Shanbhag B A, Prasad B S
Department of Zoology, Karnatak University, Dharwad, India.
J Exp Zool. 1992 Dec 15;264(4):454-60. doi: 10.1002/jez.1402640411.
Abdominal fat body mass of Calotes versicolor showed annual changes that were universal related to the changes in ovarian somatic (GSI) and hepatosomatic (HSI) indices. Fat bodies were absent in late breeding phase (June-August). Thirty day fatectomy (FBX) during prebreeding phase significantly reduced GSI, HSI, and total number of extrastromal follicles; also, recruitment of vitellogenic follicles was arrested and ateretic follicles increased. The FBX during postbreeding phase had no such effect, whereas in 30 day ovariectomised (OvX) lizards in prebreeding phase fat body mass significantly increased but HSI decreased. However, in lizards in prebreeding phase, E2 caused a significant decrease in fat body mass and an increase in HSI, while during the postbreeding phase there was a significant increase in HSI but the fat bodies were not affected. The above findings suggest that the development of the first clutch of vitellogenic follicles in the lizard utilises lipids stored in the fat bodies and that the growth of the subsequent clutches of vitellogenic follicles is met through the intake of food, which is abundant in the latter part of the breeding phase. The fat bodies are not needed for the growth of previtellogenic follicles. The fact that lipolytic action of E2 occurs only during the breeding phase suggests that responsiveness of the fat bodies to the steroid is related to the reproductive phase and that during postbreeding phase of the lizard they become refractory to E2.
变色树蜥的腹部脂肪体质量呈现出年度变化,这些变化普遍与卵巢体(GSI)和肝体(HSI)指数的变化相关。在繁殖后期(6月至8月)脂肪体不存在。繁殖前期进行30天的脂肪体切除(FBX)显著降低了GSI、HSI和基质外卵泡的总数;此外,卵黄生成卵泡的募集被阻止,闭锁卵泡增加。繁殖后期进行FBX没有这种效果,而在繁殖前期进行30天卵巢切除(OvX)的蜥蜴中,脂肪体质量显著增加但HSI降低。然而,在繁殖前期的蜥蜴中,E2导致脂肪体质量显著下降和HSI增加,而在繁殖后期HSI显著增加但脂肪体未受影响。上述发现表明,蜥蜴中第一批卵黄生成卵泡的发育利用了储存在脂肪体中的脂质,而随后几批卵黄生成卵泡的生长是通过摄取食物来满足的,在繁殖后期食物丰富。卵黄生成前卵泡的生长不需要脂肪体。E2的脂解作用仅在繁殖期发生这一事实表明,脂肪体对该类固醇的反应性与生殖阶段有关,并且在蜥蜴的繁殖后期它们对E2变得不敏感。