Molecular cloning and analysis of the partial sequence of Rhinopithecus roxellanae growth hormone gene

Growth hormone gene (GH) ofRhinopithecus roxellanae was amplified by PCR based on the sequences of the reported mammalian growth hormone gene for the first time. The amplified fragment was about 1.8 kb. It was cloned and its upper stream was sequenced. This sequencing region consists of a 5′flanking regulatory region, exon I and part of exon II, intron I of growth hormone gene. Comparing the corresponding sequences of growth hormone gene betweenRhinopithecus roxellanae and the porcine, we concluded that the homology reached 81% in the region, and there was high conservation in the 5′flanking sequence. The kinds of amino acids of exon I and exon II for about 90% were the same to those in pig. Many mutations occurred in the degenerate site of the triplet code. In the nucleotides of intron I, there were only 72% homologies with those in pig. It means that introns and 3′flanking sequence maybe play an important part in growth hormone gene regulation of the different animals.

Association of growth rate with hormone levels and myogenic gene expression profile in broilers

Background： The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1（IGF-1）, triiodothyronine（T3）, thyroxine（T4）, and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results： Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers（P 〈 0.001）. Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers（P 〈 0.05） in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds（P 〈 0.05）. However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene（myostatin） and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers（P 〈 0.05）, relative to slow-growing broilers.Conclusions： Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.

Sequencing and Analysis of G HR Gene from Genomic DNA Pools of Mink

In order to study the single nucleotide polymorphisms （SNPs） of growth hormone receptor （GHR） gene in mink populations, genomic DNA pools of Minghua black minks and silver-blue minks were constructed, and the 10^th exon of GHR gene was PCR amplified from the two DNA pools and sequenced. The results showed that two SNPs were found at position 209 （T/C） and position 533 （C/A） of the 10^th exon of GHR gene in the two mink populations.