Dietary daidzein influences laying performance of ducks (Anas platyrhynchos) and early post-hatch growth of their hatchlings by modulating gene expression.

Our previous studies demonstrated that dietary supplementation of daidzein improves egg production in duck breeders during late periods of the laying cycle. The present study was aimed to clarify whether the growth of ducklings hatched from eggs laid by daidzein-treated hens would be affected, and to elucidate the mechanisms underlying potential trans-generational effects, by determining changes of hormone levels and mRNA expression of relevant genes. Daidzein was added to the basal diet of 415-day-old duck breeders at the level of 5 mg/kg.

Effect of genotype-nutrition interaction on growth and somatotropic gene expression in the chicken.

The neuroendocrine system integrates genotype with external factors such as nutrition to regulate animal growth. To investigate the role of somatotropic axis in the interaction of genotype and nutrition, two series of experiments were conducted using broiler and layer chickens as a model. In the first experiment, both strains of chickens were raised on their respective standard diets and the mRNA expressions of somatotropic genes were investigated on day 5 (D5), D21, and D42 after hatching as composites of genotype and nutrition.

[The developmental patterns of GH-R, IGF-1 and IGF-IR gene expression in adipose tissue of Erhualian and large white pigs].

Growth hormone (GH) is essential for postnatal growth in animal, it regulates numerous cellular functions by direct effect on its receptor (GH-R) in many different tissues. In present experiment single tube semi-quantitative RT-PCR was applied to investigate the developmental patterns of GH-R, IGF-1 and IGF-I R mRNA expression in dorsal subcutaneous adipose tissue of Erhualian and Large White pigs, and 18S internal standards were used as control. Eight Erhualian pigs were sampled at birth, 3, 20, 30, 45, 90, 120, 180 days of age respectively, four Large White boars were sampled at 20, 30, 90, 120, 180 days of age respectively.

[Microsatellite analysis of genetic diversity and phylogenetic relationship of eight sheep breeds in Xinjiang].

To reveal the genetic diversity and syseighttemic relationship of main sheep breeds in north Xingjiang, the genetic polymorphisms of 10 microsatellites in 8 sheep breeds and one first filial generation (F1) in north Xinjiang were studied by means of PCR, polyacrylamide gel electrophoresis and silver staining. Number of alleles, average effective number of alleles (E) and average rates of homozygote of each breeds were counted. According to allele frequencies of ten microsatellites, polymorphism information content (PIC), mean heterozygosity (h) and genetic distances were calculated for each breeds.

[Expression of mRNAs for GHR, IGF-IR, FSHR and LHR in granulosa and theca layers of ovarian follicles of Shaoxing ducks].

Expression of genes encoding growth hormone receptor (GHR), type I insulin-like growth factor receptor (IGF-IR), follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) was measured in granulosa and theca layers of the largest (F1), third largest (F3), fifth largest (F5) preovulatory follicles and large white follicles (LWF) in the ovary of Shaoxing ducks, with relative quantitative reverse transcription-polymerase chain reaction (RT-PCR) using beta-actin as an internal standard. The results showed that GHR mRNA was more abundant in theca layer than in granulosa layer in all the follicles investigated, in theca layer, the LWF follicle expressed highest the level of GHR mRNA, while no differences in granulosa layer were observed among follicles at different stages of development. In contrast, the expression of IGF-IR mRNA in theca layer was evidently lower than that in granulosa layer, but no significant changes were found among different stages of follicles in either layers, except that LWF trended to express higher IGF-IR mRNA in the theca layer compared to other preovulatory follicles.

Developmental patterns of GHr and SS mRNA expression in porcine gastric tissue.

Aim: The present study was aimed to investigate the developmental patterns of growth hormone receptor (GHr) and somatostatin (SS) mRNA expression in porcine gastric tissue and its relationship with gastric growth and gastric functional development.

Methods: Erhualian and Large White boars were selected randomly and sampled at birth (D0), 3, 20, 30, 90, 120 and 180 days of age respectively, meanwhile the bodyweight and gastric weight were recorded. The single tube semi-quantitative RT-PCR was applied in this experiment to investigate the developmental patterns of gastric GHr and SS mRNA expression, the correlations between the patterns of mRNA expression and the relative gastric weight (ratio of gastric weight to bodyweight) and the pepsin contents in gastric mucous membrane were analyzed.

[The developmental patterns of GHr gene expression in gastric tissue of Erhualian and large white pigs].

Pituitary growth hormone (GH) is essential for postnatal growth in animal, it regulates numerous cellular functions by direct effect on it's receptor (GHr) in many different tissues. And it is believed that the abundance of GHr in different tissue determines the tissue sensitivity to GH. However, the regulation of GH on porcine stomach development is still unknown.