Gorlier, A. | Search bioRxiv

bioRxiv2021

Innovations to expand drone data collection and analysis for rangeland monitoring

In adaptive management of rangelands, monitoring is the vital link that connects management actions with on-the-ground changes. Traditional field monitoring methods can provide detailed information for assessing the health of rangelands, but cost often limits monitoring locations to a few key areas or random plots. Remotely sensed imagery, and drone-based imagery in particular, can observe larger areas than field methods while retaining high enough spatial resolution to estimate many rangeland indicators of interest. However, the geographic extent of drone imagery products is often limited to a few hectares (for resolution [≤] 1 cm) due to image collection and processing constraints. Overcoming these limitations would allow for more extensive observations and more frequent monitoring. We developed a workflow to increase the extent and speed of acquiring, processing, and analyzing drone imagery for repeated monitoring of two common indicators of interest to rangeland managers: vegetation cover and vegetation heights. By incorporating a suite of existing technologies in drones (real-time kinematic GPS), data processing (automation with Python scripts, high performance computing), and cloud-based analysis (Google Earth Engine), we greatly increased the efficiency of collecting, analyzing, and interpreting high volumes of drone imagery for rangeland monitoring. End-to-end, our workflow took 30 days, while a workflow without these innovations was estimated to require 141 days to complete. The technology around drones and image analysis is rapidly advancing which is making high volume workflows easier to implement. Larger quantities of monitoring data will significantly improve our understanding of the impact management actions have on land processes and ecosystem traits.

ecology↗

bioRxiv2019

Novel Function of Bluetongue Virus NS3 Protein in Regulation of the MAPK/ERK Signaling Pathway

Bluetongue virus (BTV) is an arbovirus transmitted by blood-feeding midges to a wide range of wild and domestic ruminants. In this report, we showed that BTV, through its virulence non-structural protein NS3 (BTV-NS3), is able to activate the MAPK/ERK pathway. In response to growth factors, the MAPK/ERK pathway activates cell survival, differentiation, proliferation and protein translation but can also lead to the production of several inflammatory cytokines. By combining immunoprecipitation of BTV-NS3 and mass spectrometry analysis from both BTV-infected and NS3-transfected cells, we identified the serine/threonine-protein kinase B-Raf (BRAF), a crucial player of the MAPK/ERK pathway, as a new cellular interactor of BTV-NS3. BRAF silencing led to a significant decrease of the MAPK/ERK activation by BTV supporting a model where BTV-NS3 interacts with BRAF to activate this signaling cascade. Furthermore, the intrinsic ability of BTV-NS3 to bind BRAF and activate the MAPK/ERK pathway is conserved throughout multiple serotypes/strains but appears to be specific to BTV compared to other members of Orbivirus genus. Inhibition of MAPK/ERK pathway with U0126 reduced viral titers, suggesting that BTV manipulates this pathway for its own replication. Therefore, the activation of the MAPK/ERK pathway by BTV-NS3 could benefit to BTV replication by promoting its own viral protein synthesis but could also explain the deleterious inflammation associated with tissue damages as already observed in severe cases of BT disease. Altogether, our data provide molecular mechanisms to explain the role of BTV-NS3 as a virulence factor and determinant of pathogenesis. ImportanceBluetongue Virus (BTV) is responsible of the non-contagious arthropod-borne disease Bluetongue (BT) transmitted to ruminants by blood-feeding midges. Despite the fact that BTV has been extensively studied, we still have little understanding of the molecular determinants of BTV virulence. In this report, we found that the virulence protein NS3 interacts with BRAF, a key component of the MAPK/ERK pathway. In response to growth factors, this pathway promotes cell survival, increases protein translation but also contributes to the production of inflammatory cytokines. We showed that BTV-NS3 enhances the MAPK/ERK pathway and this activation is BRAF-dependent. Our results demonstrate, at the molecular level, how a single virulence factor has evolved to target a cellular function to ensure its viral replication. On the other hand, our findings could also explain the deleterious inflammation associated with tissue damages as already observed in severe cases of BT disease.

microbiology↗