Analysis of the frequency of viral integrations derived from CFAV (cell-fusion agent virus) in the genome of the mosquito Aedes aegypti and its effect on the cognate virus

Abstract

Aedes aegypti is the main vector of arboviruses in the world, causing high impact on the sanitary and public health sector. In the last years of the twentieth century, arboviroses showed a dramatic emergence in different countries of the globe, showing the insufficiency of control methods based, mainly, on chemical and physical control, in an attempt to prevent the mosquito proliferation. Thus, there is a continuous search for new tools to combat the transmission of such viruses, such as different transmission blocking strategies, which focus on elements of the mosquitoes' innate immunity pathways, as well as the influence of the microbiota on different agents. pathogenic. However, new discoveries have revealed the existence of a possible adaptive immunity in invertebrate hosts, analogous to the CRISPR-Cas system found in bacteria. It has been found that some non-reverse transcription RNA viruses (non-retroviruses) are capable of integrating sequences of their genetic material into the host's genome, as called NIRVs. Such structures can generate genetic generation reaching permanent updating in the invertebrate genome. More than 200 NIRVs have already been found in the Ae aegypti genome, with the possibility of causing several biological impacts. Most NIRVs are derived from insect-specific viruses, such as the CFAV virus (vCFAV). This virus is capable of interfering in the replication of other arboviruses, for example, the infection rate of ZIKV and DENV1 when co-infected with vCFAV. On the other hand, the presence of integrations of this virus (nCFAV) in the mosquito genome showed a suppressive effect on the replication of the cognate virus. Given these interactions, candidates were found in nCFAV in the genome of two Ae. aegypti natural populations, this work proposes to validate and evaluate the prevalence of these NIRVs, as well as their possible effect on the cognate virus in the studied populations.