Saccharomyces cerevisiae, ext.

Toxicity to birds

Administrative data

Endpoint:

long-term toxicity to birds

Type of information:

other: Introduction to the workshop of the 27th International Conference on Yeast Genetics and Molecular Biology

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference Type:

review article or handbook

Title:

Introduction to the workshop "Symbiomes: yeast ecology revisited"

Author:

Cavalieri, Duccio

Year:

2015

Bibliographic source:

http://dx.doi.org/10.1002/yea.3090

Report date:

2015

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

Not applicable

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Saccharomyces cerevisiae

Cas Number:

68876-77-7

IUPAC Name:

Saccharomyces cerevisiae

Results and discussion

Effect levels

Key result

Dose descriptor:

other: Not applicable

Effect level:

0 other: Not applicable

Conc. / dose based on:

other: Not applicable

Basis for effect:

other: Not applicable

Remarks on result:

other: Review. Quantitative result was not determined.

Applicant's summary and conclusion

Conclusions:

Macroorganisms are considered as natural vectors and niches for Saccharomyces cerevisiae.

Executive summary:

Here we will survey the current knowledge on the ecology and the wild niches of S. cerevisiae discussing how human selection on specific traits of strains used in wine and beer fermentation could have influenced the evolution of this microorganism. The budding yeast Saccharomyces cerevisiae is since more than 2000 years a great companion of humanity, appreciated for its fermentative characteristics in wine, beer and bread productions. In addition to its importance in food technology, for the past 50 years S. cerevisiae has been the cradle and stage of genetics and molecular biology. This microorganism was the main player in several revolutionary technologies, from gene mapping to genetic engineering to structural and functional genomics. In the past 20 years this eukariotic model allowed genome scale reverse genetics and network analysis, leading to unprecedented discoveries on how genes interact and how fundamental processes, such as cell cycle or mating, can be modeled. Systems biology as a science is the result of these pioneering studies, and today this microorganism holds the promise to resolve more fundamental problems in science including the role of protein folding and prions as master regulators and the exploration of the potentials of Synthetic biology. All these fundamental discoveries were made on a strain that became a model for an eukariotic cell, S288c, indeed the best characterized genome after E.coli. Paradoxically very little was known till year 2000 on the ecology and evolutionary biology of Saccharomyces. Till that time yeast genome evolution and selection of S. cerevisiae as a species was though to depend only on human activities (massive fermentations) providing favourable environmental conditions in which yeasts can reproduce through vegetative budding of diploid cells. The existence of a natural cycle of this microorganism outside human-related environments was demonstrated by a small initial number of pioneering studies, some led by the very same scientist who built S288c, RK Mortimer, who, together with Mario Polsinelli, in a seminal study was able to identify several different strains from single damaged grapes (Mortimer, R. &Polsinelli M. 1999). This discovery moved the debate on S. cerevisiae domestication from the species level to the strain level, as elegantly shown in genomic level studies by Justin Fay, Maitreya Dunham, Ed Louis, Gianni Liti and collaborators. Already in the initial studies insects were considered as vectors and natural niches for S. cerevisiae (R.K. Mortimer 2000). More recently studies stemming from these initial observations demonstrated that social wasps bear yeast cells all year long (Stefanini I. et al. 2012) and feed on sources that are potentially inhabited by multiple Saccharomyces spp. strains, thus representing a potential incubator for different yeast cells to meet and mate. In addition to wasps Drosophila has been shown by the Goddard group to be an important vector for S.cerevisiae dissemination in the wild. This has led to the investigation of which genes are involved in the process of insect attraction and dispersal, one of which, ATF1, has been recently discovered by the group of Kevin Verstrepen. Along these lines, the question on what genes relevant for yeast ecology are under selective pressure and the role of yeast inversions and epigenetic regulation mechanisms in yeast evolution, is still an open question, investigated importantly by the work of the groups of Kenneth Wolfe and Daniela Delneri. Recent results from our lab further propose the insects gut as potentially the most important ecological niche of S. cerevisiae, prompting the sporulation of S. cerevisiae and favouring generation of novel genetic combinations by outcrossing and inter and intraspecific mating. These results open a new perspective to the evolution of Saccharomyces spp. yeasts, introducing insects as active players other than human activities.