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Cell shape changes and the mechanism of inversion in Volvox


, : Cell shape changes and the mechanism of inversion in Volvox. Journal of Cell Biology 75(3): 719-730

Inversion is a dominant aspect of morphogenesis in Volvox. In this process, the hollow, spheroidal Volvox embryo turns inside-out through a small opening called the phialopore to bring flagella from its inner to its outer surface. Analyses of intact, sectioned, and fragmented embryos by light, scanning electron, and transmission electron microscopy, suggest that shape changes preprogrammed into the cells cause inversion. First, cells throughout the embryo change from pear to spindle shape, which causes the embryo to contract and the phialopore to open. Then cells adjacent to the phialopore become flask-shaped, with long, thin stalks at their outer ends. Simultaneously, the cytoplasmic bridges joining all adjacent cells migrate from the midpoint of the cells to the stalk tips. Together, these changes cause the lips of cells at the phialopore margin to curl outward. Now cells progressively more distal to the phialopore become flask-shaped while the more proximal cells become columnar, causing the lips to curl progressively further over the surface of the embryo until the latter has turned completely inside-out. Fine structural analysis reveals a peripheral cytoskeleton of microtubules that is apparently involved in cellular elongation. Cell clusters isolated before inversion undergo a similar program of shape changes; this suggests that the changes in cellular shape are the cause rather than an effect of the inversion process.

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PMID: 925078


Other references

Houpt, M.; Shey, Z., 1982: A conservative occlusal restoration using fissure sealant for prevention. Compendium of Continuing Education in Dentistry 3(6): 445-448

Borkhvardt, V.G., 1969: Relation of the cartilage and bone stages in the evolution of the corpus vertebrae. Arkhiv Anatomii, Gistologii i Embriologii 57(9): 111-118

Pechet, M.M.; Carroll, E.L., 1963: Interrelationship of renal tubular sodium transport and 1,2-dehydrogenation of steroids. Jour Clin Invest 42(6): 964

Ason, B.; Handayani, R.; Williams, C.R., 2003: Mechanism of Loading the Escherichia coli DNA Polymerase III b Sliding Clamp on DNA. Bona Fida Primer/Templates Preferentially Trigger the c Complex to Hydrolyze ATP and Load the Clamp. The Journal of Biological Chemistry 278(12): 033-40

Bucci, E.; Amato, M.; Rengo, S., 1984: Literature review and clinical experiences with transformations of benign lesions of frequent occurrence in the oral cavity. Rivista Italiana di Stomatologia 53(7-8): 499-505

Belyaeva, V.B.; Levkina, L.M.; Kasteiyanos, K., 1982: Infection of tomato by Alternaria and Cercospora species in Cuba. Descriptions are given of A. tenuissima, C. [Pseudocercospora] fuligena and C. diffusa, found for the first time on tomato in Cuba. Infected plants were of Cuban and Russian origin.

Vegger, A.M., 1966: On "encephalopathy". Sovetskaia Meditsina 29(12): 125-127

Reid, R.D., 1983: Fitness trails: programming the benefits. The paper illustrates how fitness trails can provide a focus for recreation in parks together with scientifically designed health programmes. Typically, a fitness trail consists of a series of 12 to 25 exercise stations arranged individually or in...

Axelrod, S.L.; Blaivas, J.G., 1987: Bladder neck obstruction in women. Bladder neck obstruction in women is rare. The symptoms are confounding and nonspecific. The diagnosis depends on demonstrating poor uroflow, a detrusor contraction of adequate magnitude and duration, and radiographic evidence of obstruction at th...

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