Association of variants in FABP4, FASN, SCD, SREBP1 and TCAP genes with intramuscular fat, carcass traits and body size in Chinese Qinchuan cattle.

This study aimed to genotype the variants in FABP4, FASN, SCD, SREBP1 and TCAP genes, and to analyze their associations with intramuscular fat (IMF) content, carcass traits and body size in Chinese Qinchuan cattle (QC). The association studies showed that the FABP4 c.220A > G polymorphism was significantly associated with ultrasound longissimus muscle depth (ULMD) and IMF, the FASN g.16024A > G polymorphism was significantly associated with ULMD and some body size traits, the SREBP1 84 bp indel was significantly associated with back fat thickness, ULMD and some body size traits. The frequencies of well-characterized A allele in FABP4 c.220A > G in Korean cattle (KOR) and Japanese Black cattle (JB), T allele in SCD g.8586C > T in KOR, SS genotype in SREBP1 84 bp indel in KOR and JB, DELDEL genotype in TCAP g.592-597CTGCAGinsdel in KOR were significantly higher than in Chinese cattle breeds. Thus, the associated four polymorphisms were expected to be genetic selection markers for meat quality, carcass traits and body size of QC.

Bta-miR-130a regulates the biosynthesis of bovine milk fat by targeting peroxisome proliferator-activated receptor gamma.

Milk fat determines the quality of milk and is also a main targeted trait in dairy cow breeding. Recent studies have revealed important regulatory roles of microRNAs (miRNA) in milk fat synthesis in the mammary gland. However, the role of miRNA in bovine mammary epithelial cells (BMEC) remains largely unknown. In this study, we found that the overexpression of miR-130a significantly decreased cellular triacylglycerol (TAG) levels and suppressed lipid droplet formation, whereas the inhibition of miR-130a resulted in greater lipid droplet formation and TAG accumulation in BMEC. MiR-130a also significantly affected mRNA expression related to milk fat metabolism. Specifically, the overexpression of miR-130a reduced the mRNA expression of , , , and , whereas the downregulation of miR-130a increased the mRNA expression of , , , , , and . Furthermore, western blot analysis revealed the protein level of PPARG in miR-130a mimic and inhibitor transfection groups to be consistent with the mRNA expression response. Finally, luciferase reporter assays verified that PPARG was the direct target of miR-130a. This study provides the first experimental evidence that miR-130a directly affects TAG synthesis in BMEC by targeting PPARG, suggesting that miR-130a potentially could be used to improve beneficial milk components in dairy cows.

miR-27a controls triacylglycerol synthesis in bovine mammary epithelial cells by targeting peroxisome proliferator-activated receptor gamma.

Growing evidence has revealed that microRNA are central elements in milk fat synthesis in mammary epithelial cells. A negative regulator of adipocyte fat synthesis, miR-27a has been reported to be involved in the regulation of milk fat synthesis in goat mammary epithelial cells; however, the regulatory role of miR-27a in bovine milk fat synthesis remains unclear. In the present study, primary bovine mammary epithelial cells (BMEC) were harvested from mid-lactation cows and cultured in Dulbecco's modified Eagle's medium/F-12 medium with 10% fetal bovine serum, 5 µg/mL of insulin, 1 µg/mL of hydrocortisone, 2 µg/mL of prolactin, 1 µg/mL of progesterone, 100 U/mL of penicillin, and 100 µg/mL of streptomycin. We found that the overexpression of miR-27a significantly suppressed lipid droplet formation and decreased the cellular triacylglycerol (TAG) levels, whereas inhibition of miR-27a resulted in a greater lipid droplet formation and TAG accumulation in BMEC. Meanwhile, overexpression of miR-27a inhibited mRNA expression of peroxisome proliferator-activated receptor gamma (PPARG), CCAAT/enhancer-binding protein beta (C/EBPß), perilipin 2 (PLIN2), and fatty acid binding protein 3 (FABP3), whereas miR-27a downregulation increased PPARG, C/EBPß, FABP3, and CCAAT enhancer binding protein alpha (C/EBPα) mRNA expression. Furthermore, Western blot analysis revealed the protein level of PPARG in miR-27a mimic and inhibitor transfection groups to be consistent with the mRNA expression response. Moreover, luciferase reporter assays verified that PPARG was the direct target of miR-27a. In summary, these results indicate that miR-27a has the ability to control TAG synthesis in BMEC via targeting PPARG, suggesting that miR-27a could potentially be used to improve beneficial milk components in dairy cows.

