Term placenta shows methylation independent down regulation of Cyp19 gene in animals with retained fetal membranes

Retention of fetal membranes (RFM) is the major post-partum disorder in dairy cattle. Cyp19 gene encodes the aromatase enzyme responsible for catalyzing the rate limiting step in estrogen biosynthesis, an important hormone for placental maturation and expulsion. The present study was aimed for comparative analysis of Cyp19 gene expression and its epigenetic regulation in placental cotyledons of animals with and without RFM. Significantly lower expression of Cyp19 gene was found in placental samples of RFM affected animals in comparison to normal animals. Methylation analysis of 5 CpG dinucleotides of placenta specific Cyp19 gene promoter I.1 and proximal promoter, PII showed hypo-methylation of both PI.1 and PII in term placenta of normal and diseased animals. In conclusion, a mechanism other than promoter methylation is responsible for decreased aromatase expression in placental cotyledons of animals suffering from RFM.     

Detection of novel single-nucleotide polymorphisms (SNPs) in the CYP21 gene and association analysis of two SNPs for CYP21 and ESR2 with litter size in a commercial sow population

Altogether 129 F₁ sows from a commercial sow farm with at least four litters were genotyped for the oestrogen receptor 2 gene (ESR2) and cytochrome P450 hydroxylase 21 gene (CYP21) and investigated for associations on the litter‐size parameters: total number born and number born alive. Five novel polymorphisms were found in the 3′‐untranslated region for the CYP21 gene. Genotype and allele frequencies for the CYP21 (position 3462G > A) single‐nucleotide polymorphism (SNP) were 0.434 (GG), 0.504 (AG), 0.062 (AA) and 0.69 (G):0.31 (A), respectively. No association was found between this polymorphism and litter‐size parameters. For the ESR2 gene, the SNP in exon 5 associated with an amino acid substitution MET (allele A) > VAL (allele G) was investigated. Only two genotypes were found leading to allele frequencies of 0.34 (A):0.66 (G). Only number born alive piglets were significantly increased for the AG genotype (p = 0.034) with 11.64 piglets per sow and litter in comparison with the GG genotype, leading to only 10.96 piglets per sow and litter. From these data, it can be concluded that the investigated SNP of the ESR2 gene is associated with the number of liveborn piglets in the commercial population considered, and hence could be useful in selection for litter size. Therefore, this gene should be investigated in additional populations.     

Genetic polymorphism association analysis of SNPs on the species conservation genes of Tan sheep and Hu sheep

Tropical Animal Health and Production - For further understanding the genetic control mechanisms of growth and development in Tan sheep, and culturing good traits on meat performance, which is very...     

Effects of SNPs and alternative splicing within HGF gene on its expression patterns in Qinchuan cattle

Background: Identification of genetic variants, including SNPs(Single Nucleotide Polymorphisms), CNVs(Copy Number Variations) and alternative splicing, within functional genes has received increasing attention in animal science research. HGF(Hepatocyte Growth Factor) is a very important growth factor that works as a mitogen or a morphogen during tissue growth, development and regeneration. However, to date, the functions of genetic variants within the bovine HGF gene, particularly their effects on m RNA expression, have not been determined well.Results: The present study aimed to perform association analysis between genetic variants and m RNA expression for the bovine HGF gene in Qinchuan cattle using various strategies, including PCR-RFLP(Restriction Fragment Length Polymorphism), q PCR(Quantitative Real-time quantitative PCR), TA cloning, DNA sequencing and bioinformatics analysis. A total of five SNPs were identified and only SV1 locus significantly affected HGF m RNA expression in fetal skeletal muscle(P 0.05). Heterozygous genotype individuals showed significantly higher HGF expression(P 0.05), which was significantly greater in the CTCCAGGGTT combined genotype than that in theCCCCGGGGTT combined genotype(P 0.05). In addition, two alternative splicing variations, HGF-W and HGF-M,were identified, which resulted from alternative 3′ splice sites of exon 5, and HGF-W showed higher m RNA levels than HGF-M in all tissues.Conclusion: In summary, genetic variations within the HGF gene affected m RNA expression. These findings provide new insight into the molecular characteristics and functions of bovine HGF.     

