At the University of Vienna, there are three broad categories of doctoral students in the fields of biology, molecular biology, environmental sciences, or earth sciences. All PhD candidates have to complete the mandatory coursework and milestones of the PhD programme. Their position differs in terms of employment, access to workshops and eligibility to participate in VDSEE funded programmes and activities.
Two PhD positions: with Agnes Dellinger on “The geographic mosaic of pollination and fruit dispersal as source of diversity in Pyxidantheae” & with Hanna Weiss-Schneeweiss on “Evolution of the karyotypes and genomes of peppers (genus Capsicum, Solanaceae)”
For the two PhD positions:
- Job grading in accordance with collective bargaining agreement: §48 VwGr. B1 Grundstufe (praedoc) with relevant work experience determining the assignment to a particular salary grade.
- The selected candidates will be member of Vienna Doctoral School of Ecology and Evolution (VDSEE).
We expect successful candidates to sign a doctoral thesis agreement within 6-12 months and to participate in research, teaching and administration, including:
- Participation in research projects/research studies;
- Participation in publications/academic articles/presentations;
- Participation in teaching and independent teaching of courses as defined by the collective agreement;
- Supervision of students;
- Involvement in the organisation of meetings, conferences, symposiums;
- Involvement in the department administration as well as in teaching and research administration.
#2: Agnes Dellinger
PhD Research Project: The geographic mosaic of pollination and fruit dispersal as source of diversity in Pyxidantheae:
Employment details:
- Duration of employment: 3 years
- Extent of employment: 30 hours/week
Your profile
- MSc degree or equivalent in botany, ecology, evolutionary biology;
- Experience with tropical fieldwork and identification of tropical plants, ideally Melastomataceae;
- Background in (flower) morphology/morphometrics and pollination/floral scent analyses advantageous;
- Knowledge in programming for ecological/evolutionary analyses, ideally in R or Python;
- Ability to communicate scientific research in both English and Spanish;
- Ability to work independently during fieldwork in Latin America;
- Interest in networking with Latin American researchers.
Your tasks
- Document pollinators and fruit dispersers for selected species of Pyxidantheae through extensive empirical fieldwork in Latin America (Costa Rica, Colombia);
- Multivariate statistical analyses of an existing flower trait database of Pyxidantheae, expand this database by recording fruit traits and sampling and analyzing floral scent;
- Depending on timing/interest, the project may include training in NGS wet lab and data analyses for population genomics in Pyxidantheae;
- Participation in publication of results, presentation at conferences, and public outreach particularly in Spanish in the Latin American countries where the research is conducted;
- If interested, possibility of co-advising MSc students.
Description
Macroevolutionary comparative studies have demonstrated striking adaptations of flowers to distinct groups of animal pollinators, including differentiation in flower color, scent, rewards and morphology. The geographic pollinator mosaic (GPM) represents the quintessential theoretical framework for testing how these floral adaptations play out in an eco-environmental context. Specifically, the GPM proposes that across its range, a plant species encounters locally variable pollinator communities, and adapts to such variable communities through (often subtle) floral trait changes.
Despite the central role of the GPM as source of floral differentiation and lineage divergence, to date, we lack comparative models on how variation in plant-pollinator interactions across geographic and environmental contexts plays out in macroevolutionary patterns of flower diversity. Besides pollination, fruit dispersal is the second central mechanism by which (most) land plants disperse their genes, and the variability of environment-fruit-dispersal associations across a species’ distribution range also remains unclear.
Using the Latin American Melastomataceae tribe Pyxidantheae as model, it is the aim of this project to document macroevolutionary patterns of flower and fruit trait differentiation in an environmental context, and test the GPM as source of flower diversity through microevolutionary adaptations to locally variable pollinator communities.
Pyxidantheae (ca. 200 spp.) is most diverse in Colombia and Costa Rica, and primarily bee pollinated, with two independent evolutionary shifts to vertebrate pollination in the Andes. Pyxidantheae flowers stick out among Melastomataceae by their strong and differentiated floral scents, and variation in androecial symmetry, possibly a mechanism of adaptation to different bee pollinators. This project combines extensive fieldwork in Latin America to improve our understanding of the natural history of the tribe, with comparative phylogenetic trait analyses, geometric morphometrics and chemical ecology.
