PhD 10

Location: INRAE Nouzilly, Tours, and IMV Technologies, L’Aigle, France

Main Supervisors: Dr Marie Saint-Dizier, E-mail : marie.saint-dizier@univ-tours.fr, and Dr. Lucie Gavin-Plagne, E-mail: lucie.gavinplagne@imv-technologies.com

Participating researchers: Dr. Olivier Carion (IMV Technologies), Dr. Pascal Mermillod (INRAE), and Dr. Xavier Druart (INRAE).

The traditional methods used to select sperm before cryopreservation are based on assessment of sperm motility and viability. However, other sperm parameters, including the capacity to survive and acquire the ability to fertilize the oocyte during sperm migration in the female tract, have major consequences for fertility outcomes. After insemination, spermatozoa navigate through uterine and oviduct fluids and interact with luminal epithelial cells before being capacitated and reach the fertilization site in the oviduct. One major site of sperm-female interactions take place in the isthmus, i.e. the first part of the oviduct, where a sperm sub-population bind to ciliated epithelial cells to form a “sperm reservoir”. Previous data in bulls and boars indicate that sperm binding capacity to oviduct epithelial cells (OECs) in vitro is correlated with higher fertility after insemination, suggesting that binding to OECs selects a sperm population of higher quality. The main goal of the PhD is to build new in vitro models of uterus and oviduct lumen to identify the major molecular drivers of sperm-female interactions and optimize the gamete populations to be cryopreserved in pigs. We have developed a 3D porcine oviduct epithelial spheroid model that allows reproducible and quantifiable sperm-OEC interactions and identified specific lectins and glycans modulating these interactions. The objectives are now to develop an in vitro model of the porcine endometrium in order to identify new candidates modulating sperm-female tract interactions throughout sperm migration and explore the consequences on sperm physiology. As a PhD student in the ICF team, the candidate will benefit from an outstanding scientific environment at the INRAE PRC Unit and will receive specific training in cutting-edge methods (culture of cells and explants, sperm analysis, lectin arrays, confocal and electron microscopy, flow cytometry, mass spectrometry, in vitro fertilization and embryo development). The candidate will have the opportunity to collaborate with WUR and follow up with IMV Technologies and have the opportunity to participate in summer school and international conferences.

The PhD student will work 80% to 90% of his/her time at and the Physiology of Reproduction and Behavior (PRC) Research Unit (Center INRAE Val-de-Loire, Nouzilly, France) and 20 to 10% at IMV Technologies (L’Aigle, France), with a secondment at Wageningen University & Research (WUR, The Netherlands).

The PRC Research Unit is part of the French National Research Institute for Agriculture, Food and the Environment (INRAE) with the University of Tours and French National Centre for Scientific Research (CNRS) as partners. The PRC Unit conducts fundamental and applied research in reproductive biology, behavioral biology and neuroendocrinology. The Unit has the dual mission of advancing scientific knowledge on animal physiology and answering questions raised by societal issues in connection with various socio-economic players in the sectors of animal production and human health. In the field of reproductive biology, the “Cellular Interactions and Fertility” (ICF) team (13 permanent people), in which the PhD student will work, explores the cellular and molecular mechanisms within the female reproductive tract. This team focuses on the physiology of the oviduct, sperm-female tract interactions and studies the maternal regulation of fertilization and early embryo development in the face of a changing environment. The work of ICF aims at optimizing reproductive health in livestock farming and preservation of animal genetic diversity.

Expected Results:

1. Development of new specific extenders for both long-term storage (at 4°C) and for cryopreservation of boar sperm for different genetic lines. These new extenders would lead to a reduction in antibiotic use

2. Develop a complete preservation solution from sperm collection to insemination, through sperm packaging

3. Increase the efficiency of the method to get high fertility rates in coordinating fields trials

Working Laboratory:

Cell Interactions and Fertility (ICF) team, UMR INRAE-CNRS-Tours University Physiology of Reproduction and Behaviors (PRC Unit), Centre INRAE Val-de-Loire, Nouzilly, France

Planned secondment: (Host, Supervisor, timing, length, and purpose)

1. WUR, Lamy, M10, 3 M, training in sperm collection and cryopreservation and management of animal germplasm banks

2. INRAE, Mermillod, M16, 3 M, training in porcine IVF procedures and techniques to study the seminal plasma’ proteome

3. Topigs Norsvin, Louisa Zak, M25, 2 M, training in porcine collection, and quality control of semen after packaging

Candidate profile:

• Master in Cell Biology, Physiology, Biotechnology or Molecular Biology, with an interest for industrial application of its research.

• Open-minded and highly motivated, scientifically rigorous.

• Fluent in English. Basic French is preferable but not essential. Candidates will have the opportunity to learn French.

• Ability to work independently and collaboratively as a member of a team of 20 people and in a research unit of around 150 people.

• Candidates with experience in cell culture, sperm analysis or glycan analysis are encouraged to apply. Experience in statistics is also highly desirable.

Enrollment in Doctoral Degree: Yes (INRAE)

Announcement here.