Polymorphisms in the LPL gene and their association with growth traits in Jiaxian cattle.

Previous studies showed that the lipoprotein lipase (LPL) gene was involved in metabolism and transport of lipids, suggesting that the LPL is a potential candidate gene affecting growth traits in animals. The aim of this study was to identify polymorphism in the bovine LPL gene and analyze its possible association with growth traits in 218 randomly selected Jiaxian cattle. We used DNA sequencing to identify single nucleotide polymorphisms (SNPs) in the LPL gene. A sequence analysis revealed three SNPs: two in intron 5 (C18306T and C18341T) and one in exon 6 (G18362A). G18362A is a missense mutation leading to a change of the 325th glycine to serine. Based on χ(2) tests, the genotypic distributions of C18306T were in agreement with the Hardy-Weinberg equilibrium (P > 0.05), whereas the other two mutations were not (0.05 > P > 0.01). Association analyses showed that the C18341T SNP was significantly associated with several growth traits (P < 0.01 or P < 0.05), and the G18362A was associated with withers height (P < 0.05). Our results suggest that LPL gene variation may be considered molecular markers for growth traits in Jiaxian cattle.

Polymorphisms of the bovine MC3R gene and their associations with body measurement traits and meat quality traits in Qinchuan cattle.

The melanocortin 3 receptor (MC3R) gene, which belongs to the rhodopsin-like family A of the G protein-coupled receptor family, plays a crucial role in feed efficiency and energy homeostasis. The aim of this study was to examine associations between bovine MC3R gene polymorphisms and body measurement traits (BMTs) and meat quality traits (MQTs). We identified three synonymous mutations (T429C, T537C, and T663C) in exon 1 of the MC3R gene in Chinese Qinchuan beef cattle (N = 271) by sequencing. D' and r(2) values revealed that these three SNPs were in strong linkage disequilibrium (LD) (r(2) > 0.33); the T429C and T537C SNPs were in complete LD (D' = 1 and r(2) = 1). Association analyses revealed that the SNPs were significantly associated with BMTs and MQTs in Qinchuan cattle. Individuals with the wild homozygotic genotypes g.TTTT and g.TT had significantly higher values of chest depth, heart girth, back fat thickness, intramuscular fat content, and loin muscle area than the mutant heterozygotic genotypes g.TCTC and g.TC. These results suggest that the MC3R gene affects MQTs in Qinchuan cattle, and that it may be a good candidate gene for marker-assisted selection.

Association of CRTC2 gene polymorphisms with growth and meat quality traits of Qinchuan cattle.

Growth and meat quality traits play important roles in the evaluation of cattle productivity and are influenced by genetic and environmental factors. CRTC2 is a recently discovered gene related to obesity that may influence fat deposition. The aim of the current study was to detect polymorphisms of bovine CRTC2 and explore their relationships to growth and meat quality in Qinchuan cattle. Three single nucleotide polymorphisms (SNPs); g.3001 C>T; g.3034 G>A; and g.3467 T>C, were identified from sequencing results of 422 Qinchuan cattle. The genotypic distributions of both g.3034 G>A and g.3467 T>C mutations were in agreement with Hardy-Weinberg equilibrium, (P < 0.05), while the T3001C mutation was not (P > 0.05), based on χ(2) test analysis. The SNPs g.3001 C>T and g.3034 G>A are missense mutations (Ser/Phe and Ser/Thr respectively). Additionally, SNPs g.3034 G>A and g.3467 T>C showed a medium polymorphism level (0.25 < PIC< 0.50), whereas g.3001 C>T showed a low polymorphism level (PIC < 0.25). These three SNPs were significantly associated with several growth and meat quality traits in the Qinchuan cattle population (P < 0.05 or P < 0.01). Collectively, these results demonstrate that CRTC2 is involved in the regulation of cattle growth and meat quality, and suggest that CRTC2 is a potential candidate gene for marker-assisted selection in future breeding development programs for Qinchuan cattle.

Polymorphisms in the bovine CIDEC gene are associated with body measurement traits and meat quality traits in Qinchuan cattle.

