Subject: How many Rhizo make a nodule

From: "Roger A. Aeschbacher" <[email-masked]>
Date: 19 Mar 1996 08:26:27 -0000

Dear netters,

We would like to know, how many Rhizobium are making a nodule.

This might be trivial, however, we have obtained conflicting answers.
We are currently doing mass screenings of Rhizobia clones which are
transformed with plasmids of a genomic library. We now wonder, about
the following. If we obtain a nodule, how many rhizobia clones did
we screen. Is a nodule only carrying the progeny of one single rhizobia
bacteria. Some say so, however some results say that in one nodule might
be more than one clone of rhizobia.
It is important to us, to know, how many different clones are present in
one nodule, because we want to know how many nodules we have to screen
in order to have a 95% probablility that we have screened the whole
Rhizobium library.
Any help or idea is grately appreciated.

Thanks in advance

Roger A. Aeschbacher
Botanical Institute Basel
[email-masked]

---

From: "Mario de A. Lira Junior" <[email-masked]>
Date: Wed, 27 Mar 1996 09:07:57 -0800

Hello Roger

> be more than one clone of rhizobia.Usually in each nodule there is only one genotype present, but as you have 
already seen, in some cases there is the possibility of more than one 
different bacterial strain occupying the same nodule.
> Rhizobium library.One of the techniques you may use to screen the nodules, and one which is not 
 really dificult, is using monoclonal serogroups to identify, by 
agglutination, the different strains present in each screened nodule. Of 
course, this technique is based on the existence of serogroup differences 
between the strains, which is not always true. I *think* you could also 
research something about electrophoresis, but it may be more labor intensive 
than you want for an extensive screening.
Hope it can help,
Mario Lira Junior