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Titolo:
Regulation of yolk-androgen concentrations by plasma prolactin in the American kestrel
Autore:
Sockman, KW; Schwabl, H; Sharp, PJ;
Indirizzi:
Washington State Univ, Ctr Reprod Biol, Sch Biol Sci, Pullman, WA 99164 USA Washington State Univ Pullman WA USA 99164 iol Sci, Pullman, WA 99164 USA Roslin Inst, Div Integrat Biol, Roslin EH25 9PS, Midlothian, Scotland Roslin Inst Roslin Midlothian Scotland EH25 9PS 9PS, Midlothian, Scotland
Titolo Testata:
HORMONES AND BEHAVIOR
fascicolo: 4, volume: 40, anno: 2001,
pagine: 462 - 471
SICI:
0018-506X(200112)40:4<462:ROYCBP>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
MATERNAL TESTOSTERONE; CLUTCH SIZE; LUTEINIZING-HORMONE; FALCO-TINNUNCULUS; STURNUS-VULGARIS; LAYING DATE; EGGS; AROMATASE; SPARROW; PHOTOREFRACTORINESS;
Keywords:
egg laying; Falco sparverius; maternal effects; optimal reproductive tactic; seasonal breeding; yolk testosterone;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Sockman, KW Johns Hopkins Univ, Dept Psychol, Baltimore, MD 21218 USA Johns Hopkins Univ Baltimore MD USA 21218 imore, MD 21218 USA
Citazione:
K.W. Sockman et al., "Regulation of yolk-androgen concentrations by plasma prolactin in the American kestrel", HORMONE BEH, 40(4), 2001, pp. 462-471

Abstract

The concentrations of maternally derived androgens in the yolks of avian eggs vary within and among clutches, but a mechanistic basis for this variation has not been elucidated. We investigated in the American kestrel, Falcosparverius, whether changes in plasma-prolactin concentrations induced by changes in photoperiod and food supply affect yolk-androgen concentrations. Over the course of a photoinduced breeding period in the laboratory, we measured concentrations of plasma immunoreactive prolactin (ir-prolactin) in female kestrels with ad libitum food availability (control) or food availability that was reduced during the early breeding period. In a second laboratory study, we administered via osmotic mini-pumps ovine prolactin (o-prolactin) to females beginning on the day they laid their first egg of a clutch(egg-day 1) to determine the effects of high prolactin concentrations on yolk-androgen concentrations. In both this study and one on free-living kestrels, we quantified changes in yolk-androgen concentrations with date of clutch initiation. Concentrations of ir-prolactin in nonlaying females rose with date, irrespective of food treatment. Egg-day I ir-prolactin concentrations were higher in control females laying late during the breeding phase than in those laying early. This increase was absent in food-reduced females. Yolk-androgen concentrations in eggs 3 and 4 but not eggs I and 2 of the clutch were higher in clutches initiated late than in clutches initiated early in the breeding phase in both the field and laboratory. o-Prolactin treatment elevated yolk-testosterone but not androstenedione concentrations. These findings suggest that, in American kestrels, seasonal and laying-associated increases in plasma-prolactin concentrations elevate yolk-testosterone concentrations. Food availability and other factors may interact with date to regulate the effects of prolactin on yolk-testosterone deposition. (C)2001 Elsevier Science.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 02:47:34