Development, validation, and utilization of a novel antibody specific to the type III chicken gonadotropin-releasing hormone receptor

Two gonadotropin-releasing hormone receptors (GnRH-Rs) have been characterized in chickens to date: cGnRH-R-I and cGnRH-R-III, with cGnRH-R-III being the predominant pituitary form. The purpose of the present study was to first validate a novel antibody for the specific detection of cGnRH-R-III and second, using this antibody, detect changes in cGnRH-R-III protein levels in the pituitary gland of male and female chickens during a reproductive cycle. The localization of cGnRH-R-III within the anterior pituitary gland was also determined. Western blotting of pituitary extracts and transiently transfected COS-7 cell lysates revealed that our antibody is highly specific to cGnRH-R-III protein. Similarly, when used in immunocytochemistry, this antibody specifically detects cells expressing cGnRH-R-III and not cGnRH-R-I. Western blot analyses of chicken pituitary gland homogenates show that cGnRH-R-III protein levels are significantly greater in sexually mature birds than in immature birds or birds at the end of a reproductive cycle (P < 0.0001). A similar pattern was observed for both males and females. Additionally, the antibody was able to detect cGnRH-R-III in cells along the periphery of the cephalic and caudal lobes of the anterior pituitary where the cells containing the gonadotropins are located. In summary, we successfully validated a novel antibody to cGnRH-R-III and showed levels of cGnRH-R-III protein in the pituitary fluctuate with respect to the reproductive status in both male and female chickens.     

Assessment of mungbean genotypes for durable resistance to Yellow Mosaic Disease: Genotype × Environment interactions

Yellow mosaic disease (YMD) is the major constraint of mungbean for realizing high productivity worldwide. Moreover, management of disease using YMD‐resistant genotypes is the simplest approach. Therefore, based on a preliminary screening of 220 genotypes during the year 2010 and 2011 at 17 locations, a set of 25 genotypes was further selected to evaluate at six locations over 2 years for identification of more stable resistant genotypes. The genotype and genotype × environment (GGE) analysis indicated that the genotypes and environment effects were significant (P < 0.001) for YMD incidence. Interestingly, the GGE biplot analysis successfully accounted for 74.71 per cent of the total variation with three genotypes (ML 818, ML 1349 and IPM 02‐14) showing high degree of resistance and stability over the locations. Notably, a strong positive association was observed between disease reaction and temperature, relative humidity and rainfall. As crop is grown in diverse growing environments, aforementioned genotypes can be used as stable/durable sources for future breeding programme to develop YMD‐resistant cultivars.     

Pituitary progesterone receptor expression and plasma gonadotrophin concentrations in the reproductively dysfunctional mutant restricted ovulator chicken

Female mutant restricted ovulator (RO) chickens of the White Leghorn strain carry a naturally occurring single nucleotide mutation in the very low density lipoprotein receptor (VLDLR) gene. Due to this mutation, RO hens fail to express a functional VLDLR protein on the oocyte membrane, which results in an impaired uptake of circulating yolk precursor macromolecules. Mutant RO hens subsequently develop hyperlipidemia and generally fail to lay eggs due to follicular atresia. Since RO hens also reportedly have three-fold higher basal plasma estrogen concentrations, combined with four-fold lower levels of circulating progesterone as compared to wild-type (WT) hens, we hypothesized that RO hens would have an increased abundance of pituitary progesterone receptor (PR) mRNA and PR isoforms A and B as well as alterations in circulating gonadotrophin levels. Quantitative PCR assays revealed significantly greater (P相似文献