Can UV radiation and cadmium exposures induce tumors in freshwater invertebrates ?

International audienceBecause ecosystems on our planet are now polluted by mutagenic substances to a greater extent than ever before, it is increasingly suggested that human activities are oncogenic for wildlife species. To improve our knowledge on these timely issues, experimental evidence should however complete correlative field studies. Hydras and Planarians are freshwater invertebrates which sometimes develop tumors. Hydras tumors are able to be vertically transmitted during asexual reproduction. Because the etiology of these atypical tumors is unknown, our objective is to explore the extent to which they could be, at least partially, linked to human activities. Specifically, this project aims at testing if UV radiation (both UV-A and UV-B) and/or cadmium exposure can promote tumorigenesis, and to evaluate how transmissible these inducible tumors are. A second objective is to explore the extent to which UV & cadmium exposures induce tumors in planarians. This project not only represents an original contribution to the field of ecology in human-altered habitats, but also improves our knowledge on the evolutionary ecology of transmissible malignant cell lines, and host-tumor interactions

A review of the methods used to induce cancer in invertebrates to study its effects on the evolution of species and ecosystem functioning

International audience1. Cancer is an understudied but important process in wildlife that is predicted to have a significant effect on the evolution of metazoan species due to negative effects on host fitness. However, gaining understanding of the impact of cancer on species and ecosystems is currently relatively slow as the development of both animal models in which cancer can be induced and experiments that can be performed in an ecological setting are required. Invertebrates, because they are widely available and relatively easy to manipulate, are promising animal models. In this review we examine how tumours can be induced in invertebrates to use them as experimental models to study the effects of cancer on the ecology and evolution of species. We identified four main groups of invertebrates (planarian, bivalves, hydra and drosophila) in which such inductions are performed. We then reviewed the types and effectiveness of the methods employed to induce tumours in those groups. Cancer alters the phenotype of the host. We review how experiments using invertebrate models can be used to investigate the impact of cancer on tumour-bearing individuals for their movement, reproduction, feeding behaviours, social interactions, holobiont and predation risk.We provide recommendations to facilitate the development of new invertebrate models. We also highlight a series of key questions on the ecology and evolution of cancer that could be answered with the use of invertebrate models

Absence of Coronavirus RNA in Faecal Samples from Wild Primates in Gabon, Central Africa

International audienceCoronaviruses (CoVs, Coronaviridae) are a diverse group of viruses that infect mammals, birds, and fish. Seven CoVs infect humans, among which Severe Acute Respiratory Syndrome CoVs-1 and-2 and Middle East respiratory syndrome CoVs have shown how they can impact global health and the economy. Their spillover from bats-the natural reservoir-to humans has required intermediary hosts. Prevention requires that active surveillance be conducted on animals. Today, there is no data concerning the genetic diversity of CoVs naturally circulating in wild primates. This study aimed to screen wild great apes and mandrills in Gabon for CoVs. A total of 229 faecal samples of great apes and mandrills collected from 2009 to 2012 in forests and national parks were used for the detection of CoVs by nested PCR using primers targeting a conserved region of the RNA-dependent RNA polymerase. While all samples were negative, this lack of detection could be related to sample size, the transient nature of the infection, or because faecal samples are not suitable for detecting CoVs in primates. A longitudinal study should be performed and other non-invasive methods used to collect respiratory samples to better evaluate the circulation of CoVs in these primates