Chinese Holstein Cattle Research Articles

Chinese Holstein Cattle Shows a Genetic Contribution from Native Asian Cattle Breeds: A Study of Shared Haplotypes and Demographic History

The Chinese Holstein cattle breed, an introduced breed in China, has been crossbred with native cattle breeds. We hypothesised that the Chinese Holstein local population in Beijing share haplotypes with native Asian cattle breeds, the result of a sudden population expansion in the recent past. We also hypothesised that crossbreeding and population expansion left traces that shaped the genetic makeup of the breed. Evaluation of this was performed by mitochondrial DNA (mtDNA) sequence analysis of Chinese Holstein cattle from Beijing (n = 41) and a comparison of them with the published mtDNA sequences (n = 293) of 14 Asian breeds with an emphasis on Chinese native cattle breeds. Three shared common haplotypes between Chinese Holstein cattle and native Asian cattle were found. Moreover, a high level of haplotype diversity in Chinese Holstein cattle (h = 0.9557) and low nucleotide diversity (π = 0.0052) was found, indicating a past population bottleneck followed by rapid population growth. These findings are supported by the significantly negative deviation of Tajima's D (-1.82085), the star-like pattern of dominant haplotypes and the pairwise

Mannose-binding lectin 1 haplotypes influence serum MBL-A concentration, complement activity, and milk production traits in Chinese Holstein cattle

Mannose-binding lectin (MBL) is a member of the collectin protein family that binds a broad range of microorganisms and activates the lectin-complement pathway of innate immunity. MBL deficiency is associated with an increased risk for various infections and arises from five polymorphisms in the promoter and first exon of the MBL gene in humans. In this study, three novel single-nucleotide polymorphisms (SNPs) in the promoter region and two previously reported SNPs in exon 2 of the MBL1 gene were detected using PCR single-strand conformation polymorphism, restriction fragment length polymorphism, and DNA sequencing in 537 cattle from three Chinese breeds. Analysis of the genotypes and haplotypes was used to investigate the polymorphisms and their possible implications, especially their association with serum MBL-A levels, complement activity (CH50 and ACH50), and milk production traits was investigated. The g.2651G > A SNP in exon 2 affected the serum MBL-A concentrations and the serum CH50 values, whereas the g.-1330G > A SNP significantly affected CH50 and the somatic cell scores (SCSs). Statistical analysis revealed that cows with the ATGGC/ACAAC combined genotype and those with the AAGGT/ACGGT combined genotype exhibited the lowest and highest SCSs, respectively. Serum antibacterial activities were also conducted to verify the effect of the SNPs on resistance to mastitis pathogens. Results of real-time PCR showed that the liver of cows with clinical mastitis exhibited a higher MBL1 expression compared with healthy ones (P < 0.05). Findings of this study indicate that the MBL1 gene possibly contributes to bacterial infection resistance and can be used as a molecular marker of milk production traits to control mastitis.

English

Peroxisome proliferators-activated receptor gamma (PPARG) is an important regulator in the regulation of adipose differentiation and development. The mutations of the PPARG in human had been shown to be associated with type II diabetes, fat distribution and body weight. The functional importance of the PPARG makes it a good candidate to search molecular markers in marker assistant selection in cattle breeding. All the mRNA region of the&nbsp;PPARG&nbsp;gene within 760 individuals of four Chinese cattle breeds was scanned and four single nucleotide polymorphisms (SNPs) (-110G&gt;C, -27C&gt;T, +20A&gt;G, +1344G&gt;T) of the&nbsp;PPARG&nbsp;were detected in three Chinese indigenous cattle breeds (Qinchuan, Nangyang and Jiaxian cattle), rather than Chinese Holstein cattle. The mutations -110G&gt;C, -27C&gt;T and +20A&gt;G located in the Exon1 of the&nbsp;PPARG&nbsp;and were under linkage disequilibrium. The individuals with these three mutations had smaller body measurements. This information could help animal scientists to develop genetic markers or biomarkers to assist with beef production. &nbsp; Key words:&nbsp;Peroxisome proliferators-activated receptor gamma (PPARG) gene, polymorphisms, cattle, association analysis.

