RESUMEN
Recessive mutant gene c in axolotl embryos results in an absence of normal heart function. Immunofluorescence studies were done to determine the distributions of myosin, tropomyosin and alpha-actinin in the hearts of normal and mutant siblings. Anti-myosin specifically stains the A bands of myofibrils in normal hearts and reveals a progressive increase in myofibril organization with development. Mutant hearts display less staining for myosin than normal and localization is mainly in amorphous collections. Anti-alpha-actinin stains the Z lines of myofibrils in normal myocytes. Mutant cells also have significant staining for alpha-actinin but show no striations. Antitropomyosin intensely stains the I bands of myofibrils in normal cells; however, there is very little staining for tropomyosin in mutant hearts. Thus, mutant myocardial cells have reduced but significant amounts of actin (Lemanski, Mooseker, Peachey & Iyengar, 1976) and myosin, even though non-filamentous, and substantial amounts of alpha-actinin. The cells appear to contain little tropomyosin.
Asunto(s)
Actinina/metabolismo , Ambystoma/embriología , Corazón/embriología , Proteínas Musculares/metabolismo , Miosinas/metabolismo , Tropomiosina/metabolismo , Ambystoma/genética , Animales , Técnica del Anticuerpo Fluorescente , Microscopía Electrónica , Mutación , Miocardio/ultraestructura , Miofibrillas/ultraestructuraRESUMEN
Recessive mutant gene c in axolotl embryos results in an absence of heart function. Normal (+/+) anterior endoderm cultured with mutant (c/c) hearts totally corrects the defect.