Two distinct mechanisms lead to either oocyte or spermatocyte decrease in <i>C</i>. <i>elegans</i> after whole developmental exposure to γ-rays

by Elizabeth Dufourcq Sekatcheff, Christian Godon, Aymeric Bailly, Loïc Quevarec, Virginie Camilleri, Simon Galas, Sandrine Frelon

Wildlife is subject to various sources of pollution, including ionizing radiation. Adverse effects can impact the survival, growth, or reproduction of organisms, later affecting population dynamics. In invertebrates, reproduction, which directly impacts population dynamics, has been found to be the most radiosensitive endpoint. Understanding the underlying molecular pathways inducing this reproduction decrease can help to comprehend species-specific differences in radiosensitivity. From our previous studies, we found that decrease in reproduction is life stage dependent in the roundworm Caenorhabditis elegans, possibly resulting from an accumulation of damages during germ cell development and gamete differentiation. To go further, we used the same experimental design to assess more precisely the molecular determinants of reproductive toxicity, primarily decreases in gamete number. As before, worms were chronically exposed to 50 mGy·h⁻¹ external gamma ionizing radiation throughout different developmental periods (namely embryogenesis, gametogenesis, and full development). To enable cross species extrapolation, conserved molecular pathways across invertebrates and vertebrates were analysed: apoptosis and MAP kinase Ras/ERK (MPK-1), both involved in reproduction and stress responses. Our results showed that these pathways are life-stage dependent, resulting from an accumulation of damages upon chronic exposure to IR throughout the life development. The Ras/ERK pathway was activated in our conditions in the pachytene region of the gonad where it regulates cell fate including apoptosis, but not in the ovulation zone, where it controls oocyte maturation and ovulation. Additionally, assessment of germ cell proliferation via Ras/ERK pathway showed no effect. Finally, a functional analysis of apoptosis revealed that while the decrease of the ovulation rate is caused by DNA-damaged induced apoptosis, this process does not occur in spermatocytes. Thus, sperm decrease seems to be mediated via another mechanism, probably a decrease in germ cell proliferation speed that needs further investigation to better characterize sex-specific responses to IR exposure. These results are of main importance to describe radio-induced reprotoxic effects and contribute as weight of evidence for the AOP #396 “Deposition of ionizing energy leads to population decline via impaired meiosis”.

The lived experience of Omani adolescents and young adults with mental illness: A qualitative study

by Omar Al Omari, Gerald Amandu, Samir Al-Adawi, Zubaida Shebani, Ibtisam Al Harthy, Arwa Obeidat, Khloud Al Dameery, Mohammad Al Qadire, Iman Al Hashmi, Abduallh Al Khawldeh, Mohammed ALBashtawy, Maen Aljezawi

There is currently limited knowledge about the firsthand experiences of adolescents and young adults with mental health problems and the meanings they ascribe to these experiences, particularly within Arab countries. This study, therefore, aimed to explore the lived experience of Omani adolescents and young adults with a mental health problem. A sample of 15 participants aged 13–22 diagnosed with a range of mental health problems took part in the study. A qualitative interview guide consisting of open-ended questions was used to allow participants to speak in-depth about their experiences. Using the thematic analysis approach to uncover patterns in the data, three major themes emerged: “living in darkness”, “perilous journey” and “uncertain future”. Results show that the progress of adolescents and young adults with mental health problems is characterized by several challenges; the most significant of which is having insufficient knowledge about their illness, leading to unnecessary delays in their treatment. These findings shed light on the breadth and depth of the experience of adolescents and young adults with mental health problems and lay the groundwork for further examinations. Implications lie in the development of approaches for preventing or mitigating difficulties faced by adolescents and young adults with mental health problems.