Journal ArticleDOI
A serum factor requirement for the passage of cultured Vero cells through G2.
Dean L. Engelhardt,M Jen-Hao +1 more
TLDR
It is concluded that transit through G2 requires the presence of an extracellular factor, and Vero cells cannot pass through a transition point in G2.Abstract:
When Vero cells, a line derived from and African Green Monkey kidney, are grown under conditions where the saturation density is limited by serum, they deplete the growth medium of a factor necessary for cell division. The factor is a component of serum. When Vero cells are plated at low density (2 X 10(4)/cm2) in this depleted growth medium (after dialysis against serum-free Dulbecco's Modified Eagle's Medium) they initiate an unbalanced program of growth. Protein synthesis proceeds at the same rate as parallel cells in fresh serum, and and the cells accumulate protein as a function of time. DNA synthesis is also initiated in these cells, and the amount of DNA per cell increases for the next four days plating. However the cells quickly stop dividing. Measurements of DNA per cell using microspectrofluorometry show that the cells are accumulating in the late S and G2 period during this time. Thus we conclude that these cells cannot pass through a transition point in G2. When fresh serum is added to cells after three days in depleted growth medium, they divide before they begin to synthesize DNA. This further confirms that they are in late S and G2. Cell division is promoted in Vero cells in depleted growth medium by bovine fetuin, and to a lesser extent by bovine albumin. Cell division is not promoted by insulin, hydrocortisone, dexamethasone, linolenic acid, calcium, and typsin inhibitor form ovomucoid. From these data we conclude that transit through G2 requires the prescence of an extracellular factor.read more
Citations
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Journal ArticleDOI
Hormonal control of muscle growth
TL;DR: Results with purified proteins do not support the view that mitogens block myoblast differentiation; transforming growth factor‐beta and interferon are nonmitogenic proteins that inhibit differentiation, insulin‐like growth factors are mitogens that stimulate differentiation, and fibroblast growth factor is the only purified mitogen that inhibits differentiation.
Journal ArticleDOI
The Regulation of Spermatogenesis in Insects
TL;DR: The process of gametogenesis in the male insect has received far less attention than the similar event in the female because the female is generally considered far more important from a point of view of reproductive strategies and has served as the focus of biological and chemical control research.
Journal ArticleDOI
Action of growth factors in the cell cycle.
Journal ArticleDOI
A serum-free medium for the growth of muscle cells in culture
TL;DR: Primary rat myoblasts proliferated more rapidly than fibroblasts in parallel cultures when incubated in MM-1, a simple medium composed of relatively inexpensive and readily available components that should be useful for the study of muscle cell growth and differentiation.
Journal ArticleDOI
Fetuin: its enigmatic property of growth promotion
TL;DR: The present review surveys the literature concerning this enigmatic property of fetuin and summarizes three possibilities: 1) fetuin itself is active, although the majority of studies do not support this; 2) various contaminants of Fetuin preparations, including potentially unidentified ones, are responsible for the activity; and 3) one of the fetuin subspecies, one of its contaminants, or a combination of both of these is responsible for growth of a specific cell type.
References
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Journal ArticleDOI
Action of x-rays on mammalian cells.
TL;DR: Evidence, though not proof, is presented that the lethal effect is due to a radiation-induced genetic defect which, however, cannot be a simple single gene inactivation, and methods of preparing large populations of giant cells are described.
Book ChapterDOI
[105] Determination of DNA concentration with diphenylamine
TL;DR: The chapter focuses on the later modifications for the determination of DNA especially in microorganisms and animal tissues and presents the modifications described by Burton, Croft and Lubran, and Giles and Myers.
Journal ArticleDOI
Measurement of cell growth in tissue culture with a phenol reagent (folin-ciocalteau).
Vance I. Oyama,Harry Eagle +1 more
TL;DR: An analytical method for the measurement of cell growth in tissue culture is described, based on the Lowry method forthe determination of protein, and employing a phenol reagent (Folin-Ciocalteau) for color development.