Reproduction Traits In Cattle Research Articles

Identification of 19-bp indel of the Pleomorphic Adenoma Gene 1 in Bali cattle population

Pleomorphic adenoma gene 1 (PLAG1) is a zinc finger transcription factor gene located on bovine chromosome 14 (BTA14) affecting body size and reproduction traits in cattle. The objective of this study was to identify 19-bp indel of the PLAG1 gene in Bali cattle population. A total of 96 blood samples of Bali Cattle were collected from Balai Pembibitan Ternak Unggul dan Hijauan Pakan Ternak (BPTU-HPT) Denpasar. Genomic DNA was extracted from blood samples and used to detect 19-bp indel of the PLAG1 gene using following primer pair 5’-TCCGAACAACAGGTGAGGGAGAAAT-3’ and 5’-CCACTTCAGG-GGTGCTCTAGGTTTG-3’. The polymerase chain reaction (PCR) products using DNA pool samples were sequenced to validate the PCR product and to find out novel polymorphism in Bali cattle population. The result showed that there was no variation found in Bali cattle population based on 19-bp indel of the PLAG1 gene, which is indicated by 123 bp DNA band. However, sequence analysis of the PLAG1 gene resulted in a novel single nucleotide polymorphism (SNP) at nucleotide number 32235 of the PLAG1 gene that changed guanine (G) to adenine (A). This novel SNP could be furthermore genotyped and it might be a potential candidate marker for body size and reproduction traits in Bali cattle.

160 Studies of Sperm DNA Methylation Variations and Their Potential Regulations on Production and Reproduction Traits in Cattle and Pigs

Abstract Identification of inter-individual variations of sperm DNA methylation is very essential for elucidating phenotypic variation of reproduction and production traits. We had generated 28 sperm whole genome sequencing (WGBS) data from healthy individuals. We detected 46 variably methylated regions (VMRs) significantly (P < 5.77 × 10−5) associated with reproduction traits. These significant VMRs were also co-localized (±10 kb) with genes related to sperm motility and reproduction, including ZFP36L1, CRISP2 and HGF. To further identify epigenomic markers associated with reproduction and production traits, we generated WGBS dada for a specific pair of monozygotic twin artificial insemination Holstein bulls with moderately different sperm qualities (Bull1 > Bull2). We found 528 differentially methylated regions between the twin bulls, which spanned or overlapped with 309 differentially methylated genes (DMG). These DMG were particularly associated with reproduction, embryo development and the nervous system. To further obtain DNA methylation markers involved in the diversity of porcine reproduction and production traits due to long-term artificial selection, we profiled sperm DNA methylation of three commercial pig breeds--Duroc, Landrace and Large White. we found the hypomethylated regions (HMRs) were highly conserved among pig breeds, while 1040–1666 breed-specific HMRs were identified and associated with the QTLs of embryonic developmental and phenotypic changes. By integrating reduced representation bisulfite sequencing public data of pig testis, we further defined 1743 conservative HMRs between sperm and testis, which may play a role in spermatogenesis process. Overall, our studies demonstrated associations of sperm DNA methylation with bovine and porcine production and reproduction traits, highlighting the potential of epigenomic information in genomic improvement programs for livestock. (*: yuying@cau.edu.cn)

Association analysis of novel polymorphisms in 2', 5'-oligoadenylate synthetase gene with reproductive traits in indigenous and cross-bred cattle of Indian Origin.

2', 5'-Oligoadenylate synthetases (OAS) are important components of an interferon-mediated antiviral pathway. No polymorphisms in exonic regions of bovineOAS1gene have been identified and associated with reproduction traits. The objective of the study was to detect and evaluate the effects of mutations in exonic region of bovine OAS1 gene with reproduction traits in cattle. DNA samples collected from 250 individual cows of two Indian dairy breeds (Sahiwal and Frieswal) of cattle were used in the study. The genetic variants of the OAS1 gene were identified with polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequence analysis using seven set of primer pairs. The PCR-SSCP analysis revealed polymorphism in the fragments comprising of exon 2, exon 5 and first fragment of exon 6 while the fragments of exons 1, 3, 4 and second fragment of exon 6 were monomorphic in Sahiwal and Frieswal cattle. The mutations in the amplified region comprising of exon 2 were found to have significant association with age at first breeding and calving, service period, dry period and pregnancy rate. Significant associations were found between SNPs in the exon 5 and service and dry periods of the animal, whereas the genetic variants in the first fragment of the exon 6 showed significant association with age at first breeding and calving. To our knowledge, this study demonstrated for the first time that the polymorphisms in OAS1 gene were associated with reproductive traits and it can be chosen as a candidate gene for improvement of reproductive performance of cattle.