Association Between Polymorphisms in the SLC27A1 Gene and Milk Production Traits in Chinese Holstein Cattle

We assessed SLC27A1, a candidate gene for milk production traits in Chinese Holstein cattle. DNA was extracted from the blood of 48 top Chinese Holstein Cattle selected according to phenotypic character and mixed into DNA pool for SNP detection. We tested blood samples of these cattle for SNPs in exon 3 and the 3′-flanking region of the SLC27A1 gene by using polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and DNA sequencing. We found 2 polymorphic sites: 112T>C, a synonymous mutation, in exon 3 (SNP1), and 64G>A in the 3′-UTR (SNP2). We also determined the genotypes of 330 Chinese Holstein cattle by using PCR-restriction fragment length polymorphism (RFLP). We found 3 genotypes each at SNP1 (TT, TC, and CC) and SNP2 (GG, GA, and AA). The association among the different genotypes at these 2 sites and milk production traits was analyzed using a least-squares procedure. The results showed that cows with genotype CC had higher milk yields than those with genotype TC (0.01 < p < 0.05). No significant difference was detected among the 3 SNP2 genotypes in terms of milk production traits. Our results provide evidence that the C allele have potential effects on milk yield trait.

Three novel SNPs of the bovine Tf gene in Chinese native cattle and their associations with milk production traits

Transferrin (Tf) is a β-globulin protein that transports iron ions in mammalian cells. It contributes to innate immunity to microbial pathogens, primarily by limiting microbial access to iron. Thus, polymorphisms present in bovine Tf could potentially underlie inherited differences in mastitis resistance and milk production traits. We detected three novel single-nucleotide polymorphisms of the Tf gene in Chinese native cattle by screening for genetic variation of Tf in 751 individuals of three Chinese cattle breeds, namely China Holstein, Luxi Yellow and Bohai Black, using PCR-RFLP and DNA sequencing techniques. The three new SNPs, g.-1748G>A ss250608649, g.13942T>C ss250608650, and g.14037A>G ss250608651, had allele frequencies of 85.9, 86.3 and 92.5%, 64.5, 73.3 and 65.0%, and 67.6, 73.7 and 60.0%, respectively. SNP g.-1748G>A was located in the 5' flanking region of Tf. SNP g.14037A>G was located in intron 8 of Tf. SNP g.13942T>C, located in exon 8 of Tf, was a synonymous mutation (TTA > CTA), encoding a leucine (326 aa) in the Tf protein. Associations of the Tf SNPs with milk traits were also analyzed. Significant (P < 0.05) relationships among the Tf polymorphisms, somatic cell scores (SCS), and milk productive traits were observed. Cows with genotypes TT (g.13942T>C), GG (g.-1748G>A) and AG (g.14037A>G) had a lower SCS and higher protein levels and 305-day milk yield. Nineteen combinations of different haplotypes from the three SNPs were identified in Chinese Holstein cattle. The haplotype combination ATA/GCA, GCA/GCA and GCG/ GTA was dominant in cows with a lower SCS, a higher protein level and a higher 305-day milk yield, respectively. Moreover, the gene expression level of Tf was higher in mastitis-affected mammary tissues than in normal mammary tissues. These results suggest that the Tf gene affects milk production, as well as mastitis-resistance traits, in Chinese Holsteins.

