Increasing the efficiency of homologous recombination vector-mediated end joining repair by inhibition of Lig4 gene using siRNA in sheep embryo fibroblasts.

In animal cells, inhibition of non-homologous end joining (NHEJ) pathway improves the efficiency of homologous recombination (HR)-mediated double-strand brakes (DSBs) repair. To improve the efficiency of HR in sheep embryo fibroblasts, the NHEJ key molecule DNA ligase 4 (Lig4) was suppressed by siRNA interference. Four pairs of siRNA targeting Lig4 were designed and chemically synthesized.

[Detection and analysis of polymorphisms of 59571364 and 59912586 loci on X chromosome in fat-tail and thin-tail sheep flocks].

In order to analyze the correlation of tail fat deposition and two SNP loci on Ovis arise chromosome X and provide a theoretical basis for using molecular assisted selection technology in further low-fat sheep breeding, the breeds with extreme differences in tail types (Altay, Small Tail Han Sheep, Hu, Chinese Merino and Suffolk) were used to detect the polymorphisms of two SNP loci on X chromosome and the haplotypes with PCR-RFLP method. The results showed that the TT genotype at 59571364 locus and GG genotype at 59912586 locus were preponderant genotypes in thin-tailed Chinese Merino and Suffolk sheep flocks, while the percentage of the two genotypes in fat-tailed (fat-rmup) Altay and Hu flocks is less than 2%. Haplotype analysis showed that CA haplotype is the main haplotype, the percentage of CA is up to 55%, and the percentage of CA and TA haplotypes together was 88.

[Correlation analysis between polymorphism of the 59383635th locus on X chromosome and fat-tail trait in sheep].

Fat tail or fat rump is one of essential traits for surviving in harsh environments, and the mechanism of fat deposition and its inheritable characters in sheep are still unclear. Therefore, the 59383635th locus on X chromosome in our unpublished chip data was chosen as candidate SNP, PCR-SSCP method was used to detect genotypes in five sheep breeds which have extreme differences in tail types (Altay, Small Tail Han Sheep, Hu, Chinese Merino and Suffolk), and the mathematical model was employed to analyze the correlation between the polymorphism and the trait of fat tail or fat rump. The results in this study showed that the high frequency of allele T exists in Altay flock, and the frequency of allele C appears to be particularly high in the thin tail sheep breeds.

[Expression of Myogenin and MCK genes regulated by PI3K/AKT pathway].

Many intracellular signaling pathways regulate skeletal muscle differentiation. Among them, PI3K/AKT pathway plays an important role. But the mechanisms of chromatin regulation remain unclear.

[shRNAs driven by K14 promoter induce tissue-specific RNA interference].

RNA interference is an efficient method for exploring gene function. Accumulating evidence suggests that RNA Pol II promoters can direct cell- or tissue-specific gene silencing. A eGFP-shRNA fusion construct transcribed from an RNA Pol II promoter (K14 promoter) was used to induce gene-specific shRNA silencing ofBMP4 gene expression.

[Research progress on genetic diversity of sheep PRNP and resistance breeding].

Prion protein (PrP) is a pathogeny identified in recent years, which infects both mankind and other mammals. It has been proved that PrP is a sole protein able to duplicate and propagate with itself. PrP can express in many tissues and has important physiological functions in many species of animals.

Effects of SOF and CR1 media on developmental competence and cell apoptosis of ovine in vitro fertilization embryos.

The present study was to investigate effects of synthetic oviductal fluid (SOF) and Charles Rosenkrans medium (CR1) culture systems on developmental competence and cell apoptosis of ovine in vitro fertilization (IVF) embryos. Ovine presumptive IVF zygotes were cultured in the following six media: (1) SOF supplemented with amino acids (SOFaa) and 8 mg/ml bovine serum albumin (BSA) for 9 days (SOFaaBSA); (2) SOFaa supplemented with 10% fetal bovine serum (FBS) for 9 days (SOFaaFBS); (3) SOFaaBSA for first 3 days and then SOFaaFBS for later 6 days (SOFaaBSA-FBS); (4) CR1 supplemented with amino acids (CR1aa) and 8 mg/ml BSA for 9 days (CR1aaBSA); (5) CR1aa supplemented with 10% FBS for 9 days (CR1aaFBS); (6) CR1aaBSA for first 3 days and then CR1aaFBS for later 6 days (CR1aaBSA-FBS). The rates of blastocyst and hatched blastocyst in group 1, group 3 and group 6 were not different (P>0.

[A novel polymorphism of IGFBP-3 gene and its relationship with several wool traits in Chinese Merino sheep].

In this study, PCR-SSCP analysis was used to identify genetic variation in IGFBP-3 gene in Chinese Merino and Kazakh sheep. A PCR product of 178 bp corresponding to partial intron1 illustrated three unique binding patterns by SSCP analysis. Frequencies of the genotype AA, AB, BB and allele A, B in Chinese Merino sheep were 0.

[Relationship between genetic diversity of chromosome 6 determined by microsatellite markers and litter size in Hu sheep].

