This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"In northern ecosystems, winter carbon loss is estimated to exceed growing season carbon uptake, primarily because of microbial decomposition. Viruses in soil alter microbial carbon cycling by affecting metabolic pathways and killing their hosts, but whether viruses are active under anoxic and sub-freezing soil conditions remains unknown. To find out, a recent study used stable isotope probing (SIP) targeted metagenomics to investigate active microbes in Alaskan Arctic peat soils under simulated winter conditions, with a particular focus on viruses and virus-host dynamics. Overall, 46 bacterial and 243 viral populations actively took up soil water labeled with ¹⁸O and respired CO₂. Active bacteria represented a small proportion of the total microbial community but were able to ferment and degrade organic matter. In contrast, a large diversity of viruses were found to be active, one-third of which were linked to active bacteria..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"In the absence of oxygen, some prokaryotes can degrade organic matter via anaerobic digestion. This occurs in natural settings, like wetlands, and industrial ones, like wastewater treatment or biogas production. But what about viruses? Bacteriophages can impact their hosts’ community structure through selective pressure and have been used to influence microbial communities, such as through pathogen control. A recent study examined the virome of anaerobic digestion communities undergoing prophage- inducing environmental stresses. The virome was almost entirely composed of tailed bacteriophages of the order Caudovirales. Metagenome reconstruction revealed 1,092 viral genomes and 120 prokaryotic genomes, and over half of the prokaryotic genomes contained a provirus in their genomic sequence. In general, species of viruses and prokaryotes could be grouped by having similar reactions to stressors. Archaea had the most pronounced reactions to stressors and featured behaviors unique to those species..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:List the steps of replication and explain what occurs at each stepDescribe the lytic and lysogenic cycles of virus replicationExplain the transmission and diseases of animal and plant virusesDiscuss the economic impact of animal and plant viruses

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Bacteria and viruses are locked in a perpetual arms race. As bacterial viruses continuously try to penetrate and infect bacteria, bacteria are endlessly evolving anti-viral defense systems. Understanding how this struggle unfolds is critical, as bacteria are a vital component of many emerging biotechnologies and foods we eat. Scientists recently explored the battles that take place in cheese, where the presence of only a few species of bacteria makes an ideal, simple, and reproducible model system. The communities they analyzed harbored highly diverse defense mechanisms, even among nearly identical strains, suggesting rapid evolution. Additionally, the abundances of CRISPR spacers and their phage targets were correlated, suggesting that bacteria have genetic mechanisms for effectively defending against viral foes..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Blue-green algae, or cyanobacteria, are photosynthetic bacteria that live in water and are important oxygen producers. Human-driven changes are a major factor causing seasonal cyanobacterial blooms, which can cause mass death of aquatic animals. Bacteria-infecting viruses, called phages, could potentially be used to control these outbreaks with minimal environmental disruption. But to date few freshwater ‘cyanophages’ have been isolated or had their genomes sequenced. Recently, researchers isolated a strain of cyanobacteria from Lake Chaohu, a massive lake in China with seasonal cyanobacterial blooms. Using the new cyanobacteria strain, they isolated five new freshwater cyanophages with varying tail structures from the same lake. While viruses can have RNA genomes or even single-stranded DNA genomes, all five isolated phages had double-stranded DNA genomes. Further analysis suggested that they all use different DNA packaging mechanisms and are evolutionarily distinct..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Antibiotic-resistant bacteria are a threat to global health. One concern is that bacteria will pass antibiotic resistance genes (ARGs) to each other through horizontal gene transfer. A new study identified a novel source of ARGs in the environment. Bacteriophages are viruses that replicate inside bacteria, where they can incorporate bacterial genome fragments into phage capsids, allowing them to transfer those fragments to future hosts. Using metagenomics, researchers screened viral genes from an urban river for ARGs. They discovered 25 ARGs originating from bacteriophage genomes. Four genes were predicted to encode novel, functionally active beta-lactamases, conferring resistance to a variety of antibiotics. The results demonstrate that although present at low abundance, bacteriophages actively contribute functional ARGs to the freshwater metagenome, suggesting that they should be considered as a potential ARG dissemination route and included in ARG monitoring systems..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Our gut microbiomes are rich communities of bacteria, archaea, and viruses that play critical roles in our health. But although bacteria and archaea in the gut are well-characterized, the gut virome is less understood. A recent study sought to better understand a specific component of the gut virome. Double-stranded DNA bacteriophages (dsDNA phages) – viruses that infect bacteria – play pivotal roles in structuring the human gut microbiome. Using a new multilevel framework for taxonomic classification of viruses, researchers searched human gut metagenomes for phage hallmark genes. They identified 3,738 apparently complete phage genomes, representing 451 putative genera. Several of the genera were new, only distantly related to previously identified phages. Two of the candidate families – “Flandersviridae” and “Quimbyviridae” – included common members of the gut virome that infect ubiquitous gut bacteria, while the third family, “Gratiaviridae,” comprised less abundant phages..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Bacteriophages are everywhere, influencing everything from microbial evolution to biogeochemical cycling. Phages, however, remain among the least understood members of complex microbiomes. Do the tools used to identify phages introduce biases? A recent study compared ten of the most widely used bioinformatics tools designed to detect phages from metagenomics data. Overall, tool performance varied substantially in the analysis of different benchmarking datasets. For a set of artificial RefSeq contigs, PPR Meta and VirSorter2 showed the highest performance. Kraken2 showed the highest accuracy for a mock community benchmark. And generally, k-mer tools performed better than similarity- or gene-based tools. The study offers insight into the biases introduced by different tools, offers guidance into which one is best suited for different use cases, and suggests that rather than relying on any one tool, researchers may do well to combine different ones to suit their research needs..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Viruses that infect bacteria and archaea are abundant in human and environmental microbiomes. Their roles in manipulating, killing, and recycling microbes makes them key players in environmental processes and human health and disease, including inflammatory bowel diseases. In spite of their importance, the tools available for analyzing viral genomes are limited. Now, a new tool allows researchers to identify viruses and predict their functions using genomic data. VIBRANT (Virus Identification By iteRative ANnoTation), is the first software to use a hybrid machine learning and protein similarity approach. going beyond traditional limitations to maximize the identification of highly diverse viruses. In validation experiments with reference datasets, VIBRANT recovered higher-quality virus sequences and reduced false identification of non-viral genome fragments compared to other identification programs..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

Students learn how viruses invade host cells and hijack the hosts' cell-reproduction mechanisms in order to make new viruses, which can in turn attack additional host cells. Students also learn how the immune system responds to a viral invasion, eventually defeating the viruses -- if all goes well. Finally, they consider the special case of HIV, in which the virus' host cell is a key component of the immune system itself, severely crippling it and ultimately leading to AIDS. The associated activity, Tracking a Virus, sets the stage for this lesson with a dramatic simulation that allows students to see for themselves how quickly a virus can spread through a population, and then challenges students to determine who the initial bearers of the virus were.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Contamination of soil with heavy metals poses a serious health threat to people and the environment. One way researchers are exploring the effects of this contamination is through the interactions between soil bacteria and the viruses that infect them. A new study reports on these interactions in soils contaminated with high levels of chromium. Overall, the results indicate that as chromium pollution increases, the bacteria–virus relationship changes from one of antagonistic parasitism to one of beneficial mutualism. For example, viruses associated with bacteria tolerant to heavy metals increased in abundance as did viruses with the ability to infect a broad range of bacterial hosts. These correlated increases in abundance could facilitate the sharing of heavy metal resistance genes among members of bacterial communities..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.