Re: questions from P. Pontarotti
Data obtained by the C. elegans Mapping and Sequencing Consortium
indicates that the size of the X chromosome is approximately
20,000 kb. An exact value must await full contiguation of the
sequence of this chromosome.
The map coordinates displayed on ACeDB refer to genetic map positions
as determined by recombinational mapping of markers. For each linkage
group, one centrally located marker was assigned to the zero position,
and all other markers are given coordinates in cM relative to this,
either negative (for the left, or up, arm) or positive (for the right,
or down, arm).
Total measured genetic map length for the six linkage groups of
C. elegans currently adds up to 280 cM. Probably the real total
is 50 cM for each linkage group, summing to 300 cM.
----------------------------------------------------
Dr Jonathan Hodgkin
CGC Map and Nomenclature Curator
(Caenorhabditis Genetics Center Subcontract)
MRC Laboratory of Molecular Biology
Hills Road, Cambridge CB2 2QH
England
Telephone (+44) 1223 402321 (office)
(+44) 1223 402278 (lab)
Fax (+44) 1223 412142
e-mail jah at mrc-lmb.cam.ac.uk
