Biology subjects

Ros, V. I. D.

Publications and source records attributed to Ros, V. I. D..

3 recordsLinked to original sources

bioRxiv2023

Covert RNA viruses in medflies differ in their mode of transmission and tissue tropism

Numerous studies have demonstrated the presence of covert viral infections in insects. These infections can be transmitted in insect populations via two main routes: vertical from parents to offspring, or horizontal between nonrelated individuals. Thirteen covert RNA viruses have been described in the Mediterranean fruit fly (medfly). Some of these viruses are established in different laboratory-reared and wild medfly populations, although variations in the viral repertoire and viral levels have been observed at different time points. To better understand these viral dynamics, we characterized the prevalence and levels of covert RNA viruses in two medfly strains, assessed the route of transmission of these viruses, and explored their distribution in medfly adult tissues. Altogether, our results indicated that the different RNA viruses found in medflies vary in their preferred route of transmission. Two iflaviruses and a narnavirus are predominantly transmitted through vertical transmission via the female, while a nodavirus and a nora virus exhibited a preference for horizontal transmission. Overall, our results give valuable insights into the viral tropism and transmission of RNA viruses in the medfly, contributing to the understanding of viral dynamics in insect populations.

ecology↗

bioRxiv2022

Beyond viral detection: multitrophic effects of covert infection with an RNA virus in medfly.

Summary/abstractO_ST_ABSBackgroundC_ST_ABSWith the advent of high-throughput sequencing, large sets of insect-infecting RNA viruses producing apparent asymptomatic infections are being discovered. In the Mediterranean fruit fly (medfly) Ceratitis capitata, an agricultural key pest of a wide range of fruits, up to 13 different RNA viruses have been described. Recent analysis demonstrated a wide distribution of these viruses in different medfly strains collected worldwide, but little is known about the interactions between those viruses and the medfly host. Previous studies suggested that a higher abundance of Ceratitis capitata nora virus (CcaNV) decreased medfly developmental time. Here, we investigated the effect of CcaNV on a broad range of parameters related to host fitness and its interaction with other trophic levels. ResultsCcaNV purified from a naturally infected medfly strain was used to infect CcaNV-free flies orally and subsequently monitor pupal weight, adult emergence, flying ability and longevity. Our results revealed detrimental effects associated with a CcaNV infection in the medfly, in terms of reduced pupal weight and reduced adult longevity. Moreover, we tested the influence of a CcaNV infection in medflies on the parasitism performance of Aganaspis daci, a medfly endoparasitoid used in biological control programs against medflies. Our results showed that A. daci progeny increased when parasitizing on CcaNV-infected larvae. ConclusionsOur results proved that covert RNA viruses can impact on the insect ecology, directly affecting its insect host biology and indirectly influencing multitrophic interactions.

microbiology↗

bioRxiv2022

Global genomic analysis reveals the genetic origin and secondary invasion of fall armyworm in the Eastern hemisphere

The major plant pest fall armyworm (FAW), Spodoptera frugiperda, is native to the Americas and has colonized African and Asian countries in the Eastern hemisphere since 2016, causing severe damage to multiple agricultural crop species. However, the genetic origin of these invasive populations require more in-depth exploration. We analyzed genetic variation across FAW genomes of 153 newly sequenced individuals from Eastern hemisphere and 127 individuals mostly originating from the Americas. The global genetic structure of FAW shows that the FAW in American has experienced deep differentiation, largely consistent with the Z-chromosomal Tpi haplotypes commonly used to differentiate "corn-strain" and "rice-strain" populations. Results indicate that the invasive Eastern hemisphere populations are different from the American ones and have relatively homogeneous population structure, consistent with the common origin and recent spreading from Africa to Asia. Our analyses suggest that north-and central American "corn-strain" FAW are the most likely sources of the invasion into the Eastern hemisphere. Furthermore, evidence based on genomic, transcriptomic and mitochondrial haplotype network analysis suggest that there has been an earlier independent introduction of FAW into Africa that introgressed into the recent invasive population.

molecular biology↗