Differentiation ofAcmaea digitalis oocytes with special reference to lipid-endoplasmic reticulum-annulate lamellae-polyribosome relationships

The annulate lamellae--from obscurity to spotlight

This review aims to provide a comprehensive and in-depth survey of a cell organelle, the annulate lamellae, that is widely distributed and especially prevalent in both female and male sex cells as well as tumor and cancer cells. The organelle is also present in many somatic cells and plant cells. Emphasis is placed on the contributions that electron microscopy and associated experimental approaches have made in providing information about the distribution, ultrastructure, morphogenesis and relationships of annulate lamellae to other cellular organelles, especially the nuclear envelope and endoplasmic reticulum, as well as cell product. An increasing number of experimental manipulations have recently been shown to alter, either increase or decrease, the amount of annulate lamellae and these studies are explored in depth. Information about the origin and morphogenesis of annulate lamellae in different cells is summarized and extensive coverage is given to several hypotheses about possible annulate lamellae function. A detailed bibliography provides a thorough compilation of research dealing with annulate lamellae. A major goal of this extensive review is to generate increased awareness of, and interest in, this cell organelle for students and investigators of the cell who, by bringing current techniques in cell and molecular biology to bear, might focus and intensify studies on the function of an organelle whose precise role in the cell is presently enigmatic.

Effects of prolonged antitubulin culture on the ultrastructure of anterior limb bud cells of the chick embryo

The anterior limb bud mesenchyme cells of stage 24 chick embryos were dissociated by trypsinization followed by gentle pipetting, and placed in a tissue culture medium of F12 containing 10% fetal calf serum and antibiotics. As the cells became nearly confluent, some of them were exposed to colchicine or vinblastine sulfate for durations as long as 48 hr. The control and antitubulin-treated cells were processed for transmission electron microscopy and the ultrastructure of the cells was compared. Annulate lamellae (AL) were observed in small amounts in both control and antitubulin-treated cells. The amount of AL did not markedly differ in the control versus antitubulin-treated cells. Furthermore, few multinucleated cells were observed in antitubulin-treated cultures. These results indicate that prolonged culture of cells in antitubulins need not, in itself, lead to a condition of enhanced AL development as reported in several other studies using various cell types.

Effects of prolonged antitubulin culture on annulate lamellae in mouse alpha L929 fibroblasts

The fine structure of alpha L929 fibroblasts cultured in colchicine or vinblastine sulfate for periods as long as 48 hr was compared to control cells not exposed to antitubulins . In response to prolonged antitubulin culture, several changes in cell ultrastructure were noted: Control fibroblasts contain cytoplasmic annulate lamellae (AL), but prolonged exposure to either vinblastine sulfate or colchicine results in enhanced development of AL. Single pore complexes are present in the rough-surfaced endoplasmic reticulum (rER) in both control and antitubulin-treated cells, but stacked porous cytomembranes also occur under both conditions. Polyribosomes often are closely associated or continuous with the pore complexes. Many antitubulin-treated cells become multinucleate. Some nuclei in both control and antitubulin-treated cells contain large and multiple nucleoli. The large and multiple nucleoli are either attached directly to the inner membrane of the nuclear envelope or to infoldings of the nuclear envelope. Antitubulin-treated cells, after 48-hr exposure, appear also to contain enhanced quantities of smooth-surfaced endoplasmic reticulum (sER) and cytoplasmic filaments (and in some cells, lysosomes and rER as well) when compared to untreated cells. In both control and colchicine-treated cells, AL can exhibit continuity with either rER or sER. Further, all three membrane systems may at times be continuous, but the quantity of these membranes appears to be greater in colchicine-treated cells than in control cells. The results are discussed with respect to possible functional significance.

Ultrahistology of oogenesis and vitellogenesis in the spider mite Tetranychus urticae

Histology of the ovary of the spider mite Tetranychus urticae is described light and electron microscopically with special reference to oogenesis and vitellogenesis of this mite. Morphology of the ovary is comparable to the typical sac-like chelicerate ovary with oocytes protruding from the ovarian surface, thus resulting in a grape-like appearance. According to different oogenetic stages, a germ, pre-vitellogenic and vitellogenic region can be observed. Oogonia and primary oocytes characterized by extranuclear material or 'yolk nuclei' are situated in the germ region. Primary oocytes develop into three-nucleated nurse cells situated in the periphery of the pre-vitellogenic region, and into pre-vitellogenic oocytes protruding from the ovarian surface. Growth of oocytes is performed while they are in ovarian pouches by uptake of nurse cell cytoplasm and following extraovarian yolk precursors. Intraoocyte yolk synthesis interpreted from altered cytoplasmic organelles also occurs. Processes taking place during oogenesis and vitellogenesis in T. urticae are compared to published information on yolk synthesis of other animal species.