Mating in the alkane-utilizing yeast Yarrowia lipolytica

✍ Scribed by Prof. Dr. H. Weber; Cornelia Kurischko; G. Barth

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 808 KB
• Volume: 28
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620280405

✦ Synopsis

Mating in Yarrowia lipolytica can be induced by mixing cells of both complementary mating types (A and B) in yeast extract-malt-medium. By means of an inbreeding programme, strains with significantly improved mating frequencies were selected. The main events of the mating process, that have been detected so far, by means of cytological methods, are: formation of mating tubes, cell contact, cell fusion and karyogamy. During the process of conjugation, mating tubes of different lengths as and shapes are formed between haploid parental cells. Under special conditions the preformation of mating tubes was observed. Mating in the dimorphic yeast Y. lipolyticu has been shown to be a distant mating and to occur between cells of a different shape and size. Cells involved in conjugation are no changed morphologically, except for the formation of special copulation structures. Several events of mating and the morphology of zygotes are different than those in the C&BB of baker's yeasts. It is supposed that there is in this yeast also an action of diffusible factors that trigger mating.

Yeast organisms possess the ability to reproduce both vegetatively as well as sexually. Sexuality was first observed in several yeasts as early as the end of the lgth and the beginning of the 20th century by HANSEN, SCHONNMG, GUILLIERMOND and several other authors (for ref. see MORTIMER and HAWTHORNE 1969). Some years later the existence of a life cycle in sporogenous yeasts, i.e. yeasts involving a sexual process and alternating haplophase and diplophase, was established (for ref. see FOWELL 1969). I n Sacch. cerevisiae and Schiz. pombe, which during the past