Two Novel SNPs inHSF1Gene Are Associated with Thermal Tolerance Traits in Chinese Holstein Cattle

Heat-shock transcription factors (HSFs) play an important role in regulating heat stress response. The activation of heat-shock protein (HSP) genes is mediated by HSFs, which bind to promoters of HSP genes. In this research, two novel single nucleotide polymorphisms, T909C and G4693T, and their association with thermal tolerance were investigated in 951 Chinese Holstein cattle. Linkage disequilibrium and haplotype construction were analyzed using SHEsis software. Four haplotypes were constructed, and nine haplotype combinations were found. Potassium content in erythrocytes (PCE), decreased rate of milk production (R), rectal temperature (RT), and heat-tolerance coefficient (HTC) were selected for the thermotolerance index. Association analysis showed that thermal tolerance in Chinese Holstein cattle was significantly affected by T909C and G4693T. The PCE of cows with CC or TC genotype was lower than that of TT at the 909 position (p < 0.05). Cows with TT genotype had lower PCE (p < 0.01) and higher HTC (p < 0.05) at the 4693 position. Cows with H2H4 haplotype combination had lower PCE (p < 0.01), R (p < 0.05) and RT (p < 0.05) and higher HTC (p < 0.05) than those with H1H3 haplotype combination. Bioinformatic analysis predicted that the 4693 position was located in the microRNA-binding (bta-miR-484) region. Quantitative reverse transcription-polymerase chain reaction demonstrated that 4693-T mutation caused the disruption of microRNA target binding, resulting in the relief of the transcriptional repression, which, in turn, resulted in increased expression. Thus, the HSF1 gene is useful in dairy cattle thermal tolerant breeding.

Variability of Osteocalcin Status in Chinese Holstein Cattle: Do Phylogeny, Vitamin D or Gene Polymorphisms Matter?

Osteocalcin (OC), a marker of bone turnover, displays patterns in relation to physiological and genetic factors. Here, we present an association study in a population of Chinese Holstein cattle (n = 24) with OC serum concentration as a phenotypic trait. We hypothesised that OC status is associated with phylogeny, vitamin D serum level and single nucleotide polymorphisms (SNPs). Mitochondrial DNA (mtDNA) was used as an unlinked marker to examine phylogeny and linkage to measured phenotypic traits of vitamin D and OC status. Following an association study with OC serum variability as the trait, genotyping of SNPs (n = 27) in OC-related genes was performed. Candidate SNPs were chosen in genes with an emphasis on the vitamin D and vitamin K pathways. Multivariant factor analysis revealed a correlation between vitamin D serum concentration and a SNP in the gene GC (rs43338565), which encodes a vitamin D-binding protein, as well as between a SNP in NFATc1 (rs42038422) and OC concentration. However, univariate analysis revealed that population structure, vitamin D serum levels and SNPs were not significant determinants of OC status in the studied group.

Novel SNPs in HSP70A1A gene and the association of polymorphisms with thermo tolerance traits and tissue specific expression in Chinese Holstein cattle

Heat stress induces heat shock proteins (HSPs) expression and HSP70 family is one of them that have been reported to involve in cellular protection against heat stress. But whether there is any association of genetic variation in the HSP70A1A gene with thermo tolerance is unknown. PCR-SSCP and DNA sequencing were used to detect possible SNPs in HSP70A1A gene in 890 Chinese Holstein cattle. Three fragments were amplified and five novel mutations were found in HSP70A1A gene in Chinese Holstein cattle. G/A mutation was found at nucleotide 1524 in coding region that resulting two genotypes of AA and AB. T/C mutation was found at nucleotide 3494 in 3'-UTR resulting three genotypes of CC, CD and DD. The other three point mutations, G/C at nucleotide 6400, C/T at nucleotide 6600 and G/A at nucleotide 6601 were also found in 3'-UTR resulting six genotypes of EE, EF, FF, EG, FG and GG. Linkage disequilibrium (LD) analysis showed that the nucleotide 6400, 6600 and 6601 were in strong LD (D>0.75). Association analysis indicated that AB, DD and FF genotype were the thermo tolerance genotype. SBYE Green I was used to quantify HSP70A1A mRNA expression in different tissues through quantitative real-time PCR assay. The results of the real-time PCR showed that the expression of HSP70A1A mRNA in the heart was significantly higher than that in the other tissues (P<0.05). We presume that these mutations could be used in marker assisted selection for anti-heat stress cows in our breeding program.

