Biology subjects

Griffiths, D. J.

Publications and source records attributed to Griffiths, D. J..

4 recordsLinked to original sources

bioRxiv2025

Genome sequence and annotation of ovine herpesvirus-1

Ovine herpesvirus 1 (OvHV-1) was first identified over 50 years ago in sheep with ovine pulmonary adenocarcinoma (OPA). An aetiological role in OPA was later ruled out and OvHV-1 was found to be a common infection in sheep in several countries. Here, we report the sequence and annotation of the complete OvHV-1 genome. The virus has a similar genomic architecture to members of the Macavirus genus of the subfamily Gammaherpesvirinae and is most closely related to bovine gammaherpesvirus 6 (BoGHV6). The OvHV-1 genome comprises a 144,637 base pair unique region predicted to encode at least 74 proteins bounded by multiple copies of a 699 base pair GC-rich repetitive terminal repeat. Predicted genes include 61 ORFs conserved among all gammaherpesviruses, and 12 genes present only in macavirus genomes, including a homologue of ovine interleukin-10, previously reported only in ovine gammaherpesvirus-2, and an ornithine decarboxylase, previously described only in BoGHV6. A further gene appears unique to OvHV-1 among macaviruses, encoding a viral-FLIP (FLICE-like inhibitory protein), similar to those found in some other gammaherpesviruses. Notably, several macavirus genes previously predicted in BoGHV6 are defective in OvHV-1. The availability of the genome sequence of OvHV-1 will facilitate studies on its relationship to other macaviruses and its role, if any, in disease.

microbiology↗

bioRxiv2022

Multivalent interactions essential for lentiviral integrase function

A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi-visna virus (MVV), an ovine lentivirus, revealed a large assembly containing sixteen IN subunits (1). Herein, we report cryo-EM structures of the lentiviral intasome prior to engagement of target DNA and following strand transfer, refined at 3.4 and 3.5 [A] resolution, respectively. The structures elucidate details of the protein-protein and protein-DNA interfaces involved in lentiviral intasome formation. We show that the homomeric interfaces involved in IN hexadecamer formation and the -helical configuration of the linker connecting the C-terminal and catalytic core domains are critical for MVV IN strand transfer activity in vitro and for virus infectivity. Single-molecule microscopy in conjunction with photobleaching revealed that the MVV intasome can bind a variable number, up to sixteen molecules, of the lentivirus-specific host factor LEDGF/p75. Concordantly, ablation of endogenous LEDGF/p75 resulted in gross redistribution of MVV integration sites in human and ovine cells. Our data confirm the importance of the expanded architecture observed in cryo-EM studies of lentiviral intasomes and suggest that this organization underlies multivalent interactions with chromatin for integration targeting to active genes.

biochemistry↗

bioRxiv2021

Jaagsiekte sheep retrovirus infection induces changes in microRNA expression in the ovine lung

Ovine pulmonary adenocarcinoma (OPA) is an infectious neoplastic lung disease of sheep caused by jaagsiekte sheep retrovirus. OPA is an important veterinary problem and is also a valuable large animal model for human lung adenocarcinoma. JSRV infects type 2 alveolar epithelial cells in the lung and induces the growth of tumors, but little is known about the molecular events that lead to the activation of oncogenic pathways in infected cells. MicroRNAs (miRNAs) are small RNA molecules of approximately 22 nucleotides with important roles in regulating gene expression in eukaryotes and with well-established roles in cancer. Here we used small-RNA sequencing to investigate the changes in miRNA expression that occur in JSRV-infected ovine lung. After filtering out low abundance miRNAs, we identified expression of 405 miRNAs, 32 of which were differentially expressed in JSRV-infected lung compared to mock-inoculated control lung. Highly upregulated miRNAs included miR-182, miR-183, miR-96 and miR-135b, which have also been associated with oncogenic changes in human lung cancer. Network analysis of genes potentially targeted by the deregulated miRNAs identified their involvement in pathways known to be dysregulated in OPA. We found no evidence to support the existence of miRNAs encoded by JSRV. This study provides the first information on miRNA expression in OPA and identifies a number of targets for future studies into the role of these molecules in the pathogenesis of this unique veterinary model for human lung adenocarcinoma. IMPORTANCEOvine pulmonary adenocarcinoma is a neoplastic lung disease of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is a significant welfare and economic concern for sheep producers and is a valuable large animal model for human lung adenocarcinoma. MicroRNAs are small RNA molecules of approximately 22 nucleotides with important functions in regulating gene expression in eukaryotes and with well-established roles in cancer. In this study, we examined the changes in microRNA expression that occur in the lung in response to JSRV infection. We identified differential expression of a number of host-encoded microRNAs in infected tissue, including microRNAs with roles in human cancer. We found no evidence that JSRV encodes a microRNA. This study provides new insights on the cellular response to JSRV infection in the ovine lung, which will inform future studies into the pathogenesis of OPA in sheep and its use as a model for human lung adenocarcinoma.

microbiology↗

bioRxiv2020

New water and air pollution sensors added to the Sonic Kayak citizen science system for low cost environmental mapping

Sonic Kayaks are low-cost open-source systems for gathering fine-scale environmental data. The system is designed to be simple to fit on to standard kayaks or canoes, and full instructions have been made available for anyone wishing to build their own. The first version included temperature sensors and a hydrophone for recording underwater sound. Here we outline the design and integration of two new sensors, for underwater turbidity and above water air particulate pollution. All sensors record continually, and the GPS location, time and date are also stored for every data point, allowing fine-scale environmental data mapping. The data being collected by the sensors is sonified (turned into sound) in real-time, allowing the paddler to hear the data as they are collecting it, making it possible to locate and follow interesting occurrences. We present proof-of principle data for the first time for all the sensors, demonstrating how the system can be used for environmental mapping, and discuss potential future applications and adaptations. We believe the Sonic Kayak system offers particular promise for citizen science and environmental activism, as well as allowing professional researchers to gather data that was previously difficult or impossible to obtain.

ecology↗