Previous studies have shown that the cell death-inducing DFF45-like effector-C (CIDEC) gene is involved in lipid storage and energy metabolism, suggesting that it is a potential candidate gene that affects body measurement traits (BMTs) and meat quality traits (MQTs). The aim of this study was to identify polymorphisms of the bovine CIDEC gene and analyze their possible associations with BMTs and MQTs in 531 randomly selected Qinchuan cattle aged between 18 and 24 months. DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism were employed to detect CIDEC single nucleotide polymorphisms (SNPs). We found five SNPs: two in exon 5 (SNP1, g.9815G>A and SNP2, g.9924C>T) and three in the 3'-untranslated region (SNP3, g.13281C>T; SNP4, g.13297A>G; and SNP5, g.13307G>A). SNP1 was a missense mutation that resulted in an arginine to glutamine amino acid change, and exhibited two genotypes (GG and AG). SNP2 was a synonymous mutation that exhibited three genotypes (CC, CT, and TT). SNP3, 4, and 5 were completely linked, and only exhibited two genotypes (CC-AA-GG and CT-AG-GA). We found significant associations between these polymorphisms and BMTs and MQTs (P < 0.05); GG, CT, and CT-AG-GA appeared to be the most beneficial genotypes. Therefore, CIDEC may affect BMTs and MQTs in Qinchuan cattle, and could be used in marker-assisted selection.

C/EBPα gene as a genetic marker for beef quality improvement.

Intramuscular fat (IMF) or intramuscular triglycerides are interspersed throughout the skeletal muscles. The IMF, also called marbling, imparts meat with flavor and juiciness and is one of the core criteria for judging carcass value. The quantity of IMF is influenced entirely by genetics. Recently, understanding the underlying genetic bases of IMF has been a focus particularly in the beef industry. In this study, with the deep insights of ameliorating the beef quality by genetic means, the role of the CCAAT/enhancer binding protein alpha (C/EBPα) gene was investigated by over-expressing C/EBPα in bovine muscle stem cells (MSCs) to initiate the adipogenic program. Prior to this, bovine MSCs were isolated and induced to differentiate into adipocytes from cells that were exposed to dexamethasone isobutylmethylxanthine and indomethacin; the presence of insulin and fetal bovine serum was examined. Either ectopic expression of C/EBPα or treatment with dexamethasone and insulin induced the accumulation of fat droplets and the expression of adipogenic induction genes (LPL, PPARγ, C/EBPß, and C/EBPδ). The expression levels of myoblast-related genes (MyoD, Myf5, and Pax7) were also measured to assess the accuracy of the differentiation process. This study provides evidence that the C/EBPα gene is essential for cattle adipose tissue growth and development. Hence, this finding can contribute to improving beef carcass quality.

Efficient construction of recombinant adenovirus expression vector of the Qinchuan cattle LYRM1 gene.

In this study, we cloned the coding DNA sequence (CDS) region of Qinchuan cattle LYR motif-containing 1 (LYRM1) and constructed a recombinant adenovirus expression vector to examine the function of LYRM1 on the cellular level. Total RNA was extracted from the adipose tissue of Qinchuan cattle, cDNA was obtained by reverse transcription, and polymerase chain reaction was used to amplify the CDS region of the LYRM1 gene. The CDS-containing fragment was inserted into the shuttle vector pAdTrack-CMV to construct pAdTrack-CMV-LYRM1 vector. After linearization of pAdTrack-CMV-LYRM1 and the negative control vector pAdTrack-CMV by restriction endonuclease PmeI, the vectors were transformed into Escherichia coli BJ5183 containing pAdEasy-1 to obtain the recombinant adenovirus vector pAd-LYRM1 and pAd-CMV through homologous recombination. pAd-LYRM1 and pAd-CMV were then digested by PacI and transfected into the 293A cell line. The recombinant adenovirus Ad-LYRM1 and Ad-CMV was obtained at a concentration of 7 x 108 and 1.3 x 109 green fluorescent units/mL, respectively. Preadipocytes derived from Qinchuan cattle were separately infected with Ad-LYRM1 and Ad- CMV. Quantitative real-time polymerase chain reaction demonstrated that the expression of LYRM1 was increased by approximate 28,000-folds after the infection with recombinant adenovirus for 48 h. In conclusion, we successfully cloned the CDS region of the Qinchuan cattle LYRM1 gene, constructed the recombinant adenovirus expression vector, and obtained the adenovirus with high titer, providing valuable materials for studying the function of LYRM1 at the cellular level.

Identification of single nucleotide polymorphisms of the signal transducer and activator of transcription 3 gene (STAT3) associated with body measurement and carcass quality traits in beef cattle.

