Paleovirology: Blessing or Curse of Ancient Viruses - A Review

Abstract

Ancient virus genomes preserved as fossils and carried by host within their genome. Although viral genomes evolve rapidly, their rate of change slows to the same pace as that of the host’s DNA after insertion, making it possible to study viral DNA sequences that are many millions of years old. Paleovirology is the study of viral fossil records typically over prehistoric or geological timescales and the effects that these agents have had on the evolution of their hosts. Viruses sometimes heritably integrate into the genomes of their hosts, resulting in genomic features known as endogenous viral elements (EVEs). Using EVEs, the field of paleovirology investigates the long term evolution of viruses and their impact on hosts. One of the fruitful outcomes of high throughput genomics is the widespread availability of whole genome data, offering the unprecedented opportunity to investigate EVEs at a large scale. This review, highlights the utility of antiviral gene evolution for the study of paleovirology, the consequent surge in paleovirology and the main methodological techniques used to study them. EVEs can only be understood within an evolutionary framework and we outline a generalized workflow for conducting paleovirology studies.

Antibiogram and Biofilm Phenotypic Characterization of E.coli Isolates from Milk and Environmental Sources

“…The biofilm production study show positivity in 47.05% E. coli isolates. Thakrey et al, (2016) and Warke et al, (2017) reported 82.08 % and 77.67% biofilm producer isolates of fecal and environmental samples from cattle farm on Congo red agar. Parul et al, 2014 recorded percent positivity of 44.28% for feces and 5% for soil was reported on Congo red dye assay while in our study it was found to be 54.5% and 20% respectively.…”

Ancient Faunal History Revealed by Interdisciplinary Biomolecular Approaches

“…RNA, a molecule until recently considered an improbable source of information for studying ancient fauna, has provided some first insights into the taxonomy and tissue-specific gene regulation of Late Pleistocene canids [19]. More recently, studies have begun to focus on palaeovirology as a means to elucidate the role of ancient viruses in ancient faunal evolutionary history (e.g., extinctions, island isolations, migrations), in addition to modern consequences on extant species [20,21].…”