Three novel single-nucleotide polymorphisms of MBL1 gene in Chinese native cattle and their associations with milk performance traits

Mannan-binding lectin (MBL), a pattern recognizing serum protein, participates in the innate immune system of mammals as an opsonin. In humans, single-nucleotide polymorphisms (SNPs) in MBL2 gene were found to cause various innate immune dysfunctions. In the present study, we discovered three single-nucleotide polymorphisms of the MBL1 gene in Chinese native cattle and analyzed their associations with milk traits. By screening the genetic variation of MBL1 in 1053 individuals of three Chinese native cattle breeds including China Holstein, Luxi Yellow and Bohai Black using created restriction site–polymerase chain reaction (CRS–PCR), PCR–restriction fragment length polymorphism (PCR–RFLP) and DNA sequencing techniques, three new SNPs, g.855G>A, g.2651G>A and g.2686T>C, were found to have allele frequencies of 0–12.65%, 24.07–42.39% and 56.95–73.68%, respectively. While SNP g.855G>A is located within intron І, the other two SNPs reside in the exon II region with one mutation being non-synonymous (GTT (Val) > ATT (Ile)) and the other synonymous (GCT (Ala) > GCC (Ala)). Among the 596 Chinese Holstein cattle with at least 3 lactation Dairy Herd Improvement (DHI) records, eight different haplotypes and 19 genotype combinations were detected. Statistical analyses revealed no correlation between either g.855G>A or g.2686T >C and somatic cell score (SCS), however significant association was found between g.2651G >A and SCS, suggesting a possible role of this SNP in the host response against mastitis. Our data also suggested that the combined genotypes of GGC/AAC with the lowest SCS, AAT/AAT with the highest protein content and AGC/AGC with the highest 305-d milk yield were favorable combinations for mastitis resistance and milk production traits. Therefore, GGC/AAC, AAT/AAT and AGC/AGC can be used as possible candidates for marker-assisted selection in the dairy cattle breeding program.

Relationship of Somatic Cell Count with Milk Yield and Composition in Chinese Holstein Population

The objective of this study was to analyze the relationship of somatic cell count (SCC) with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chinese Holstein population. The 10 524 test-day records of 568 Chinese Holstein Cattle were obtained from 2 commercial herds in Xi'an region of China during February 2002 to March 2009. Milk yield, fat percentage, fat and protein yield initially increased and then dropped down with parity, whereas protein percentage decreased and SCC increased. Analysis of variance showed highly significant effects of different subclasses SCC on milk yield and composition ( P < 0.01). Compared with milk yield with SCC ≤ 200 000 cells mL-1, milk yield losses with SCC of 200 000-500 000 cells mL-1, 501 000-1 000 000 cells mL-1, ≥ 1 000 000 cells mL-1 were 0.387, 0.961 and 2.351 kg, respectively. The highly significant negative correlation coefficient between somatic cell score (SCS) and milk and protein yield, milk yield and fat and protein percentage, protein percentage and fat yield were −0.084, −0.037, −0.061, −0.168, and −0.088, respectively (P < 0.01). The highly significant positive correlation coefficients between SCS and fat yield and fat and protein percentage, milk yield and fat and protein yield, fat percentage and protein percentage and fat yield, protein yield and protein percentage and fat yield were 0.041, 0.177, 0.105, 0.771, 0.865, 0.122, 0.568, 0.318, and 0.695, respectively ( P < 0.01). There was no significant relationship between fat percentage and protein yield ( P > 0.05). The results of the present study first time provide the relevant base-line data for assessing milk production at Xi'an region of China.

