Expression analysis of melatonin receptor subtypes in the ovary of domestic chicken

Melatonin (N-acetyl-5-methoxytryptamine), an indole hormone, regulates various biological functions through three different receptor subtypes (Mel-1a, Mel-1b, and Mel-1c). However, the distribution of different melatonin receptor subtypes in chicken reproductive tissues was not known. In the present investigation, the partial sequences of ovarian melatonin receptor subtypes (Mel-1a, Mel-1b, and Mel-1c) were characterized. Further, the expression profile of melatonin receptor subtypes in the granulosa and theca layers of different preovulatory and postovulatory follicles (POF) were studied by semi-quantitative RT-PCR. The expression of all three subtypes of melatonin receptors were observed in the ovary of domestic chicken. Analysis of partial sequences of ovarian melatonin receptors revealed that the melatonin subtypes were identical to the brain receptors. In small white ovary follicles, we observed only the expression of mel-1b receptors, but not mel-1a or mel-1c receptors. In yellow follicles, all the three subtypes of receptors expression were noticed. Interestingly, we observed the expression of mel-1a receptor only in thecal layer, but not in granulosa layer. In contrast, mel-1b and -1c receptors were expressed in both granulosa and thecal layer. During the regression of POF, we observed significant upregulation of melatonin receptors (mel-1a and 1c) expression, that downregulated in the later stages of regression. We assume that the expression of melatonin receptors might have been influenced by the atresia or apoptosis of different follicular layers in POF. Our findings suggest that the differential distribution of melatonin receptor subtypes might have distinct downstream cellular functions in the ovarian tissues.     

Dietary administration of androgens induces sterility in the female-heterogametic black molly, Poecilia sphenops (Cuvier & Valenciennes, 1846)

Treatment of newly born Poecilia sphenops (Cuvier & Valenciennes, 1846) with 50 mg 17α-methyl-testosterone or 200 mg androstenedione per kg diet for 30 days induced a maximum of 59% males; attempts to increase masculinization by increasing dose or treatment duration resulted in higher mortality. The growth of the treated males was significantly (25-53% retarded. Anabolic enhancement of relative growth (percentage of control) of the treated males and females was apparent in juveniles but not in adults. Hormonal induction of masculinization impaired the gonadal development and courtship activity, and led to the production of sterile males and females.     

Investigation on mechanical behaviour of twisted natural fiber hybrid composite fabricated by vacuum assisted compression molding technique

Nowadays, automotive, packaging and sport equipment industries are using natural fibre based composite materials as they are cheap, abundantly available and having a lot of ecological advantages. The main objective of this paper is to introduce a new concept of fibre twisting and to investigate the effect of twisting and the fibre orientation on the mechanical properties of bio degradable green composites. Here, the composites are fabricated by vacuum assisted compression molding technique in which the problems of hand lay process are eliminated. Here, two fibers namely twisted neem and twisted kenaf are sandwiched between layers of glass fibres to enhance the stiffness and strength of the laminates. Initially, the fibers are alkalized to increase the mechanical properties. The result shows that there is a significant improvement in mechanical properties of composites due to the presence of twisted fibers. It also shows the influence of fiber orientation on mechanical properties.     

Effect of Incorporation and Unincorporation of Azolla Biofertilizer on the Grain Yield of Rice

Azolla pinnata R. Brown was used as a biofertilizer for rice crop in early and late wet seasons of 1985–86. Azolla as dual crop with rice increased the grain yield significantly over uninoculated control. Incorporation of Azolla increased the yield components and grain yield higher than leaving Azolla on water surface without incorporation. Azolla incorporation with 90 kg nitrogen/ha recorded the highest plant height, tiller numbers/ hill, panicles/m² and 1000 grain weight and grain yield of rice.