xia'nan cattle and 178 published cattle genomic data. RESULT: The ancestry estimating composition analysis showed that the ancestry proportions for Xia'nan cattle were mainly Charolais with a small amount of Nanyang cattle. Through the genetic diversity studies (nucleotide diversity and linkage disequilibrium decay), we found that the genomic diversity of Xia'nan cattle is higher than that of specialized beef cattle breeds in Europe but lower than that of Chinese native cattle. Then, we used four methods to detect genome candidate regions influencing the excellent traits of Xia'nan cattle. Among the detected results, 42 genes (θπ and CLR) and 131 genes (FST and XP-EHH) were detected by two different detection strategies. In addition, we found a region in BTA8 with strong selection signals. Finally, we conducted functional annotation on the detected genes and found that these genes may influence body development (NR6A1), meat quality traits (MCCC1), growth traits (WSCD1, TMEM68, MFN1, NCKAP5), and immunity (IL11RA, CNTFR, CCL27, SLAMF1, SLAMF7, NAA35, and GOLM1). CONCLUSION: We elucidated the genomic features and population structure of Xia'nan cattle and detected some selection signals in genomic regions potentially associated with crucial economic traits in Xia'nan cattle. This research provided a basis for further breeding improvements in Xia'nan cattle and served as a reference for genetic enhancements in other crossbreed cattle.

POLB Regulates Proliferation and Apoptosis of Bovine Primary Myocytes.

DNA polymerase ß (DNA polymerase beta (POLB)) belongs to a member of the DNA polymerase X family, mainly involved in various biological metabolic processes, such as eukaryotic DNA replication, DNA damage repair, gene recombination, and cell cycle regulation. In this study, the muscle development-related gene POLB was screened by selection signature and RNA-seq analysis and then validated for the proliferation and apoptosis of bovine primary myocytes. It was also found that overexpression of the POLB gene had a pro-apoptosis effect, but interfering with the expression of the gene had no significant effect on cells. Then, the analysis of related apoptotic genes revealed that POLB overexpression affected CASP9 gene expression.

The Identification of Goat KCNJ15 Gene Copy Number Variation and Its Association with Growth Traits.

(1) Background: Copy number variation (CNV) is a critical component of genome structural variation and has garnered significant attention. High-throughput screening of the KCNJ15 gene has revealed a correlation between the CNV region and the growth traits of goats. We aimed to identify the CNV of the KCNJ15 gene in five goat breeds and analyze its association with growth characteristics. (2) Methods: We utilized 706 goats from five breeds: Guizhou black goat (GZB), Guizhou white goat (GZW), Bohuai goat (BH), Huai goat (HH), and Taihang goat (TH). To evaluate the number of copies of the KCNJ15 gene using qPCR, we analyzed the correlation between the CNV and growth characteristics and then used a universal linear model. The findings revealed variations in the distribution of different copy number types among the different goat breeds. (3) Results: Association analysis revealed a positive influence of the CNV in the KCNJ15 gene on goat growth. In GZB, individuals with duplication types exhibited superior performance in terms of cannon bone circumference (p < 0.05). In HH, individuals with duplication types exhibited superior performance in terms of body slanting length (p < 0.05). Conversely, normal TH demonstrated better body height and body weight (p < 0.05), while in GZW, when CN = 3, it performed better than other types in terms of body weight and chest circumference (p < 0.05). However, in BH, it had no significant effect on growth traits. (4) Conclusions: We confirmed that the CNV in the KCNJ15 gene significantly influences the growth characteristics of four distinct goat breeds. The correlation between KCNJ15 gene CNVs and goat growth traits offers valuable insights to breeders, enabling them to employ precise and efficient breeding methods that enhance livestock welfare, productivity, and overall economic benefits in the industry.

Bovine enhancer-regulated circSGCB acts as a ceRNA to regulate skeletal muscle development via enhancing KLF3 expression.