Genetic diversity and relationship with litter size were analyzed in Hu sheep using 6 microsatellite markers LSCV043, BMS2508, GC101, 300U, Bulge5, and 471U, which were closely linked to FecB gene. Thirty-four alleles and 53 genotypes were detected at 6 microsatellite loci, which were all polymorphic. Three markers LSCV043, BMS2508 and 300 U were highly polymorphic loci.

[The preparation of oligonucleotide chips for detecting BMPR-IB gene polymorphism in sheep].

BMPR-IB gene increases ovulation rate and litter size as a major gene in Chinese Merino, because of 746 A to G mutation. The aim of this study was to make oligonucleotide chips to determine single nucleotide polymorphism (SNP) in BMPR-IB gene. The oligonucleotide chips were manufactured by using six sequence-specific oligonucleotide probes derived from polymorphic regions in the mutation and spotting the probes by microarrayer onto the aldehyde modified glass slides.

[Relationship between microsatellite DNA polymorphism and hind-quarter development in sheep chromosome 18].

Ten highly polymorphic microsatellite loci possibly linked to or correlated with the Callipyge gene were selected, according to the genetic map and linkage map of sheep chromosome 18. They were ILSTS54, TGLA337, HH47, TGLA122, BP33, OB2, BM3413, MCM38, MCMA26 and CSSM18. Polymorphisms of these microsatellites were detected in 61 Dorset (male) x Xinjiang fine wool sheep (female) samples and 76 Suffolk (male) x Xinjiang fine wool sheep (female) samples.

The tissue distribution and developmental changes of ghrelin mRNA expression in sheep.

Male Kazak sheep and Xinjiang fine wool sheep, six for each different age group (days 2, 30, 60, 90 and 120), were used in the present study to investigate the tissue distribution and developmental changes of ghrelin mRNA expression in abomasum; however, there was no 120-day-old Kazak sheep. After measurement of body weight, the tissues such as hypothalamus, pituitary, heart, liver, rumen, reticulum, omasum, abomasum, duodenum, and longissimus dorsi muscle were sampled. And the total RNA of different tissues was extracted to determine the abundance of ghrelin mRNA by RT-PCR and real-time PCR.

Polymorphism of FecB gene in nine sheep breeds or strains and its effects on litter size, lamb growth and development.

Nine sheep breeds or strains, including 615 individuals were screened with forced PCR RFLP method for the FecB gene to study the polymorphism and its effects on litter sizes, body weights and body sizes. Results show that the polymorphism frequencies of FecB gene are significantly imbalanced in these breeds or strains. The Hu sheep were all homozygous carriers (BB).

[Polymorphism analysis of genes associated with hindquarters muscular development on chromosome 18 in Xinjiang meat sheep].

Through polymorphism analysis of genes associated with hindquarters development on chromosome 18 in Xinjiang meat sheep, we sought genes that are associated with increased hindquarters musculature in the hope to provide theoretical guidance to molecular marker-assisted selection of meat sheep. The polymorphism of Callipyge (CLPG) gene was analyzed by PCR-SSCP and PCR-RFLP in populations of Dorset and Suffolk breeds and their F1 and F2 crosses with local Xinjiang Fine Wool sheep. Results showed that there was no PCR-RFLP polymorphism at 103849 bp in the region between DLK1 and GTL2 on chromosome 18, which suggested that hindquarters over-development was not controlled by the callipyge gene (CLPG) in Xinjiang meat sheep group.

The developmental changes and effect on IMF content of H-FABP and PPARgamma mRNA expression in sheep muscle.

Male Kazak sheep and Xinjiang fine wool sheep of different ages were selected to investigate the developmental changes and effect on intramuscular fat (IMF) content of heart fatty acid-binding protein (H-FABP) and peroxisome proliferator-activated receptor gamma (PPARgamma) mRNA expression in muscle. Longissimus dorsal muscle was sampled to measure IMF content; and total RNA was extracted to determine H-FABP and PPARgamma mRNA expression levels by real-time PCR. The results showed that: (1) The IMF content increased continuously with growing and showed significant differences (P<0.

Polymorphism of FecB gene in nine sheep breeds or strains and its effects on litter size, lamb growth and development.

Nine sheep breeds or strains, including 615 individuals were screened with forced PCR RFLP method for the FecB gene to study the polymorphism and its effects on litter size, body weight and body size. Results showed that the polymorphism frequencies of FecB gene were significantly imbalanced in these breeds or strains. The Hu sheep were all homozygous carriers of FecB gene(BB).

[Development of a rapid mismatch PCR method using tetra-primer ARMS for detection of BMPR-IB gene mutation in sheep].

Tetra-primer ARMS PCR is a rapid, simple and efficient method for the detection of single nucleotide polymorphism (SNP). Bone morphogenetic protein receptor IB (BMPR-IB) gene is a major effect gene that controls prolific trait in Booroola Merino sheep. The aim of this study was to establish a tetra-primer ARMS PCR method for the detection of BMPR-IB genotype.

[Detection of major gene on litter size in sheep].

The current study was designed to detect SNPs within BMP15 and BMPR-IB gene and investigate the effect of the genes on sheep litter size. Four sheep lines, HU-Yang, Chinese Merino monotocous, Chinese Merino multiparous for wool production and Chinese Merino multiparous for mutton production, were used in this study. Litter sizes were recorded for each ewe in the four lines.