Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042755 (masculinization)
 2,562 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Masculinization of the larynx in Xenopus laevis frogs is essential for the performance of male courtship song. During postmetamorphic (PM) development, the initially female-like phenotype of laryngeal muscle (slow and fast twitch fibers) is converted to the masculine form (entirely fast twitch) under the influence of androgenic steroids. To explore the molecular basis of androgen-directed masculinization, we have isolated cDNA clones encoding portions of a new Xenopus myosin heavy chain (MHC) gene. We have detected expression of this gene only in laryngeal muscle and specifically in males. All adult male laryngeal muscle fibers express the laryngeal myosin (LM). Adult female laryngeal muscle expresses LM only in some fibers. Expression of LM during PM development was examined using Northern blots and in situ hybridization. Males express higher levels of LM than females throughout PM development and attain adult levels by PM3. In females, LM expression peaks transiently at PM2. Treatment of juvenile female frogs with the androgen dihydrotestosterone masculinizes LM expression. Thus, LM appears to be a male-specific, testosterone-regulated MHC isoform in Xenopus laevis. The LM gene will permit analysis of androgen-directed sexual differentiation in this highly sexually dimorphic tissue.
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PMID:Sexually dimorphic expression of a laryngeal-specific, androgen-regulated myosin heavy chain gene during Xenopus laevis development. 142 43

The masculinizing gene her-1 in Caenorhabditis elegans (Ce-her-1) encodes a novel protein, HER-1A, which is required for male development. To identify conserved elements in her-1 we have cloned and characterized two homologous nematode genes: one by synteny from the closely related free-living species C. briggsae (Cb-her-1) and the other, starting with a fortuitously identified expressed sequence tag, from the distantly related parasite Brugia malayi (Bm-her-1). The overall sequence identities of the predicted gene products with Ce-HER-1A are only 57% for Cb-HER-1, which is considerably lower than has been found for most homologous briggsae genes, and 35% for Bm-HER-1. However, conserved residues are found throughout both proteins, and like Ce-HER-1A, both have putative N-terminal signal sequences. Ce-her-1 produces a larger masculinizing transcript (her-1a) and a smaller transcript of unknown function (her-1b); both are present essentially only in males. By contrast, Cb-her-1 appears to produce only one transcript, corresponding to her-1a; it is enriched in males but present also in hermaphrodites. Injection of dsRNA transcribed from Cb-her-1 into C. briggsae hermaphrodites (RNA interference) caused XO animals to develop into partially fertile hermaphrodites. Introducing a Cb-her-1 construct as a transgene under control of the C. elegans unc-54 myosin heavy chain promoter caused strong masculinization of both C. briggsae and C. elegans hermaphrodites. Introduction of a similar Bm-her-1 construct into C. elegans caused only very weak, if any, masculinization. We conclude that in spite of considerable divergence the Cb gene is likely to be a functional ortholog of Ce-her-1, while the function of the distantly related Bm gene remains uncertain.
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PMID:Homologs of the Caenorhabditis elegans masculinizing gene her-1 in C. briggsae and the filarial parasite Brugia malayi. 1043 May 84