Interpreted
by DHH Feb 2007
Durbin
studied about 19 early embryos in serial thin sections, most often covering the
tail region and posterior ventral cord, but sometimes extending further forward
(see his thesis on published on WormAtlas at http://www.wormatlas.org/durbinv1.2/toc.html
). His fixation technique is discussed in detail there.
His
most complete wild type embryo series were RDA, RDB, RDC, and RDD (these
animals are often cited in his thesis as A, B, C, D, etc.; ages were 480-550
min). He also did a series of laser
ablated embryos, where one or rarely two single pioneer neurons were removed
prior to axon outgrowth, allowed to develop to about 500-550 min, and then
fixed and studied in serial sections by TEM.
These series are named on WormImage according to the ablated cell.
To
conserve materials, most of the images were originally printed in sets of 2, so
that two consecutive sections lay on a single page, with section numbers marked
on the corner in light blue wax pencil.
We have scanned the prints and left the images in duos – thus most
images will show two thin sections, side by side. As in most WormImage photo sets, prints are
oriented to show ventral at the bottom.
In
many EM images, individual neuron processes or cell bodies were marked by their complete cell names. More often, a shorthand code was used to
conserve space. A few codes are
ambiguous, or may have been used differently in certain contexts. Thus cells were often marked in blue marker
as:
A = DVA
B = rectal epithelial cell (DVB precursor)
C = DVC
F = rectal epithelial cell
G = AVG
K = rectal epithelial cell (DVB precursor)
K’ = rectal epithelial cell
T = PVT
U = rectal epithelial cell
Y = PDA precursor
AL = PHAL
AR = PHAR
BL = PHBL
BR = PHBR
PL = PVPL
PR = PVPR
QL = PVQL
QR = PVQR
VA = DVA process
VL = rectal valve or hyp7 precursor?
VC = DVC process, or rectal valve, or hyp7
precursor?
A6 = DA6
A7 = DA7
A8 = DA8
A9 = DA9
B6 = DB6
B7 = DB7
D4 = DD4
D5 = DD5
D6 = DD6
epD = rectD, rectal gland cell
epVL = rectVL, rectal gland cell
Rarely, single axons are numbered (1,2,3,4…),
and we have not tried to identify these further.