Description du sujet de thèse

Description of the thesis topic:

Understanding the establishment of reproductive barriers between incipient species is what allows us to understand the origin of new species and ultimately the generation of species diversity on Earth. Reproductive barriers can accumulate as a consequence of species-specific adaptation of ecological traits or mating preferences, or originate from incompatibilities between two or more loci that interact with each other in the genomic background of interspecific hybrids. Since recombination between the genetic material of incipient species can dissolve species boundaries, a thorough comprehension of the evolution and regulation of meiotic recombination during the speciation process is central to our understanding of species formation. While geographic barriers that prevent sexual reproduction are thought of playing an important role in the initiation of the speciation process, molecular mechanisms that suppress recombination between incipient species are suggested to play a role to maintain species boundaries in sympatry. For example, chromosomal rearrangements may play a central role in local suppression of recombination in heterokaryotype individuals and promote speciation through coupling of adaptive combinations of alleles in the re-arranged regions. The presence of heterozygote chromosomal rearrangements can also result in improper chromosome segregation during meiotic cell division and incite a breakdown of meiosis. Hence, accumulation of chromosomal rearrangements between parental genomes is hypothesized to severely compromise fertility in their F1 hybrids and act as a source of reproductive isolation Similarly, genetic incompatibilities in the recombination machinery that have accumulated in the parental species can be involved in hybrid sterility. The role of meiotic recombination in speciation can thus be manifold, but little is known about its role during speciation in songbirds. The PhD project aims to fill this gap and investigate recombination rate regulation in two songbirds of the genus Ficedula.



Activities:

The PhD project will use two independent approaches to retrieve recombination rate estimates in collared and pied flycatchers. Then, one aim will be to investigate the fine-scale regulation of the recombination landscape in these two songbirds. As another angle, the influence of large-scale chromosomal rearrangements on the recombination landscape and their role in speciation will be investigated. The PhD project will thus address the causes and consequences of recombination rate variation across the avian genome, covering fine-scale and broad-scale regulation of recombination rate, and the role of the recombination machinery in species-specific adaptation and hybrid sterility.



Profile and skills required:

The candidate should have a strong interest in evolutionary genomics and ecology; should be willing to acquire an extensive training in bioinformatics and statistical data analysis; should have good communication skills in English and enjoy collaborative work.

Contexte de travail

-he PhD student will join the Laboratory of Biometry and Evolutionary Biology (LBBE - https://lbbe.univ-lyon1.fr/) under the direction of Carina MUGAL and co-direction of Laurent DURET. The PhD student will be provided with an office space and a laptop, and will also have access to the high-performance cluster of the CC LBBE/PRABI. Most of the genomic data used within the PhD project are already sequenced and readily available to the student. Newly sequenced genomic data will be generated in the first year of the PhD project, with funding resources already secured as part of 4-year ANR-funded project SpeCular. The PhD project will also benefit from an established international research collaboration on speciation research in Ficedula flycatchers, Anna Qvarnström, Uppsala University, Sweden, and David Wheatcroft, Stockholm University, Sweden.

Our little extras
:• A stimulating work environment in contact with research staff
• Professional support with internal training at the laboratory
• The possibility of teleworking
• A company restaurant offering lunch at an attractive price.
• Partial reimbursement of transportation costs (75%) + sustainable mobility allowance of up to €300/year
• A site accessible by public transportation (Tram T1 + T4 + bus)
• 44 days of vacation/RTT per year
• Financial contribution to mutual insurance costs