Phase‐cinemicrographic Observations on Cultured Cells. I. Formation of Transvacuolar Strands in Euphorbia Marginata

Mahlberg, P.G., and S. Venketeswaran. (U. Pittsburgh, Pittsburgh, Pa.) Phase‐cinemicrographic observations on cultured cells, I. Formation of transvacuolar strands in Euphorbia marginata. Amer. Jour. Bot. 50(6): 507–513. Illus. 1963.—Living and vacuolated plant cells frequently possess a network of transvacuolar strands. In the dynamics of the strand system, individual strands can be observed to disappear as well as to become re‐formed from the cytoplasm in characteristic patterns. A strand can disappear from the reticulum either by total contraction, or by fusion of the entire length with adjacent cytoplasm. New strands are delimited from the surrounding cytoplasm when vacuoles become evident in an aggregated mass of the cytoplasm within a localized portion of a cell. During subsequent movements of the new strands, the vacuoles enlarge and become confluent with the total vacuolar content of the cell. Streaming within the new strands becomes uni‐ or bi‐directional in contrast to a multi‐directional pattern within the aggregated cytoplasm. The formation of new strands is associated with an increase in the cytoplasmic membrane area in contact with the vacuole. The membrane is interpreted as possessing a proteinaceous lattice structure. Changes in area and movement of the strands are interpreted to be reversible involving alteration of the structural proteins, their addition or removal, from the lattice of the membrane.