Durbin Embryo Color Codes

 

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.