FYI. Absolute best penguin show in town… hope you can make it!* (Serena
Teo)*

*** Register for transport to St John's ***

Three short talks about half-hour each will be held back-to-back at TMSI
Seminar Room on St John's Island. All are welcome.
*Date: 21st June 2007 (Thursday)*
*Time: 1030 -1200 hrs*

Titles and abstracts (see below)

Speakers: Drs Melody Clark, Simon Morley and Ms Stephanie Martin (British
Antarctic Survey); Mr Lai Chien Houng (TMSI, NUS)

Venue: Seminar Room, Admin Blk,
Tropical Marine Science Institute NUS @ St John's Island

TMSI will provide a ferry which will depart Pasir Panjang Ferry Terminal at
*0930* hrs for St John's Id. The return ferry will depart St John's Id at
1230 hrs. As ferry seats are limited, please contact me (tmstanks@...)
by 15 June (Friday) latest if you are interested to attend the talks.

Thank you
Yours sincerely
Dr Tan Koh Siang
Tropical Marine Science Institute
National University of Singapore
14 Kent Ridge Road
Singapore 119223
Tel: +65 9822 3846 or +65 6774 9656

Fax: +65 6774 9654 or +65 9714 6451

e-mail: tmstanks@...

*Three talks by researchers at the British Antarctic Survey, UK*
*&Tropical Marine Science Institute*

*NUS Seminar Room, TMSI St John's Island *
*21 June 2007 (Thurs) 1030–1200 hrs *


*1) The heat shock response in Antarctic marine organisms— Dr Melody Clark *

The survival success of any organism depends not only on niche adaptation,
but also the ability to survive environmental perturbation from homeostasis,
a situation generically described as stress.

Although species-specific mechanisms to combat "stress" have been described,
there is one universally described stress response; the production of Heat
Shock Proteins (HSPs), such as HSP70. This classic heat shock response
involves a strong up-regulation of HSP70 production and has been
demonstrated in all organisms examined to date with the exception of Hydra
oligactis, an Antarctic ciliate Euplotes focardii and several species of
Antarctic notothenioid fish.

The latter case is complex: three distantly related species of Antarctic
fish, Trematomus bernacchii, Pagothenia borchgrevinki and Lycodichthys
dearborni permanently express the inducible form of HSP70 but the
Nototheniidae lack the ability to further up-regulate this gene in response
to elevated environmental temperatures.

Given these data, the question arises as to whether the permanent expression
of HSP70 and lack of a heat shock response in Antarctic notothenioids is
species-specific, or a consequence of adaptation to highly stable, cold
Antarctic seawater temperatures and therefore a general phenomenon extending
to other non-piscine Antarctic marine organisms.

We present the results of an investigation into the expression of HSP70 gene
family members in a range of Antarctic marine organisms and discuss the
implications with reference to species ability to cope and survive during
observed ocean warming and also the reorganisation of the cellular protein
machinery of species living in extreme environments.



*2) Living in the Antarctic—Dr Simon Morley and Ms Stephanie Martin *
A light hearted look at scientists and naturalists living and working in the
Antarctic.

*3) Heat shock protein (hsp) expression in limpets on Hong Kong rocky
shores—Mr Lai Chien Houng *

The kinetics of hsp synthesis were studied in two intertidal limpets,
Cellana grata and C. toreuma, in response to environmental conditions such
as heat and desiccation stress to determine if this biochemical indicator
correlates with the zonation pattern of these species. Cellana grata are
common on the upper shore, while C. toreuma lives in the lower intertidal.

A shore survey, conducted from December 2004 to July 2005, was designed to
establish the diurnal and seasonal variation of hsp expression from winter
to summer for limpets in different microhabitats. This was combined with
laboratory experiments to elicit the specific effects of time, heat shock,
desiccation and low salinity shock on hsp expression.

On the shore, hsp induction was typically associated with the receding tide
and subsequent exposure to heat/desiccation stress. In the laboratory, a
second induction was observed when limpets were awash by a simulated
incoming tide. C. grata generally showed a faster induction and
downregulation of hsp in response to heat stress and stress removal
respectively than C. toreuma which, in contrast, showed continuously
elevated hsp synthesis.

Given that hsp synthesis, function and downregulation are all energy
demanding processes, the efficiency of hsp regulation in C. grata implies
that this species is better adapted to a high shore environment than C.
toreuma. This variation in response corresponds to the respective intertidal
zonation patterns of the two species, and possibly provides an explanation
for the success of C. grata higher on the shore, and the observed heavy
summer mortality in C. toreuma.


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