Extreme Environment Analysis

It is well known that all organisms require at least some water to survive, even the most hardy creature on the planet earth, the tardigrade, Hypsibius dujardini, which can survive near complete dehydration, exposure to extreme radiation, vacuum, temperature and pressure, must be rejuvenated with water if it is to resume life after near complete desiccation (Gabriel, et al. 2007). H. dujardini, famous for surviving some of the harshest conditions of any organism we know of, is a perfect example of what we consider an extreme environment, that is, any environment considered to be extreme is one in which water cannot be easily accessed, for example in both extreme hot and extreme cold, water is difficult to access, either because it has vaporized, or because it is trapped in its solid form. Another form of a water starved environment is environments with high salinity, such as the environments where you would find Haloarcula marismortui, an extreme halophilic archaea from …show more content…
marismortui’s two pch proteins, pch1 and pch2, are structurally very similar and in fact both contain a TrkA N-domain (Figure A and D) (Mitchell, et al. 2015). Despite these similarities, both show dissimilar expression patterns in Har. marismortui under low potassium stress conditions (20mM potassium) after acclimatization at normal potassium levels (120mM potassium). When experiencing low potassium shock, pch1 mRNA has a large expression spike 4 hours after introduction to new conditions compared to pch2, which does not show a significant change in expression at any time interval or potassium level (Short, et al. 2016). Despite similarities between the pch proteins, pch1 originates on a plasmid within Har. marismortui, and pch2 is chromosomal, these differences, as well as the figure B low potassium expression data point to pch1 and pch2 playing different roles in Har. marismortui, details of their roles are unknown at present. Interestingly, pch1 and pch2 both contain a TrkA N