Shenrong Hu

aPCR-SSCP and DNA sequencing detecting two silent SNPs at KAP8.1 gene in the cashmere goat

Keratin-associated proteins 8.1 gene (KAP8.1) is a structural gene responsible for the cashmere. KAP8.1 protein contains high glycine and tyrosine, which concerns regulation and function of the matrix structure fiber. In this study, the polymorphism of KAP8.1 gene was detected by methods of aPCR-SSCP (asymmetric polymerase chain reaction single-strand conformation polymorphism) and DNA sequencing in 791 individuals from two breeds. The results showed that there were two mutations in this gene. The mutations were described as c.63 T>G and c.66 C>G, which would result in two synonymous mutations in KAP8.1 protein. The findings go against previous research, in which there was not polymorphism at KAP8.1 gene. The reasons might be that different cashmere breeds were detected in two studies. Further analysis of results leads us to believe that the polymorphism of KAP8.1 gene might be relevant to fiber diameter.

A novel c.-274C>G polymorphism in bovine SIRT1 gene contributes to diminished promoter activity and is associated with increased body size

SIRT1, a mammalian homologue for yeast silent information regulator 2 (SIR2), is a NAD(+) -dependent deacetylase that belongs to the class III histone deacetylases. It plays an important role in diverse cellular processes, including stress resistance, mitochondrial function, suppression of inflammation and DNA repair. In this study, we screened and identified a novel polymorphism (c.-274C>G) in the SIRT1 promoter region. In silico prediction reveals that this SNP is in the core of cell cycle-dependent element (CDE)-binding motif. Interestingly, the G allele abolished a CDE-binding site, which suggested its functional significance. In the luciferase assay system, we found that the G allele-containing construct displayed a strikingly lower promoter activity compared with the C allele, which may downregulate SIRT1 expression levels. Additionally, we observed a significant association between the c.-274C>G polymorphism and growth traits in Nanyang cattle, suggesting that anomalous transcription factor-based repression of SIRT1 may increase bovine fat mass and body size.

Novel Polymorphism at the 3′ UTR of the Caprine Adiponectin Gene

As an adipose-derived plasma protein, adiponectin (also called ADIPON, ACRP30), is an adipose tissue-specific secretory protein that plays an important role in the development of metabolic and atherosclerotic disorders, such as obesity, hypertension, type 2 diabetes, and cardiovascular disease, which can stimulate fatty acid oxidation, suppress hepatic gluconeogenesis, and inhibit inflammatory responses (Diez and Iglesias 2003; Yang et al. 2004). It is significantly associated with obesity and weight loss. Moreover, it improves insulin sensitivity by stimulating glucose utilization and fatty acid oxidation through the phosphorylation and activation of AMPK in both skeletal muscle and liver (Yang et al. 2004). Numerous human genetic studies on adiponectin and the metabolic syndrome strongly suggest that adiponectin is one of the causative factors in its pathogenesis, providing significant insights into the genetic makeup of the metabolic syndrome (Yang and Chuang 2006).

Relationships between polymorphisms of IGFBP-3 gene and Cashmere traits in Cashmere goats.

Abstract Lan, X.Y., Pan, C.Y., Zhang, C.L., Hu, S.R., Liu, S.Q., Zhang, Y.B., Lei, C.Z. and Chen, H. 2009. Relationships between polymorphisms of IGFBP-3 gene and cashmere traits in Cashmere goats. J. Appl. Anim. Res., 35: 29–32. To analyze associations of polymorphisms of IGFBP-3 gene with cashmere traits in Inner Mongolia white Cashmere (IMWC) goat, significant statistical results are found in cashmere yields between individuals with H1H1 and H2H2 genotypes (P<0.05). The individuals with genotype H1H1 had higher cashmere yield than that of genotype H2H2 in three-year-old (P<0.05), but trend was reversed in five-year-old (P<0.05). Therefore, this study provided possible support for influence of IGFBP-3 gene on cashmere yield which might be at least partially dependent on age and circulating levels of PRL in Inner Mongolia white Cashmere goats.

A dual color fluorescent reporter system for the real time detection of promoter activity

Understanding the mechanisms controlling transcription of a gene requires the identification and characterization of its cis-acting regulatory elements. A highly useful approach to the identification and characterization of cis-acting elements has been the systematic coupling of genomic fragments to reporter constructs, so called “promoter bashing”. The expression from such reporters must be normalized for differences in transient transfection efficiency between cells and replicates. A novel dual color fluorescent reporter system to assay the promoter activity of a genomic DNA fragment of interest was established by cloning a Discosoma red fluorescent protein gene and a green fluorescent protein gene into a single vector, giving a system in which the ratio between red and green fluorescence is proportional to promoter activity. This system allows real time quantitative monitoring of promoter activity. We validated this approach by assaying the cis-acting regulatory potential of the peroxisome proliferators-activated receptor gamma2 gene.