There is room for employing a population genomic approach in combination with field documentation of pollinators and dispersers to explore the relative contribution of different pollinator and fruit disperser assemblages in population differentiation. The successful applicant will be integrated into the Plant-Animal-Interactions lab at the University of Vienna.
Contact: agnes.dellinger@univie.ac.at and APPLY NOW
#3: Hanna Weiss-Schneeweiss
PhD Research Project: Evolution of the karyotypes and genomes of peppers (genus Capsicum, Solanaceae):
Employment details:
- Duration of employment: 4 years
- Extent of employment: 30 hours/week
Your profile
- MSc degree in biology (evolutionary biology, cell biology, genomics) or a related field
- Experience with cytogenetic, molecular and cell biology techniques; basic bioinformatics skills as well as experience in working with plant chromosomes are desired; theoretical knowledge of genome structure and evolution
- Good English skills and the ability to communicate scientific research in English
- The ability to work in an international and multicultural team
- Motivation, interest in the research field, ability and willingness to master the broader skill set necessary for the successful completion of a research project
Your tasks
- Adapting the method of chromosome painting to genomes of selected Capsicum species
- Analyses of karyotype rearrangements in selected species and reconstruction of major karyotypic events leading to variation observed in extant species of the genus
- Reconstruction an ancestral karyotype of the genus and interference of the temporal sequence of major structural karyotypic and genomic events in the evolutionary history of the genus Capsicum
- The work will combine wet lab tasks (molecular cytogenetics, molecular biology) and basic bioinformatics and phylogenetics analyses
- Presentations of results at (inter)national conferences, public outreach, and the publication of the results
- Participation in co-supervision of MSc students and in teaching (according to the collective agreement)
Description
Chromosomal-level changes accompany species diversification and speciation, including polyploidy, chromosomal rearrangements, and dynamic changes of the repetitive DNA fraction. One of the approaches allowing for inference of structural genomic changes is chromosome painting which relies on the mapping of DNA sequences representing whole chromosomes or their fragments using fluorescence in situ hybridization (FISH). Although chromosome painting of plant genomes is still challenging due to a large proportion of repetitive DNA elements populating their genomes, recent methodological developments, offer new possibilities to overcome those challenges, as demonstrated in several species, including Capsicum.
The genus Capsicum encompasses about 40 species native mostly to South America with five species domesticated and cultivated all over the world. All chile peppers species are diploid based on two base chromosome numbers, x = 12 or 13, with the former inferred to represent the ancestral number, and the latter inferred to have originated twice independently.
Despite rather stable chromosome numbers, genome sizes in the genus vary nearly 4-fold, due to different dynamics of various repetitive DNA families. These taxa are particularly suited for analyses of chromosomal evolution because of the lack of polyploidy, availability of chromosomal level genome assemblies for domesticated species, well established phylogenetic relationships and an extensive collection of wild species.
This PhD project aims to elucidate the evolution of karyotypes during the evolution of Capsicum. Chromosome-level painting of the genomes of chile peppers with oligo probes based on genomic and cytogenetic resources available for Capsicum annuum will provide the basis for comparative analyses of karyotypes of domesticated and wild species representing all major phylogenetic clades and closest sister genus, Lycianthes.
The specific aims of this project are: (1) reconstruction of ancestral karyotype of the genus, (2) identification of mechanisms involved in karyotype rearrangements and reconstruction of the sequence of events leading to the karyotypic variation after 14 million years of the evolution of the genus, (3) testing the hypotheses of base chromosome number evolution, and (4) inferences of the impact of human-assisted selection on the dynamics of the genome evolution by comparing the domesticated with the wild species.
We offer:
- A friendly, collaborative and productive working atmosphere in the Plant Evolutionary Cytogenetics group.
- An employment starting in Summer/Autumn 2023, limited to 48 months (4 years)
- Work in a research centre with state of the art facilities and collaborations with scientists/experts from different countries
Contact: hanna.schneeweiss@univie.ac.at and APPLY NOW
How to apply: details on eligibility criteria and application portfolio to be submitted are described at [APPLY NOW] Application and on the submision portal Apply@VDSEE.
Apply until: 16.06.2023