Single-Stranded DNA Viruses in Antarctic Cryoconite Holes

Antarctic cryoconite holes, or small melt-holes in the surfaces of glaciers, create habitable oases for isolated microbial communities with tightly linked microbial population structures. Viruses may influence the dynamics of polar microbial communities, but the viromes of the Antarctic cryoconite holes have yet to be characterized. We characterize single-stranded DNA (ssDNA) viruses from three cryoconite holes in the Taylor Valley, Antarctica, using metagenomics. Half of the assembled metagenomes cluster with those in the viral family Microviridae (n = 7), and the rest with unclassified circular replication associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses (n = 7). An additional 18 virus-like circular molecules encoding either a Rep, a capsid protein gene, or other unidentified but viral-like open reading frames were identified. The samples from which the genomes were identified show a strong gradient in microbial diversity and abundances, and the number of viral genomes detected in each sample mirror that gradient. Additionally, one of the CRESS genomes assembled here shares ~90% genome-wide pairwise identity with a virus identified from a freshwater pond on the McMurdo Ice Shelf (Antarctica). Otherwise, the similarity of these viruses to those previously identified is relatively low. Together, these patterns are consistent with the presence of a unique regional virome present in fresh water host populations of the McMurdo Dry Valley region

Importance of Festivals to Antarctic Culture

Antarctica is the most remote and desolate continent on earth and those who find themselves there are among the most isolated. Communication with the outside world is more limited than nearly anywhere else and even communication between different bases on Antarctica is sometimes minimal. The importance of Antarctic culture and traditions on morale have been crucially important since the earliest expeditions but this culture is constantly evolving with time as people attempt to make working in this place more enjoyable. Festivals and events have grown in frequency and popularity and provide a greater sense of community and belonging. They act to lift the spirits of everyone involved and make this extremely harsh environment much more hospitable and home-like. Events such as the Midwinter Festival, Icestock, and the 48-hour film festival all successfully bring people out of the isolation of working in Antarctica and are fundamentally necessary to pushing the research communities goals forward on this continent

Viruses contribute more to Antarctica than the common cold: a review on viral importance in Antarctic lakes

The role viruses play in mediating the ecology of Antarctic lakes is vastly underrepresented and the effects climate change may have on these roles is widely unknown. At the microbial level viruses are involved in the important roles of limiting host population densities, selecting for host diversity, and contributing dissolved organic carbon to the aquatic environment. These roles are especially important in Antarctic lakes as they are dominated by microorganisms. The ecology of the lake is dependent on viruses as they control microbe population levels and increase nutrient levels into the environment. Climate change may alter Antarctic lake compositions by causing an increase in incidence of blooms, increase in lysogenic viral infections, and an increase in viral decay due to UV-B radiation. These changes will likely have profound impacts on the microbe populations currently residing in Antarctic lakes. Further research needs to be conducted in order to determine if viruses in Antarctic lakes will be able to continue carrying out their important roles in the changing environment

Antarctic sea ice and its implications.

Global warming has caused a significant decrease in sea ice coverage in the Arctic. This is having far reaching implications for the ecosystems, as well as dramatically changing the way that humans interact with the Arctic environment. Climate models predicted that a similar decrease in sea ice would occur in the Antarctic. However, since regular observations began in 1979, the sea ice extent in the Antarctic has been increasing. We review current research that identifies numerous atmospheric and oceanic factors that are influencing sea ice trends. These factors have helped to explain some of the changes observed in sea ice extent at a regional level, but still do not accurately predict sea ice trends for the Southern Ocean as whole. A significant anomaly in sea ice extent that occurred in the austral spring of 2016-17 has confounded scientists, and highlights the limitations of current science and climate models to foresee the trend in sea ice in the Antarctic. Furthermore, we explore the potential implications for Antarctic ecosystems through a review of current literature. This emphasises the critical role of sea ice in the life history of a vast majority of Antarctic species, making them extremely vulnerable to changes in sea ice extent. Finally, we consider the implications for human activities in the Antarctic through a series of case studies. These identify the organisations and industries that will be affected by changes in sea ice, and who will rely on the development of accurate models and predictions to safely plan their future activities in the Antarctic

Single-Stranded DNA Viruses in Antarctic Cryoconite Holes

Antarctic cryoconite holes, or small melt-holes in the surfaces of glaciers, create habitable oases for isolated microbial communities with tightly linked microbial population structures. Viruses may influence the dynamics of polar microbial communities, but the viromes of the Antarctic cryoconite holes have yet to be characterized. We characterize single-stranded DNA (ssDNA) viruses from three cryoconite holes in the Taylor Valley, Antarctica, using metagenomics. Half of the assembled metagenomes cluster with those in the viral family Microviridae (n = 7), and the rest with unclassified circular replication associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses (n = 7). An additional 18 virus-like circular molecules encoding either a Rep, a capsid protein gene, or other unidentified but viral-like open reading frames were identified. The samples from which the genomes were identified show a strong gradient in microbial diversity and abundances, and the number of viral genomes detected in each sample mirror that gradient. Additionally, one of the CRESS genomes assembled here shares ~90% genome-wide pairwise identity with a virus identified from a freshwater pond on the McMurdo Ice Shelf (Antarctica). Otherwise, the similarity of these viruses to those previously identified is relatively low. Together, these patterns are consistent with the presence of a unique regional virome present in fresh water host populations of the McMurdo Dry Valley region