Novel single nucleotide polymorphisms (SNPs) of the bovine STAT4 gene and their associations with production traits in Chinese Holstein cattle

Signal transducer and activator of transcription 4 (STAT4) belongs to the STATs family which may play important roles in the activation of milk protein genes and the development of mammary glands. Four novel single nucleotide polymorphisms (SNPs) (g.2624A>C ss175327225, g.60330A>G ss175327226, g.63823G>C ss175327227, g.66912C>T ss175327228) of the STAT4 gene were investigated in 966 cattle of three breeds (Chinese holstein, Luxi yellow and Bohai black cattle) in China by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP), PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing methods. The SNP (g.60330A>G ss175327226) could be genotyped into three genotypes (AA, AG and GG) with PCR-RFLP using Msp I and another SNP (g.66912C>T ss175327228) only into two genotypes (CC and TC) by PCR-SSCP. The allelic frequencies of the SNP (g.60330A>G) were different among the three different cattle breeds (P G) markedly affected the 305 d matured equivalency (P T) had no significant relationship with the milk production traits (P > 0.05). Together, the SNP (g.60330A>G) of the STAT4 gene may serve as a molecular marker for the differentiation of various cattle populations and selection of the milk yield and fat content in bovine breeding program.

Kappa Casein Gene Polymorphism and its Impact on Milk Yield and Reproductive Performance Traits of Chinese Holstein Cattle

Kappa Casein Gene Polymorphism and its Impact on Milk Yield and Reproductive Performance Traits of Chinese Holstein Cattle

Validation of 17 Microsatellite Markers for Parentage Verification and Identity Test in Chinese Holstein Cattle

To develop an efficient DNA typing system for Chinese Holstein cattle, 17 microsatellites, which were amplified in four fluorescent multiplex reactions and genotyped by two capillary electrophoresis injections, were evaluated for parentage verification and identity test. These markers were highly polymorphic with a mean of 8.35 alleles per locus and an average expected heterozygosity of 0.711 in 371 individuals. Parentage exclusion probability with only one sampled parent was approximately 0.999. Parentage exclusion probability when another parent's genotype was known was over 0.99999. Overall probability of identity, i.e. the probability that two animals share a common genotype by chance, was 1.52×10 -16 . In a test case of parentage assignment, the 17 loci assigned 31 out of 33 cows to the pedigree sires with 95% confidence, while 2 cows were excluded from the paternity relationship with candidate sires. The results demonstrated the high efficacy of the 17 markers in parentage analysis and individual identification for Chinese Holstein cattle.

Restriction fragment length polymorphism in the exon 2 of the BoLA-DRB3 gene in Chinese Holstein of the south China

The genetic diversity of the exon2 of BoLA-DRB3 (BoLA-DRB3.2) in Chinese Holstein cattle of the south China was investigated by hemi-nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Six, four and eleven RFLP patterns were found after digestion with the restriction enzymes Hae III, Bst YI and Rsa I, respectively. The DNA sequence showed and twenty- five DRB3.2 alleles. GLM model analysis indicated that lactation and calving season have positive correlation with SCC (Somatic Cell Count) (p<0.01), BoLA-DRB3.2*3, *8, *18 and *26 were associated with lower SCC (p<0.01). The present findings concluded that mastitis is a severe hinder of milk production and technology. Therefore, future re-searches should focus on associations of mastitis with BoLA haplotypes rather than single BoLA genes

Preliminary Evidence for Association of Prolactin and Prolactin Receptor Genes with Milk Production Traits in Chinese Holsteins

Hu, X., Lü, A., Chen, H., Gao, X., Xu, H., Zhang, C., Fang, X. and Lei, C. 2009. Preliminary evidence for association of prolactin and prolactin receptor genes with milk production traits in Chinese Holsteins. J. Appl. Anim. Res., 36: 213–217. Genetic polymorphisms of prolactin (PRL) and prolactin receptor (PRLR) genes in Chinese Holstein cattle were detected by PCR-SSCP methods. Polymorphisms were observed in both genes and direct sequencing confirmed the A>G mutation at position 8398 in exon 4 of PRL gene and the A>C mutation at position 7866 in intron 9 of PRLR gene. The frequencies of allele A/B and C/D were 0.894/0.106 and 0.781/0.219 for PRL and PRLR genes, respectively. Chinese Holstein cows with genotype BB were observed to be higher milk yielders than genotypes AA and AB (P<0.05). It is concluded that the polymorphism in the PRL gene may be a genetic marker in breeding for milk yields in Holsteins, but further validation is required.

