PhD 5

Epigenetic changes after sperm cryopreservation in fish, consequences for the offspring

Location: Fish Physiology and Genomics Unit, French National Research Institute for Agriculture, Food and Environment (INRAE), France

Main Supervisor: Dr. Catherine Labbé, E-mail: catherine.labbe@inrae.fr

Participating researchers: Dr. Audrey Laurent, Dr. Tim Rittinghaus (LUH), Dr. Rosa Pereira (INIAV)

Objectives:

  1. Characterize the DNA methylation changes in fish spermatozoa after cryopreservation and identify the fragility sites in two species bearing two different packing proteins (protamines in salmonids and histones in cyprinids).

  2. Identify whether cryopreservation-induced changes in DNA methylation are associated with local modifications of the chromatin compaction features.

  3. Decipher whether cryopreserved spermatozoa transmit epigenetic alteration to the progeny.

Expected Results:

  1. RRBS profile of DNA methylation in rainbow trout and carp spermatozoa before and after cryopreservation in optimal and sub-optimal conditions, and map of the similarities and discrepancies between the two species.

  2. ATAC seq data from fresh and cryopreserved spermatozoa and comparative analysis between fresh and cryopreserved samples.

  3. On the species with the strongest DNA methylation alterations, RRBS profile of the embryonic cells prior to genome activation in embryos sired by fresh or cryopreserved spermatozoa.

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

  1. INIAV, M15, 1 M, training on mammalian embryo cryopreservation and viability assessment, to gain background in mammals.

  2. JU (USB), Psenicka, M12, 3 M, training on carp sperm collection and cryopreservation. Preparation of carp samples (sperm and embryos DNA). Gaining insight into the specificities of carp sperm and embryo manipulation.

  3. LUH, Glasmacher, M24, 1 M, training in Raman spectroscopy and its application to cryobiology, to gain skills in biophysics.

Enrollment in Doctoral Degree: Yes (INRAE)