Adaptation to extreme environments: The Antarctic volunteer.

1966 ◽  
Author(s):  
E. K. Gunderson
Keyword(s):  
Extreme Environments ◽  
The Antarctic

scholarly journals The Parallel Molecular Adaptations to the Antarctic Cold Environment in Two Psychrophilic Green Algae

2019 ◽  
Vol 11 (7) ◽  
pp. 1897-1908 ◽  
Author(s):  
Zhenhua Zhang ◽  
Changfeng Qu ◽  
Ru Yao ◽  
Yuan Nie ◽  
Chenjie Xu ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Positive Selection ◽  
Green Algae ◽  
Large Scale ◽  
Extreme Environments ◽  
Photosynthetic Apparatus ◽  
Antioxidant Systems ◽  
Significant Evidence ◽  
The Antarctic ◽  
Molecular Convergence

Abstract Psychrophilic green algae from independent phylogenetic lines thrive in the polar extreme environments, but the hypothesis that their psychrophilic characteristics appeared through parallel routes of molecular evolution remains untested. The recent surge of transcriptome data enables large-scale evolutionary analyses to investigate the genetic basis for the adaptations to the Antarctic extreme environment, and the identification of the selective forces that drive molecular evolution is the foundation to understand the strategies of cold adaptation. Here, we conducted transcriptome sequencing of two Antarctic psychrophilic green algae (Chlamydomonas sp. ICE-L and Tetrabaena socialis) and performed positive selection and convergent substitution analyses to investigate their molecular convergence and adaptive strategies against extreme cold conditions. Our results revealed considerable shared positively selected genes and significant evidence of molecular convergence in two Antarctic psychrophilic algae. Significant evidence of positive selection and convergent substitution were detected in genes associated with photosynthetic machinery, multiple antioxidant systems, and several crucial translation elements in Antarctic psychrophilic algae. Our study reveals that the psychrophilic algae possess more stable photosynthetic apparatus and multiple protective mechanisms and provides new clues of parallel adaptive evolution in Antarctic psychrophilic green algae.

4. Polar marine biology

2020 ◽  
pp. 71-86
Author(s):  
Philip V. Mladenov
Keyword(s):  
Climate Change ◽  
Food Webs ◽  
Marine Biology ◽  
Extreme Environments ◽  
The Arctic ◽  
Polar Regions ◽  
Light Levels ◽  
The Arctic Ocean ◽  
The Antarctic ◽  
The Impact

Flourishing marine biological systems are present in the extreme environments of the Arctic and Antarctic polar regions of the planet. Both these regions are characterized by constantly cold sea temperatures, ice-covered oceans, and extreme seasonal fluctuations in light levels, but ‘Polar marine biology’ explains how they have evolved strikingly different and unique marine ecosystems. The Arctic Ocean is largely landlocked while the Southern Ocean surrounds the Antarctic continental land mass and is in open contact with the Atlantic, Indian, and Pacific oceans. The impact of human-induced climate change is also discussed, which will affect the Arctic and Antarctic food webs in profound ways.

Identification, characterization and expression analysis of the chalcone synthase family in the Antarctic moss Pohlia nutans

2019 ◽  
Vol 31 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Xinghao Yao ◽  
Tailin Wang ◽  
Huijuan Wang ◽  
Hongwei Liu ◽  
Shenghao Liu ◽  
...  
Keyword(s):  
Plant Resistance ◽  
Chalcone Synthase ◽  
Expression Profiles ◽  
Extreme Environments ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Pcr Analysis ◽  
The Antarctic ◽  
Pohlia Nutans ◽  
Antarctic Moss

AbstractMosses have adapted to the Antarctic environment and are an ideal medium for studying plant resistance to abiotic stress. Chalcone synthase is the first committed enzyme in the flavonoid metabolic pathway, which plays an indispensable role in plant resistance to adversity. In this study, six genes (Pn021, PnCHS088, Pn270, PnCHS444, PnCHS768 and Pn847) were identified in the Antarctic moss Pohlia nutans Lindberg transcriptome by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Sequence alignment and three-dimensional structure analysis revealed the conserved amino acid residues of the enzymes of the chalcone synthase family, including three catalytic residues (Cys164, His303 and Asn336) and two substrate recognition residues (Phe215 and Phe265). Phylogenetic analysis indicated that PnCHS088, PnCHS444 and PnCHS768 might be chalcone synthase but that Pn021 is more like stilbenecarboxylate synthase. These genes were located at the transition between fungi and advanced plants in the phylogenetic tree. In addition, real-time PCR analysis revealed that the expression profiles of the six P. nutans genes were influenced by diverse abiotic stresses as well as by abscisic acid and methyl jasmonate. The results presented here contribute to the study of the CHS gene family in polar mosses and further reveal the mechanisms underlying the adaptation of mosses to extreme environments.