Skeletal muscle growth and development in livestock and poultry play a pivotal role in determining the quality and yield of meat production. However, the mechanisms of myogenesis are remained unclear due to it finely regulated by a complex network of biological macromolecules. In this study, leveraging previous sequencing data, we investigated a differentially expressed circular RNA (circSGCB) present in fetal and adult muscle tissues among various ruminant species, including cattle, goat, and sheep. Our analysis revealed that circSGCB is a single exon circRNA, potentially regulated by an adjacent bovine enhancer. Functional analysis through loss-of-function tests demonstrated that circSGCB exerts inhibitory effects on bovine myoblast proliferation while promoting myocytes generation. Furthermore, we discovered that circSGCB primarily localizes to the cytoplasm, where it functions as a molecular sponge by binding to bta-miR-27a-3p. This interaction releases the mRNAs of KLF3 gene and further activates downstream functional pathways. In vivo, studies provided evidence that up-regulation of KLF3 contributes to muscle regeneration. These findings collectively suggest that circSGCB operates via a competing endogenous RNA (ceRNA) mechanism to regulate KLF3, thereby influencing myogenesis in ruminants and highlights it may as potential molecular targets for enhancing meat production in livestock and poultry industries.

Impact of STAT5A-CNVs on growth traits in Chinese beef cattle breeds.

CNVs, which are a type of structural variation, make a substantial impact on diverse characteristics in multiple species. Q-PCR and data association analysis were used for STAT5A gene copy in this study. This study aimed to investigate the copy number variation (CNV) of the STAT5A gene in seven Chinese cattle breeds, namely Qinchuan cattle, Xianan cattle, Yunling cattle, Ji'an cattle, Jiaxian Red cattle, Qaidam cattle, and Guyuan yellow cattle. Blood samples were collected for CNV typing, and the correlation between CNV type and growth traits was analyzed using SPSS 23.0 software and ANOVA. The findings revealed variations in the distribution of different copy number types among the different cattle breeds. Furthermore, association analysis demonstrated a positive impact of CNV in the STAT5A gene on cattle growth: in the JX, individuals with duplication types exhibited superior performance in terms of rump length (P < 0.05). Conversely, normal GY cattle demonstrated better body height and abdomen circumference (P < 0.05), while QD cattle exhibited a significant correlation between weight and body length with normal individuals (P < 0.05). Moreover, QC bovine duplication individuals outperformed other types, with copy number variation significantly associated with chest depth, chest width, and body length (P < 0.05). The results validate the correlation between copy number variation (CNV) of the STAT5A gene and growth characteristics in five different cattle breeds, providing a reliable benchmark for the purpose of cattle breeding.

Identification and Functional Analysis of Transcriptome Profiles, Long Non-Coding RNAs, Single-Nucleotide Polymorphisms, and Alternative Splicing from the Oocyte to the Preimplantation Stage of Sheep by Single-Cell RNA Sequencing.

Numerous dynamic and complicated processes characterize development from the oocyte to the embryo. However, given the importance of functional transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms, and alternative splicing during embryonic development, the effect that these features have on the blastomeres of 2-, 4-, 8-, 16-cell, and morula stages of development has not been studied. Here, we carried out experiments to identify and functionally analyze the transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms (SNPs), and alternative splicing (AS) of cells from sheep from the oocyte to the blastocyst developmental stages. We found between the oocyte and zygote groups significantly down-regulated genes and the second-largest change in gene expression occurred between the 8- and 16-cell stages. We used various methods to construct a profile to characterize cellular and molecular features and systematically analyze the related GO and KEGG profile of cells of all stages from the oocyte to the blastocyst. This large-scale, single-cell atlas provides key cellular information and will likely assist clinical studies in improving preimplantation genetic diagnosis.

Copy number variation of the ZNF679 gene in cattle and its association analysis with growth traits.