Previous studies have shown that the signal transducer and activator of transcription 3 gene (STAT3) is involved in lipid storage and energy metabolism, suggesting that STAT3 is a potential candidate gene that affects body measurement and carcass quality traits in animals. Therefore, the aim of this study was to identify polymorphisms in bovine STAT3 and to analyze their possible associations with body measurement and carcass quality traits in 493 individuals of 2 native Chinese cattle breeds: Qinchuan (N = 371) and Jiaxian cattle (N = 122). DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were employed to detect STAT3 single nucleotide polymorphisms (SNPs). We found 5 SNPs: 1 in an exon (g.65812G>A: exon 16) and 4 in introns (g.43591G>A: 13 intron, g.67492T>G: 19 intron, g.67519T>C: 19 intron, and g.68964G>A: 20 intron). Both g.65812G>A and g.68964G>A were not in Hardy- Weinberg equilibrium (HWE), whereas individual frequencies of each genotype were consistent with HWE for other SNPs in Qinchuan cattle populations. For the Jiaxian cattle, the genotype distributions of the 4 mutations were in HWE except for g.67519T>C. The results indicate that these SNPs have a significant association with some body measurements and carcass quality traits (P < 0.05 or P < 0.01). Therefore, STAT3 might have potential effects on production traits in beef cattle populations and could be used for marker-assisted selection.

Novel polymorphisms of the PRKAG2 gene and their association with body measurement and meat quality traits in Qinchuan cattle.

Body measurement and meat quality traits play important roles in the evaluation of productivity and economy in cattle, which are influenced by genes and environmental factors. PRKAG2, which encodes the γ2 regulatory subunit of AMPK, is associated with key metabolic pathways in muscle. We detected bovine PRKAG2 gene polymorphisms and analyzed their associations with body measurement and meat quality traits of cattle. DNA samples were taken from 578 Qinchuan cattle aged 18-24 months. DNA sequencing, polymerase chain reaction-restriction fragment length polymorphism, and time-of-flight mass spectrometry were used to detect PRKAG2 single nucleotide polymorphisms (SNPs). Sequence analysis revealed three SNPs in exon 3 (g.95925G>A, g.95973G>C, and g.95992A>G) and one g.96058T>C mutation in intron 3. g.95973G>C, g.95992A>G, and g.96058T>C each showed 3 genotypes: GG, GC, and CC; AA, AG, and GG; and TT, TC, and CC, respectively. In contrast, g.95925G>A only showed 2 genotypes, GG and GA. Analysis showed that g.95925G>A had no effects on body measurement and meat quality traits, whereas the other 3 polymorphisms were significantly associated with some of the body measurement and meat quality traits in the Qinchuan cattle population. It is inferred that the PRKAG2 gene can be used for marker-assisted selection to improve the body measurement and meat quality traits in the Qinchuan cattle population.

Polymorphisms in the SIRT5 gene and their association with body measurement and ultrasound traits in Qinchuan cattle.

Silent information regulator 5 (SIRT5), a member of the Sirtuin family class III nicotinamide adenine dinucleotide-dependent protein deacetylases, plays an important role in metabolic and aging processes in mammals. We identified 4 single-nucleotide polymorphisms (SNPs) (G22010A, G22052A, G22119T, and G22245C) in the 3' untranslated regions of the SIRT5 gene from 572 Qinchuan cattle by sequencing and investigating their association with growth and ultrasound traits. The frequencies of genotype GG and allele G were high at the 4 SNPs. Based on the X(2) test, the genotypic distributions of the 4 SNPs were not in Hardy-Weinberg equilibrium (P < 0.05 or P < 0.01). Association analysis of individual SNPs and haplotype combinations revealed that the 4 loci were significantly associated with some body measurement and ultrasound traits in Qinchuan cattle, and the H1H5 (AG-GA-GG-GG) diplotypes had better performance than other combinations in Qinchuan cattle. Our results demonstrate that SIRT5 may be a candidate for marker-assisted selection in future breeding programs for Qinchuan cattle.

Polymorphisms of the Osteocrin gene and its association with meat quality traits in Qinchuan cattle.

Here, we detected 2 SNPs, A85C and T335C, that were located on the 3rd exon and the 3 untranslated regions of the bovine Osteocrin gene, respectively, using 413 Qinchuan cattle DNA samples. PCR-SSCP and DNA sequencing methods were specifically used. Three genotypes (AA, AC, and CC) were found at A85C; yet, only 2 genotypes (TC and CC) were found at T335C. Association analysis showed that both loci were associated with certain meat quality traits, including back fat thickness and loin muscle area. At the A85C locus, individuals with the CC genotype had greater back fat thickness. In comparison, at the T335C locus, individuals with the TC genotype had greater back fat thickness and a larger loin muscle area. Therefore, these 2 SNPs could be used as genetic markers to enhance Qinchuan cattle breeding programs.

