The effect of castration on developmental patterns of the thyroid expression of TTF-1 and TTF-2 genes was examined by real-time fluorescence quantitative PCR in castrated and intact male Jinhua pigs at d 60, 90 and 120. The results showed that the expression of TTF-1 and TTF-2 genes increased slightly in intact pigs, while they were relatively stable in castrated pigs. Expression of TTF-1 and TTF-2 genes in castrated pigs was higher than in intact animals at d 60 and 90 (P>0.05) and lower at d 120, but differences were not significant (P>0.05). The results indicated that the expression of TTF-1 and TTF-2 genes initially increased after castration. There were significant correlations between TTF-1 gene expression and intramuscular protein and water contents of the longissimus.

In order to make more effective use of the genetic resource of Min pigs, this study was designed to clone the TLR4 gene in Min pig and to identify its alternative splicing isoforms with overlap extension RT-PCR combined with nested PCR methods, and to characterize its tissue expression pattern with competitive RT-PCR method. Three splicing isoforms of TLR4 gene were identified in the Min pig including a special splicing mechanism, the excision of an internal segment of a whole exon. Competitive RT-PCR analysis showed that the three isoforms were ubiquitously expressed in all tissues examined. The results indicated the complexity of structure and function of the porcine TLR4 gene.

In this study, mitochondrial distribution and mitochondrial DNA (mtDNA) copy number changes in porcine oocytes at different periods during maturation in vitro were observed using Mito-Tracker Green and real-time quantitative PCR. The results showed that mitochondria were gradually translocated from the cortex to the perinuclear area of oocytes, and then spread throughout the cytoplasm, and mitochondrial clusters became larger, and stained more deeply. MtDNA copy numbers at 0 h (2520±940), 11 h (3421±346) and 22 h (9748±1928) were not significantly different (P>0.05). mtDNA copy number at 33 h was (39914±1180), significantly higher than that at 0,11 and 22 h (P<0.05) and was (130074 ±78119), at 44 h which was significantly higher than at 33 h (P<0.05). In conclusion, mitochondrial activity was enhanced and mtDNA copy number increased during the course of oocyte maturation.

 This experiment was conducted to study the mechanism of FSH regulation of GDNF expression in Sertoli cells. Inhibitors or activators of signaling pathways were added to Sertoli cells cultured in vitro, and RT-PCR and Western blotting were used to detect the effect of FSH on GDNF expression (mRNA and protein). The results showed that: (1) FSH (50 ng/mL) convincingly activated ERK1/2 with maximum stimulation at 30 min. (2) dbcAMP (100 μmol/L) increased the activity of ERK1/2 and enhanced the level of GDNF protein and its mRNA with a maximum stimulation at 2 h. (3) pre-treatment with U0126 (10 μmol/L, MEK1/2 inhibitor) or H89 (10 μmol/L, PKA inhibitor) inhibited the FSH-stimulation of GDNF protein and mRNA. (4) the FSH-activation of ERK1/2 in cultured SC was time-dependent, with a peak at 20 min and this activation was blocked by the PKA inhibitor H89. These results indicate that FSH can activate ERK1/2 via cAMP-PKA, which then increases the expression of GDNF in Sertoli cells.

The effect of ghrelin on development of chicken prehierarchical follicles was evaluated in this study. The abundance of growth hormone secretagogue receptor (GHSR) mRNA was determined by RT-PCR, and effects of Ghrelin and follicle-stimulating hormone (FSH) on morphology of prehierarchical follicles and laminin (LN) and connexin 43 (Cx43) labeling indexes in granulosa cells were estimated by histological and immunohistochemical methods. The results showed that GHSR mRNA was expressed in both granulosa and theca layers with a stage-specific pattern, and the mRNA abundance reached the peak in the large white follicle (LWF) and small yellow follicle (SYF), and then decreased in larger follicles. After treatment in vitro with ghrelin and FSH for 24 h in vitro, the thicknesses of granulosa and theca layers and density of granulosa cells were significantly increased in both LWF and SYF (P<0.05). In addition, the labelling indexes of LN and Cx43 were remarkably elevated in the granulosa cells (P<0.05). An additive effect of FSH with Ghrelin was demonstrated. In conclusion, the above results indicated that Ghrelin promoted the expression of LN and Cx43 in granulosa cells to enhance intra-follicular cell-cell interactions, subsequently stimulated the proliferation of the granulosa cells, and cooperated with FSH to regulate chicken prehierarchical follicle development.