Prolactin opens the sensitive period for androgen regulation of a larynx-specific myosin heavy chain gene

Christofer J. Edwards, Kazutoshi Yamamoto, Sakae Kikuyama, Darcy B. Kelley

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    9 Citations (Scopus)


    The larynx of Xenopus laevis is a sexually differentiated vocal organ in which male muscle is entirely fast twitch and expresses high levels of a fast twitch myosin heavy chain gene, LM. Female muscle, however, is mostly slow twitch and expresses little LM. Androgen is unable to induce expression of LM until after metamorphosis is complete. The expression of LM during metamorphic and early postmetamorphic development parallels secretion and expression of the pituitary hormone prolactin. Here, we show that exposure to prolactin is necessary to allow androgen-induced LM expression in postmetamorphic froglets. In prolactin-deprived animals, androgen-induced changes in the contactile properties of laryngeal muscle are blocked, which prevents the rapid rates of muscle contraction required for males to produce courtship songs. Thus, prolactin opens the sensitive period for androgen- induced LM expression in the larynx and controls the ability of male sex hormones to masculinize the vocal system both at the level of gene expression and vocal organ physiology.

    Original languageEnglish
    Pages (from-to)443-451
    Number of pages9
    JournalJournal of Neurobiology
    Issue number4
    Publication statusPublished - 1999



    • Larynx
    • Masculinization
    • Metamorphosis
    • Muscle fiber type
    • Testosterone

    ASJC Scopus subject areas

    • Neuroscience(all)

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