Single nucleotide polymorphisms, haplotypes and combined genotypes of lactoferrin gene and their associations with mastitis in Chinese Holstein cattle

Lactoferrin (Lf) is naturally produced by the mammary gland, having biological functions of antibacterial and anti-inflammatory activities. To investigate whether the Lf gene is associated with mastitis in dairy cattle, a DNA sequencing approach was used to identify single nucleotide polymorphisms (SNPs) in the gene. Three previously reported SNPs in the 5' flanking region and one novel SNP in exon1 of Lf gene were identified. A total of 353 individuals from Holstein cattle populations were genotyped for their SNPs using Created Restriction Site PCR (CRS-PCR) and PCR-RFLP methods. Twenty-two and nineteen combinations of three SNPs (g.3440T>G, g.3879_3880insG, and g.4432T>C) and another three SNPs (g.3429G>A, g.3440T>G, g.3879_3880insG) were observed, respectively. The result of haplotype analysis of four SNPs showed that fourteen different haplotypes were identified. Two major haplotypes (GECB and GECA) occurred with a frequency of 22.5 and 18.5% in the study population, respectively. Statistical analyses revealed no significant association between one single SNP of Lf gene and SCS, whereas significant associations between their combined genotypes of three SNPs, haplotype and SCS. Combined genotype EFCDBB and GGEFDD with the lowest SCS were favorable for the mastitis resistance. They may be used as a possible candidate for marker-assisted selection in dairy cattle breeding program.

Genetic polymorphism of &lt;I&gt;Nramp1&lt;/I&gt; gene and correlation with mastitis in Holstein cattle

In this research, PCR-SSCP technique was used to analyze the polymorphisms of the exon 11 of Nramp1 gene in Chinese Holstein cattle (n=344), and correlation between polymorphisms of Nramp1 with somatic cell score (SCS) and milk production traits was analyzed. The results show that three genotypes namely AA, BB, and AB were detected. Allele A was predominant and the frequencies of alleles A and B were estimated to be 0.767 and 0.233, respectively. Chi-square test indicated that the polymorphic locus in Chinese Holstein fitted Hardy-Weinberg equilibrium (P>0.05). Sequencing analysis showed two polymorphic sites at positions 200 bp (C/G) and 254 bp (T/G), which resulted in amino acid alteration Ala356Pro and Leu374Met. The least squares means of SCS in Holstein cattle was lower for genotype AA than that for genotypes AB and BB (P<0.05). The least squares means of milk yield of genotype AA and AB were higher than that for genotype BB (P<0.05, P<0.01, respectively). Genotype AA was beneficial to mastitis resistance. This suggested that Nramp1 may be a candidate gene responsible for mastitis in Holstein cattle.

The stimulatory effect of insulin-like growth factor-1 on the proliferation, differentiation, and mineralisation of osteoblastic cells from Holstein cattle

This study investigated the effect of exogenous insulin-like growth factor (IGF)-1 on the proliferation and differentiation of osteoblastic cells from Chinese Holstein cattle and the resultant bone nodule formation and mineralisation in vitro. The osteoblastic cells were isolated and cultured, then identified using Giemsa and alkaline phosphatase (ALP) staining methods. The effect of different concentrations of IGF-1 on cell growth was assessed by MTT assay. The ALP activity and osteocalcin (OC) concentration in the osteoblastic cells were measured by a colorimetric assay and a radioimmmunoassay, respectively. Calcium nodules were observed using alizarin red S stain, while the content of matrix calcium was determined by atomic absorption spectrophotometry. Cell proliferation in the cultures was stimulated by IGF-1 at concentrations ranging from 1 to 200 ng/mL, with the maximum effect observed at 100 ng/mL. This effect was observed from day 1 and peaked at day 5, but decreased at day 7. At concentrations of 10 ng/mL and 100 ng/mL, IGF-1 significantly induced ALP activity, OC level, matrix calcium content, and nodule formation of the osteoblastic cells by 20–180% ( P < 0.05 or P < 0.01), compared to controls. The results suggested that IGF-1 is an anabolic agent for the proliferation, differentiation, mineralisation and calcium content of dairy cow osteoblasts, and could therefore act as a potential treatment for the metabolic bone diseases in these animals.

