01464nas a2200181   4500008004100000022001400041245014100055210006900196260001200265520082200277653002101099653002001120653002301140653001801163653001001181100002901191856006201220       2024                        eng d  a0028-646X00aLong days and long nights: An integrative study reveals survival strategies of an Antarctic diatom during the cold and dark polar winter0 aLong days and long nights An integrative study reveals survival   c01/20243 a<p>The vast majority of photosynthetic organisms on Earth have evolved under a circadian cycle, with many cellular processes being regulated by the predictable patterns of day and night. Polar algal species living in Arctic and Antarctic aquatic habitats are faced with bizarre light environments of continuous light during the short summer months and 24-h darkness during the winter, that is one long day transitioning into one long, cold night. It is well known that polar phytoplankton survive the winter and return in the summer to form blooms. In an article recently published in New Phytologist, Joli et al. (2023, doi: 10.1111/nph.19387) use an integrative approach to dissect how an Antarctic marine diatom not only survives the long, dark polar winter, but also recovers rapidly upon the onset of summer.</p>10aaquatic habitats10acircadian cycle10alight environments10aphytoplankton10apolar1 aMorgan-Kiss, Rachael, M.  uhttps://nph.onlinelibrary.wiley.com/doi/10.1111/nph.1953602399nas a2200217   4500008004100000245008500041210006900126260005400195490000700249520171000256653001501966653001701981653002401998653001402022653002402036653001002060653002402070100002502094700002102119856004102140       2022                        eng d00aEffect of climate history on the genetic structure of an Antarctic soil nematode0 aEffect of climate history on the genetic structure of an Antarct  aProvo, UT, USAbBrigham Young Universityc12/20220 vMS3 a<p>Historical climate disturbances such as glacial cycling and fluctuating stream, lake, and sea levels strongly influence the distribution and evolutionary trajectories of Antarctic terrestrial species. Antarctic invertebrates, with limited long-range mobility, including the ubiquitous sentinel nematode species <i>Scottnema lindsayae</i>, are especially sensitive to climate disturbances. We tested hypotheses associated with the historical geographic and population genetic structure of this species as it occurs across the McMurdo Dry Valleys (MDVs) of Antarctica. In order to reconstruct the influence of climate disturbance and ecological conditions on this species, partial mitochondrial COI gene sequences were sequenced and analyzed from individual <i>S. lindsayae</i> collected from sites across the MDVs reflecting a opposing gradients of climate disturbance during the Last Glacial Maximum (LGM). We found that populations were strongly geomorphic barriers with distinct haplotypes associated with valleys except among valleys that experienced glacial advance and retreat during the LGM. One monophyletic clade corresponds with valley systems that were undisturbed during the LGM indicating putative refugia areas. A second monophyletic clade corresponds to recent dispersal and expansion of evolutionarily younger populations into valleys that were strongly reworked by glacial activity during the LGM. Our work shows that contemporary populations of these animals are strongly structured by prior climate history. Such findings can be useful for interpreting long-term monitoring of demographic shifts of soil organisms in response to changing climate trends in the McMurdo Dry Valleys.</p>10aAntarctica10abiogeography10aclimate disturbance10aevolution10aMcMurdo Dry Valleys10apolar10apopulation genetics1 aJackson, Abigail, C.1 aAdams, Byron, J.  uhttp://hdl.lib.byu.edu/1877/etd1262202485nas a2200229   4500008004100000245009100041210006900132260001200201490000600213520181500219653001302034653002802047653001102075653001302086653001002099653002102109653002102130653002502151100001702176700002002193856004202213       2019                        eng d00aBiotic interactions in experimental Antarctic soil microcosms vary with abiotic stress0 aBiotic interactions in experimental Antarctic soil microcosms va  c08/20190 v33 a<p>Biotic interactions structure ecological communities but abiotic factors affect the strength of these relationships. These interactions are difficult to study in soils due to their vast biodiversity and the many environmental factors that affect soil species. The McMurdo Dry Valleys (MDV), Antarctica, are relatively simple soil ecosystems compared to temperate soils, making them an excellent study system for the trophic relationships of soil. Soil microbes and relatively few species of nematodes, rotifers, tardigrades, springtails, and mites are patchily distributed across the cold, dry landscape, which lacks vascular plants and terrestrial vertebrates. However, glacier and permafrost melt are expected to cause shifts in soil moisture and solutes across this ecosystem. To test how increased moisture and salinity affect soil invertebrates and their biotic interactions, we established a laboratory microcosm experiment (4 community &times; 2 moisture &times; 2 salinity treatments). Community treatments were: (1) Bacteria only (control), (2) Scottnema (<em>S. lindsayae</em> + bacteria), (3) Eudorylaimus (<em>E. antarcticus</em> + bacteria), and (4) Mixed (<em>S. lindsayae</em> + <em>E. antarcticus</em> + bacteria). Salinity and moisture treatments were control and high. High moisture reduced <em>S. lindsayae</em> adults, while high salinity reduced the total <em>S. lindsayae</em> population. We found that <em>S. lindsayae</em> exerted top-down control over soil bacteria populations, but this effect was dependent on salinity treatment. In the high salinity treatment, bacteria were released from top-down pressure as <em>S. lindsayae</em> declined. Ours was the first study to empirically demonstrate, although in lab microcosm conditions, top-down control in the MDV soil food web.</p>10abacteria10abiological interactions10adesert10anematode10apolar10asoil communities10atop-down effects10atrophic interactions1 aShaw, Ashley1 aWall, Diana, H.  uhttps://www.mdpi.com/2571-8789/3/3/57