IMMUNOLOGY OF THE YEAST HANSENULA WINGEI

Physiology of the conjugation process in the yeast Hansenula wingei.

The yeast Hansenula wingei is a favourable organism for study of the physiology of the conjugation process (cell fusion). Microscopic observations on fusion are presented which reveal that the mating cells in contact fuse by a softening of the cell wall, followed by formation of a conjugation tube, dissolution of the cross-walls between them, and formation of a new bud a t the point of juncture...

Molecular basis of mating in the yeast hansenula wingei.

Association constant of the sex-specific agglutinin in the yeast, Hansenula wingei.

Association constants were determined for absorption of the sex-specific agglutinin from mating type 5 of Hansenula wingei by cells of type 21, the opposite mating type. Absorption was determined by following the radiolabeled sulfur in purified agglutinin extracted from cells grown in 35S-labeled medium. Association was proved to be reversible under conditions where cell agglutination was In se...

Meiosis in Hansenula holstii and H. wingei.

Diploid isolates of Hansenula holstii Wick. and H. wingei Wick. usually produce two or three ascospores per ascus. An unusual nuclear event during meiosis might account for less than the expected number of four. When acridine orange or Feulgen staining was used, meiosis in both species followed the pattern established in higher plants and animals. Deoxyribonuclease treatment destroyed nuclear s...

Cooperation among the active binding sites in the sex-specific agglutinin from the yeast, Hansenula wingei.

Changes in properties of 5-agglutinin were examined during the course of the reaction to inactivate it by cleaving disulfide bonds. During this reaction both agglutinative titer and apparent free energy of absorption decreased rapidly with a relatively small proportion of disulfide bonds reacted. Fractionation experiments disclosed that very little biologically inactive material appeared until ...