TY - JOUR TI - An identical effect mediated by thyroid deficiency or oncogene v-erbA in the chick embryo. AU - Bachnou, N AU - Saule, S AU - Dieterlen-Lievre, F T2 - The International Journal of Developmental Biology AB - We have shown earlier that the association of v-myc and v-erbA (MAHEVA construct) is responsible for the appearance of a specific phenotype in chick embryos inoculated at E3. This phenotype comprises rapidly growing heart rhabdomyomas (induced by v-myc alone) and within these tumors secondarily appearing cartilage nodules (Bachnou et al., Oncogene 6: 1041-1047, 1991). Here we report that v-erbA can be replaced by thyroid deficiency. When decapitated embryos were inoculated with virus MC29 (v-myc alone) or when v-myc inoculated embryos were treated with thiourea, 100% of the embryos reaching E17 to E19 displayed tumoral hearts bearing cartilage nodules. We thus report in vivo evidence that v-erbA acts by antagonizing the effects of thyroid hormones. Remarkably, thyroid deficiency rendered embryos more sensitive to the effect of v-myc, since 100% developed heart rhabdomyomas and cartilage nodules, versus about 70% affected when either v-myc or MAHEVA were inoculated. Thyroid deficiency did not alter the species-specific character of transdifferentiation, since only chick but not quail embryos developed cartilage nodules after thyroidectomy or MAHEVA infection. PY - 1996 VL - 40 IS - 2 SP - 491 EP - 497 J2 - Int. J. Dev. Biol. LA - en SN - 0214-6282 SN - 1696-3547 UR - https://ijdb.ehu.eus/article/8793620 Y2 - 2024/12/25/06:06:45 ER -