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.

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.

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.

FOXO1 is a tumor suppressor in cervical cancer.

Forkhead box protein O1 (FOXO1) is an important transcriptional regulator of cell proliferation, and is considered essential for tumor growth and progression. However, the function of FOXO1 in human cervical cancer remains unclear. In this study, we investigated the role of FOXO1 in cervical cancer. Our results showed that FOXO1 expression was lower in cervical cancer than in cervical intraepithelial neoplasia and normal cervix by immunohistochemical analysis (P < 0.05). The level of FOXO1 in high-grade lesions was significantly lower than in low-grade lesion (P < 0.05), indicating that deficient expression of FOXO1 is involved in tumor progression and significantly associated with late-stage tumors (P < 0.05), which was further supported by clinicopathological, real-time polymerase chain reaction, and Western blotting analysis. Moreover, we confirmed that the overexpression of FOXO1 remarkably repressed cell growth and blocked cell proliferation, accompanied by cell-cycle arrest in the G2/M phase and upregulation of caspases-3 and -9 gene expression. Collectively, our data suggest that FOXO1 plays a vital role in inhibiting cervical cancer development by inducing cell-cycle arrest and apoptosis. FOXO1 expression is a favorable prognostic factor for human cervical cancer.

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.

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.

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.