Research Interests

Welcome to our website. We are a group of biologist fascinated by the diversity and evolution of living organisms, populations and ecological systems. Our primary goal is to understand the basic principles underlying both macro and micro evolutionary changes using plants as model organisms. In particular, our interest extends over several fields of plant biology, including ecology, population genetics, molecular evolution, evo-devo, systematics and comparative genomics with special attention to basal groups of land plants. We combine field-based ecological and lab-based molecular/reverse genetic approaches including computationally intensive modeling and genome analysis to understand evolutionary processes both at the macro- and microevolutionary scales.

We are officially hosted at the University of Zurich and are affiliated with the following institutions/centers:

Zurich-Basel Plant Science Center
URPP Evolution in Action
Institute of Evolutionary Biology and Environmental Studies
Institute of Systematic Botany and Botanical Gardens
Institute of Plant Biology
Swiss Institute of Bioinformatics

Evolution of phased-biased gene expression in land plants

All sexually reproducing land plants alternate between a haploid gametophytic and a diploid sporophytic phase. Nevertheless, relative dominance, morphology, function and trophical interrelationship of the gametophyte and sporophyte phases vary tremendously across groups of land plants. For instance in the bryophytes the haploid-phase is dominant and the sporophyte is relatively short-lived. In contrast, the diploid phase predominates in vascular plants and the haploid phase is significantly reduced. To understand the evolutionary mechanisms underlining the elaboration of the diploid phase and the reduction of the haploid phase we are studying the evolution of phase-biased gene expression across the land plant tree of life combining RNA-seq data and complex phylogenomic analysis.


Evolution of sex chromosomes and sex determination in haploid dioecy

Evolution of sex chromosomes is well-studied in organisms in which sex is expressed in the diploid phase. In such organisms the lack of recombination and the asymmetry in haploidy are assumed to lead to the progressive decay of the Y chromosome. In organisms in which sex is expressed in the haploid phase both U and V chromosomes are equally devoid of recombination and show no asymmetry in recombination suppression. This provides a unique opportunity to tease apart the effect of this two factors on the evolutionary trajectory of sex chromosomes. We are using a combination of classical genetic and comparative genomic approaches to test hypotheses concerning sex chromosome evolution in haploid dioecy using liverworts as a suitable model system (Marchantia polymorpha, Preissia quadrata and many more).

 
​Hornworts as a model system of evo-devo

Bryophytes are the extant representatives of the first plants that colonized the land about 480 million years ago. Morphological and functional complexity of land plants has rapidly increased after colonization from the relatively simple bryophytes to the highly complex vascular plants. Therefore, bryophytes are key to understand the evolutionary trajectories of developmental mechanisms during the land plant tree of life. Although, model systems are available for the lineages  of mosses and the liverworts but investigation on the biology of hornworts was until now hindered by the lack of a proper model system and available genomic data. Therefore, we have established A. agrestis as a model system and are currently sequencing its genome.
As a parallel project we are also working on the molecular regulation of the hornwort-cyanobacterium symbiosis and the molecular mechanism of pyrenoid assembly and function.


The Funaria hygrometrica genome and the genetic bases of rapid morphological evolution