Panagrolaimus superbus is a species of terrestrial free-living
nematode (
roundworm). P. superbus, like other species within the Panagrolaimus genus, exhibits the ability to enter
anhydrobiosis for extended periods of time.[2]
Ecology
P. superbus is a non-parasitic terrestrial
bacterivore, commonly found on grasses such as
rye.[3][4] It is found in continental Europe, as well as
Surtsey, Iceland.[5][3]
Metabolism
In order to combat rapid
desiccation, P. superbus has several
constitutive genes that allow the accumulation of
trehalose, even under normal metabolic circumstances, that acts as a protective layer and an intracellular protection mechanism.[5][6]P. superbus also has several inducible genes that
upregulate in response to desiccation, genes responsible for enzymes such as
gpx,
dj1 and
1 Cys-Prx to help scavenge and reduce
reactive oxygen species,
mitogen-activated protein kinases that
phosphorylateheat shock proteins such as
Hsp27 to stabilise
microfilaments, and
casein kinase 2 that helps in
DNA repair, among others.[7]P. superbus's ability to enter anhydriobiosis has given it polyextremotolerance, a tolerance of various extreme environments, being the first multi-cellular organism able to withstand immersion and reproduce in
heavy water, albeit with a reduced metabolic rate, withstand immersion in
gallium, and tolerate
g-forces up to 400,000 times the Earth's.[8][9][10]