EVALUATION AND NATURE OF THE NEAR-DIPLOID CELLS OF CHINESE HAMSTER (CRICETULUS GRISEUS) IN VITRO

Abstract

After several years of transfer and subculture from time to time in different laboratories with different media and sera, the Chinese hamster V cell strain still contains the same percentage of near-diploid cells. The majority of the cells contain 23 chromosomes and most of these possess the same chromosome pattern, which is therefore taken as representative of the line. However, 34 different types of chromosome constitution were found in the cells studied. With some exceptions the cells having different chromosome complements are nevertheless similar in chromosome constitution. On the other hand, cells having the same number of chromosomes may be of different patterns. The aberrations which give rise to changes in chromosome morphology and number seem to occur only on certain chromosomes and on certain regions of these chromosomes. Hence, the difference between cells having different chromosome complements depends upon the number of extra chromosomes that have appeared. The "normal" chromosomes of the same type present in cells of different chromosome complements are very similar.