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Extraocular Modification of Photoreception in Intact and Pinealectomized Coturnix

1974; Elsevier BV; Volume: 53; Issue: 6 Linguagem: Inglês

10.3382/ps.0532035

1525-3171

T.D. SIOPES, Wilbor O. Wilson,

Avian ecology and behavior

The single and combined effects of pinealectomy and bilateral ocular enucleation on sexual maturation and the photo-gonadal response of male and female coturnix (Japanese quail, Coturnix coturnix japonica) were studied. Observations were made on cloacal gland activity in males and rate of egg production in females. Immature males and females were exposed to short (6L:18D) photoperiods until sexually mature. Thereafter, a period of either short days (6L:18D) or total darkness was used alternately with long days (16L:8D) to induce gonadal regression or recrudescence, respectively. These alternating periods were continued until the birds were 59 weeks old. Neither the presence of the eyes nor the pineal gland were essential to gonadal maturation and function in the coturnix. Accelerated sexual maturity of males was observed after enucleation, and pinealectomy did not alter this response. Enucleated coturnix were resistant to photo-induced gonadal regression, and pinealectomy did not prevent this response. Thus, the eyes appeared to be necessary for the termination of egg production and cloacal gland activity due to shortened photoperiods. The data indicated an extraocular modification of the photo-induced gonadal activity but did not implicate the pineal as a functional mediator of these responses.