Project description:We sequenced and assembled de novo the coding transcriptomes in four species of Notothenioid fish: Neopagetopsis ionah (Jonah’s ice fish), Pseudochaenichtys georgianus (South Georgia icefish), Harpagifer antarcticus (Antarctic spiny plunderfish) and Parachaenichthys charcoti (Charcot’s dragonfish). We sampled 1-4 individuals and 1-14 tissues (brain, white muscle, liver, head kidney, trunk kidney, skin, heart, red muscle, spleen, ovary, testis, whole blood, gill, red blood cells) in each species, depending on tissue availability.
Project description:The Western Antarctic Peninsula (WAP) is among the areas of the planet showing some of the most significant increases in air and water temperature. It is projected that increasing temperature will modulate communities of coastal ecosystems at species ecological performance and molecular composition. The main way that the organisms can cope with large thermal variation is by having a reversible phenotypic plasticity, which provides the organisms with a compensatory physiological response when facing challenging conditions. However, since Antarctic organisms have evolved in a very cold and stable environment. The giant Antarctic isopod Glyptonotus antarcticus is one of the most abundant in Antarctic waters. This species has a larval development inside of maternal marsupium, where juveniles have a short period to acclimate to environmental conditions after birth. In this sense, we hypothesize that juveniles exposed to unusual temperature increases even for short periods, would not respond adequately showing a narrow phenotypic plasticity. We assessed if early juveniles of G. antarcticus have the molecular plasticity when exposed to increased temperature at 5¡C during 1, 6, 12, and 24 hours in comparison to control 0¡C. Sequenced HIseq2000 libraries were compared between control and each treatment to detect differentially expressed transcripts. The main molecular pathways affected by thermal stress were antioxidants, proteases, endopeptidases, and ubiquitination transcripts which were up-regulated, and mitochondrial respiratory chain, cuticle, cytoskeleton, and a molt transcript which were down-regulated. Considering HSP transcript, only 3 were up-regulated at least in two points of the stress kinetic, without classical HSP70 and HSP90 transcripts. This study shows that juveniles of G. antarcticus do not show molecular phenotypic plasticity to cope with acute short-term heat stress, even for one or few hours of exposure without an eco-physiological capacity to respond. This may have consequences at the ecological population level, showing a reduced individual ability to survive decreasing population recruitment.
Project description:The ability of the Antarctic microarthropod, Cryptopygus antarcticus (Collembola, Isotomidae), to survive low temperatures has been well studied at the physiological level. These investigations have indicated the importance of the moulting process in conferring this ability. This study investigated gene expression in groups of C. antarcticus that have distinct differences in their ability to survive low temperatures. A microarray containing 5,400 C. antarcticus expressed sequence tags was used to investigate gene expression differences between groups of animals with different supercooling points (SCP), and to low temperatures close to their SCP. By demonstrating the involvement of moulting genes in the differential survival of two groups of C. antarcticus with distinct SCPs, the results of this investigation add support to the role moulting plays in conferring cold tolerance in C. antarcticus.
Project description:High group animals with supercooling point (SCP) above -15°C and selected low group animals with SCP below -15°C were prepared from Cryptopygus antarcticus collected from wet moss (Sanionia uncinata (Hedw.)) during the austral summer of 2005 at the British Antarctic Survey's research station at Rothera Point, Adelaide Island (67'34'S, 66'8'W).
Project description:TagSeq tissue specific expression data for Antarctic Harpagifer antarcticus and tropical African cichlid Astatotilapia (Haplochromis) burtoni
| PRJNA758918 | ENA
Project description:Rhodoferax antarcticus cultured from Antarctic Lake Fryxell mat
Project description:Because of severe abiotic limitations, Antarctic soils represent simplified ecosystems, where microorganisms are the principle drivers of nutrient cycling. This relative simplicity makes these ecosystems particularly vulnerable to perturbations, like global warming, and the Antarctic Peninsula is among the most rapidly warming regions on the planet. However, the consequences of the ongoing warming of Antarctica on microorganisms and the processes they mediate are unknown. Here, using 16S rRNA gene pyrosequencing and qPCR, we report a number of highly consistent changes in microbial community structure and abundance across very disparate sub-Antarctic and Antarctic environments following three years of experimental field warming (+ 0.5-2°C). Specifically, we found significant increases in the abundance of fungi and bacteria and in the Alphaproteobacteria-to-Acidobacteria ratio. These alterations were linked to a significant increase in soil respiration. Furthermore, the shifts toward generalist or opportunistic bacterial communities following warming weakened the linkage between bacterial diversity and functional diversity. Warming also increased the abundance of some organisms related to the N-cycle, detected as an increase in the relative abundance of nitrogenase genes via GeoChip microarray analyses. Our results demonstrate that soil microorganisms across a range of sub-Antarctic and Antarctic environments can respond consistently and rapidly to increasing temperatures, thereby potentially disrupting soil functioning.
Project description:Using RNAseq of small RNA libraries isolated from the gill tissue of the Antarctic fish Trematomus bernacchii we have characterized the termal sensitivity of miRNA homologues in these highly stenothermic fish.