Spirogyra nucleus

Pau · Post by **Pau** » Fri Nov 23, 2012 1:16 pm

The nucleus and perinuclear plasma are round shapped, unlike many other images I saw googling.

Leitz NPL Fluotar 40 0.70, DIC

René · Post by **René** » Fri Nov 23, 2012 3:08 pm

Is it? It looks quite normal to me. The dense round body I always take for a nucleolus, the whole round body is the nucleus. Could be wrong of course, I will do a DAPI staining next spring. Not the right season now to hunt for flab.
Best wishes, René

Pau · Post by **Pau** » Fri Nov 23, 2012 4:53 pm

René, thanks for pointing it, altough I still think that the internal more dense sphere may be the whole nucleus and the clear part surronding it the "pocket of cytosol":

http://digicoll.library.wisc.edu/WebZ/F ... currecno=2

(link edited, I hope now it will work OK)

Charles Krebs · Post by **Charles Krebs** » Mon Nov 26, 2012 12:52 pm

Pau,

It does look a little unusual... more typically I see supporting cytoplasmic strands branching out from the nucleus to the cell walls.

Pau · Post by **Pau** » Mon Nov 26, 2012 3:46 pm

Charles Krebs wrote:It does look a little unusual... more typically I see supporting cytoplasmic strands branching out from the nucleus to the cell walls.

Yes, is because its strange round shape why I posted the pictures. May be the cells were damaged during the slide making, the second one definitively is, but the first one seems intact.

carlos.uruguay · Post by **carlos.uruguay** » Mon Nov 26, 2012 4:37 pm

Very interesting conversation and beautiful photos!
carlos

Ecki · Post by **Ecki** » Tue Nov 27, 2012 9:57 am

Nice DIC images, Pau.

Here is another image of a Spirogyra nucleus that shows the plasma bridges:

40x, Phase Contrast

It maybe that the plasma bridges become invisible if the algae cell is damaged and dead. Pau's Spirogyra looks a bit rotten

Next time when there are no visible bridges, I will check with Basic Orange fluorescence whether the cell is still alive.

regards
Ecki

Pau · Post by **Pau** » Tue Nov 27, 2012 10:30 am

Ecki, thanks for your contribution. It's a very good phase image and shows very clearly the cytoplasmic strands. About the clear area surronding what I think is the true nucleus and René thinks is the whole nucleus, what do you think?

Many thanks also to the other posters.

Ecki · Post by **Ecki** » Tue Nov 27, 2012 10:47 am

Pau, I think the dark center of the plasma is the nucleus. I don't think the nucleolus is visible.

regards
Ecki

arturoag75 · Post by **arturoag75** » Tue Nov 27, 2012 10:52 am

very nice and clear shots!

RogelioMoreno · Post by **RogelioMoreno** » Tue Nov 27, 2012 11:08 am

Pau,

Very interesting!

Rogelio

René · Post by **René** » Tue Nov 27, 2012 9:38 pm

Hello guys,

The nucleolus usually has a very dense structure and is well visible. I don't have access to my botanical images at the moment, but here's an example from a nucleolus in a diatom, check figure 3 http://www.microscopy-uk.org.uk/mag/art ... atom1.html Images are not that great, the stuff is mounted in glycerin jelly (so the silica is barely visible) and the contents are heavily bleached. The nucleus is usually surrounded by only a thin layer of cytoplasm, here very dark by the presence of Golgi bodies (which is typical for diatoms). The nucleolus lies as a small sphere in the nucleus.

Such a thick layer of cytoplasm around the nucleus, like shown in the Spirogyra images here is highly unusual for plant cells. In fact, the dark body in Ecki's image is right on size for the nucleolus in this EM study:
http://jcs.biologists.org/content/4/1/3.full.pdf
And in a more recent study: http://jcs.biologists.org/content/95/3/343.full.pdf

Hope that clarifies things,
René[/url]

Pau · Post by **Pau** » Wed Nov 28, 2012 11:42 am

René,
after a very quick read of the linked documents and few others I find googling I'm now pretty sure you are right. I will do a more carefull reading when I had the time.
Many thanks for the follow up with the links. Bibliography search is a must when discussing about scientific matters.
It makes a very transparent nucleus and a big nucleolus for what I'm used to see.

Ecki · Post by **Ecki** » Wed Nov 28, 2012 11:49 am

Rene and Pau,

if I look at the image from Pau I would always say, the large disk is the nucleus and the round spot in the middle is the nucleolus. In amoebae etc. that would certainly be true.

In Canter-Lund's Freshwater Algae there is a phase contrast image of Spirogyra that shows the same structure as my image and the dark spot is called nucleus. That maybe an oversight or a simplification.

Before I answered yesterday I look into the book - now I tend to agree with Rene. We need some fluorescence to be sure.

Regards
Ecki

uaalgae · Post by **uaalgae** » Tue Dec 11, 2012 2:38 pm

Just for my two cents: if you think of the nucleus in the image as a fried egg, the white portion of the egg is the nucleus and the yolk is the nucleolus.