Macromolecular Composition and Nuclear Division During Spore Germination in Aspergillus nidulans

Abstract

SUMMARY Germ-tube emergence in Aspergillus nidulans exhibits partial synchrony. Germ tubes were first detected at 210 min. after inoculation of spores into a liquid medium. Almost all spores produced germ tubes within 360 min., 493 % of them doing so between 240 and 300 min. Increase in dry weight was first detected at 120 min. and various constituents at the following times: RNA (30 min.), Kjeldahl nitrogen (30 min.), protein (150 min.) and DNA (180 min.). Pauses in the increase of DNA, RNA and protein were observed. The DNA content per nucleus during the first replication cycle reached twice that of the resting spore, but at later stages of germination values only 10 % higher were observed. Spores containing 2, 4 and 8 nuclei were first detected at 270, 390 and 480 rnin. respectively.