Universlty of Manitoba, ln Partîal Fulfiìlment - MSpace at the ...

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the lesions. The interpretation of these cha.nges was complicated by
the artifactual distorsion of some embryos, which was assessed by a
detaÌled tabulatîon of the appearance of each region in every embryo
(see Sect ion 6.4) .
Group I {Stajç ll0 Embryós)
a) the neural plate în two experimena"l .rb.yo, showed slight eversion
of the neural fo¡ds at the pos.terior rhomboid sinus, compared to the
elevatîon or flattening seen in control embryos.
Group ll (Staqe 11-12 Embrvos)
a) the neural plate in all experimental embryos showed some delay in
closui'e, and in one case showed defînlte eversion of neural folds at
the posteríor rhomboid sinus
b) the appearance of the overlap zone was retêrded in all experimental
emb ryos .
Group lll
(Stagg t3-16 Embryos)
a) early myeloschlsis (caudar to the somite region) consisted of wrdery
everted neural folds in continuity wittr adjacent ectoderm, lying dorsal
to more normal taîl-bud materîal
b) several embryos wìth myeloschisis when compared to their controls
showed loss of contact between protosomite mesoderm and neural tissue
c) early myelodysplasla showed narrowly everted neural tissue 'in
cont¡nuity with tail-bud material, but apparently deficient in neural
plate mater i a I
d) ectoderm wâs present over the cranial and caudal sections of myelodysplasia,
but in the exposed middle sectíon was not in such smooth
cont¡nuity wlth adjacent neural tissue as in myeloschisis