PhD Studentship in tardigrade and sex evolution at the Jagiellonian University (Kraków, Poland) in collaboration with Wellcome Sanger Institute (Cambridge, UK)
The Project
The co-existence of sexual and asexual
reproduction is one of the major conundrums in life sciences. On one hand,
asexual reproduction has clear advantages, such as the lack of the cost of
producing males (who do not produce offspring), no risks stemming from mating
(time costs of mate searching, injuries in fights for mates, increased predation
risk due to sexual ornaments and mating, sexually transmitted infections, sexual
conflict, etc.), and higher dispersal potential (a single female is sufficient
to colonise a new environment and there is no risk of inbreeding depression
compared to sexuals with small founding populations). On the other hand, theory
predicts that sexual lineages should be more persistent and successful over
evolutionary timescales than asexual lineages, because recombination and sexual
selection are thought to facilitate both the spread of advantageous alleles
through populations and the purging of the deleterious alleles via recombination
and sexual selection. That is why it is expected that abandoning sexual
reproduction with all its shortcomings, even though initially may be beneficial,
it inevitably leads to the accumulation of the mutational load, which results in
lineage extinction. Hence, it has been predicted and observed that asexual
lineages represent short-lived twigs on the phylogenetic tree of life, scattered
among old large and widely spread branches of sexually reproducing lines.
Importantly, however, there are notable exceptions to this pattern, such as
bdelloid rotifers or oribatid mites, often termed as ‘evolutionary scandals’
exactly because their existence clashes with our understanding of evolution.
Thus, the question is why are some asexual lineages able to persist over long
evolutionary time, whereas the majority of them seem to be evolutionary dead
ends? Are they examples of when it is possible to benefit from characteristics
of both asexual and sexual reproduction without producing males and all costs it
involves? Until very recently there were no tools which would allow for reliable
testing if these ancient asexuals may genetically compensate for the lack of
males, either by unknown means of recombination or incorporation of genetic
variability via horizontal gene transfer, and a handful of studies provide mixed
results, which only make the question more intriguing.
Therefore, this large-scale project takes
advantage of the cutting-edge methodology of genome sequencing and analysis of
tardigrades, a poorly explored animal group known to a wider audience thanks to
their abilities to withstand extreme environmental conditions, to test whether
ancient asexuals found a way around to circumvent the costs of losing sex while
benefiting from clonal reproduction. To achieve this, we will use two groups of
tardigrades: the family Murrayidae and the genus
Paramacrobiotus, both placed in the superfamily Macrobiotoidea.
Exclusively parthenogenetic murrayids are considered ancient asexuals. On the
other hand, Paramacrobiotus comprises
a mixture of dioecious and parthenogenetic species, which indicates the
asexuality is recent and evolved independently multiple times. The main
hypothesis to be tested in the project is that ancient asexuals have been able
to persist because they compensate the loss of males by other means of genetic
recombination. The prediction, therefore, is that murrayids exhibit genomic
signatures of recombination, whereas parthenogenetic
Paramacrobiotus spp. do not Thus, the project will provide first
large scale, systematic comparative analysis of the genomic architecture of
ancient and recent asexuals. Importantly, thanks to the very recent advancements
in genome sequencing of micrometazoans, tardigrade genomes will be obtained from
single individuals (to date, the very few available tardigrade genomes were
obtained from pooling thousands of animals).
In addition to the main goal, the project
will also result in the first experimental estimation of mutation rates in
tardigrades and the first tardigrade phylogeny based on genomes. Finally, a
large number of barcoding data collected in the project will translate to a
tardigrade biodiversity survey of an unprecedented geographic and taxonomic
resolution and accuracy, which will constitute important information from the
point of view of nature conservation and will be a sound reference point for
monitoring future changes in micrometazoan communities.
The position is a part of a recently
awarded research grant titled "Can you really make it alone? Phylogenomic
deciphering of evolution of asexual reproduction."
Employment
duration
This is a 4-year, full time PhD position
that is expected to commence on the 01.10.2024 and terminate on the 30.09.2028.
Opportunities
The PhD studentship presents a great and
unique opportunity to answer one the fundamental questions in life sciences
using a fascinating model and cutting edge methods. Importantly, the position
also offers additional training in genomics and transcriptomics in one of the
world’s leading institutions in genomics, the
Wellcome Sanger Institute in
Cambridge, UK.
Prof. Mark Blaxter, Head of the
Tree of Life Programme
at Sanger, is a formal and the key collaborator on the project. Although the
evolution of sex and tardigrades are the central project aims, the system
provides potential for a dedicated student to explore their own ideas on other
topical tardigrade biology and evolutionary questions. A dedicated student will
have a great chance not only to learn a range of transferrable skills, but also
to build a sound publication record which will help them to get an attractive
PostDoc or industry position in the future.
Tasks
The successful candidate will be involved
in will be involved in field work (sample collection), tardigrade
identification, culturing, DNA extraction, genome & transcriptome sequencing and
assembly, as well as in phylogeny reconstruction. The PhD Student will be also
required to prepare first drafts of some manuscripts and will be involved in the
promotion of results at seminars and conferences.