Protective effects of ascorbic acid and vitamin E on antioxidant enzyme activity of freeze-thawed semen of Qinchuan bulls.

The aim of this study was to determine the protective effects of the combination of ascorbic acid (Vc) and vitamin E (VE) on antioxidant enzyme activity, sperm motility, viability, and acrosome integrity of Qinchuan bulls after freeze-thaw. In this study, we determined the effects of Vc and VE on the activity of the antioxidant enzyme defense system comprising glutathione peroxidase (GSH-Px), glutathione reductase (GR), catalase (CAT), and superoxide dismutase (SOD). The combination of Vc and VE had protective effects on sperm motility and viability. With respect to acrosome integrity and the activity of GR and SOD, differences were observed between the experimental groups with added Vc (7 mg/mL) and VE (0.12 IU/mL) and the control group. The activity of GSH-Px in the experimental group (1400 IU/mL Vc and 0.12 IU/mL VE) was not different (P > 0.05) compared with that in the control group, while the activity of CAT showed a significant difference between the 2 groups (P < 0.05). Therefore, we inferred that the combination of Vc (1400 IU/mL) and VE (0.12 IU/mL) protected the sperm quality in the freeze-thaw process.

Genetic polymorphisms of the FATP1 gene and their associations with meat quality traits in Chinese Qinchuan cattle.

Fatty acid transport protein 1 (FATP1), an integral membrane protein that facilitates long-chain fatty acid influx, is involved in the genetic network for oleic acid synthesis. The aim of this study was to examine the association of FATP1 polymorphisms with live animal meat quality traits in Chinese Qinchuan cattle. Quantitative real-time PCR analysis demonstrated that FATP1 has a broad tissue distribution in Qinchuan cattle and is highly expressed in longissimus dorsi muscle and back fat. Using direct DNA sequencing of the FATP1 gene in 458 Qinchuan cattle, four single nucleotide polymorphisms (SNPs; g.28265 G>C, g.28381 G>A, g.28470 T>C, and g.28672 G>A) were identified for genotyping within a 671-bp region, including exon 3, intron 3, exon 4, intron 4, and part of exon 5 of the FATP1 gene. Positive effects of genotypes CC (g.28470 T>C locus) and AA (g.28672 G>A locus) on meat quality traits were obtained by association analysis. These results indicate the associations of g.28470 T>C and g.28672 G>A with meat quality traits in Qinchuan cattle. Thus, the FATP1 gene may be used in marker-assisted selection of beef cattle in breeding programs.

Genetic diversity of Y-short tandem repeats in Chinese native cattle breeds.

The aim of this study is to use Y-chromosome gene polymorphism method to investigate regional differences in genetic variation and population evolution history of the Chinese native cattle breeds. Six Y-chromosome short tandem repeat (Y-STR) loci (UMN0929, UMN0108, UMN0920, INRA124, UMN2404, and UMN0103) were analyzed using 1016 healthy and heterogenetic males and 90 females of 9 native cattle breeds (Qinchuan, Jinnan, Zaosheng, Luxi, Nanyang, Jiaxian, Dabieshan, Yanbian, and Menggu) in China. Allele frequency and gene diversity were calculated for the various populations. The results indicated that Y-STRs in the 6 loci have polymorphisms and genetic diversity in Chinese cattle populations. The genetic diversity analysis revealed that the Chinese cattle populations have a close genetic relationship. The analysis of INRA124, UMN2404, and UMN0103 loci revealed the original history of Chinese cattle because of which cattle belonging to Bos taurus or Bos indicus could be determined. Interestingly, a declining zebu introgression was displayed from South to North and from East to West in the Chinese geographical distribution, which implied that cattle population from various regions of China had been subjected to somewhat different evolutionary history. This conclusion supported other evidences such as earlier archaeological, historical research, and blood protein polymorphism analysis.

Association of SIRT2 gene polymorphisms with body measurement and growth traits of Qinchuan cattle.