Copy number variation (CNV) is an important member of genetic structural variation that exists widely in animal genomes and is between 50 bp and several Mb in length and widely used in research's of animal genetics and breeding. ZNF679 is an important transcription factor, which has been found association with diseases in the human genome many times. This gene has also been found to be associated with cattle growth traits in previous re-sequencing studies. We tested the CNVs of the ZNF679 gene in 809 individuals from 7 Chinese cattle breeds and tested the association between the CNVs and growth traits in 552 individuals from 5 breeds. The results demonstrated the correlation the correlation between the CNVs of the ZNF679 gene and some Chinese cattle (QC cattle and XN cattle) growth traits. To sum up, this study indicated that ZNF679-CNVs can be used as a candidate gene for molecular genetic marker-assisted selection breeding for cattle growth traits to contribute to the development of genetic improvement of Chinese cattle.

Genetic diversity and signatures of selection in BoHuai goat revealed by whole-genome sequencing.

BACKGROUND: Cross breeding is an important way to improve livestock performance. As an important livestock and poultry resource in Henan Province of China, Bohuai goat was formed by crossing Boer goat and Huai goat. After more than 20 years of breeding, BoHuai goats showed many advantages, such as fast growth, good reproductive performance, and high meat yield. In order to better develop and protect Bohuai goats, we sequenced the whole genomes of 30 BoHuai goats and 5 Huai goats to analyze the genetic diversity, population structure and genomic regions under selection of BoHuai goat. Furthermore, we used 126 published genomes of world-wide goat to characterize the genomic variation of BoHuai goat. RESULTS: The results showed that the nucleotide diversity of BoHuai goats was lower and the degree of linkage imbalance was higher than that of other breeds. The analysis of population structure showed that BoHuai goats have obvious differences from other goat breeds. In addition, the BoHuai goat is more closely related to the Boer goat than the Huai goat and is highly similar to the Boer goat. Group by selection signal in the BoHuai goat study, we found that one region on chromosome 7 shows a very strong selection signal, which suggests that it could well be the segment region under the intense artificial selection results. Through selective sweeps, we detected some genes related to important traits such as lipid metabolism (LDLR, STAR, ANGPTL8), fertility (STAR), and disease resistance (CD274, DHPS, PDCD1LG2). CONCLUSION: In this paper, we elucidated the genomic variation, ancestry composition, and selective signals related to important economic traits in BoHuai goats. Our studies on the genome of BoHuai goats will not only help to understand the characteristics of the crossbred but also provide a basis for the improvement of cross-breeding programs.

Copy number variation of GAL3ST1 gene is associated with growth traits of Chinese cattle.

Copy number variation (CNV) is a type of genomic structural variation, and the research on it has flourished in recent years. According to the high-throughput sequencing data, we found that the copy number variation region of the GAL3ST1 gene was correlated with the growth traits of bovine. It is significant that we study the CNV of GAL3ST1 gene and process the association analysis between results of Q-PCR and growth traits of Chinese cattle. In this research, SPSS software was used to detect the distribution of GAL3ST1 gene copy number in four cattle breeds and the correlation of growth traits was analyzed. Correlation analysis showed that GAL3ST1 CNV had positive effects on some growth traits of bovine (p < 0.05). In addition, the study detects the expression of GAL3ST1 gene in different tissues of Xia'nan cattles on mRNA level. The result showed that GAL3ST1 gene has different expression conditions in different tissues, results showed that the expression level was high in intestine and low in liver tissue. In a word, we speculated that the GAL3ST1 gene can be used as a molecular marker and this study confirmed that the CNV of it can provide theoretical basis for molecular breeding of cattle in China.

Association between copy number variation of SERPINA3-1 gene and growth traits in Chinese cattle.

Serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3 (SERPINA3) belongs to the serine protease inhibitor family A subtype, and contains 8 genes from SERPINA3-1 to SERPINA3-8. Although the regulatory effects of these 8 genes have been revealed one by one in recent years, the related effects of SERPINA3-1 gene on cattle growth is still unclear. This study used quantitative Real time PCR (qPCR) to detect the type of copy number variation (CNV) of SERPINA3-1 gene in a total of 542 Chinese cattle, and expression of SERPINA3-1 gene in different tissues of Qinchuan cattles (adult) on mRNA level. Then association analysis was conducted between the detection results and cattle growth traits. The results showed that the Duplication type in SERPINA3-1 gene performed better on the growth traits and the CNV was significantly correlated with multiple growth traits (p < 0.05). In addition, SERPINA3-1 gene has different expression conditions in different tissues, results showed that SERPINA3-1 gene has a low expression in muscle. In conclusion, we speculate that the SERPINA3-1 gene can be used as a molecular marker and the result of this study could be a basic material for candidate functional genes for beef cattle growth and development.

In order to detect the gene expression diversification of the SERPINA3-1 gene, blood samples were collected from five Chinese cattle breeds, we detected related signal and made an associated analyze with cattle growth traits. We determined the copy number variation distribution of the SERPINA3-1 gene in cattle populations and found that the SERPINA3-1 gene has a certain promoting effect on the growth and development of Chinese cattle. For example, Pinan cattle with Duplication type copy number have a better performance on growth traits. This study has enriched the candidate genes of Chinese cattle molecular breeding and provided basic data for Chinese cattle breeding.

CNV analysis of VAMP7 gene reveals variation associated with growth traits in Chinese cattle.

Copy number variant (CNV), a common genetic polymorphism, is closely related to the phenotypic variation traits of organisms. Vesicle-associated membrane protein 7 gene (VAMP7) codes a protein, which is a member of the SNARE proteins family and plays an important role in the process of intracellular vesicle transport. In this study, a total of four cattle breeds (Yunling cattle, Xianan cattle, Pinan cattle, Jiaxian red cattle) were used to investigate the copy numbers, and we found an association relationship between CNV of VAMP7 gene and growth traits of cattle by SPSS 20.0 software. The results showed that the CNV type of VAMP7 gene in four cattle breeds had the same distribution, Duplication type occupies a dominant position among the four varieties. In Yunling cattle, the Duplication type of VAMP7 is significantly related to the height at the hip cross (p < 0.05), Individuals with Duplication type commonly have less performance on growth and development, which indicates that the Duplication type of the VAMP7 gene may have a negative effect on cattle growth. Individuals with the other two CNV types may become the breeding direction of the VAMP7 gene. This study provided a new perspective and basic material for the molecular genetics of the CNV of the VAMP7 gene, and also promoted the breeding progress of Chinese local cattle.

Association between the copy number variation of CCSER1 gene and growth traits in Chinese Capra hircus (goat) populations.

Recently, Coiled-coil serine-rich protein 1 (CCSER1) gene is reported to be related to economic traits in livestock, and become a hotspot. In our study, we detected CCSER1 gene CNV in 693 goats from six breeds (GZB, GZW, AN, BH, HG, TH) by quantitative real-time PCR (qPCR) and the association analysis between the types of CNV and growth traits. Then, CCSER1 gene expression pattern was discovered in seven tissues from NB goats. Our results showed that the CCSER1 gene copy numbers were distributed differently in the aforementioned six breeds. The type of CCSER1 gene CNV was significantly associated with body weight and heart girth traits in GZW goat, in which individuals with deletion type were dominant in body weight trait (P < 0.05), while the normal type individuals were more advantageous in heart girth trait (P < 0.01); and there was a significant association with heart girth in TH goat (P < 0.05), which normal type was the dominant one. The expression profile revealed that CCSER1 gene has the highest level in the lung, followed by the small intestine and heart. In conclusion, our result is dedicated to an in-depth study of the novel CCSER1 gene CNV site and to provide essential information for Chinese goats molecular selective breeding in the future.

High-density genotyping reveals candidate genomic regions for chicken body size in breeds of Asian origin.