Promoter variants of OAS1 gene are associated with reproductive performance and incidence of normal calving in cattle

2′,5′-oligoadenylate synthetase (OAS) are important components of an interferon-mediated antiviral pathway. But no polymorphisms have yet been identified and associated with reproduction and reproduction traits in the bovine OAS1 gene. The objective of this study was to detect and evaluate the effects of mutations in the promoter region of bovine OAS1 gene with production and reproduction traits in cattle. Two single nuclear polymorphisms were identified, including A to T transversion (rs715937117:A>T) and A to G transition (rs480985443:A>G) and subsequently genotyped in Sahiwal and Frieswal populations. Three haplotypes were constructed including H1 (A-A), H2 (T-A) and H3 (T-G), among them H2 was the most abundant in the Sahiwal (0.677) and Frieswal (0.838) population. The analysis revealed that genotypes of promoter region had significant effect (P ≤ 0.05) on age at first breeding, age at first calving, service period and pregnancy rate. The animals with H1H2 diplotype had higher age at first breeding and age at first calving compared to H2H2 genotyped animals. Further logistic regression analysis also revealed that the probability of normal calving was found more in H2H2 diplotype, as the odds ratios of H1H2 and H2H3 in comparison to H2H2 were 0.516 and 0.486, respectively. H2H2 diplotyped animals also exhibited higher milk production also in terms of total milk yield, 300 day milk yield and peak yield. These results outlined that the bovine OAS1 gene can be used as candidate genes for simultaneous improvement of both production and reproductive performance of cattle.

Meta-assembly of genomic regions and variants associated with female reproductive efficiency in cattle

Decline in fertility in last few decades, especially in high milk producing dairy cows, is a major concern in many countries. Fertility is a compound trait of many events leading up to successful calving and subsequent lactation. Fertility traits in cattle have relatively low heritability. Recently a number of studies have searched for genomic regions and variants associated with various reproduction traits in cattle. We constructed a systematic meta-assembly of 35 QTL studies and separately for 23 genome-wide association studies (GWAS) related to female fertility in cattle representing over 101,000 genotyped individuals. We separately compiled and discussed additional candidate gene studies, fine-mapping studies, selection signatures and other novel potential biomarkers associated with female reproduction in cattle. Despite individual studies being low powered, inherent low heritability of fertility traits and low success of genomic selection for fertility traits, a substantial number of strong signals, causative mutations and biomarkers for fertility have been identified throughout the genome. A number of embryonic lethal mutations and haplotypes have been identified using novel approaches. These markers can be used for population screening, genomic-assisted mating plans, and can be incorporated in a marker assisted framework for genetic improvement in the fertility. The studies investigating the role of epigenomic markers are in the early stages, and may provide important biomarkers in near future. Novel approaches linking metabolomic and epigenetic markers, and high resolution genome content to high quality phenotypes will assist in our understanding of the genetic architecture of complex traits underlying fertility in cattle.

Genetic variants affecting meat and milk production traits appear to have effects on reproduction traits in cattle

Polymorphisms located in the genes ABCG2, DGAT1, LEP, PRLR, RORC, CAPN1 and CAST previously have been associated with milk or meat production traits. In this study, these polymorphisms were examined for significant effects on reproductive traits [age at puberty (AGECL), post-partum anoestrus interval (PPAI) and the ability ovulate prior to weaning (PW)] and on a panel of correlated traits such as weight, growth and serum concentration of insulin-like growth factor I. The effects of the polymorphisms were examined in two samples of tropically adapted beef cattle: Brahman (N = 932) and Tropical Composites (N = 1097). A polymorphism in the gene DGAT1 was associated with age at puberty in the combined sample (P = 0.042), and two polymorphisms in CAPN1 were associated with PPAI (P = 0.033) and with the ability ovulate PW (P = 0.017). The favourable allele for reproductive traits was not always the favourable allele associated with production traits. The effects of these polymorphisms on reproductive traits were small compared to their effects on the traits for which they were originally discovered.