Supervisor
Prof. Łukasz Michalczyk is an evolutionary
biologist who happens to love tardigrades. He did his MSc at the Jagiellonian
University (Kraków, Poland), then a PhD (2009) and a PostDoc at the University
of East Anglia (Norwich, UK), followed by a Fellowship at the University of
Western Australia (Perth, Australia). Currently, he holds a permanent position
of an Associate Professor at the Jagiellonian, where he leads a dynamically
developing group of young researchers. He published over a 150 research papers
in international journals, including top periodicals such as
Science and
Nature (GoogleScholar
profile). He has also been a Principal Investigator in projects
concerning some of the key areas of evolutionary biology inquiry such as sexual
selection, inbreeding, phenotypic plasticity, and phylogeography.
Lab
Our lab is located in the new building of
the Institute of Zoology and Biomedical Research (part of the Faculty of
Biology). The lab is fully equipped with the state-of-the-art equipment,
including high class phase and differential interference contrast microscope, a
number of stereomicroscopes, DNA lab, and incubators for tardigrade culturing.
There are SEM and DNA sequencing facilities on the campus. Our lab has the
largest collection of tardigrade strains in the world. Our Institute also owns a
Mountain Station in
the
Gorce Mts., where we go every summer and winter for short seminars
and team integration excursions.
University
Jagiellonian
University, founded in 1364, not only is
the oldest Polish University but it is also one of the oldest universities in
the world. Together with the Warsaw University, it is ranked as the top
university in Poland. Our Institute is located in the new university campus in
the Ruczaj district, which is surrounded by meadows and lies in the vicinity of
the Vistula river. The campus is conveniently communicated with the city centre
(20 min by tram). Famous Jagiellonian alumni include the astronomer Nicolaus
Copernicus and Nobel Laureate Wisława Szymborska.
City
Kraków
is one of the oldest
Polish cities
and it is also considered as one of the most beautiful in the country. With
nearly 200 000 students studying at 20 universities and academies, it is a
vibrant place with many pubs, clubs and other
student attractions. Kraków is located in the south of Poland, thus
gorgeous
Tatra
Mts.,
Pieniny Mts.,
Gorce
Mts., and other mountain ranges are only two hours away by coach.
PhD programme
The PhD programme in Biology is run
entirely in English and it includes some obligatory and facultative classes.
The programme is open to all nationalities and there are no tuition fees.
The PhD studentship will take four years: it will commence on the 1st October 2024 and the student
is required to submit the PhD thesis by the 30th September 2028. The viva should take
place by the end of 2024. The PhD thesis is planned to be in a form of a series
of 3–4 research papers published in high rank journals.
Scholarship
The tax-free stipend is ca.
5 500 PLN/month on average for the duration of four years. If you choose to lead
a typical PhD student life in Kraków, you will spend ca. 4 000 PLN/month, thus
the stipend assures a good standard of life and also allows for saving some
money for the future.
Requirements
Formal: An MSc diploma (or an equivalent that
allows to enter a PhD course) in biology or in a related field, already in
possession or to be obtained no later than on the 31st of July 2024.
Personal: I am looking for an enthusiastic,
motivated and hardworking person who is not afraid to learn new things and
skills, someone who gets along with people and is happy to work in a team but is
also able to operate independently, without a constant supervision and
micromanagement. A strong interest in evolutionary biology, with emphasis on
reproductive modes, phylogeny, genomics and bioinformatics is a must, as is
fluency in English (especially in writing) and fondness for tardigrades.
Evidence supporting the declared interests and skills (such as a BSc and/or MSc
thesis, co-authorship of research papers, conference presentations on the
topics) is strongly advantageous.
Recruitment
procedure
The recruitment procedure is a two-step
process. In the first step, a candidate will be preselected and then they will
be given the opportunity to apply for a PhD position at the Jagiellonian
University.
Step I: To enter the first step of the
recruitment, please
download
the Application Form, fill it, and send it with all specified
information and attachments to
LM@tardigrada.net
by the 6th
of June 2024
(please put “PhD application” in the subject line; please try to apply as soon
as possible rather than wait until the deadline – this will help us to select
candidates for project interviews). Based on applications and references,
several top candidates will be chosen for project interviews. These online
interviews will take place around the middle of
June 2024. You must pass this first
step to be eligible to apply for the second step of recruitment (described
below).
Step II: The best candidate selected in the first
step will be then given help and advice to prepare for the official university
entrance interviews, which will take place in the very beginning of July 2024.
Detailed information about the university recruitment procedure will be provided
soon (online interviews for international candidates are possible). University
interviews focus on the project and related topics. A track record of published
scientific papers and documented experience in research projects extremely
increase the chances of obtaining the PhD position.
If you know anyone who might be interested
in this position, please send them the link to this website:
http://tardigrada.edu.pl/PhD.htm
Thank you!
:-)