El-Magd MA, Ayman A. Saleh, Reda M. Abd El-Aziz, Mohammed F. Salama
الملخص العربي
Expression of chick early B cell factor 1-3 (cEbf1-3)
genes in regions of high retinoic acid (RA) activity, such as
somites and pharyngeal arches (PAs), and regulation of other
EBF members by RA raise the possibility that the internal cue
RA may regulate cEbf1-3 expression in these tissues. To check
this possibility, RA gain and loss of function experiments were
conducted. Ectopic expression of RA led to up-regulation of
cEbf2, 3 but did not change cEbf1 expression in somites.
Expectedly, inhibition of RA by disulfiram resulted in downregulation
of cEbf2, 3, but did not change cEbf1 expression in
somites. The same RA gain and loss of function experiments
did not change cEbf1-3 expression in PAs. However, ectopic
expression of RA in the cranial neural tube before migration of
neural crest cells downregulated cEbf1, 3 and up-regulated
cEbf2 expression in the PAs. The same experiment, but with
application of disulfiram, resulted in downregulation of cEbf2,
but did not alter the expression of the other two genes. We
conclude that the three cEbf genes act differently in response to
RA signals in somitic mesoderm. cEbf1 may be not RA
dependant in somites; however, the other two cEbf genes
positively respond to RA signalling in somites. Additionally,
only the migratory cEbf-expressing cells into the PAs are
affected by RA signals.
محمد رزق ابو المجد الغنام | Mohammed Rizk Abu El-Magd El-Ghannam | 8902