Pattern regulation of mesoderm in transplanted and supernumerary limbs of the cockroach. II. Time course of muscle dedifferentiation

✍ Scribed by Steinbach, Paul A.

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 760 KB
• Volume: 212
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402120203

✦ Synopsis

Abstract

The extent and time course of muscle dedifferentiation was followed histologically in transplanted mesothoracic limbs of the cockroach Periplaneta americana. The limbs were grafted to contralateral leg sockets and were oriented such that the anterior‐posterior axis of the graft was reversed relative to that of the socket. The muscles in such a graft dedifferentiate before the first postoperative molt. Muscle dedifferentiation is characterized by the loss of muscle fibers and the appearance of mononuclear cells in the graft. Dedifferentiation begins proximally near the host/graft junction and progressively spreads to distal levels until the only remnants of the original muscle organization are aggregates of mononuclear cells around distal apodemes. Muscles in the thorax which were damaged. During transplantation also de differentiate before the first postoperative molt. Redifferentiation of identifiable muscle can begin as early as the second intermolt period. The dedifferentiation of transplanted mesoderm in not due to the axis reversal, since the muscles in a graft without axis reversal dedifferentiate to the same extent as in grafts with reversed transverse axes. The results are interpreted as indicating that developmental information from nonmuscular tissues in the limb is required for reformation of identifiable muscles.