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SURFACE CHARACTERS OF DIVIDING CELLS III. UNEQUAL DIVISION CAUSED BY STEEP TEMPERATURE GRADIENT IN GRASSHOPPER SPERMATOCYTE
Author(s) -
ISHIZAKA SHOZO
Publication year - 1969
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1969.00104.x
Subject(s) - cleavage furrow , grasshopper , division (mathematics) , temperature gradient , anaphase , cell division , spermatocyte , biology , cytokinesis , biophysics , physics , chemistry , mathematics , cell , meiosis , meteorology , cell cycle , ecology , genetics , arithmetic , gene , biochemistry
A bstract Division of the spermatocytes of the grasshopper, Acrida lata , was studied under a steep temperature gradient. When a temperature gradient is applied along the spindle, the development of the aster on the warmer side is accelerated which, in turn, pushes the spindle toward the cooler side of the cell and the division becomes unequal. A condition to obtain such an unequal division is to shift the spindle by the temperature gradient and hold it eccentric during anaphase. Future cleavage plane is foreshadowed by the tongue of the mitochondria at anaphase before the cell departs from sphericity. If a temperature gradient is applied across the spindle, the spindle slides towards the cooler side sideways and the furrow is formed earlier, on the farther side of the cells from the spindle on the warmer side, although the size of the daughter cell is equal. The result indicates that the advance of the furrow is endothermically accelerated.