Cytochemical study of larval skin in Amphibia: occurrence of ruthenium red positive cells in cutaneous gland anlagen.
During a cytochemical investigation into the development of cutaneous gland buds in amphibian larvae (both anuran and urodele), ruthenium red (RR) positive cells were found in the anlagen. These cells, with diffuse deposits of the polycation dye in their cytoplasms, were first detected on the lateral surface of still intraepidermal gland buds. Later, during segregation of anlagen from the epidermis, the reactive cells were followed whilst they converged towards the apex of the gland nest. These findings of a remarkable penetration of RR through intact plasma membranes are discussed in the light of the staining characteristics of the polycation dye. Furthermore, the mechanism regulating morphogenesis of amphibian cutaneous glands is briefly compared with the morphogenetic patterns of large exocrine glands in higher vertebrates. It is suggested that during fixation RR penetrates morphogenetically active cells, following the same pathways as calcium under physiological conditions. Calcium inflow correlates with the occurrence of thin, possibly contractile, filaments in these cells and also agrees with cell migration during morphogenesis.
Delfino
G
G
Dipartimento di Biologia animale e Genetica dell' Università di Firenze, Italia.
Brizzi
R
R
Ferrante
P
P
D000818:Animals; D001001:Anura / Q000033:anatomy & histology*; D002454:Cell Differentiation; D007814:Larva; D008675:Metamorphosis, Biological; D008854:Microscopy, Electron; D012430:Ruthenium Red; D012627:Sebaceous Glands / Q000166:cytology*; D012867:Skin / Q000166:cytology*; D014562:Caudata / Q000033:anatomy & histology*
D012430:Ruthenium Red