Body size is one of the main selection indices in chicken breeding. Although often investigated, knowledge of the underlying genetic mechanisms is incomplete. The aim of the current study was to identify genomic regions associated with body size differences between Asian Game and Asian Bantam type chickens. In this study, 94 and 107 chickens from 4 Asian Game and 5 Asian Bantam type breeds, respectively, were genotyped using the chicken 580K single nucleotide polymorphism (SNP) array. A genome-wide association study (GWAS) and principal component analyses (PCA) were performed to identify genomic regions associated with body size related-traits such as wing length, shank length, shank thickness, keel length, and body weight. Hierarchical clustering of genotype data showed a clear genetic difference between the investigated Asian Game and Asian Bantam chicken types. GWAS identified 16 genomic regions associated with wing length (2, FDR ≤ 0.018), shank thickness (6, FDR ≤ 0.008), keel length (5, FDR ≤ 0.023), and body weight (3, FDR ≤ 0.041). PCA showed that the first principal component (PC1) separated the 2 chicken types and significantly correlated with the measured body size related-traits (P ≤ 2.24e-40). SNPs contributing significantly to PC1 were subjected to a more detailed investigation. This analysis identified 11 regions potentially associated with differences in body size related-traits. A region on chromosome 4 (GGA4) (17.3-21.3 Mb) was detected in both analyses GWAS and PCA. This region harbors 60 genes. Among them are myotubularin 1 (MTM1) and secreted frizzled-related protein 2 (SFPR2) which can be considered as potential candidate genes for body size related-traits. Our results clearly show that the investigated Asian Game type chicken breeds are genetically different from the Asian Bantam breeds. A region on GGA4 between 17.3 and 21.3 Mb was identified which contributes to the phenotypic difference, though further validation of candidate genes is necessary.

Bta-miR-200b promotes endometrial epithelial cell apoptosis by targeting MYB in cattle.

Embryonic mortality is considered to be one of the main reasons for reduced conception rates in the cattle industry. Insufficient endometrial receptivity is a major factor resulting in embryo implantation failure and losses. Apoptosis of endometrial epithelial cells is an important process during establishment of uterine receptivity and embryo implantation. The aim of this study was to explore the role of bta-miR-200b on endometrial epithelial cell apoptosis in cattle. Overexpression of bta-miR-200b upregulated the expression of proapoptotic gene BCL2 associated X, apoptosis regulator (BAX) and endometrial receptivity marker gene osteopontin (OPN) at mRNA and protein level in bovine endometrial epithelial cells. Moreover, overexpression of bta-miR-200b was able to inhibit proliferation and promote apoptosis of bovine endometrial epithelial cells by arresting the cell cycle at the G0/G1 phase. MYB Proto-Oncogene (MYB) was verified to be a target of bta-miR-200b in bovine endometrial epithelial cells using dual-luciferase reporter assay. Transfection of bta-miR-200b mimics decreased the mRNA and protein expression of MYB. Overexpression of MYB decreased the effect of bta-miR-200b on apoptosis of bovine endometrial epithelial cells. Our findings suggest that bta-miR-200b can affect the apoptosis of endometrial epithelial cells in cattle by targeting the MYB gene.

The relationship between MUC19 copy number variation and growth traits of Chinese cattle.

Copy number variation (CNV), as one of the important variations in the biological genome, refers to the deletion and duplication of genomic segments between 1 kb and 50 kb caused by genomic rearrangements. Currently, many copy number variations have been found to be significantly associated with important economic traits such as growth, development and reproduction of cattle. However, the study of MUC19 gene has not been reported. In this study, we detected an appropriate correlation between MUC19 gene and growth traits of Chinese cattle. We detected the distribution of MUC19-CNV across Qinchuan cattle (QC), Pinan cattle (PN), Xianan cattle (XN), Yunling cattle (YL), Guyuan cattle (GY), Jiaxian cattle (JX), and analyzed the association between types of MUC19-CNV and growth traits through SPSS20.0 software and method of ANOVA. The results showed that various types of CNV were present in each breed of cattle, but there were discrepancies in the distribution of copy number variant types. The Association analysis result showed that CNV of MUC19 gene showed a postive effect in cattle growth traits: the copy number of MUC19 was significantly correlated with hip width of PN cattle (P < 0.01), height at hip cross and withers height of PN cattle (P < 0.05), hip width and body length of JX cattle (P < 0.05), Huckle bone width of YL cattle (P < 0.05).