滩羊“两年三产”营养水平的研究

为了探究滩羊两年三产生产体系的最适营养需要,选择2~4岁断奶空怀滩羊母羊90只,根据不同生理阶段(0~90 d空怀期和妊娠前期,91~150 d妊娠后期和151~210 d泌乳期)随机分成3组,每组30只,每个生理阶段分别设计高、中、低3种营养水平日粮,测定滩母羊各繁殖阶段体重变化、妊娠率、繁殖率等相关指标。结果显示:高营养组90%完成两年三产,年繁殖率、妊娠期增重最高,羔羊初生重显著高于中营养组(P0.05)、极显著高于低营养组(P0.01),且饲养成本最低。结果表明:高营养组为滩羊两年三产生产体系的最适营养需要。     

绵羊FecB基因研究进展

Booroola merino羊的多胎性能开辟了影响动物繁殖性状主基因研究的新篇章,可为提高羊的繁殖性能从分子水平提供理论指导.作者综述了绵羊FecB基因的最新研究进展.     

Association of SNPs in exon 2 of the MHC B-F gene with immune traits in two distinct chicken populations: Chinese Beijing-You and White Leghorn

Abstract

Antibody titers raised for vaccinations against avian influenza (AI) and Newcastle disease (ND) were higher in Chinese Beijing-You (BJY) than in White Leghorn (WL) (P<0.001), but there was no breed difference in titers for sheep red blood cells (SRBC). Genotyping by PCR-SSCP identified seven haplotypes in WL and 17 in BJY. After sequencing PCR products (35 and 85, respectively), 43 (WL) and 47 (BJY) single nucleotide polymorphisms (SNPs) were found in the 264 bp of exon 2. In WL chickens, significant associations were found with antibody responses to AI (two SNPs), ND (six SNPs), and SRBC (one SNP), while in BJY there was association with responses to ND (two SNPs) and SRBC (two SNPs), but none with AI. These results indicate that the genomic region bearing exon 2 of the major histocompatibility complex B-F gene has significant effects on antibody responses to SRBC and vaccination against AI and ND. Different SNPs affected antibody titers for each of the antigens and they differed between these very distinct breeds.     

Seven novel single nucleotide polymorphisms identified within river buffalo (Bubalus bubalis) lactoferrin gene

The present study aimed at identifying single-nucleotide polymorphic (SNP) sites in different coding and non-coding regions of lactoferrin gene in Indian riverine buffaloes. A total of 102 animals from six different river buffalo breeds were screened at six bubaline lactoferrin gene loci. Single-strand conformation polymorphism (SSCP) analysis revealed monomorphic patterns at three loci LtfE2, LtfE11, and LtfE14 while a total of eight distinct patterns were observed in the other three loci viz. LtfE5, LtfE10, and LtfE16 which correspond to respective exons and their flanking regions. Sequence analysis of different SSCP variants revealed the presence of two SNP sites within the coding (exon 16) region and five SNP sites in flanking non-coding regions (intron 4 and intron 9). Both SNPs within exon 16 were found to be synonymous. The SNPs and haplotypes identified in the present study could serve as potential markers for association with susceptibility/resistance to mastitis in buffaloes.     

绵羊Callipge基因的研究进展

从遗传方式、基因座定位、遗传效应及在动物育种中的应用等方面,对一个引起绵羊双臀性状的Callipyge基因进行了阐述,旨在加强对Callipyge基因的认识和理解,从而为其今后的开发利用提供理论依据.     

绵羊FecB基因打靶载体构建

利用peGFP-C1,pRET.IL.PGK-TK和pMD19-T Simple等基本质粒,构建绵羊FecB基因打靶载体。以克隆载体pMD19-T Simple为载体骨架,插入一个正选择标记eGFP基因、一个负选择标记基因HSV-tk基因,并在eGFP基因两侧各添加一个同源长臂和同源短臂,从而构建绵羊FecB基因打靶载体。结果:经多个限制性内切核酸酶酶切鉴定和测序证实,所构建的基因打靶载体符合设计要求,表明成功构建了绵羊FecB基因打靶载体。     

Relationship between three novel SNPs of BRCA1 and canine mammary tumors

The BRCA1 gene plays an important role in the development of human breast cancer, and recent research indicated that genetic variations of BRCA1 are also related to canine mammary tumors (CMTs). Here, using rapid amplification of cDNA ends (RACE), we cloned the 5′- and 3′-UTRs of BRCA1. By direct sequencing of the flanking sequences of the 5′- and 3′-UTRs of BRCA1, three previously unreported single-nucleotide polymorphisms (SNPs) were identified, two (−1228T >C, −1173C >T) in the putative promoter regions and one non-synonymous SNP (63449G >A) in exon 23. Compared with 16 normal samples, the sequences from 34 CMTs suggested that SNP (−1173C >T) was associated with the development of CMTs (odds ratio (OR)=2.57, 95% confidence interval (CI): 1.07–6.15).     

