Ovarian and body weight responses of female redheaded bunting to ultra-short photoperiods: demonstration of circadian involvement.
Ultra-short photoperiods, of 3 h less than the threshold photoperiodic demand of female redheaded bunting, when used in variable time cycles (T cycles) cause ovarian growth and an increase in body weight depending upon the period of the cycle. The cycles of period 24 h or close to that (22 h and 26 h) were non-stimulatory whereas 18 h, 20 h, 28 h and 30 h were photo-stimulatory. These results indicate the presence of a circadian component within the bird which regulates their photoperiodic responses.
Tripathi
B K
BK
Department of Zoology, Pachhunga University College, North-Eastern Hill University, Aizawl, India.
D000818:Animals; D001717:Birds / Q000502:physiology*; D001835:Body Weight / Q000528:radiation effects*; D002940:Circadian Rhythm / Q000528:radiation effects*; D005260:Female; D008027:Light; D009929:Organ Size / Q000528:radiation effects*; D010053:Ovary / Q000528:radiation effects*