. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Figure 8. Surface at the oral end of one of the two stomodaeal walls of B. forska/i (darkheld). The curved lip edge is at the top of the figure. Macrocilia appear brighter and extend downward from the lip edge as tapering longitudinal stripes (s). The adhesive strip runs longitudinally along the midline of the stomodaeal wall (arrowheads). Scale bar. mm. made and broken and remade again than in junctions" (Trinkaus, 1984, p 171). These cell-cell appositions in fi- broblasts are believed to be "a prime candidate
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Figure 8. Surface at the oral end of one of the two stomodaeal walls of B. forska/i (darkheld). The curved lip edge is at the top of the figure. Macrocilia appear brighter and extend downward from the lip edge as tapering longitudinal stripes (s). The adhesive strip runs longitudinally along the midline of the stomodaeal wall (arrowheads). Scale bar. mm. made and broken and remade again than in junctions" (Trinkaus, 1984, p 171). These cell-cell appositions in fi- broblasts are believed to be "a prime candidate for the kind of adhesion that moving cells require" (Trinkaus, 1984, p 171). Similarly, such appositions would seem well- designed for the reversible type of tissue adhesion required to seal Berne's mouth. The physical or chemical mechanisms of such cell-cell adhesions are not well understood in any system (Trin- kaus, 1984). Suggested mechanisms range from non-spe- cific molecular attraction, such as London-van der Waals forces (Nachtigall, 1974; Trinkaus, 1984), to chemical bonding by molecular "glues" or specific cell adhesion molecules (Takeichi, 1990, 1991; Edelman and Crossin, 1991). Month opening and possible regulation of tissue adhesion Using egg-white as a feeding stimulus to induce mouth opening, we found that the mouth does not open all at once, as assumed previously (Tamm, 1982), but is peeled apart starting at a site of vigorous muscular tension on Figure 7. Mouth opening of Berne sp. induced by egg white (viewed orally). A. Local muscular twitches pull the left sides of both lips away from the adhesion zone (line inside the lips). B. Muscular tension separates the adhesive zone (arrow) and pulls open the lips on the left side of the mouth. C, Continued muscular activity peels apart the adhesive seal from left to right (2 s later). D, Peeling apart of the adhesion zone and opening of the mouth has almost reached the right side ( s later). E, The
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