Early stages of development in Usnea antarctica Du Rietz in the South Shetland Islands, northern maritime Antarctica

2004 ◽  
Vol 36 (6) ◽  
pp. 413-423 ◽  
Author(s):  
Sieglinde OTT
Keyword(s):  
Growth Rate ◽  
Extreme Environments ◽  
South Shetland Islands ◽  
Shetland Islands ◽  
Morphological Adaptations ◽  
Terrestrial Habitats ◽  
Juvenile Stages ◽  
The Antarctic ◽  
First Time ◽  
Juvenile Development

Juvenile development has been investigated for the first time in an Antarctic lichen species—Usnea antarctica—in the northern maritime Antarctic, Livingston Island (South Shetland Islands, 62°27′–62°48′S, 59°45′–61°15′W). Here, U. antarctica grows on rocks and forms the dominant vegetation on this site together with a few other macrolichens. This species reproduces mainly by vegetative diaspores (soredia), which include both the photobiont and the mycobiont. To understand the early ontogenetic strategies in U. antarctica, culture experiments were performed in an Antarctic field site where the species occurs naturally. This paper focuses on the different developmental steps seen between the initial colonization of soredia to the formation of a small well-developed thallus, and also on the growth rate of the respective juvenile stages. Compared with growth rates of lichens from temperate European regions the early development of U. antarctica is extraordinarily slow, taking 5–6 years until an adult thallus has been formed. The low photobiont content in the juvenile stages probably limits the growth rate. It is suggested that juvenile development of U. antarctica is controlled by a combination of ecophysiological and morphological adaptations that are required for success in extreme environments such as the terrestrial habitats of the Antarctic.

scholarly journals Smart Wearables for Cardiac Autonomic Monitoring in Isolated, Confined and Extreme Environments: A Perspective from Field Research in Antarctica

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1303
Author(s):  
Michele M. Moraes ◽  
Thiago T. Mendes ◽  
Rosa M. E. Arantes
Keyword(s):  
Physiological Responses ◽  
Extreme Environments ◽  
Field Research ◽  
Extreme Environment ◽  
Energy Restriction ◽  
Summer Camps ◽  
Cardiac Monitoring ◽  
Health Tracking ◽  
Snow Water ◽  
The Antarctic

Antarctica is a space-analog ICE (isolated, cold, and extreme) environment. Cardiovascular and heart autonomic adjustments are key-adaptive physiological responses to Antarctica, both in summer camps and in research stations winter-over. Research fieldwork in ICE environments imposes limitations such as energy restriction, the need for portable and easy-to-handle resources, and resistance of materials to cold and snow/water. Herein, we present the methods we use for cardiac monitoring in the Antarctic field, the limitations of the equipment currently available, and the specific demands for smart wearables to physiological and health tracking in ICE environments, including the increased remote monitoring demand due to COVID-19 restrictions.

scholarly journals Diversity of toxin and non-toxin containing cyanobacterial mats of meltwater ponds on the Antarctic Peninsula: a pyrosequencing approach

2014 ◽  
Vol 26 (5) ◽  
pp. 521-532 ◽  
Author(s):  
J. Kleinteich ◽  
F. Hildebrand ◽  
S.A. Wood ◽  
S. Ciŕs ◽  
R. Agha ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Intergenic Spacer ◽  
Rrna Gene ◽  
Polar Regions ◽  
Organic Mass ◽  
Cyanobacterial Mats ◽  
Operational Taxonomic Units ◽  
Similar Range ◽  
The Antarctic ◽  
First Time

AbstractDespite their pivotal role as primary producers, there is little information as to the diversity and physiology of cyanobacteria in the meltwater ecosystems of polar regions. Thirty cyanobacterial mats from Adelaide Island, Antarctica were investigated using 16S rRNA gene pyrosequencing and automated ribosomal intergenic spacer analysis, and screened for cyanobacterial toxins using molecular and chemical approaches. A total of 274 operational taxonomic units (OTUs) were detected. The richness ranged between 8 and 33 cyanobacterial OTUs per sample, reflecting a high mat diversity. Leptolyngbya and Phormidium (c. 55% and 37% of the OTUs per mat) were dominant. Cyanobacterial community composition was similar between mats, particularly those obtained from closely adjacent locations. The cyanotoxin microcystin was detected in 26 of 27 mats (10–300 ng g-1 organic mass), while cylindrospermopsin, detected for the first time in Antarctica, was present in 21 of 30 mats (2–156 ng g-1 organic mass). The latter was confirmed via liquid chromatography-mass spectrometry and by the presence of the cyrAB and cyrJ genes. This study demonstrates the usefulness of pyrosequencing for characterizing diverse cyanobacterial communities, and confirms that cyanobacteria from extreme environments produce a similar range of cyanotoxins as their temperate counterparts.

