Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!hao!boulder!pell
From: pell@boulder.Colorado.EDU (Anthony Pelletier)
Newsgroups: sci.bio
Subject: Re: E. coli genetic linkage map:  A new edition?
Message-ID: <3659@sigi.Colorado.EDU>
Date: 31 Dec 87 20:20:22 GMT
References: <1521@aecom.YU.EDU> <1522@aecom.YU.EDU>
Sender: news@sigi.Colorado.EDU
Reply-To: pell@boulder.Colorado.EDU (Anthony Pelletier)
Organization: University of Colorado, Boulder
Lines: 28
Keywords: Eubacteria, microbiology, molecular genetics

>In article <1521@aecom.YU.EDU>, diaz@aecom.YU.EDU (Dandy) writes:
>
>> Also, does anyone know about attempts to harmonize Bachman's genetic map
>> with Cassandra Smith's recently released physical map? 
>> 
In article <1522@aecom.YU.EDU> werner@aecom.YU.EDU (Craig Werner) writes:
>	In the restriction map paper itself, there is a full-page vertical
>figure showing the alignment of the physical and genetic map.  The agreement
>is relatively extraordinary.  Of course, since this is only a map for a
>single 8-base cutter, the true alignment awaits the hexamer restriction
>map, which may be a few years in getting here (or maybe not...).
>	        Craig Werner   (future MD/PhD, 3 years down, 4 to go)
>	     werner@aecom.YU.EDU -- Albert Einstein College of Medicine

Actually, one does not have to wait at all.  Kohara et al. have already
published a complete map of the coli chromosome with 8 (count 'em, 8)
different 6-cutters.  I am afraid I only have the pre-print, but it was
submitted to Cell in April or May and I do remember seeing it out, but not
exactly when.  It is a rather remarkable bit of work.
A rather strange aside, the map was done on W3110, because Bachman likes
this strain.  It has been abused less than alot of others.
But, of course, it has that big inversion between the rrn clusters at
72 and 90 minutes (inv(rrnB-rrnD), I think).  Kohara et al. did correct
for this in the published map, of course.  The agreement between physical
and genetic distance is fairly good, but not perfect.
Over large distances, say, from the origin to the terminus, the genetic
map is off by a few per cent.

-tony