Transcriptional Changes in the Ovaries of Perch from Chernobyl

Abstract

Fish have been highly exposed to radiation in freshwater systems after the Chernobyl Nuclear Power Plant (NPP) accident in 1986 and in freshwater and marine systems after the more recent Fukushima NPP accident in 2011. In the years after the accident, the radioactivity levels rapidly declined due to radioactive decay and environmental processes, but chronic lower dose exposures persisted. To gain insights into the long-term effects of environmental low dose radiation on fish ovaries development, a high-throughput transcriptomic approach including a de novo assembly was applied to different gonad phenotypes of female perch: developed gonads from reference lakes, developed/irradiated from medium contaminated lake, and both developed/irradiated and undeveloped from more highly contaminated lakes. This is the most comprehensive analysis to date of the gene responses in wildlife reproductive system to radiation. Some gene responses that were modulated in irradiated gonads were found to be involved in biological processes including cell differentiation and proliferation (ggnb2, mod5, rergl), cytoskeleton organization (k1C18, mtpn), gonad development (nell2, tcp4), lipid metabolism (ldah, at11b, nltp), reproduction (cyb5, cyp17A, ovos), DNA damage repair (wdhd1, rad51, hus1), and epigenetic mechanisms (dmap1). Identification of these genes provides a better understanding of the underlying molecular mechanisms underpinning the development of the gonad phenotypes of wild perch and how fish may respond to chronic exposure to radiation in their natural environment, though causal attribution of gene responses remains unclear in the undeveloped gonads.

Spatial Proteomics for Further Exploration of Missing Proteins: A Case Study of the Ovary

“…Four proteins have been identified to carry out ovary-specific or reproduction-related processes in other species, including the orphan receptor GPR63 that has been described to participate in egg production in ducks, 16 and the neuropeptide QRFP that in rats is suggested to enhance LH secretion directly at the level of the pituitary (Navarro2006). Other examples are the hydrolase RERGL, identified as one of the genes in fish eggs that were affected by radiation after the Chernobyl Nuclear Power Plant accident 17 and the ligase TTLL3 which is essential for blastocyst formation in cows. 18 None of these proteins has previously been mentioned in the context of human ovary or reproduction.…”

Transcriptomics and Spatial Proteomics for Discovery and Validation of Missing Proteins in the Human Ovary

“…Four of these proteins (CTXN1, GPR63, RERGL, and TRIM61) were identified also in our previous study, suggesting a potential role in the human ovary, and interestingly, two have previously been linked to reproductive function in the literature. GPR63 has been associated with egg production in ducks, and the response of the RERGL gene was altered in irradiated perch gonads . While the staining of nine proteins was not restricted to oocytes or granulosa cells only, all these candidates were distinctly expressed in follicle cells based on both methods and it is still possible that these proteins possess ovary-specific functions despite lower levels of expression being observed in other surrounding cell types.…”

“…GPR63 has been associated with egg production in ducks, 17 and the response of the RERGL gene was altered in irradiated perch gonads. 18 While the staining of nine proteins was not restricted to oocytes or granulosa cells only, all these candidates were distinctly expressed in follicle cells based on both methods and it is still possible that these…”

Population dynamics and genome-wide selection scan for dogs in Chernobyl

“…Though Chernobyl wildlife has been the subject of previous ecological and genetic studies (e.g., [22][23][24]), little is known about the genetics of a population of over 500 dogs occupying the area surrounding the CNPP and Chernobyl City. This dog population has expanded in the decades following the accident and is thought to be comprised at least partially of descendants of pets left behind during the chaotic evacuation in 1986 [25].…”