Silent information regulator 2 (SIRT2), a member of the Sirtuin family of class III nicotinamide adenine dinucleotide-dependent protein deacetylases, plays an important role in senescence, metabolism, and apoptosis. This study was conducted to detect potential polymorphisms of the bovine SIRT2 gene and explore their relationships with meat quality and body measurement traits (BMTs) in Qinchuan cattle. Four single nucleotide polymorphisms (A7445G, C7711T, G17937A, and G20937A) in the fourth intron, fourth exon, ninth exon, and twelfth exon of the SIRT2 gene, respectively, were identified according to the sequencing results of 520 individuals of a Qinchuan cattle population. The genotypic distributions of both A7445G and G20937A were in agreement with the Hardy-Weinberg equilibrium (P < 0.05), whereas the other two mutations were not (0.05 < P < 0.01), based on the X(2) test. Association analysis indicated that the four loci were significantly correlated with several BMTs and meat quality traits. When in combination, the H1H1 (AA-CC-GG-CC) diplotypes showed better BMT and meat quality traits than those by other combinations. Collectively, the results show that SIRT2 is involved in the regulation of the growth and meat quality of cattle, suggesting that the SIRT2 gene may be a candidate gene for marker-assisted selection in the development of future breeding programs for Qinchuan cattle.

Effects of bovine SMO gene polymorphisms on the body measurement and meat quality traits of Qinchuan cattle.

Beef cattle breeding programs focus on improving important economic traits, including growth rates, and meat quantity and quality. Molecular marker-assisted selection based on genetic variation represents a potential method for breeding genetically improved livestock with better economic traits. Smoothened (SMO) protein is a signal transducer that contributes to the regulation of both osteogenesis and adipogenesis through the hedgehog pathway. In this study, we detected polymorphisms in the bovine SMO gene of Qinchuan cattle, and we analyzed their associations with body measurement traits (BMTs) and meat quality traits (MQTs). Using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism, 3 novel single nucleotide polymorphisms were identified in the SMO gene of 562 cattle: 1 G > C mutation on exon 9 (G21234C) and 2 C > T mutations on exon 11 (C22424T and C22481T). Association analysis showed that polymorphisms on both the G21234C and C22424T loci significantly affected certain BMTs and MQTs (P < 0.05 or P < 0.01), whereas those on the C22481T locus did not (P > 0.05). Therefore, the SMO gene could be used as a candidate gene to alter BMTs and MQTs in Qinchuan cattle or for marker-assisted selection to breed cattle with superior BMTs and MQTs.

Novel extraction method of genomic DNA suitable for long-fragment amplification from small amounts of milk.

Isolation of genomic DNA is a prerequisite for assessment of milk quality. As a source of genomic DNA, milk somatic cells from milking ruminants are practical, animal friendly, and cost-effective sources. Extracting DNA from milk can avoid the stress response caused by blood and tissue sampling of cows. In this study, we optimized a novel DNA extraction method for amplifying long (>1,000 bp) DNA fragments and used it to evaluate the isolation of DNA from small amounts of milk. The techniques used for the separation of milk somatic cell were explored and combined with a sodium dodecyl sulfate (SDS)-phenol method for optimizing DNA extraction from milk. Spectrophotometry was used to determine the concentration and purity of the extracted DNA. Gel electrophoresis and DNA amplification technologies were used for to determine DNA size and quality. The DNA of 112 cows was obtained from milk (samples of 13 ± 1 mL) and the corresponding optical density ratios at 260:280 nm were between 1.65 and 1.75. Concentrations were between 12 and 45 µg/µL and DNA size and quality were acceptable. The specific PCR amplification of 1,019- and 729-bp bovine DNA fragments was successfully carried out. This novel method can be used as a practical, fast, and economical mean for long genomic DNA extraction from a small amount of milk.

New polymorphisms in the novel LYRM1 gene are associated with body measurement and meat quality traits in Qinchuan cattle.

Body measurement and meat quality traits play important roles in the evaluation of productivity in cattle; they are influenced by genetic and environmental factors. Recent studies have shown that LYRM1 is a novel gene related to obesity and may influence fat deposition. We screened for new polymorphisms in the bovine LYRM1 gene and analyzed their association with body measurement and meat quality traits in cattle. DNA samples were obtained from 572 Qinchuan cattle aged from 18 to 24 months. DNA sequencing was used to find the LYRM1 single nucleotide polymorphisms (SNPs). Sequence analysis of LYRM1 revealed four novel SNPs in exon 3: G50A in coding region, C126A, A127T, and T128A in a 3'-untranslated region. G50A, A127T and T128A showed two genotypes: AG and GG, AA and AT, AT and TT, respectively; while C126A showed three genotypes: AA, AC and CC. Analysis showed that these four polymorphisms were significantly associated with body measurement and meat quality traits in the Qinchuan cattle population. We suggest that the LYRM1 gene can be used for marker-assisted selection to improve body measurement and meat quality traits in the Qinchuan cattle population.