Exploring basal glucose, thyroid hormones and gene expression dynamics during sexual maturation in Japanese quail

Shit, N., Sastry, K.V.H., Singh, G., Singh, R. and Mohan, J. 2023. Exploring basal glucose, thyroid hormones and gene expression dynamics during sexual maturation in Japanese quail. Indian Journal Poultry Science, 58(3): 273–279.

The aim of the present study was to explore and correlate the changes of basal glucose, thyroid hormones and mRNA expression of caspase-2, B-cell lymphoma -XL (Bcl-XL) and heat shock protein-70 (HSP-70) genes in Japanese quail during sexual maturation. Sixty quail pullets (5 weeks) were managed under uniform husbandry condition at 14:10 h photo-schedule. Six quail hens each were sacrificed on 1, 3, 7, 10, 13, 16, 19, 22, 25 and 28 days of the study. The mean concentration of serum glucose and thyroid hormones (T₃ and T₄) were assessed by GOD-POD and EIA method, respectively. The mRNA expression of caspase-2, Bcl-XL and HSP-70 genes was performed in reproductive tissues including hierarchical follicles i.e. F₁, F₂ and F₃ using real-time PCR. The concentration of basal glucose was significantly (P<0.05) increased at the initiation of maturation and changed invariably thereafter. The mean T₃ concentration showed a significant (P<0.05) reduction in advance to the attainment of sexual maturity without noticeable change in T₄ concentration. A significant (P<0.05) up-regulation in the magnitude of expression of caspase 2 and Bcl XL gene was noticed in F₃ and F₁ follicle respectively when HSP 70 varied inconsistently in both ovary and follicles. It concludes that alteration in biochemical attributes and mRNA expression of certain genes may positively be related in attaining sexual maturity in Japanese quail.