CYTOGENETIC STUDY OF NOCARDIA CORALLINA ,

Abstract

Cytogenetic procedures, applicable to microbiology, were selected and tested on a suitable organism as a basis for the valid application of these procedures to other microorganisms. The crystal violet nuclear stain, the thionine-S02 nuclear stain, the crystal violet-tannic acid-congo red cell wall stain, and phase microscopy, were found to be valid tools of microbial cytology if interpreted with restraint. The correlation of cytological and radiobiological findings indicates that, in N. corallina, a diploid coccoidal stage gives rise to coenocytic diploid hyphal stage which fragments through a nuclear reduction division to form haploid binucleated bacillary cells. The bacillary cell nuclei fuse and the cell divides to form diploid coccoids. The haploid "chromosome" number is suggested as 3 for this organism. It has been demonstrated that a microbial cytogenetic approach involving the correlation and integration of cytological procedures with genetic and radiobiological methods can aid in solving basic problems of microbial cytology and genetics.