Cloning and SNP screening of the TLR4 gene and the association between its polymorphism and somatic cell score in dairy cattle

Toll-like receptor 4 (TLR4) is a cell-surface receptor that activates innate and adaptive immune responses. Recognizing a broad class of pathogen-associated molecular patterns (PAMPs), TLR4 is implicated as a receptor mediating cellular activation in response to bacterial lipopolysaccharide (LPS), a cell-wall component of gram-negative bacteria, which is the principal PAMP of TLR4. TLR4 is a candidate gene for resistance to a large number of diseases. Human models, in particular, suggest TLR4 to be a candidate gene associated with resistance to sepsis, immunodeficiencies, atherosclerosis and asthma. In this study the bovine TLR4 mRNA and genomic DNA were sequenced and their gene structures were determined through alignment of the genomic DNA sequence to the mRNA sequence. Its mRNA sequence consisted of a 2526-bp open reading frame (ORF) flanked by a 470-bp 5′-untranslated region (UTR) and a 743-bp 3′-UTR; and its genomic DNA is 11,013-bp in length and includes the three exons and two introns. Thirty-one single nucleotide polymorphisms (SNPs) were detected by sequencing polymerase chain reaction (PCR) products from 15 cattle, consisting of five randomly selected individuals from Chinese Simmental, Holstein and Sanhe cattle breeds each. Sixteen of these SNPs were in coding regions (cSNP). However, the 3′-untranslated region was comparatively conservative and no SNP was found in it. The SNP (g.8664C>T) found in the Toll IL-1 receptor (TIR) domain of the bovine TLR4 gene leads to amino acid substitution from Thr (C allele) to Ile (T allele). Three hundred and ninety seven cows from Chinese Simmental, Holstein and Sanhe cattle breeds were genotyped for SNP (g.8664C>T) using the method of created restriction site PCR together with restriction fragment length polymorphism (RFLP) by Hinf I. An association study between the SNP and somatic cell score (SCS) in the three breeds showed that the SCS of individuals with a CC genotype was significantly lower than that of the TT genotype. Keywords : Cattle, TLR4, SNP, mastitis, SCS, somatic cell count South African Journal of Animal Science Vol. 38 (2) 2008: pp. 101-109

Analysis of POU1F1 Gene Polymorphisms in Qinchuan Cattle and Chinese Holstein Cattle

PCR-RFLP was applied to analyze the polymorphisms of POU1F1 gene in 218 Qinchuan cattle (QQ) and Chinese Holstein cattle (HC). Results demonstrated Hinf I polymorphisms in the 451 bp PCR product in the two populations. The frequencies of alleles A/B in QQ and HC populations were 0.232/0.768 and 0.132/0.868, respectively. The frequencies of three genotypes AA, AB and BB were 0.030/0.403/0.567 and 0.007/0.251/0.742, respectively. Qinchuan cattle population was at Hardy-Weinberg equilibrium at this locus, but Chinese Holstein cattle population was not. The gene heterozygosity/effective allele gene number/Shannon information entropy/polymorphism information content of Qinchuan cattle and Chinese Holstein cattle populations were listed for 0.356/1.553/0.541/0.292 and 0.229/1.297/0.390/0.203, respectively. All indices were higher in the Qinchuan cattle population.