0000000000546943
AUTHOR
Fiorenza De Bernardi
Adhesive papillae ofAscidia malacaswimming larvae: investigations on their sensory function
Summary Swimming larvae of Ascidia malaca bear, in the anterior region of cephalenteron, three adhesive papillae through which they can attach to a substratum prior to metamorphosis. The ultrastructural investigations described in the present work have mainly revealed the presence of three cell types constituting the papillae: (a) collocytes, (b) axial columnar cells, (c) sensory cells. Collocytes, whose ultrastructure is typical of secretory cells, form the adhesive secretion. The ultrastructural observations of the axial columnar cells are insufficient to explain their function. Probably this cell type plays a supporting role though some sensory function cannot be excluded due to the pres…
Zoologia. Cordati invertebrati
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Synthesis of β-tubulin mRNA in neural induction and specification
Ľibridazionein situ condotta su embrioni diXenopus laevis con cDNA di β-tubulina ha dimostrato un forte incremento nelle cellule della piastra neurale e delľectoderma laterale dopo la gastrulazione, quando il cordomesoderma viene a contatto con ľectoderma. Esperimenti condotti su espianti di ectoderma neurale presuntivo eseguiti prima e dopo ľinduzione neurale suggeriscono che le cellule abbiano gia un orientamento specifico in senso neurale allo stadio di blastula. prima che ľinduzione avvenga.