Polymorphism in GHRH gene and its association with growth traits in Chinese native cattle

Growth hormone-releasing hormone (GHRH) is secreted by the hypothalamus and stimulates growth hormone (GH) released from the pituitary. Mutations detected in GHRH gene showed associations with animal production traits. The purpose of this study was to investigate the association of the GHRH gene with growth traits in Chinese native cattle. PCR-SSCP and sequencing were used to detect mutations of the GHRH gene in this study. One novel mutation 4251nt (C>T) was found and the frequencies of C allele were 0.8778 and 0.8476 for Qinchuan and Nanyang cattle, respectively. Body weight with the CT genotype was significantly higher (P<0.05 or P<0.01) than those with CC genotype for different growth periods (6, 12, 18, and 24 months old) in Nanyang cattle. Our findings suggested that polymorphism in bovine GHRH might be one of the important genetic factors to influence body weight.     

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 ?, 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.     

The association analysis between Cytb polymorphism and growth traits in three Chinese donkey breeds

The aim of this study was to investigate the effects of haplotypes in Cytb (Cytochrome b) gene on growth traits in three Chinese donkey breeds, Yunnan donkey (YN), Dezhou donkey (DZ) and Liangzhou donkey (LZ). The samples were genotyped for the Cytb gene by single strand conformation polymorphism (SSCP), and association analysis was conducted with growth traits. The results show that in most cases the effects of the gene on growth traits were not significant and that for the three different donkey breeds, the effects of the gene are different. For YN donkeys, there was a significant effect of the gene on the rump width (P < 0.05) and the effect of genotype AA was larger than that of BB genotype (1.6 cm and 5.4% of the trait mean in YN donkeys, P < 0.05). For DZ donkeys, the effect of gene on body height was significant (P < 0.05). The results also verify that the SSCPs are caused by two cytosine to thymine and one guanine to adenine transitions, corresponding to amino acid substitutions of leucine for proline (L ↔ P) and isoleucine for valine (I ↔ V).     

Relationship of the bovine growth hormone gene to carcass traits in Japanese black cattle.

The bovine growth hormone gene (bGH) possesses three haplotypes, A, B and C, that differ by amino acid mutations at positions 127 and 172 in the fifth exon: (leucine 127, threonine 172), (valine 127, threonine 172) and (valine 127, methionine 172) respectively. The correlation between meat quality or carcass weight and these haplotypes was investigated in Japanese black cattle. Altogether, 940 bGH haplotypes were compared with respect to six carcass traits: carcass weight, longissimus muscle area, rib thickness, subcutaneous fat thickness, beef marbling score and beef colour. The frequency of the B haplotype was higher (0.421) than that of A (0.269) and C (0.311). High carcass weight and low beef marbling were associated with haplotype A (p < 0.05 and p < 0.01 respectively), whereas beef marbling was increased by haplotype C (p < 0.05). Estimated regression coefficient of the A haplotype substitution effect for carcass weight and beef marbling score were 5.55 (13.1% of the phenotypic SD) and -0.31 (17.0%) respectively. That of the C haplotype for beef marbling score was 0.20 (11.0%). The other traits showed no relationship to the haplotypes examined. The results of this investigation suggest that information pertaining to bGH polymorphisms in Japanese black cattle could be used to improve the selection of meat traits.     

Association of genetic variants of bovine growth hormone with milk production traits in Holstein cattle

