Worm Breeder's Gazette 2(2): 10b
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
Before each moult, the seam cells (i.e. the lateral hypodermal stem cells, together with an extra cell anteriorly) take on a characteristic granular appearance in Nomarski optics. Electron microscopy reveals large Golgi bodies in the seam cells at these times. Presumably this means that the lateral cuticle is specialized in some way (maybe mechanically). The seam is required for ala formation. When groups of seam cells are destroyed by the laser microbeam in the L3 or young L4, corresponding gaps appear in the adult alae. E1348 (lin-5 II) and E1466 (lin-6 I) both have defective seams; both have defective alae as dauers and usually none as adults. Regions without a seam fail to undergo the diametric shrinkage- normally characteristic of dauer maturation. Thus dauer larvae of E1348 and E1466 have a lumpy appearance. They are also less resistant to SDS than N2 dauers. Laser experiments indicate that the excretory system is not essential for moulting. The g1 pharyngeal glands are very active just before ecdysis; their secretions may well be necessary to weaken the head cuticle.