Figure 7. Jagged1 expression is not altered in Sfswap^Tg/Tg ears but its downstream target Hey1 is reduced at E10.5.

(A): Cochleas from E13.5 Sfswap^Tg/Tg and wild-type mice co-stained with antibodies to p27^kip1 (green) to reveal the prosensory domain and Jag1 (red) to show its expression in the adjacent Kölliker's organ. No significant difference is seen in Jag1 expression in the mutant cochlea. (B): Whole mount in situ hybridization of E10.5 Sfswap^Tg/Tg and wild-type mice reveals no significant change in Jag1 expression, but a significant down-regulation of its candidate downstream target, Hey1 (C). Otocysts are denoted with white arrow. (D): cDNAs from E15.5 Sfswap^Tg/Tg and wild-type inner ears were examined for splicing differences in Notch pathway genes by RT-PCR. No significant differences in splicing were detected in any gene except for Sfswap. The extra band in Sfswap mRNA in Sfswap^Tg/Tg corresponds to 111 bp of transgene sequence that is spliced into the Sfswap mRNA exclusively in homozygous Sfswap^Tg mice (data not shown). Levels of Neurl1 Numb mRNA were reduced, and MamlD1 expression was not detected. X refers to no cDNA controls.