Orange Montastrea cavernosa recruits?
woodley at uwimona.edu.jm
Fri Aug 4 08:29:56 EDT 2000
Does the fluorescence make more of the energy of uv light available for
photosynthesis? I am not sufficiently familiar with the action spectra to
judge for myself.
PO Box 269, McMaster University, Tel: (905) 627-0393
1280 Main Street West, Fax: (905) 627-3966
Hamilton, ON L8S 1C0, woodley at uwimona.edu.jm
Canada. or chopwood at hwcn.org
On Fri, 4 Aug 2000, Mikhail Matz wrote:
> Dear Dr. Murray,
> thank you very much for your posting. So, here comes the reasoning
> against photoprotection function of fluorescent pigments from corals.
> These pigments are (in the majority of cases) proteins homologous to
> green fluorescent protein (GFP) from Aequorea victoria, as we recently
> found out (Matz et al, Nat.Biotechnol. 17: 969-973, 1999).
> We already had a bit of this discussion with prof. Ove
> Hoegh-Guldberg of the University of Queensland (oveh at uq.edu.au), who was
> also suggesting photoprotection as the major role of fluorescent
> proteins. Here is a part of what I wrote to him directly in responce:
> Concerning photoprotection I would rather disagree with you. First of
> all, corals possess a multitude of low-molecular sunscreen
> compounds for this purpose (see, for example, Dunlap, W.C. et al.
> Nature's sunscreen from the Great Barrier Reef, Australia. International
> Journal of Cosmetic Science 20, 41-51 (1998)), so additional recruitment
> of specialized proteins
> for the same purpose seems rather tedious. Still, if it still was
> protection from UV, there is no difference which
> fluorescent color to use - green or red, they are both UV-excitable.
> Meanwhile, our most recent data on molecular features of red-emitters
> suggest that they are advanced versions of greens, so that a point
> mutation would most likely damage
> the red protein making it green. Therefore, red color should have some
> special role in nature (different from green!)
> to be maintained by natural selection, otherwise all the red-emitters
> would have long since deteriorated into greens due to mutation pressure.
> In addition, red-emitters are heavily suboptimal in comparison to greens
> in terms of photoprotection - they all have much lower quantum yields of
> So, I think that the coral fluorescence file is still far from being
> I would be happy to continue this discussion, especially taking in
> account that the question of the fluorescent proteins function in corals
> is exactly the subject of my current research.
> sincerely yours
> Mikhail Matz, Ph.D.
> Institute of Bioorganic Chemistry
> Miklukho-Maklaya 16/10
> 117871 Moscow, Russia
> Robert Murray wrote:
> > Hi Iain et al,Coral photobiology is not my area of study, although I
> > did examine the topic some years ago. I believe it is fairly common
> > for many corals to exhibit brightly coloured fluorescence pigments
> > (especially those in shallowest water conditions where light intensity
> > is greatest).From some of the literature I have read I seem to
> > remember a plausible case for these pigments operating as some sort of
> > protection against the destructive energy of short (UV) wavelengths,
> > by liberating some of this energy as harmless (less energetic) visible
> > fluorescence. Perhaps this is one of the discredited theories now. If
> > so, I would be interested to hear the evidence against it.Regards to
> > allRobert Murray.(What's up Iain?)=======================
> > ROBERT MURRAY BSc, FGA,
> > Discovery Bay Marine Laboratory,
> > Discovery Bay, Jamaica, W.I.
> > Tel. (876) 973 2946
> > Fax. (876) 973 3091
> > rmurray at infochan.com
> > WWW.DBML.ORG
> > =======================
> > ----- Original Message -----
> > From: Mikhail Matz
> > To: Iain Macdonald ; coral list
> > Sent: Tuesday, July 25, 2000 11:33
> > Subject: Re: Orange Montastrea cavernosa recruits?
> > Hi Iain,
> > we know a little bit what is the substance causing the
> > fluorescence in
> > corals,
> > and observations, measurements and photos were made about
> > this
> > (see http://www.nightsea.com/references.htm for the list of
> > related
> > papers and websites)
> > Moreover, in particular M.cavernosa fluorescence was
> > measured (in situ)
> > by Charles Mazel
> > and is studied by me (in vitro) right now.
> > However, so far we have absolutely no clue as to the
> > function of this
> > fluorescence in
> > nature (if we forget for a moment about older hypotheses all
> > of which
> > seem wrong by now),
> > and the subject is my primary interest. Your observation is,
> > as far as I
> > know, the first
> > information which might help to link fluorescence to some
> > aspect of coral
> > ecology. I would be
> > extremely grateful if you could provide some more details on
> > your
> > observations.
> > I would like to ask all coral listers as well - perhaps you
> > saw
> > something like Iain? Anything
> > which could give a hint about the function of fluorescence?
> > Or perhaps I
> > simply missed something
> > in literature?
> > best wishes,
> > Mike Matz
> > Iain Macdonald wrote:
> > > During a recent field trip i noted the following along my
> > transects.
> > >
> > > M. cavernosa recruits (i use the plural as this was seen
> > three
> > > different times), of only one polyp was noted at approx.
> > 15-20m depth
> > > to appear to the unaided eye as fluorescent orange. Close
> > by (ie
> > > 10cm away) 5 polyps were the typical olive green colour
> > with this
> > > "day glow" orange colour around its edges. Again a few cms
> > away
> > > larger colonies 20-25 polyps were only olive green. Is
> > this typical
> > > for recruits (i think not) or maybe as a result of some
> > stress
> > > (sediment) stimulus? I was startled to see such colour
> > from this type
> > > of coral and would like to konw of any other observations.
> > >
> > > Cheers
> > >
> > > Iain Macd.
> > >
> > > Room E402 John Dalton Extension Building,
> > > Department of Environmental and Geographical Science,
> > > Manchester Metropolitian University,
> > > Chester Street,
> > > Manchester,
> > > M1 5GD
> > > Tel: 0161 247 6234
> > > Fax: 0161 247 6318
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