caa a22 4500 477095801 CHVBK 20180405111527.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF00196311 doi (NATIONALLICENCE)springer-10.1007/BF00196311 Expression of Fǵf-3 in relation to hindbrain segmentation, otic pit position and pharyngeal arch morphology in normal and retinoic acid-exposed mouse embryos [Elektronische Daten] [Radma Mahmood, Ivor Mason, Gillian Morriss-Kay] The gene Fgf-3 is expressed in rhombomeres 5 and 6 of the hindbrain and has been functionally implicated in otic development. We describe new sites of expression of this gene in mouse embryos in the forebrain, the midbrain-hindbrain junction region, rhombomere boundaries, a cranial surface ectodermal domain that includes the otic placode, and in the most recently formed somite. In the early hindbrain, high levels of Fgf-3 transcripts are present in rhombomere 4. The surface ectodermal domain at first (day 81/2) extends laterally from rhombomeres 4 and 5 (prorhombomere B), in which neuroepithelial levels of expression are highest, to the second pharyngeal arch ventrally; at day 9, when the region of highest level of neuroepithelial Fgf-3 expression is in rhombomeres 5 and 6, the dorsal origin of the surface ectodermal domain is also at this level, extending obliquely to the otic placode and the second arch. The initially high level of Fgf-3 transcripts in the otic placode is downregulated as the placode invaginates to form the otic pit. Fgf-3 is a good marker for the epithelium of pharyngeal arches 2 and 3, and our in situ hybridization results confirm the dual identity of the apparently fused first and second arches in some retinoic acid-exposed embryos, and the fusion of the first arch with the maxillary region in others. Correlation between Fgf-3 expression and morphological pattern in craniofacial tissues of normal and retinoic acid-exposed embryos indicates that prorhombomere B, the second arch and the otic ectoderm represent a cranial segment whose structural integrity is maintained when hindbrain morphology and pharyngeal arch morphology are altered. Comparison of normal Fgf-3 expression domains with those of Fgf-4 and with the phenotype of Fgf-3-deficient mutant embryos suggests that there is some functional redundancy between Fgf-3 and Fgf-4 in otic induction and second arch development. Springer-Verlag, 1996 Fibroblast growth factor nationallicence Tretinoin nationallicence Rhombencephalon nationallicence Pharyngeal arches nationallicence Developmental biology nationallicence Mahmood Radma Department of Human Anatomy, South Parks Road, 0X1 3QX, Oxford, UK aut Mason Ivor MRC Brain Development Programme, Division of Anatomy and Cell Biology, UMDS Guy's and St Thomas' Hospitals, SE1 9RT, London, UK aut Morriss-Kay Gillian Department of Human Anatomy, South Parks Road, 0X1 3QX, Oxford, UK aut Anatomy and Embryology Springer-Verlag 194/1(1996-07-01), 13-22 0340-2061 194:1<13 1996 194 429 https://doi.org/10.1007/BF00196311 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00196311 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mahmood Radma Department of Human Anatomy, South Parks Road, 0X1 3QX, Oxford, UK aut NATIONALLICENCE 700 1- Mason Ivor MRC Brain Development Programme, Division of Anatomy and Cell Biology, UMDS Guy's and St Thomas' Hospitals, SE1 9RT, London, UK aut NATIONALLICENCE 700 1- Morriss-Kay Gillian Department of Human Anatomy, South Parks Road, 0X1 3QX, Oxford, UK aut NATIONALLICENCE 773 0- Anatomy and Embryology Springer-Verlag 194/1(1996-07-01), 13-22 0340-2061 194:1<13 1996 194 429 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer