Marine Ecosystems Research Department - jamstec japan agency ...

Japan Marine Science and Technology Center
Frontier Research System for Extremophiles
A
B
Fluorescence Light
0.1 MPa 30 MPa 50 MPa 0.1 MPa 70 MPa
Fluorescence Light
Fig. 5 a, E. coli responding to high pressure. b, M. japonica responding to high pressure.
grown at MPa (Fig. b). Thus, the high-pressure
inducible promoters were successfully delivered to a
mesophile and piezophiles and they were still functional
under high-pressure conditions.
(c) Whole genome analysis for gene expression
responding to high hydrostatic pressure in bacteria
We analyzed the effect of high pressure on transcription
in E. coli in terms of whole genome analysis
using a DNA tip. Numbers of low-temperature
inducible genes were also expressed under high-pressure
condition, suggesting that low-temperature and
high-pressure have overlapping effects to E. coli cells.
In our future study, we will construct a DNA tip for
S. violacea to perform the first entire analysis for transcription
in piezophile.
3. Biological response to Deep-Sea Environments
3.1. Biological response research
(a) Research of adaptation mechanism to the extremity
environment for deep-sea multicellular organisms
Not only microbes but multicellular organisms also
inhabit the deep sea. The purpose of this research
was to clarify the deep-sea environment and deep-sea
multicellular organisms, and especially correlations
in single cells. We developed and improved the
capture device for deep-sea multicellular organisms
(deep-sea fish etc.), the land-based high-pressure
environment system, and the high-pressure cell observation
microscope. Raising multicellular organisms
and culturing its cell are resulting in very positive
research achievements.
(i) Capture device for benthic multicellular organisms
Capture devices were carried in the payload pallets
of the research submersibles (Shinkai , Shinkai
and Hyper Dolphin), and their operating state
was confirmed. Sampling was performed in Sagami
Bay, the Japan Trench, and the Chishima Trench at
depths from m to m. Capture devices could
be installed on all payload palettes, and proved to be
effective in collecting deep-sea samples. Captured
multicellular organisms could maintain a high survival
rate if the device was connected to the high-pressure
circulation system promptly.
(ii) Keeping benthic multicellular organisms (DEEP
AQUARIUM)
Alvinocaris longirostris and Simenchelys parasiticus
(Fig. ) were captured near the Caryptogena soyoae
colony off Hatsushima, Sagami bay at a depth of
,m. These organisms were maintained at a constant
pressure in DEEP AQUARIUM. It was kept at
MPa ˚C, and continuation for month was confirmed
with Simenchelys parasiticus. The organisms fed
normally in DEEP AQUARIUM, and external stress
could not be confirmed. Alvinocaris longirostris had
eggs at the time of capture. After maintaining pressure
for three months, the water tank was steadily decompressed
to atmospheric pressure. This report was
the first examination of such atmospheric pressure
adaptation. We subjected the sample to repeated com-
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