Circulating testosterone and feather-gene expression of receptors and metabolic enzymes in relation to melanin-based colouration in the barn owl.

Details

Serval ID
serval:BIB_7766D8425557
Type
Article: article from journal or magazin.
Collection
Publications
Title
Circulating testosterone and feather-gene expression of receptors and metabolic enzymes in relation to melanin-based colouration in the barn owl.
Journal
General and Comparative Endocrinology
Author(s)
Béziers P., Ducrest A.L., Simon C., Roulin A.
ISSN
1095-6840 (Electronic)
ISSN-L
0016-6480
Publication state
Published
Issued date
2017
Peer-reviewed
Oui
Volume
250
Pages
36-45
Language
english
Abstract
Knowledge of how and why secondary sexual characters are associated with sex hormones is important to understand their signalling function. Such a link can occur if i) testosterone participates in the elaboration of sex-traits, ii) the display of an ornament triggers behavioural response in conspecifics that induce a rise in testosterone, or iii) genes implicated in the elaboration of a sex-trait pleiotropically regulate testosterone physiology. To evaluate the origin of the co-variation between melanism and testosterone, we measured this hormone and the expression of enzymes involved in its metabolism in feathers of barn owl (Tyto alba) nestlings at the time of melanogenesis and in adults outside the period of melanogenesis. Male nestlings displaying smaller black feather spots had higher levels of circulating testosterone, potentially suggesting that testosterone could block the production of eumelanin pigments, or that genes involved in the production of small spots pleiotropically regulate testosterone production. In contrast, the enzyme 5α-reductase, that metabolizes testosterone to DHT, was more expressed in feathers of reddish-brown than light-reddish nestlings. This is consistent with the hypothesis that testosterone might be involved in the expression of reddish-brown pheomelanic pigments. In breeding adults, male barn owls displaying smaller black spots had higher levels of circulating testosterone, whereas in females the opposite result was detected during the rearing period, but not during incubation. The observed sex- and age-specific co-variations between black spottiness and testosterone in nestling and adult barn owls may not result from testosterone-dependent melanogenesis, but from melanogenic genes pleiotropically regulating testosterone, or from colour-specific life history strategies that influence testosterone levels.
Keywords
5-Alpha reductase, Androgen receptor, Estrogen receptor, Gene expression, Melanin, Sex hormones, Testosterone
Pubmed
Web of science
Create date
09/05/2017 18:31
Last modification date
18/01/2020 7:17
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