scholarly journals THE RELATIONSHIP OF CILIA WITH CELL DIVISION AND DIFFERENTIATION

1971 ◽  
Vol 49 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Virginia G. Fonte ◽  
Robert L. Searls ◽  
S. Robert Hilfer
Keyword(s):  
Cell Division ◽  
Relationship Of ◽  
The Relationship

scholarly journals Cell Division in the Formation of the Stomatal Complex of the Young Leaves of Wheat

1966 ◽  
Vol 1 (1) ◽  
pp. 121-128
Author(s):  
J. D. PICKETT-HEAPS ◽  
D. H. NORTHCOTE
Keyword(s):  
Cell Division ◽  
Mother Cell ◽  
Cell Plate ◽  
Stomatal Complex ◽  
Guard Mother Cell ◽  
Young Leaves ◽  
Subsidiary Cells ◽  
Relationship Of ◽  
The Relationship ◽  
Characteristic Manner

During the formation of stomata in the young leaves of wheat the cells divide in a characteristic manner; two of the cell divisions are asymmetrical and produce cells of unequal sizes. A study of the fine structure of the cells during mitosis has shown that a band of microtubules appears at each preprophase stage. This band, although it is not present in the subsequent stages of mitosis, indicates the location on the wall of the mother cell where the cell plate will join it at the final division of the cytoplasm at telophase. Thus the future plane of cell division is indicated by these microtubules at preprophase. Microtubules are also found at the growing edge of the cell plate and appear to function in directing the vesicles which are brought up to extend the plate. The cell plate which is formed to cut off the subsidiary cells on either side of the guard mother cell is curved, and the microtubules present in conjunction with this plate during its formation could function to align and hold it on the required position. The relationship of the guard mother cell to the divisions of the adjacent epidermal cells which form the subsidiary cells is discussed, and related to general problems of growth and differentiation.

The role of yan in mediating the choice between cell division and differentiation

Development ◽  
1995 ◽  
Vol 121 (12) ◽  
pp. 3947-3958 ◽  
Author(s):  
R. Rogge ◽  
P.J. Green ◽  
J. Urano ◽  
S. Horn-Saban ◽  
M. Mlodzik ◽  
...  
Keyword(s):  
Cell Division ◽  
Growth Factor Receptor ◽  
Developmental Context ◽  
Eye Disc ◽  
A Cell ◽  
Epidermal Growth ◽  
Notch Pathways ◽  
Relationship Of ◽  
The Relationship

An allele of the yan locus was isolated as an enhancer of the Ellipse mutation of the Drosophila epidermal growth factor receptor (Egfr) gene. This yan allele is an embryonic lethal and also fails to complement the lethality of anterior open (aop) mutations. Phenotypic and complementation analysis revealed that aop is allelic to yan and genetically the lethal alleles act as null mutations for the yan gene. Analysis of the lethal alleles in the embryo and in mitotic clones showed that loss of yan function causes cells to overproliferate in the dorsal neuroectoderm of the embryo and in the developing eye disc. Our studies suggest that the role of yan is defined by the developmental context of the cells in which it functions. An important role of this gene is in allowing a cell to choose between cell division and differentiation. The relationship of the Egfr and Notch pathways to this developmental role of yan is discussed.

Observations on the Nature of the Relationship between Cell Division and Carbohydrate Metabolism

Development ◽  
1954 ◽  
Vol 2 (1) ◽  
pp. 26-37
Author(s):  
R. J. O'Connor
Keyword(s):  
Cell Division ◽  
Carbohydrate Metabolism ◽  
Adult Mouse ◽  
Tricarboxylic Acid Cycle ◽  
Relative Importance ◽  
Low Oxygen ◽  
Cultured Fibroblasts ◽  
Oxygen Tensions ◽  
Relationship Of ◽  
The Relationship

Although there is considerable evidence that carbohydrate metabolism plays an important part in the process of cell division (see Bullough, 1952), conclusions have differed regarding the relative importance of glycolysis and catabolism involving respiration. In the adult mouse epidermis Bullough & Johnson (1951) found that cell division was dependent upon the respiratory oxidation of pyruvate by the tricarboxylic acid cycle. On the other hand, Pomerat & Willmer (1939) showed that, in tissue culture, agents that inhibited respiration had little immediate effect on cell division, while Laser (1933) found that growth of cultured fibroblasts could continue when respiration was greatly diminished by low oxygen tensions. Further, Warburg (1930) concluded that cell growth is associated with glycolysis. A similar difference in the relationship of mitotic activity to the respiratory and glycolytic forms of carbohydrate metabolism was indicated by changes occurring in the midbrain and the red-blood cells of the chicken embryo during embryonic development.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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