Extended Data Fig. 1: Ventilatory responses to hypoxia and genotyping in wild-type and Olfr78^−/− mice.

a, Plethysmographic recordings (breathing frequency as a measure of time) of the ventilatory response to hypoxia (10% O₂). Each data point represents the mean ± s.e.m. of the values for control mice (n = 10; 7 wild-type and 3 heterozygous mice pooled together) and Olfr78^−/− mice (n = 9) of the FRA colony. The grey-shaded area indicates the first five consecutive measurements after the transition to hypoxia used for quantification (see Supplementary Information). b, Breathing frequency in normoxia (basal) and during exposure to hypoxia (10% O₂) of control FRA mice (n = 10, 7 wild-type and 3 heterozygous mice) and Olfr78^−/− FRA mice (n = 9). Data are mean ± s.e.m. Statistically significant differences compared to basal values are indicated; *P < 0.001. c, Schematic of the wild-type and gene-targeted Olfr78 alleles. Olfr78, intronless coding region of Olfr78; GFP, green-fluorescent protein; IRES, internal ribosome entry site; taulacZ, fusion of bovine tau with β-galactosidase. The arrows indicate the position and orientation of PCR primers used for genotyping. d, Genotyping of genomic tail DNA of wild-type (Olfr78^+/+) and homozygous (Olfr78^−/−) mice by PCR. The PCR primer pair ‘CONTROL’ amplifies the wild-type Olfr78 allele; the PCR primer pair ‘GFP’ amplifies internal GFP sequences; and the PCR primer pair ‘MUT’ amplifies the gene-targeted Olfr78 allele.