Fig. 1

Genomic organization of the class I OR cluster and identification of a cis-regulatory element. a Genomic region of the mouse class I OR gene cluster on chromosome 7. The vertical lines represent the positions of 158 class I OR genes (black) and 5 β-globin genes. Genes transcribed in the centromeric (Cen) to the telomeric (Tel) direction are drawn above the horizontal line; those transcribed in the telomeric to centromeric direction are drawn below. The red arrowheads depict the transcriptional orientation of β-globin genes, and a red box represents the LCR of the β-globin cluster. b Nucleotide percent identity plots of the centromeric end of the class I OR gene clusters of mouse and other mammals using VISTA. The arrowheads indicate the transcriptional orientations of β-class I OR genes (blue) and α-class I OR genes (intact genes, black; a pseudogene, gray). Highly conserved regions ( > 70% identity) in coding exons, noncoding exons and intergenic regions are shown in blue, cyan, and pink, respectively. The orange bars indicate the non-OR genes Trim21, Rrm1, and Stim1. c Deletion series of Olfr544 transgenes. The number of EGFP-positive independent founders and lines among the total analyzed is shown on the right. d Representative whole-mount images of the medial aspect of the MOE (Tg-220) and the OB of Tg mice from the deletion series. Arrowheads indicate each glomerulus. The scale bar is 500 μm