C. Hearn et D. Newgreen, Lumbo-sacral neural crest contributes to the avian enteric nervous system independently of vagal neural crest, DEV DYNAM, 218(3), 2000, pp. 525-530
Most of the avian enteric nervous system is derived from the vagal neural c
rest, but a minority of the neural cells in the hindgut, and to an even les
ser extent in the midgut, are of lumbo-sacral crest origin, Since the lumbo
-sacral contribution was not detected or deemed negligible in the absence o
f vagal cells, it had been hypothesised that lumbo-sacral neural crest cell
s require vagal crest cells to contribute to the enteric nervous system. In
contrast, zonal aganglionosis, a rare congenital human bower disease led t
o the opposite suggestion, that lumbo-sacral cells could compensate for the
absence of vagal cells to construct a complete enteric nervous system. To
test these notions, we combined E4 chick midgut and hindgut, isolated prior
to arrival of neural precursors, with E1.7 chick vagal and/or E2.7 quail l
umbo-sacral neural tube as crest donors, and grafted these to the chorio-al
lantoic membrane of E9 chick hosts. Double and triple immune-labelling for
quail cells (QCPNA), neural crest cells (HNK-1), neurons and neurites (neur
ofilament) and glial cells (GFAP) indicated that vagal crest cells produced
neurons and glia in large ganglia throughout the entire intestinal tissues
. Lumbo-sacral crest contributed small numbers of neurons and glial cells i
n the presence or absence of vagal cells, chiefly in colorectum, but not in
nearby small intestinal tissue, Thus for production of enteric neural cell
s the avian lumbo-sacral neural crest neither requires the vagal neural cre
st, nor significantly compensates for its lack. However, enteric neurogenes
is of lumbo-sacral cells requires the hindgut microenvironment, whereas tha
t of vagal cells is not restricted to a particular intestinal region. (C) 2
000 Wiley-Liss, Inc.