SUMMARY: Gene and genotype frequencies of alleles, identified by PCR/RFLP technology, at leucine 127/valine127 (L/V) and C/D loci of the growth hormone gene of Ayrshire, Holstein and Jersey breeds were determined. The frequency of the V allele at the L/V mutation locus was 0.29, 0.09 and 0.24 for the Ayrshire, Holstein and Jersey breeds, respectively. The frequencies of the D allele at the C/D mutation locus were 0.00, 0.13 and 0.30 for the three breeds, respectively. Different growth hormone genotypes of Holstein AI bulls were compared for their estimated transmitting abilities (ETA) of milk, fat and protein yields using the samples of unrelated bulls and samples of the top, medium and bottom groups of ETA. The L/V locus was significantly (p < 0.05) associated with fat and protein ETAs of the selected groups and approached significance (p = 0.06) for milk ETA, with the V allele being more frequent in the top than in the bottom group of bulls. The C/D polymorphic locus was significantly (p = 0.02) associated with differences among the top, middle and bottom groups of bulls for milk ETA, but not significantly (p > 0.05) associated with fat and protein ETAs. The results suggest a possible association of growth hormone gene polymorphism with milk production traits in Holstein bulls. However, the results were not conclusive due to the small sample size and low frequencies of the V and D alleles. Much larger sample sizes are needed to obtain a reasonable number of VV and DD genotypes for a critical comparison. ZUSAMMENFASSUNG: Zusammenhang genetischer Varianten des Rinderwachstumshormons mit Milchleistungsmerkmalen bei Holstein Rindern Gene und Genotyp Frequenzen von Allelen, identifiziert mittels PCR/RFLP Technik, an Leucin(127) /Valin(127) (L/V) und C/D Loci des Wachtumshormon Genes wurden bei Ayrshire, Holstein und Jerseys bestimmt. Die H?ufigkeiten des V Alleles waren 0.29, 0.09 und 0.24, jene des D Alleles 0, 0.13, und 0.30 bei den drei Rassen. Der Vergleich verschiedener Genotypen bei Holstein KB Stieren hinsichtlich gesch?tzter Nachkommenüberlegenheit (ETA) für Milch, Fett und Protein Mengen umfa?te Stiere mit hohen, mittleren und niedrigen ETA. Der L/V Locus zeigte statistisch signifikanten Einflu? bei Fettund ProteinETA und p = 0.06 bei Milch, wobei das V Allel in der Spitzengruppe h?ufiger als bei neidrigen war. Der C/D Locus war signifikant (p<0.02) mit Unterschieden hinsichtlich Milch, nicht aber mit jenen hinsichtlich Fett und Protein assoziiert. Die Ergebnisse deuten auf Zusammenh?nge, jedoch beintr?chtigt geringe Zahl der Tiere und niedrige H?ufigkeit der V und D Allele allgemeine und bindende Schlu?folgerungen.     

Genetic variation in monoamine oxidase A and analysis of association with behaviour traits in beef cattle

Husbandry of beef cattle requires animals that do not behave aggressively or timidly. The enzyme monoamine oxidase A and the coding gene (MAOA) play an important role in the complex regulation of behaviour. The complete coding region and a part of the non‐coding sequence of the bovine MAOA gene have been analysed in 20 German Angus and 20 German Simmental bulls and cows with the aim of detecting genetic variability. These two cattle breeds are known to differ regarding their behaviour during handling. Five single nucleotide polymorphisms (SNPs) were identified, three of which were found in the coding region of the gene (exons III and XV). One of the SNPs located in exon XV ( NC_007331.3 :g.80340C>T) was found to be a non‐synonymous mutation. The minor allele frequency of this resulting amino acid substitution was significantly different between 543 German Angus and 417 German Simmental calves (0.39 and 0.49, respectively). The potential functional impact of this polymorphism has been tested by in silico analysis, as well as by association analysis using behaviour scores of the genotyped calves for three behaviour tests that assessed the animals’ temperament during tethering, weighing or social separation. In silico analysis did not deliver consistent results arguing for or against a functional impact of the studied amino acid substitution on the function of the biological protein. No significant association was found between this MAOA polymorphism and the behaviour‐related scores analysed in the study.     

Concentration effect of prostaglandin E2 on the growth factor expression and cell proliferation in bovine endometrial explants and their kinetic characteristics

Bovine endometrium undergoes various physiological and histological changes that are necessary for blastocyst implantation during oestrous cycle. From pro‐oestrus to late‐oestrus, endometrium thickens gradually for implantation preparation and exhibits remarkable capacity for self‐repair after uterine lining shedding while implantation does not occur. The prostaglandin E₂ (PGE ₂) secretion pattern is synchronized with endometrial growth during oestrous cycles in bovine endometrium; however, limited information is available regarding the association between PGE ₂ secretion and endometrial growth. In this study, the concentration (10^?9 to 10^?5 M) and time effect (2–36 hr) of PGE ₂ treatment on a series of growth factors are essential for endometrial growth including connective tissue growth factor (CTGF ), fibroblast growth factor‐2 (FGF ‐2), interleukin‐8 (IL ‐8), transforming growth factor‐β1 (TGF ‐β1), matrix metalloproteinase‐2 (MMP ‐2), and vascular endothelial growth factor A (VEGFA ) mRNA and protein expression, and proliferation of epithelial and fibroblast cells was investigated in bovine endometrial explants in vitro. The results indicated that PGE ₂ at concentration about 10^?7 to 10^?5 M could up‐regulate CTGF , FGF ‐2, IL ‐8, MMP ‐2, TGF ‐β1, VEGFA mRNA and protein expression, and could induce the proliferation of epithelial and fibroblast cells and reduce the proapoptotic factor (caspase‐3) expression in bovine endometrial explants in vitro. These results collectively improved the possibility of PGE ₂ functions in endometrial growth during oestrous cycles.     

