Only you can answer this question! It has been one year since we asked for new mapping data and I'm sure all you mappers have been very busy since then. In order for the Caenorhabditis Genetics Center to provide you with a truly current, juicy version of the map at Cold Spring Harbor in May, we will need your previously unreported data on copies of the 'CGC Genetic Data Sheet' included in this issue. ( Directions for reporting three-factor cross results are included below. ) Please send us completed forms for new genes you have mapped or old genes you have moved, no later than March 1, 1981. Send to: Caenorhabditis Genetics Center, Division of Biological Sciences, 110 Tucker Hall, University of Missouri, Columbia, Missouri 65211. Three-factor cross results: (i.e., counts from recombinants of A & B phenotypes from progeny of ab +/+ +c.) Indicate results showing determined order and the number of recombination events in each interval. A.) The order can only be determined unambiguously when the single trans marker 'c' is located between the other two markers 'a' and 'b'. In those cases, indicate results as in the following example. For example: Of 269 recombination events between
dpy-5 and
unc-13, 264 were in the interval between
unc-15 and
unc-13. (expressed as): dpy- 5(264/269) 269) nB.) When a precise order is not defined and instead we can only establish that one of the markers is outside, the ambiguity is indicated by parentheses. For example: All of 50 unc and none of 25 dpy recombinants from
unc-17 e him progeny. Thus,
him-8 is either right of
dpy-13 or close to and left of
dpy-13. (expressed as:
unc-17(75/75)
him-8)) Note: In this case, the trans marker is never written in the middle position so that in the example given, it should be readily apparent from the way the markers are written that
him-8 is either on the side of
dpy-13 opposite that of
unc-17 or on the same side but close to
dpy-13.