Supernumerary limb induction in the anura

✍ Scribed by Balinsky, B. I.

• Book ID: 102889969
• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 675 KB
• Volume: 188
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401880207

✦ Synopsis

Abstract

Induction of supernumerary limbs in Bufo tadpoles was achieved by transplanting the transverse neural fold with adjoining tissue from neurulae into tail bud stage embryos. The graft differentiated into brain, eyes, noses and mouthparts. Induced limb rudiments were associated with either noses or mouthparts. The author rejects the suggestion made by Perri that the induction is due to release of products of cytolysis from the graft and suggests that limb induction is due to a disorganization or reduction of the subepidermal basement membrane (layer of collagen fibres) by certain grafts, and that as a result the potentially limb forming flank mesenchyme is allowed to interact with the epidermis — a precondition for limb development. In support of this view the author presents electronmicrographs in which it is shown that at the edge of the nostril, and on the mouthparts (lips, oral papillae), the basal membrane is attenuated and disorganised, allowing processes of mesenchyme cells to penetrate through the layer of collagen fibres and reach the inner surface of the epidermis.