+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Ultrastructure of primary mesenchyme cell ingression in the sea urchin lytechinus pictus

, : Ultrastructure of primary mesenchyme cell ingression in the sea urchin lytechinus pictus. Journal of Experimental Zoology 213(2): 231-246

The ultrastructural changes associated with primary mesenchyme cell formation in the sea urchin L. pictus were studied by transmission (TEM) and scanning electron microscopy (SEM). Early during ingression, about 30 presumptive primary mesenchyme cells can be recognized which form a ring around 8 central cells located at the apex of the vegetal pole. The 1st steps involve the loss of the basal lamina in the vegetal plate region and the loss of cilia from the 30 presumptive primary mesenchyme cells. These cells then elongate into bottle-shaped cells which have bulbous, appendage-free basal ends that protrude into the blastocoel, and thin neck regions that form numerous apical cell processes. Longitudinally oriented microtubules are observed in the peripheral cytoplasma in the neck regions of the bottle-shaped cells and in the adjacent cytoplasm of closely adherent neighboring non-mesenchymal blastomeres. After the disappearance of apical junctions, the neck regions of the bottle-shaped cells shorten, resulting in the transposition of the cells into the blastocoel as rounded primary mesenchyme. Mesenchyme cell displacement results in the temporary formation of fenestrae in the blastular wall, which are filled in by apical cell processes that extend from neighboring blastomeres. These morphological changes have several features in common with other examples of cells which exit from epithelia and are consistent with a morphological sequence involving the relaxation of the basal cytoplasm of the presumptive primary mesenchyme cells, followed by their active elongation and lateral compression by adjacent cells.


DOI: 10.1002/jez.1402130211

Other references

Grunert Brigitte; Grunert Siegfried; Schneider H., 1978: The methodology of geological sciences applied to technical problems of building materials. Zeitschrift fuer Geologische Wissenschaften 6(2): 261-274

Freude, K.A.; Sandler, L.S.; Zieve, F.J., 1981: Electrical stimulation of the liver cell: activation of glycogenolysis. To examine the role of ionic factors in the regulation of glycogen metabolism, we examined the effects of electrical stimulation on liver glycogen cycle enzymes. Passage of electric current through a suspension of rat hepatocytes caused the conver...

Sadlier, D.M.; Magee, C.C., 2007: Prevalence of 25(OH) vitamin D (calcidiol) deficiency at time of renal transplantation: a prospective study. 25(OH) Vitamin D (calcidiol) is the major circulating form of vitamin D and is considered the most reliable measure of vitamin D status. Adequate vitamin D status is important for bone health but there is increasing evidence that low serum concent...

Phillips R.L. (investigator); Luepke Gretchen (investigator), 1980: Shallow shelf and beach heavy-mineral concentrations. U S

Onopriyenko Y.I., 1977: Lower Carboniferous Rugosa of the northwestern Pacific region. Pages 50-62 1977

Malanoski, A.P.; Johnson, B.J.; Erickson, J.S.; Stenger, D.A., 2016: Development of a Detection Algorithm for Use with Reflectance-Based, Real-Time Chemical Sensing. NlmCategory="UNASSIGNED">Here, we describe our efforts focused on development of an algorithm for identification of detection events in a real-time sensing application relying on reporting of color values using commercially available...

Kahlert, H.; Weber, B.; Teppke, M.; Wahl, R.; Cromwell, O.; Fiebig, H., 1995: Characterization and quantification of two major allergens from Parietaria extracts with monoclonal antibodies. Journal of Allergy & Clinical Immunology 95(1 PART 2): 162

Bansal, A.; Singhal, O.P., 1991: Preservation of milk samples with formalin -effect on acidity. Composite samples of cow and buffalo milk were treated with 0.2, 0.3, 0.4 and 0.5% (v/v) formalin, and stored in glass bottles at room temp. (16-36 degrees C) for up to 1 yr. During storage, milk separated into 3 layers and acidity gradually incre...

Lacy, R.C.; Ballou, J.D., 1996: Effectiveness of selection for the removal of the genetic load during generations of inbreeding. Bulletin of the Ecological Society of America 77(3 SUPPL PART 2): 248

Yadav, L.; Tamene, F.; Göös, H.; van Drogen, A.; Katainen, R.; Aebersold, R.; Gstaiger, M.; Varjosalo, M., 2017: Systematic Analysis of Human Protein Phosphatase Interactions and Dynamics. Coordinated activities of protein kinases and phosphatases ensure phosphorylation homeostasis, which, when perturbed, can instigate diseases, including cancer. Yet, in contrast to kinases, much less is known about protein phosphatase functions and...