Comparison of DNA Polymorphism of Bovine Pituitary-Specific Transcription Factor and Leptin Gene Between Iranian Bos indicus and Bos taurus Cattle Using PCR-RFLP

Variations at DNA level contribute to the genetic characterization of livestock populations and this may help to identify possible hybridization events as well as past evolutionary trends. The leptin and Pit-1 are attractive candidate genes for production and reproduction traits in cattle. A total of 247 animals from four breeds from two species of Iranian cattle populations in include Bos taurus (Sarabi, Golpayegani) and Bos indicus (Sistani, Taleshi) were genotyped for the Pit-1 Hinfl and leptin Sau3AI polymorphisms by the Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP). The genotype and gene frequencies for each group were determined and shown to be quite variable among the breeds. The allele B for the leptin gene and allele A for the Pit-1 gene were investigated high frequency in Bos indicus. Candidate gene approach may be a useful method to measure of genetic distance for cross breeding program between taurin and indicine cattle.

DNA Polymorphism of Bovine Pituitary-Specific Transcription Factor and Leptin Gene Between Iranian <i>Bos indicus</i> and <i>Bos taurus</i> Cattle

Problem statement: Variations at DNA level contribute to the genetic characterization of livestock populations and this may help to identify possible hybridization events as well as past evolutionary trends. Approach: The leptin and Pit-1 are attractive candidate genes for production and reproduction traits in cattle. A total of 247 Animals from four breeds from two species of Iranian cattle populations in include Bos taurus (Sarabi, Golpayegani) and Bos indicus (Sistani, Taleshi) were genotyped for the Pit-1 HinfI and leptin Sau3AI polymorphisms by the Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP). Results: The genotype and gene frequencies for each group were determined and shown to be quite variable among the breeds. The allele B for the leptin gene and allele A for the Pit-1 gene were investigated high frequency in Bos indicus. Conclusion: Present result supported the previously proposed long evolutionary separation of these cattle subrace. Candidate gene approach may be a useful method to measure of genetic distance for cross breeding program between taurin and indicine cattle.

Genetic polymorphisms of leptin and leptin receptor genes in relation with production and reproduction traits in cattle.

Leptin and leptin receptor genes are considered as production traits markers in dairy or beef cattle. The aim of this study was to verify the associations of polymorphisms in bovine LEP and LEPR genes with production and reproduction traits in Slovak Spotted and Pinzgau cows. Long-life production was evaluated: milk, protein, and fat yield and reproduction traits: age at first calving, calving interval, days open, and insemination interval. In total, 296 blood samples of Slovak Spotted and 85 hair roots samples of Pinzgau cows were analyzed. In order to detect LEP/Sau3AI (BTA 4, inron 2) and LEPR/T945M (BTA 3, exon 20) genotypes PCR-RFLP method was used. In Slovak Spotted and Pinzgau cows allele frequencies were 0.838/0.162 and 0.694/0.306 for A and B LEP variants, and 0.954/0.046 and 0.912/0.088 for C and T LEPR variants, respectively. For testing the associations between SNPs LEP/Sau3AI and LEPR/T945M and evaluated traits, the General Linear Model procedure in SAS Software was used. Statistical analysis showed that SNP LEP/Sau3AI significantly affected milk, protein and fat yield (P<0.05), and age at first calving (P<0.01) in analyzed population of cows. Statistically, SNP LEPR/T945M affected significantly calving interval (P<0.01) only. Results of our study suggest that especially leptin is a candidate gene, which influences mainly milk production traits and might be implemented in breeding strategies to improve the production performance of both analyzed cattle breeds.