GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE306nnn/GSE306148/primaryOK200TranscriptomicsMus musculusExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE306148GEOGSEfalseFucci-G1 insertion partially disrupts Shh expressionThe Fucci mouse lines are valuable tools for tracing cell cycle stages during development and in postnatal tissues; however, the insertion loci for the transgenes remain unidentified. Here, we report the genomic insertion sites of both the Fucci-G1 and -S/G2/M transgenes, identified through whole genome sequencing. Interestingly, the Fucci-G1 transgene is located proximal to the Shh lung gut enhancer (SLGE) on chromosome 5. Homozygous Fucci-G1 embryos survive until embryonic day 18.5 (E18.5), exhibiting craniofacial and foregut-related defects, but are perinatal lethal. Expression of Shh and canonical targets are down-regulated in the pharyngeal arches of E11.5 homozygous Fucci-G1 embryos. Furthermore, in situ hybridization analysis showed diminished Shh expression in the pharyngeal ectoderm and foregut endoderm, consistent with disruptions to SLGE activity. Our results indicate that heterozygous Fucci-G1 mice are suitable for cell cycle studies; however, we caution potential genetic interference when investigating SHH-related pathways.2026/06/16GSE306148GSM9194092GSM9194081GSM9194091GSM9194080GSM9194083GSM9194082GSM9194093GSM9194090GSM9194089GSM9194078GSM9194077GSM9194088GSM9194079GSM9194085GSM9194084GSM9194087GSM9194076GSM919408634290306148Mus musculus