High zooplankton diversity in the extreme environments of the McMurdo Dry Valley lakes, Antarctica

2011 ◽  
Vol 24 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Lars-Anders Hansson ◽  
Samuel Hylander ◽  
Herbert J.G. Dartnall ◽  
Sven Lidström ◽  
Jan-Erik Svensson
Keyword(s):  
Distribution Pattern ◽  
Extreme Environments ◽  
Dry Valley ◽  
Antarctic Continent ◽  
The Antarctic ◽  
Freshwater Environments

AbstractThe McMurdo Dry Valley lakes of Antarctica constitute some of the harshest and most isolated freshwater environments on Earth which might be expected to limit the biogeographical expansion of many organisms. Despite this, we found that the biodiversity of rotifer zooplankton is the highest ever recorded on the Antarctic mainland. We identified in total nine rotifer taxa, of which six are new to the Antarctic continent, in Lake Hoare, and also the first sub-adult crustacean copepod belonging to the genus Boeckella. A possible explanation for the high biodiversity is that many of the recorded species have arrived in the region in relatively recent times and then established invasive populations, suggesting that their distribution pattern was previously limited only by biogeographical borders. Interestingly, we show that the cosmopolitan rotifer taxa identified are relatively abundant, suggesting that they have established viable populations. Hence, our study suggests that the biogeographical maps have to be redrawn for several species.

Photosynthesis in extreme environments: responses to different light regimes in the Antarctic algaKoliella antarctica

2014 ◽  
Vol 153 (4) ◽  
pp. 654-667 ◽  
Author(s):  
Nicoletta La Rocca ◽  
Katia Sciuto ◽  
Andrea Meneghesso ◽  
Isabella Moro ◽  
Nicoletta Rascio ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Light Regimes ◽  
The Antarctic

Evolution of the coping strategies in an isolated group in an Antarctic base

Polar Record ◽  
2001 ◽  
Vol 37 (201) ◽  
pp. 111-120 ◽  
Author(s):  
Marta Barbarito ◽  
Simona Baldanza ◽  
Antonio Peri
Keyword(s):  
Stress Response ◽  
Coping Strategies ◽  
Extreme Environments ◽  
Basic Component ◽  
Human Adaptation ◽  
Operational Environment ◽  
Ways Of Coping ◽  
The Antarctic ◽  
Antarctic Environment ◽  
Behavioural Strategies

AbstractThe Antarctic environment is well known for its hostility (cold, isolation, and confinement). The effects of the Antarctic experience on human health are controversial, as some studies emphasise negative (‘pathogenic’) and others positive (‘salutogenic’) effects. In the process of human adaptation to extreme environments, the cognitive and behavioural strategies — defined as coping — that individuals use are a basic component.This study investigated the use and the changes of coping strategies in nine Antarctic wintering-over expeditioners by administering the COPE questionnaire three times during the year. The results showed a composite use of the coping strategies in the group. The ways of coping, focusing on problem solving and developing personal maturity, were judged to be those most used over the period. Some variations connected with the specific environment were noticed. There was an increase in self-distancing from problems, disengaging from the socio-operational environment, procrastinating, and emotional levelling, particularly in mid-winter. This lethargic, apathetic attitude, which is called ‘freezing,’ may represent a defence against useless energy expenditure and may reduce stress response. This ‘immobilisation’ strategy, well reflected in the symptoms of the ‘winter-over syndrome,’ appears to be adaptive in an environment where the control an individual can exert is highly limited. The results seem to support the salutogenic effects of the winter-over experience.

scholarly journals Life In and Under the Antarctic Ice Sheets

2008 ◽  
Vol 16 (3) ◽  
pp. 6-9
Author(s):  
Shawn Doyle ◽  
Pierre Amato ◽  
Brent Christner
Keyword(s):  
Extreme Environments ◽  
Ice Sheets ◽  
Microscopic Analysis ◽  
Ice Crystals ◽  
Glacial Ice ◽  
Microbial Life ◽  
The Antarctic ◽  
Antarctic Ice Sheets

The discovery of viable microbial life in ancient glacial ice has opened up a plethora of questions related to how life can be sustained in such extreme environments. Cryo-microscopic analysis of lab prepared ice samples indicates that microbes are located in the small veins of water that exist between individual ice crystals. Crucial to these studies is to obtain an understanding of the physicochemical habitat for life through physiological and microscopic analysis.

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