Genetic analysis of growth,visual scores,height, and carcass traits in Nelore cattle

Covariance components were estimated for growth traits (BW, birth weight; WW, weaning weight; YW, yearling weight), visual scores (BQ, breed quality; CS, conformation; MS, muscling; NS, navel; PS, finishing precocity), hip height (HH), and carcass traits (BF, backfat thickness; LMA, longissimus muscle area) measured at yearling. Genetic gains were obtained and validation models on direct and maternal effects for BW and WW were fitted. Genetic correlations of growth traits with CS, PS, MS, and HH ranged from 0.20 ± 0.01 to 0.94 ± 0.01 and were positive and low with NS (0.11 ± 0.01 to 0.20 ± 0.01) and favorable with BQ (0.14 ± 0.02 to 0.37 ± 0.02). Null to moderate genetic correlations were obtained between growth and carcass traits. Genetic gains were positive and significant, except for BW. An increase of 0.76 and 0.72 kg is expected for BW and WW, respectively, per unit increase in estimated breeding value (EBV) for direct effect and an additional 0.74 and 1.43, respectively, kg per unit increase in EBV for the maternal effect. Monitoring genetic gains for HH and NS is relevant to maintain an adequate body size and a navel morphological correction, if necessary. Simultaneous selection for growth, morphological, and carcass traits in line with improve maternal performance is a feasible strategy to increase herd productivity.     

郏县红牛TAFA1基因多态性及其与生长性状的关联分析

本研究旨在探讨TAFA趋化素样家族成员1（TAFA1）基因多态性与郏县红牛生长的关联性。试验共采集了79头郏县红牛成年母牛的血样并提取基因组DNA,利用直接测序法对TAFA1基因上的错义突变SNP rs137516577进行基因型分型,并与郏县红牛体高、体长、胸围、腰角宽、坐骨端宽、尻长、十字部高、荐高、胸深、胸宽、体重等11个生长和体尺性状进行关联分析。同时根据“Animal Omics Datebase”数据库对TAFA1基因的组织表达情况进行分析。结果发现该SNP与体长、腰角宽、坐骨端宽、尻长和体重等性状显著相关（P<0.05）,且GC型个体体长、腰角宽、坐骨端宽、尻长和体重均显著高于GG型（P<0.05）。TAFA1基因在牛大脑组织中表达量最高。结果表明,TAFA1基因上错义突变SNP rs137516577与郏县红牛生长性状相关,可作为郏县红牛生长性状的分子标记。     

Association of single nucleotide polymorphisms in the growth hormone and growth hormone receptor genes with blood serum insulin-like growth factor I concentration and growth traits in Angus cattle

This study was conducted to identify polymorphisms in the promoter and coding regions of the bovine growth hormone and growth hormone receptor genes and to study association of polymorphisms identified in these genes with growth traits and serum insulin-like growth factor-I (IGF-I) concentration. The denaturing gradient gel electrophoresis method and sequencing were utilized to identify three new single nucleotide polymorphisms in the promoter region of the growth hormone gene in Angus cattle. Polymerase chain reaction-based restriction fragment length polymorphism procedures were developed for rapid determination of the single nucleotide polymorphism genotypes in the growth hormone and the growth hormone receptor genes among Angus calves from lines divergently selected for high or low blood serum IGF-I concentration. The IGF-I concentration and growth traits were analyzed using animal models. The single nucleotide polymorphism in the promoter region of the growth hormone receptor gene was associated with serum IGF-I concentration on d 42 of the postweaning test and with mean IGF-I concentration. The associated effects of the markers need to be verified in other populations.     

Copy number variations at LEPR gene locus associated with gene expression and phenotypic traits in Chinese cattle

Current evidences show that copy number variations (CNVs) are linked to complex phenotypic traits. Leptin receptor (LEPR) gene plays a critical role in energy homeostasis and fat development and re‐sequencing of the cattle genome revealed the CNV region (herein referred to as “I3 DNA”) within the LEPR intron 3. In the present study, we qualified copy numbers of I3 DNA within LEPR gene in four cattle breeds (Qinchuan, Nanyang, Jinnan and Xianan) by quantitative PCR, and explored their impacts on LEPR gene expression and phenotypic traits in Qinchuan and Nanyang cattle. The results showed that more individuals in Nanyang are with loss of the I3 DNA copy number than that in the others. Additionally, I3 DNA CNVs exhibited a significant negative correlation with LEPR gene expression (P < 0.05). Association analysis showed that gain/normal copy number types performed better traits of body weight, body height and body length than the loss type in Nanyang. To the best of our knowledge, this is the first evidence of the association between LEPR CNVs and cattle traits, and this may help deep understanding of the function of CNVs which may be promising markers for beef cattle breeding and genetics. © 2015 Japanese Society of Animal Science     

