Utility of HoxB2 enhancer-mediated Cre activity for functional studies in the developing inner ear.
The rhombomere 4(r4)-restricted expression of the mouse Hoxb2 gene is regulated by a 1.4-kb enhancer-containing fragment. Here, we showthat transgenic mouse lines expressing cre driven by this fragment (B2-r4-Cre), activated the R26R Cre reporter in rhombomere 4 and the second branchial arch, the epithelium of the first branchial arch, apical ectodermal ridge of the limb buds and the tail region. Of particular interest is Cre activity in the developing inner ear. Cre activity was found in the preotic field and otic placode at E8.5 and otocyst at E9.5-E12.5, in the cochleovestibular and facio-acoustic ganglia at E10.5 and the vestibular and spiral ganglia and all the otic epithelia derived from the otocyst at E15.5 and P0. Our data suggest that the B2-r4-Cre transgenic mice provide an important tool for conditional gene manipulation and lineage tracing in the inner ear. In combination with other transgenic lines expressing cre exclusively in the otic vesicle, the relative contributions of the hindbrain, periotic mesenchyme and otic epithelium in otic development can be dissected.
Department of Biochemistry and Centre for Reproduction, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
Irene Y Y
IY
Szeto
Keith K H
KK
Leung
Mai Har
MH
Sham
Kathryn S E
KS
Cheah
D000818:Animals; D007758:Ear, Inner / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005821:Genetic Techniques; D018398:Homeodomain Proteins / Q000235:genetics*; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D007763:Lac Operon / Q000235:genetics; D008648:Mesoderm / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D012249:Rhombencephalon / Q000196:embryology / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics*; D001616:beta-Galactosidase / Q000378:metabolism
D018398:Homeodomain Proteins; C490111:Hoxb2 protein, mouse; D014157:Transcription Factors; C045073:Cre recombinase; D019426:Integrases; D001616:beta-Galactosidase