Conservation of animal genetic resources in the world and its enlightenment to China.

Animal genetic resources in the world are rich and varied. Local species have strong adaptability to the local environment. They are precious resources, and need to be protected by the whole world.

Antibiotic resistance of Streptococcus agalactiae from cows with mastitis.

The aim of this study was to characterise the phenotypic and genotypic antibiotic resistance patterns of Streptococcus agalactiae isolated from cows with mastitis in China. Antibiotic resistance was based on minimum inhibitory concentrations and detection of resistance genes by PCR. S.

[Individual identification and paternity testing of bulls using microsatellite].

The polymorphism distributions of 14 microsatellite loci were detected using the Bovine Paternity PCR Typing Kit (including 11 X-STR) and 3 selected Y-STR microsatellite DNA markers. The genetic diversity were evaluated, and the feasibility of the application to individual identification and paternity testing were discussed. The results showed that all the 14 microsatellite loci had genetic polymorphisms in bulls, and the polymorphism information content (PIC) in loci MCM158 was the biggest (0.

Mitogen-activated protein kinase regulates FSH-induced expression of tissue-type plasminogen activator through an activator protein 1 response element.

We have analyzed a possible role of mitogen-activated protein kinase (MAPK) and activator protein-1 (AP-1) in the regulation of FSH-induced tissue type plasminogen activator (tPA) production in granulosa cells (GCs) prepared from DES-treated immature rats; Treatment of the cells in the presence of FSH with MAPK inhibitors, such as UO126 or SB203580, significantly decreased the FSH-induced tPA production, suggesting that multiple signaling pathways may be involved in FSH-regulated tPA expression. We further examined possible signaling action involved in FSH-activated ERK1/2 and p38 MAPK on tPA production, and observed that FSH receptor occupancy led to both ERK1/2 and p38 MAPK phosphorylation. Such action might be through a protein kinase A-dependent pathway because the observed activation was destroyed by the addition of its specific inhibitor H89 to the culture.

Dose-related actions of GnRH II analog in the cycling rhesus monkey.

Introduction: Gonadotropin-releasing hormone (GnRH) II expression, specific high-affinity receptors for GnRH II and its potent bioactivity in human and baboon tissues led us to hypothesize that GnRH II is a bioactive peptide in primates. We recently demonstrated the contraceptive activity of GnRH II analog in rhesus monkeys. In the present experiment, we extended those studies to the dose-related action of this analog on parameters of luteal function and conception.

Activation of the p38 MAPK pathway by follicle-stimulating hormone regulates steroidogenesis in granulosa cells differentially.

In the present study, we started out to test whether the follicle-stimulating hormone (FSH)-activated p38 MAPK signaling cascade was involved in the regulation of steroidogenesis in granulosa cells (GCs). GCs were prepared from the ovaries of DES-treated immature rats and cultured in serum-free medium. Treatment of GCs with FSH (50 ng/ml) induced the phosphorylation of p38 MAPK rapidly with the phosphorylation being observed within 5 min and reaching the highest level at 30 min.

Stem cell factor modulates the expression of steroidogenesis related proteins and FSHR during ovarian follicular development.

Stem cell factor (SCF) is essential for the development of primordial follicles. By using cultured ovaries from neonatal rats, the effect of SCF on early follicular development was investigated. Steroidogenesis is a hallmark of follicular development.

Role of ERK1/2 in FSH induced PCNA expression and steroidogenesis in granulosa cells.

Follicular development is characterized by both proliferation and differentiation of granulosa cells (GCs) under the control of FSH. However, the cellular mechanism by FSH is not known. Using cultured GCs, we examined whether FSH activated ERK1/2 was involved in the regulation of the proliferation related gene proliferating cell nuclear antigen (PCNA) and steroidogenesis.

Anti-apoptotic action of stem cell factor on oocytes in primordial follicles and its signal transduction.

Stem cell factor (SCF) is essential for the development of primordial follicles. One of its functions is to prevent oocytes from apoptosis. However, the underlying mechanism remains largely unknown.

Contraceptive action of a gonadotropin-releasing hormone II analog in the rhesus monkey.

GnRH I (mammalian GnRH) was previously thought to be the only isoform of GnRH expressed in mammals, but GnRH II (chicken II GnRH) has now been identified in tissues of numerous mammalian species. Specific high-affinity receptors, which bind GnRH II and its analogs, have been identified throughout the reproductive tract, and GnRH II regulation of progesterone and human chorionic gonadotropin have been demonstrated. Thus, we hypothesized that GnRH II acts as a paracrine factor to regulate extrahypothalamic tissue functions and could be used as an effective contraceptive agent.