Linked Life Data

7567793

Source:http://linkedlifedata.com/resource/pubmed/id/7567793

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-11-21
pubmed:abstractText
In mallards the bright nuptial plumage of the drake represents the neutral, sex hormone-independent coloration of the species that both sexes eventually exhibit after castration. We compared the pheo- and eumelanin contents of feathers from the head, breast, flank, and under-tail coverts in five groups of mallards after the post-nuptial molt in summer: intact hens, intact drakes, castrated drakes, castrated drakes injected with testosterone during the spring, and castrated drakes injected with 5 alpha-dihydrotestosterone during the spring. In the head feathers and under-tail coverts, the gonadal hormones of the intact birds and the testosterone injections into castrates significantly reduced the eumelanin content, tended to increase the pheomelanin content, and, thereby, changed the melanin type from eumelanic in the untreated castrates to mixed melanic in the other three groups. The eumelanin contents of the flank feathers did not differ among the groups, but the pheomelanin contents at this site was significantly elevated in the two intact groups and the testosterone-treated compared to the uninjected castrates. Again, the melanin type changed from eumelanic in the castrates to mixed melanic in the other three groups. The high pheomelanin content of the breast feathers in the castrated birds was significantly reduced in the hens, intact drakes, and testosterone-injected castrates with a concomitant tendency for elevated eumelanin contents. At this site, a change occurred from pheomelanic to mixed melanic. 5 alpha-dihydrotestosterone was clearly less effective than testosterone in affecting the melanin contents in castrates and resulted in an intermediate coloration.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0893-5785
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
164-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Influences of sex, castration, and androgens on the eumelanin and pheomelanin contents of different feathers in wild mallards.
pubmed:affiliation
Institut für Haustierkunde, Christian-Albrechts-Universität, Kiel, Germany.
pubmed:publicationType
Journal Article, Comparative Study