Mitosis-Like Activity in Bacillus Sp. A

Abstract

The organism used was isolated from the soil and grown on glucose agar. In size and fermentation it corresponds in a measure with Bacillus mesentericus. Only the R type was used since the staining reaction of the S type was not satisfactory. A twelveto thirteen-hour culture was used as the parent culture. Since stains of the growing culture were to be made at different time intervals, as many transfers were made as time intervals, thus giving a separate culture for each staining period. After the transfers were made cells were removed from the parent culture and stained (figs. 1 and 2). Some of these cells stained throughout. Others had more heavily stained structures within the cytoplasmic region. The arrangement of these structures, within limits, constituted a type of configuration. The cells from the two-hour culture (fig. 3) may or may not stain. Some of the figures resemble in a measure those characteristic of the parent cells while others may contain one or even two spherical bodies. Some of these cells stain rather uniformly throughout, while others give a motley effect. A more deeply stained spherical body may appear in cells otherwise uniformly stained. Where two spherical bodies appear they may be equal or unequal in size and occur separately or partially united. The wall region of some cells remains unstained. The stoning pic

The Occurrence of Mitosis in Bacillus Megaterium and Its Relation to the Growth Cycle

“…Studies of nuclear changes during the bacterial growth cycle have been attempted by a number of workers. Chance (1938) in his study of "mitosis-like" activity in B. mesentericus observed the single spherical bodies in young cultures. These are somewhat comparable to the resting nuclei described in this paper.…”

“…The criterion for determining whether a nucleus divides mitotically rather than amitotically is the formation of a metaphase spindle. A number of workers (Barnard, 1930;Chance, 1938;Boivin et al, 1948;Johnson and Gray, 1949) have indicated that mitotic nuclear division takes place in bacteria, but in no case was a metaphase spindle adequately demonstrated. However, a good demonstration of metaphase spindles in a number of organisms has been presented by DeLamater (1951a).…”

“…Barnard (1930), studying several species of bacteria with dark-field, ultraviolet illumination, found structures which he interpreted as nuclear components undergoing mitotic division. Chance (1938), staining Bacillus mesentericus by a reduction-oxidation technique, indicated that "mitosis-like" nuclear division takes place, though no specific structures were implicated by him. Boivin et al (1948) observed mitotic figures in bacteria through the use of ribonuclease and desoxyribonuclease.…”

The Morphology and Cytology of Myxococcus xanthus , N. Sp

“…Although he did not actually observe the conjugation of two cells he could distinguish two types of chromosomes and considered them to be o and 9. Chance's (1938) observations on Bacillus mesentericus disclosed a reorganization and redistribution of chromatin comparable to a mitotic division in higher forms, and Allen, Appleby and Wolf (1939) gave evidence of meiosis having taken place in a species of Bacillus which they studied. These same investigators also witnessed and accounted for at least two methods of spore formation in the one organism, and methods of reproduction other than the usual transverse fission.…”