Thinking of doing a PhD at the interface of Molecular & Evolutionary Biology?

The Research Training Group 2526 "Gene Regulation in Evolution“ (GenEvo), which is funded by the DFG (German Research Foundation), is offering projects on all levels of organismic complexity, from changes in genes and proteins to the evolution of symbiotic and parasitic behavior. As a GenEvo PhD student, you will join a community of passionate scientists who are applying a broad spectrum of methods on model and non-model organisms.

PhD project:

In the PhD Programme “Gene Regulation in Evolution”, Susanne Foitzik, Peter Baumann, and Joan Barau offer the following PhD project: Molecular manipulation of host phenotype via regulatory interference

Background:

Many parasites with complex life cycles actively increase the transmission probability by altering the phenotype of their intermediate hosts. This manipulation was termed the parasites’ extended phenotype and recently even the extended epiphenotype as parasites could alter host traits via epigenetic processes. However, the exact mechanisms by which parasites manipulate host behavior, physiology or life history traits are often still unknown. Our model is the parasitic cestode Anomotaenia brevis, whose infection strongly alters the phenotype of its intermediate host, workers of the ant Temnothorax nylanderi. Infected ants are inactive (Beros et al. 2015), have a weakly sclerotized and melanized cuticle (Scharf et al. 2012) and atrophied muscles (Feldmeyer et al. 2016). Remarkably, they show a significantly extended lifespan (Beros et al. 2021). These changes could increase transmission to the final host, a woodpecker. Our project aims to unravel the molecular mechanisms underlying these changes, including those in transcriptional activity (Stoldt et al. 2021; Feldmeyer et al. 2016, Sistermans et al. 2023), and whether they are caused by active parasitic interventions. Our recent proteomic study (Hartke et al. 2023) revealed that parasitic proteins, including antioxidants and epigenetic regulators, account for seven percent of all proteins in the hosts’ hemolymph. The genome of the parasitic cestode, which we have just completed, revealed that parasite load and transcriptionally activity is closely linked to host gene expression (Sistermans et al. 2023, in prep.).

PhD project description:

This exciting PhD project is based on the hypothesis that the parasitic cestode Anomotaenia brevis manipulates the phenotype of its intermediate host, the ant Temnothorax nylanderi, by interfering with its gene regulation. Based on evidence of cestode proteins secreted into the host’s haemolymph, some of which with gene regulatory functions, we ask whether, how and in which tissues the parasites interfere with host gene regulation.

In particular, we will analyze whether parasite-induced shifts in host gene activity are regulated by histone modifications (CUT&TAG), DNA methylation (Whole-Genome Bisulfite Sequencing) or microRNAs. To this end, the epigenetic landscape of infected ants will be compared with that of uninfected ants, also considering the parasite load. In parallel, we will investigate the transcriptional activity of the cestodes and compare it with changes in the host. Since infected workers live more than four times as long as their uninfected nestmates, we want to uncover the epigenetic and transcriptional underpinnings of these extreme differences in life expectancy. In addition, we will use RNAi to downregulate differentially expressed host genes as well as the expression of cestode genes encoding the most abundantly secreted proteins by injecting dsRNA into the hemolymph of the ants. Since many secreted cestode proteins are not yet annotated, we aim to analyze their effects on the host phenotype, including its transcriptional activity. For their characterization we can rely on the recently generated genome of the cestode, as well as of the host, of course.  Finally, we aim to analyze whether and how frequently extracellular vehicles are released by the cestode and what exactly they contain.

What we offer:

• Exciting, interdisciplinary projects in a vividly international environment, with English as our working language
• Advanced training in scientific techniques and professional skills
• Access to state-of-the-art Core Facilities and their technical expertise
• 14 funded PhD positions (employment contract)
• A lively community of34 PhD students supported by 28 Principal Investigators
• Collaboration with the International PhD Programme (IPP) at IMB with more than 200 PhD students from 40 different countries

Within the programme the Faculty of Biology of Mainz University (JGU) and the Institute of Molecular Biology (IMB) collaborate — both modern research institutions located on the bustling campus of Mainz University in Germany. With a population of 210,000, of which about 40,000 are students, the city of Mainz is charming and open-minded and within easy reach of cosmopolitan Frankfurt and its international airport, the Rhine valley region with its castles, vineyards, and nature reserves, and the equally picturesque cities of Wiesbaden and Heidelberg.

Requirements:

Are you an ambitious, young scientist looking to push the boundaries of research while interacting with colleagues from multiple disciplines and cultures? Then joining GenEvo is your opportunity to give your scientific career a flying start!

All you need is:

• Master or equivalent
• Motivation to contribute to the forefront of science in molecular and evolutionary biology
• Interactive personality & good command of English
• 2 letters of reference

The deadline for applications is 15 July 2024. Interviews will take place on 9-10 September 2024. Starting date will be 1 January 2025.

For more details on the projects offered and how to apply via our online form, please visit https://www.genevo-rtg.de/application