The influence of photoperiod on the reproductive activity of female Honey possums, Tarsipes rostratus (Marsupialia: Tarsipedidae): assessed by faecal progestagens and oestradiol-17beta.
Gen Comp Endocrinol
; 139(2): 103-12, 2004 Nov.
Article
em En
| MEDLINE
| ID: mdl-15504387
ABSTRACT
Six female Honey possums were kept on a 15L9D light regime to simulate a long daylength over summer. After seven weeks, three females (Group 2) were changed to a shorter daylength of 10L14D, while the other three females (Group 1) were maintained on the long daylength. Faecal oestradiol-17beta and progestagen levels were measured during the experiment to detect any changes in reproductive rhythm, such as resumption of blastocyst development. Group 2 females were found to have very large and greatly expanded blastocysts with significantly higher levels of progestagens after the change to short photoperiod (p<0.05). In contrast, the Group 1 females had very small diapausing blastocysts and progestagen levels did not change throughout the study. Overall oestradiol levels also increased significantly in Group 2 females (p<0.05) but not in Group 1 females. These results demonstrate that a change from long to short days stimulates increased progestagen output (and oestradiol-17beta to a lesser extent) that supports the growth and expansion of the blastocysts. Photoperiod, in particular its change to a shortening daylength, appears to be a stimulus for terminating diapause in the Honey possum during its first reproduction of the year. However, as subsequent breeding later in the year occurs when daylength is increasing, a similar role for photoperiod cannot be attributed and females may be entrained to other factors such as food resources.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Progestinas
/
Reprodução
/
Blastocisto
/
Estradiol
/
Marsupiais
Limite:
Animals
Idioma:
En
Revista:
Gen Comp Endocrinol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Austrália