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

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5.2 MALFoRMAT I 0NS .P¡OpUCEp BY \ir l ND0Vill NG .
Analysîs of the nalformatlons produced by the windowing technic
required culture of treated embryos to the perìod when the external embryonic
form had been establ lshed. By this time, however, the mortal ity among
developing embryos was substantial, and many of the dead embryos were so
necrotlc that full examìnatlon was impossible.
For thîs reason, embryos wlndowed at 26 hours and developing to
5 days or 12 days were compared to the 72 hour (3 days) group in Section
5.1.
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Rs ihis was an analysis of the external malformatîons produced by
the wlndowing technlc, it includetl only well-preserved experimental embryos
showing con'tinued dèvelopment after windowìng. Table 9
and Fi9.11
show the external defects recorded at 3,5 and 12 days of incubation,
expressed âs percentages of those developlng embryos which could be examined
fully. These values do not represent the ou..ull malformadion rates in
treated embryos but, rather, reflect the changing pattern of malformations
wi th prolonged g rowth .
ln Fi9. Il the most striking finding is the uniformly high incidence
of open cord defects in all three groups.
0f the non-neural ma I fo rma t,îions , def ects învolving the face-and beak,
trunk, rump and ta¡1, anterior body wall,and lower I imbs appear with íncreasing
frequency at progressively later stages of development.