ANALYSE DES LESIONS SQUELETTIQUES DES MEMBRES POSTERIEURS CHEZ LES SOURIS Dh/+

The skeletal anomalies of the hind limbs were studied on 100 youth mice +heterozygotes concerning the Dh gene (Dominant Hemimelia). The gene is dominant, not sexlinked and provokes apart from the skeletal malformations, a constant agenesia of the spleen and a microstomach. The fore limb is not affected in the heterozygotes animals. The limbs were coloured by the alizarin sulfonic acid, according to Dawson's method, and examined in pure glycerin. A study of the articulation of the instep on microscopic slides after Masson's trichromic coloration was made on animals affected by partial or total hemimelia. The greater part of the skeletal lesions may be classified into 2 groups: anomalies by excess (hyperphalangism or preaxial polydactylism) and anomalies by defect (total or partial hemimelia of the zeugopode). These 2 malformations are not associated in the same limb although they can be found associated in both limbs of the same embryo. There is an exception to this rule: the case of syndactylism I-II that implies some excess lesions, e.g. a supernumerary phalanx, and preaxial hemimelia in the same limb. The expressivity of the gene is non existant at the hind limb level in 9% of the cases.SCOPUS: NotDefined.j