Lack of evidence for bovine Y-chromosomal variation in beef traits. A Bayesian analysis of Simmental data

Y-chromosomal loci are genetically responsible for some male-specific biological processes. The sex determining region Y (SRY), a protein with DNA-binding activity, is known as the trigger for sex differentiation in mammals. In humans the SRY is encoded by a single exon located on the short arm of the Y chromosome, close to the pseudoautosomal boundary (S inclair et al. 1990). Moreover, the Y chromosome harbours the male-specific histocompatibility antigen (reviewed by S impson et al. 1997) and there are at least two regions of the Y chromosome, which have been shown to be essential for normal spermatogenesis in mice (E lliott and C ooke 1997). The sexual dimorphism of aggression in mice has led to a search for its foundation on the Y chromosome. The existence of Y-chromosomal genetic variation for aggressiveness with genetic factors borne both on the pseudoautosomal (YPAR) and on the nonpseudoautosomal (YNPAR) region of the Y chromosome (S luyter et al. 1996) has been shown. Another example for Y-induced genetic variation in mice is the testis autosomal trait (occurrence of ovaries or ovotestes in XY animals), which is observed when specific Y chromosomes interact with the autosomal background of certain laboratory mouse lines (E isner et al. 1996). A comparison of the resemblance of different types of relatives indicated a nonzero Y-chromosomal variance for body weight in mice (B& uuml ; nger et al. 1995). In cattle the Y chromosomes of the Bos taurus and Bos indicus subspecies can be morphologically distinguished: its shape is submetacentric in B. taurus and acrocentric in B.indicus. This difference is caused by a pericentric inversion (G oldammer et al. 1997) and has frequently been used to investigate the introgression of zebu genes into B. taurus breeds. The polymorphism of the bovine Y chromosome itself and the results of mouse research both direct the scientific curiosity on the possible contribution of the bovine Y chromosome to quantitative genetic variation in cattle, a question which, to the authors’ knowledge, has not been investigated before. In this paper we first discuss the contribution of autosomal, imprinted, and sex-linked genes to the resemblance of full and half sibs and then present a Bayesian estimation of a Y-chromosomal variance component for each of four beef traits in young Simmental bulls using mixed linear and threshold models.     

Genetic relationship of feed efficiency traits of bulls with growth and carcass traits of their progeny for Japanese Black (Wagyu) cattle

Genetic parameters for feed efficiency traits of 740 Wagyu bulls and growth and carcass traits of 591 of their progeny, and the genetic relationship between the traits of bulls and their progeny were estimated with the residual maximum likelihood procedure. The estimations were made for the test periods of 140 days (77 bulls), 112 days (663 bulls) and 364 days (591 steer progeny). Feed efficiency traits of bulls included feed conversion ratio (FCR), phenotypic residual feed intake (RFI_phe) and genetic residual feed intake (RFI_gen). Progeny traits were bodyweight at the start of the test (BWS), bodyweight at finish (BWF), average daily gain (ADG), rib eye area (REA), marbling score (MSR), dressing percentage (DRS) and subcutaneous fat thickness (SFT). The estimated heritability for MSR (0.52) was high and for BWS (0.35), BWF (0.40) and ADG (0.30) were moderate, whereas REA, DRS and SFT were low. Positive genetic correlations among BWS, BWF, ADG and SFT and negative genetic correlations between MSR and DRS and between REA and SFT were found. The genetic correlations between residual feed intake (RFI_phe and RFI_gen) of bulls and bodyweights (BWS and BWF) of their progeny ranged from ?0.27 to ?0.61. Residual feed intake was positively correlated with REA and DRS and negatively correlated with MSR and SFT. No responses in ADG and weakly correlated responses in REA and DRS of progeny were found to select against feed efficiency traits of bulls. The present experiment provides evidence that selection against lower RFI (higher feed efficiency) would be better than selection against lower FCR for getting better correlated responses in bodyweights.     

