Zoological Studies

Age and Sex Dependent Variations in the Arginine Vasotocin Gene in Response to Dehydration in the Chicken and Japanese Quail

Rohit Seth and Chandra Mohini Chaturvedi (2004) The present study was conducted to investigate and compare age- and sex-dependent central and peripheral effects of osmotic stress (4 d of water deprivation) in 2 poultry species: the chicken (Gallus gallus domesticus) and Japanese quail (Coturnix coturnix japonica). Following dehydration in sexually immature (young) and mature (adult) birds of both sexes, Northern blot analysis was performed, and changes in body weight and plasma osmolality were estimated. Following 4 d of water deprivation, young and adult quail of both sexes exhibited significant losses of body weight and increases in plasma osmolality compared to their hydrated controls. Northern blot analysis revealed 1.24- and 1.95-fold increases in AVT transcripts in water-deprived adult male and female and 1.45- and 1.42-fold increases in young male and female quail, respectively; whereas 1.27- and 1.6- and 1.44- and 1.65-fold increases compared to the controls in water-deprived adult and young, male and female chickens, respectively, were found. We concluded that osmotic stress induced by water deprivation is a potent stimulator for hypothalamic gene expression in the chicken and Japanese quail, and that the response of the AVT system varies with the reproductive age and sex of the birds. In view of the remarkable difference in the amount of hypothalamic AVT transcripts and the peripheral responses of young and adult birds to osmotic stress, the present study suggests a modulatory role of sex steroids in water homeostasis.