Internship Proposal - Master 2

To examine these developmental peculiarities, the intern will first participate in our spiny chromis husbandry by monitoring the spawning events and by sampling eggs from the time of fertilization to hatching. A first part of the work will be to establish a developmental table for the spiny chromis by sampling eggs daily, to photograph them under a stereomicroscope to describe and illustrate embryo morphology and pigmentation, and to fix them for subsequent histological analyses characterizing embryonic histological development with an emphasis on thyroid follicles. On other eggs samples collected at the same developmental steps, the intern will quantify thyroid hormone levels, as well as the expression of key genes from the thyroid hormone signaling pathway, in order to examine the ecophysiology of metamorphic endocrinological proceedings in this species. As a second part of this internship, the intern will evaluate the effects of chemical pollutants (e.g. CuSO4, chlorpyrifos, glyphosate), on the spiny chromis embryonic development previously described. To do so, we have developed a protocol to rear spiny chromis eggs in small-volume aquarium (e.g., petri dishes), allowing us to conduct ecophysiological and ecotoxicological studies in a convenient laboratory set up. Indeed, we showed that TH endocrine disruption induced by anthropogenic stressors such as increased temperatures and pesticides can impair metamorphic changes in marine fishes with a classical life cycle, and the spiny chromis would allow us to evaluate these effects directly on eggs.

The intern will thus (i) gain knowledge in fish sampling, husbandry, ecophysiology, ecotoxicology, neuroendocrinology, and histology, (ii) develop biomolecular skills in qPCR and histology; (iii) practice bioinformatic techniques for analyzing and visualizing data; and (iv) acquire communication skills to present and share scientific results.