Prolactin and gonadal steroids during the reproductive cycle of the Bengalese finch (Lonchura striata var. domestica, Estrildidae), a nonseasonal breeder with biparental care.
Plasma levels of prolactin (Prl), testosterone (T), and progesterone were determined throughout the breeding cycle in pairwise caged Bengalese finches (Lonchura striata var. domestica, Estrildidae), a monogamous altricial passerine with nonseasonal breeding, in which parental behavior including incubation is equally shared between males and females. In both sexes, Prl titers increased 4- to 10-fold during incubation period compared to values during nestbuilding. Likewise, Prl levels after fledging of the young were significantly lower compared to titers during incubation. In males, T increased significantly (15-fold) during nestbuilding compared to all other stages of the breeding cycle. In females, T remained basal throughout the entire breeding cycle. Thus, T levels were elevated only during stages with low Prl titers and vice versa. Progesterone titers were elevated during egg-laying in females and fluctuated without any obvious pattern in males. These results suggest that (1) high levels of Prl are involved in the control of parental behavior of male and female Bengalese finches and (2) Prl secretion is controlled by proximate factors of the early reproductive cycle since reproduction is independent of seasonal factors in this species.
Seiler
H W
HW
Department of Biology, University of Kaiserslautern, Germany.
Gahr
M
M
Goldsmith
A R
AR
Güttinger
H R
HR
D000818:Animals; D001717:Birds / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008297:Male; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood*; D011863:Radioimmunoassay; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D012726:Sexual Behavior, Animal / Q000502:physiology; D013739:Testosterone / Q000097:blood
D012739:Gonadal Steroid Hormones; D013739:Testosterone; D011374:Progesterone; D011388:Prolactin