Letter from Barbara McClintock to Charles R. Burnham
This brief letter that illustrates the role cooperation plays in scientific discovery. In it, McClintock conveyed some recent
data regarding the order of the c-sh-wx chromosome and indicated that Beadle's work might compliment her findings. McClintock's
work on this matter would result in an article in the "Proceedings of the National Academy of Sciences" later in 1931.
Item is handwritten. Item is a photocopy.
Number of Image Pages:
2 (122,285 Bytes)
1931-03-01 (March 1, 1931)
Burnham, Charles R.
Original Repository: University of Minnesota, University Archives. Charles Burnham Papers
Reproduced with permission of the University of Minnesota, University Archives. Charles Burnham Papers
Medical Subject Headings (MeSH):
The Order of the Genes C, Sh, and Wx in Zea Mays with Reference to a Cytologically Known Point in the Chromosome (1931)
Letter from Barbara McClintock to Charles R. Burnham (March 12, 1931)
Letter from Barbara McClintock to Charles R. Burnham (April 11, 1931)
Letter from Barbara McClintock to Charles R. Burnham (May 12, 1931)
Letter from Barbara McClintock to Charles R. Burnham (June 11, 1931)
Box Number: 3
Folder Number: 4
March 1, 1931
Our plants have been very late. I have just started looking at the c-sh-wx chromosome. From what I have seen it seems clear
that the knobbed chromosome, the 2nd smallest, is the c-sh-wx chromosome. In the material I have there are 3 size differences
of the knob. Very large, small, and smaller or about [diagram] and no knob. In one plant the synapsis showed 2 of the type
3 and one of type 2. I am going to cross this plant with type 1. This points toward the fact (which will be verified in a
few weeks) that the c-sh-wx genes are arranged [diagram]. I hope Beadle will be able to find on which side of the spindle
fiber region the different genes are.
Harriet tells me that Beadle has been finding many knobs in teosinte: I saw many in his material last spring -- 2 on a chromosome,
etc. In fact, I believe the reason for the appearance of longer chromosomes in teosinte as compared with maize may be due
to the added amount the knobs give to the metaphase chromosome. I feel convinced that such is the case with the satellite
Will let you know whether the 3rd smallest (number 8) comes thru in my other stock. Do you want me to send you some stock?
I will let you know how it comes in a few weeks.
[END PAGE ONE]
[BEGIN PAGE TWO]
Trisomic synapsis is interesting. In the early stages it looks as if Newton and Darlington were right. In many cases it was
obvious that only 2 chromosomes synapse at any one place. Change of partner looks like -- [diagram] I have seen some nice
cases. I don't know whether 3 chromosomes lie side-by-side thru accident or whether it amounts to 3 chrs. synapsing. I
think it is accidental, however and that synapsis is 2-by-2. In some cases one of the 3 chromosomes was entirely free in the
early prophase. A univalent thru out probably. If synapsis is by chance (2-by-2) this might occur.
So much for the present dope -- I have been at it 2 days only, so much is inchoate. Will let you know any interesting developments,