Localisation and characterisation of ovine immunglobulin within the sheep scab mite, Psoroptes ovis

Ovine IgG was detected in homogenates of repeatedly washed Psoroptes ovis. Some of the immunoglobulin in the homogenates was fragmented although the host IgG present in mite washings was largely intact. The host immunoglobulin was immuno-localised to the surface or cytoplasm of the gut cells of feeding stages of freshly harvested P. ovis examined by cryosectioning. A similar distribution of rabbit IgG was detected in P. cuniculi. The IgG demonstrated in the mite gut represented partially digested as well as intact immunoglobulin. The presence of intact host immunoglobulin suggests that P. ovis may be susceptible to vaccination by the gut antigen approach, a method used successfully for blood-feeding ectoparasites like Boophilus microplus.     

Haemolytic activity of sheep complement for two assay systems

Sheep complement (C) is haemolytic for sheep erythrocytes sensitized with rabbit antibody (sheep E-rabbit A) provided serum is used as soon as possible after collection. If left at 4 °C to separate from the clot, serum C activity for sheep E-rabbit A is markedly reduced. Heparinized plasma retains its haemolytic titre for at least 24 h at 4 °C. Plasma from Mg²⁺-ethyleneglycoltetraacetic acid (EGTA) blood is non-haemolytic, but addition of Ca²⁺ partially restores the titre. A high concentration of rabbit A is necessary to sensitize sheep E.Sheep C is haemolytic for human erythrocytes sensitized with sheep antibody (human E-sheep A) in the presence of Mg²⁺-EGTA. This C activity is stable at 4 °C for 24 h in serum, Mg²⁺-EGTA plasma and heparinized plasma. Haemolytic activity of serum heated at 50 °C for 30 min was restored by a factor B containing CM-cellulose fraction of foetal lamb serum in the presence of Mg²⁺-EGTA for human E-sheep A but not sheep E-rabbit A.These findings show that sheep C haemolysis of sheep E-rabbit A requires a Ca²⁺-Mg²⁺-dependent pathway that is labile in vitro for 24 h at 4 °C.     

A novel T177P missense variant in the HSPA8 gene associated with the low tolerance of Awassi sheep to heat stress

Tropical Animal Health and Production - This study was conducted to identify the association of coding variations in the HSPA8 gene with heat stress in two different breeds of sheep. All the coding...     

A novel approach to the control of anthelmintic-resistant Haemonchus contortus in sheep

This paper reports attempts to control a resistant strain of Haemonchus contortus on pasture by replacing it with a susceptible strain. By making use of artificially infected donor sheep, six camps (paddocks) were seeded with a resistant field strain of H. contortus until it was confirmed by means of worm-free tracer lambs that the grazing had become infective. Thereafter, using donor sheep infected with a susceptible laboratory strain of H. contortus for seeding the pasture, attempts were made at various times of the year to replace the resistant strain on the pasture with the susceptible strain in five of the camps. The sixth remained as a control camp, in which no attempt was made to replace the resistant strain. In two of the five test camps, the susceptible strain was introduced in the autumn after 8-10 weeks of nil grazing; in the remaining three camps the introduction was made in spring (two camps) or summer without having a period of nil grazing. The susceptibility of the worm strains introduced initially, as well as of those that developed in the various camps, was gauged both by controlled non-parametric anthelmintic slaughter trials at the beginning and at the conclusion of the trial, and by an in vitro egg hatch test. A reversion to susceptibility occurred in three of the five camps. These included both of the camps infested with the susceptible strain in the spring and one of the two infested in the autumn. Possible reasons for the failure to replace the resistant strain in the remaining two test camps are discussed.     

5号染色体两候选SNP基因定位以及与绵羊臀尾性状的关联分析

脂尾(臀)性状是绵羊逆境生存的耐逆性状,其臀尾部大量储积脂肪的基因组变异研究目前仍是空白。本研究以国外新近报道的5号染色体上存在的可能与尾脂性状相关联的两处SNP为研究对象,分别采用PCR-RFLP和PCR-SSCP的方法检测两SNP在我国尾型极端差异的阿勒泰羊、湖羊、细毛羊以及藏羊群体中的多态性、基因型与等位基因分布,验证两SNP是否可作为我国低脂绵羊新品种培育的分子标记。研究结果表明:两SNP在我国脂尾(臀)型阿勒泰羊、湖羊与瘦尾型中国美利奴羊细毛羊和藏羊群体中高度分化,两SNP的T等基因与A等位基因在瘦尾型绵羊品种中高频出现,存在与瘦尾性状密切相关的趋势,提示此两个SNP可作为选育低脂绵羊新品种的有效分子标记。