Copy number variations of LRRFIP1 gene and the relationship with growth traits in four Chinese sheep.

CNVs (copy number variations) are the novel and common structural variants that could cover entire genes found in plenty of species. CNV may influence economically important traits or disease susceptibility in livestock species. Based on the whole genome resequencing results, we found that there was a CNV region on the LRRFIP1 gene. Then we used qPCR to detect the copy number type distribution in 553 individuals of four sheep breeds and used them for association analysis. The results showed that: (1) In the CKS, the sheep with gain type had a larger heart girth (p = 0.049). (2) For the HS, the CNV could significantly affect rump breadth (p = 0.037) and circumference of the cannon (p = 0.035). And the sheep with median type showed better performance in rump breadth and circumference of cannon. (3) At the STHS, the CNV was significantly correlated with chest width (p = 0.000) with loss type as the most favorable CNV type. Meanwhile, the best was the loss type, and the lowest was the median. (4) This CNV had no significant effect on the LTHS. So, the CNV of LRRFIP1 was related to the growth traits of these three sheep breeds and it may be used as a molecular marker for sheep.

Copy number variation of EIF4A2 loci related to phenotypic traits in Chinese cattle.

BACKGROUND: Generally, copy number variation (CNV) is a large-scale structural variation between 50 bp and 1 kb of the genome. It can affect gene expression and is an important reason for genetic diversity and phenotypic trait diversity. Studies have shown that the eukaryotic translation initiation factor 4A2 (EIF4A2) gene plays an essential role in muscle development in both humans and pigs. However, the influence of bovine EIF4A2's copy number change on phenotypic traits has not been reported. OBJECTIVES: To detect the tissue expression profile of the EIF4A2 gene in adult cattle and individuals' CNV type of variation. Then, we explored the correlation between EIF4A2-CNV and growth traits in Chinese cattle breeds. METHODS: Real-time fluorescent quantitative reverse transcription PCR (qRT-qPCR) was used to determine the expression profile of the EIF4A2 gene. Real-time fluorescent quantitative PCR (qPCR) was used to detect the CNV type of bovine populations. Then, SPSS 26.0 was used for association analysis. RESULTS: In this study, a total of 513 individuals in four cattle breeds (Qinchuan cattle [QC], Yunling cattle [YL], Pinan cattle [PN] and Jiaxian cattle [JX]) were detected for EIF4A2 gene's CNV. The results showed that EIF4A2-CNV has an essential impact on hip width (HW) and rump length (RL) in QC, heart girth (HG), chest depth (CD) and RL in YL and HW in PN. However, it had no significant effect on JX. CONCLUSIONS: The above results suggest that EIF4A2 gene's CNV can be used as a molecular marker for cattle breeding, which is helpful to accelerate the breeding of superior beef cattle breeds.

Assessing genomic diversity and signatures of selection in Pinan cattle using whole-genome sequencing data.

BACKGROUND: Crossbreeding is an important way to improve production beef cattle performance. Pinan cattle is a new hybrid cattle obtained from crossing Piedmontese bulls with Nanyang cows. After more than 30 years of cross-breeding, Pinan cattle show a variety of excellent characteristics, including fast growth, early onset of puberty, and good meat quality. In this study, we analyzed the genetic diversity, population structure, and genomic region under the selection of Pinan cattle based on whole-genome sequencing data of 30 Pinan cattle and 169 published cattle genomic data worldwide.  RESULTS: Estimating ancestry composition analysis showed that the composition proportions for our Pinan cattle were mainly Piedmontese and a small amount of Nanyang cattle. The analyses of nucleotide diversity and linkage disequilibrium decay indicated that the genomic diversity of Pinan cattle was higher than that of European cattle and lower than that of Chinese indigenous cattle. De-correlated composite of multiple selection signals, which combines four different statistics including θπ, CLR, FST, and XP-EHH, was computed to detect the signatures of selection in the Pinan cattle genome. A total of 83 genes were identified, affecting many economically important traits. Functional annotation revealed that these selected genes were related to immune (BOLA-DQA2, BOLA-DQB, LSM14A, SEC13, and NAALADL2), growth traits (CYP4A11, RPL26, and MYH10), embryo development (REV3L, NT5E, CDX2, KDM6B, and ADAMTS9), hornless traits (C1H21orf62), and climate adaptation (ANTXR2). CONCLUSION: In this paper, we elucidated the genomic characteristics, ancestry composition, and selective signals related to important economic traits in Pinan cattle. These results will provide the basis for further genetic improvement of Pinan cattle and reference for other hybrid cattle related studies.