Allele frequencies of TYR and MC1R in Chinese native cattle

In order to estimate the influence of TYR and MC1R on the color of the cattle hide, the MC1R and TYR in Luxi Yellow, Bohai Black, China Holstein black‐white and China Holstein red‐white cattle (20 animals of each of the four breeds) were sequenced. The comparison of TYR among the four hide color phenotypes revealed no sequence difference. The sequences of the MC1R coding region revealed three alleles (E^D, E⁺ and e), which were previously reported. Furthermore, we found an important single nucleotide polymorphism at 725 position of the MC1R coding region, which may help in cattle breed identification. A polymerase chain reaction‐restriction fragment length polymorphism was performed to investigate the gene frequencies of the four breeds. Most China Holstein black‐white cattle had E^D and E⁺ alleles (E^D = 0.12, E⁺ = 0.80) and no homozygous e/e and most Bohai Black cattle had E^D and E⁺ alleles (E^D = 0.52, E⁺ = 0.47). Therefore it is consistent with the hypothesis that E^D and E⁺ induce black pigment synthesis. On the other hand, most of the China Holstein red‐white cattle and Luxi Yellow cattle had the e allele (e/e = 0.95). Unexpectedly, the E⁺/e genotype was present in China Holstein red‐white cattle and Luxi Yellow cattle.     

Detection of bovine leukocyte adhesion deficiency (BLAD) in Turkish native and Holstein cattle

The purpose of this work was to study whether the bovine leukocyte adhesion deficiency (BLAD) allele is present in native cattle breeds and the Holstein breed in Turkey. Blood samples were obtained from 120 Holstein, 20 Brown Swiss, 20 Anatolian Black, 20 Turkish Grey, 20 South Anatolian Red and 20 East Anatolian Red cattle. The isolated DNA materials were multiplied in PCR using the primer developed by Kriegesmann et al. (1997). In order to determine the area of mutation in PCR products, the PCR products were digested with TaqI endonuclease enzyme. The resulting fragments were analysed on 2% agarose gel for the absence of a TaqI restriction site. It was found that two of the Holstein cattle (a bull and a cow) were heterozygote BLAD carriers. There was no homozygote BLAD animal. The BLAD allele was not found in the other breeds used in the study. The mutant BLAD allele frequency in the 120 Holstein cattle calculations was 0.0084.     

Association analysis between variants in bovine progesterone receptor gene and superovulation traits in Chinese Holstein cows

The objective of this study was to identify a predictor to forecast superovulation response on the basis of associations between superovulation performance and gene polymorphism. The PCR-RFLP method was applied to detect two reported single nucleotide polymorphisms (SNPs) of G59752C and T81637C (rs41614030) located in introns 3 and 4 of the bovine progesterone receptor (PGR) gene in 171 Chinese Holstein cows treated for superovulation and evaluate its associations with superovulation traits. In polymorphic locus 81637, all cows without superovulation response were g.81637TC and g.81637TT genotypes. Association analysis showed that these two SNPs had significant effects on the total number of ova (TNO) (p<0.05), and the T81637C polymorphism was significantly associated with the number of transferable embryos (p<0.05). In addition, significant additive effects (p<0.05) on TNO were detected in the polymorphisms of G59752C and T81637C. These results showed for the first time that the G59752C and T81637C polymorphisms in PGR gene were associated with superovulation traits and indicated that PGR gene can be used as a predictor for superovulation in Chinese Holstein cows.     

Estimation of dominance genetic variances for reproductive traits and growth traits of calves in Japanese Black cattle

The dominance genetic effects for reproductive and calf growth abilities in the practical Japanese Black populations were examined using average information (AI) algorithm restricted maximum likelihood (REML) under animal models. The reproductive traits were observed in Japanese Black cattle maintained at Tottori and Okinawa prefectures, and growth traits of calves were observed in cattle at Okinawa. The average of dominance relationships in Tottori ranged from 0.2 to 0.4%, while the level in Okinawa was lower and sparse compared with Tottori. The proportions of the dominance variances to sum of additive and dominance variances () were all 0.02 for reproductive traits in Tottori. In contrast, the proportion was 0.02–0.64 in Okinawa regardless of the level of dominance relationships. These proportions suggested that the dominance might affect the expression of calving interval, days open and gestation length in Okinawa, where breeding units were spread over many islands. Although the dominance variances could not estimate birthweight, w as 0.34 for calf market weight and 0.27 for average daily gain from birth to calf market in Okinawa. These values also suggested that the dominance might affect the early growth of calves. In the near future, genetic relationships will become more complicated with continuation of the current selection and mating systems. Therefore, genetic evaluation accounting for dominance effects would be necessary for particular traits and populations.