Copy number variation of the CCDC39 gene is associated with growth traits in Chinese cattle.

BACKGROUND: Copy number variation (CNV) has become an essential part of genetic structural variation. Coiled-coil domain containing 39 (CCDC39) is a gene that related to the growth and development of organs and tissues. It is identified that it has a CNV region by animal genome resequencing. OBJECTIVE: In this study, we detected the phenotypic traits and different distributions of CCDC39 gene copy numbers in five Chinese cattle breeds (Qinchuan (QC) cattle, Yunling (YL) cattle, Xianan (XN) cattle, Pinan (PN) cattle and Jiaxian (JX) cattle). METHODS: Five hundred and six cattle were randomly selected for CNV distribution detection. Blood samples were taken and genomic DNA was extracted. Different tissues were obtained from adult (n = 3) XN cattle, including heart, liver, kidney, skeletal muscle and lung. The genome qPCR experiment was performed with SYBR Green in triplicate. CDNA qPCR was used to detect the expression level of CCDC39 in different tissues and varieties. Using SPSS v20.0 software, the relationship between CCDC39 CNV and the growth traits of PN, XN, QC, NY and YL cattle breeds was analyzed by one-way analysis of variance (ANOVA). RESULTS: The results showed that the expression of CCDC39 in lung was higher than that in other tissues. The expression in liver and kidney was similar, but the expression in heart and muscle was less. It can be seen that the duplication type of QC cattle CCDC39 CNV is higher than the deletion or normal in the height at hip cross. The normal type of PN cattle in body length and hip width was better than duplication and deletion (p < 0.05). In XN cattle, the deletion type of CNV had superior growth characteristics in heart girth and cannon bone circumference compared with the duplication type and the normal type (p < 0.05). CONCLUSION: The study revealed a significant association between CNV of CCDC39 gene and growth traits in different Chinese cattle breeds.

The copy number variation of DMBT1 gene effects body traits in two Chinese cattle breeds.

Copy number variations (CNVs) belong to mutations in the genome level with loci in the region of genic or intergenic. It is through different effects (such as position effect and dose effect) that influence complex traits and diseases. Deleted in Malignant Brain Tumors 1 (DMBT1) gene is a member of the scavenger receptor cysteine-rich super family. In cattle, this gene has been associated with the susceptibility to bovine tuberculosis. In this study, a new CNV was found in DMBT1 gene of Chinese cattle breeds and tested in two different Chinese cattle breeds (Jiaxian red and Pinan) for frequency distribution analysis. Besides, the body size data such as body length, body height, chest girth, chest width, rump length, and rump girth for Jiaxian (JX) and Pinan (PN) cattle were collected and associated with the newly identified CNV. The CNV was significantly associated with the body length and chest girth of JX cattle, and the rump length of PN cattle (P < 0.05). Furthermore, the expression profile of the DMBT1 gene was tested in calves' tissues and the myoblasts differentiation. It was found that the DMBT1 gene expression was high in tuberculosis susceptible tissues (liver and lungs) at the calf stage and high in myoblast early differentiation. These tests were done using the qPCR method. As the result, the CNV of DMBT1 gene could be used as a candidate marker for bovine growth and health in marker-assisted selection (MAS) breeding.