Article Figures & Data
Figures
- Figure 1.
Identification of the olfactory receptor genes in the septal organ. A, Schematic drawing of a rodent nasal septum. Arrows indicate the medial air streams (Kimbell et al., 1997). SO, Septal organ; OB, olfactory bulb; NPH, nasopharynx. B, A coronal section was hybridized with an OMP antisense RNA probe, showing the location of the septal organ. Pictures in C–I were taken approximately from the area within the rectangle. C–I, Sections were hybridized with the following antisense RNA probes: MOR256-3 (C), MOR244-3 (D), MOR0-2 (E), MOR235-1 (F), MOR122-1 (G), MOR160-5 (H), and MOR232-2 (I). Arrowheads indicate stained cells.
- Figure 2.
The septal organ expresses a subset of the olfactory receptor genes in different patterns. Sections were hybridized by FLU-labeled (green) and DIG-labeled (red) probes in double in situ hybridization. A1–A3, OMP (red, A1), MOR256-3 (green, A2), and a combined image (A3). B1–B3, OMP (green, B1), Mix8 (red, B2) of the eight genes in Category I and II and a combined image (B3). C, Summary of the stained cells by different probes, relative to OMP-positive cells. Mix5 contains the top five genes in Table 1, and Mix8 contains the top eight. Error bars represent SDs. D, The 11 genes listed in Category I–III (Table 1) account for ∼95% of the cells in the septal organ.
- Figure 3.
The major septal olfactory receptor genes fall into a few subfamilies in an unrooted phylogenetic tree of the mouse olfactory receptors. The full-length protein sequences of 893 mouse olfactory receptors (Zhang and Firestein, 2002) were aligned using web-based ClustalW, and the resulting multiple alignment was used as input for TreeExplorer to generate the tree. The major septal olfactory receptor genes are in thick and dark lines. The Class I receptors are labeled, and the remaining belong to Class II.
- Figure 4.
Potential cross-hybridization between related olfactory receptor probes. A1–A3, The section was hybridized by DIG-labeled MOR235-1 (red, A1) and FLU-labeled MOR236-1 (green, A2) probes. The two probes share 74% identity, and there was no cross-hybridization (A3). B1–B3, The section was hybridized by DIG-labeled MOR244-1 (red, B1) and FLU-labeled MOR244-2 (green, B2) probes. The two probes share 91% identity, and there was cross-hybridization (B3). Arrows mark stained cells.
- Figure 5.
A single neuron expresses only one receptor gene in the septal organ. The section was hybridized by FLU-labeled MOR256-3 (green) and DIG-labeled (red) probes containing MOR244-3, MOR0-2, MOR235-1, and MOR122-1. The entire septal organ section (A), and part of it at higher magnification (B) are shown.
- Figure 6.
The major septal receptor genes are also expressed in the MOE and concentrated in certain areas. A, Different zones (zone 1 in green and zone 4 in blue) are approximately indicated in an MOE hemisection. Pictures B–D were taken approximately from the area within the rectangle. B–D, The mid-anteroposterial MOE sections were hybridized with the following antisense RNA probes: MOR256-3 (B), MOR244-3 (C), and MOR232-2 (D). E, Most of the major septal olfactory receptor genes are also concentrated in the areas indicated by red lines within zone 4. Ecto 2, Ectoturbinate 2. F1, F2, The MOE sections were hybridized by FLU-labeled OMP (green) and DIG-labeled (red) probes containing MOR256-2, MOR244-3, MOR235-1, MOR160-2, MOR236-1, MOR244-2, MOR271-1, and MOR232-2. Two images (F1, F2) were taken in the areas indicated in E. The white lines in F2 indicate relatively “cold areas”, where fewer cells were labeled.
Tables
- Table 1.
Summary of the olfactory receptor genes expressed in the septal organ confirmed by different means
Gene name NBT—BCIP-positive cells per section (mean ± SD) Percentage in OMP-positive cells (mean ± SD) Fold-change (SO vs MOE) in genechips cDNA cloning Specific RT-PCR Category I MOR256-3 49.8 ± 0.9%; n = 12 31.1 + Category II MOR244-3 35.7 ± 12.1; n = 18 12.2 ± 0.8; n = 10 26.3 + MOR0-2a 23.9 ± 8.8; n = 16 8.0 7.2 + MOR235-1 19.4 ± 8.6; n = 17 6.5 3.2 ++++ MOR160-2 14.2 ± 4.1; n = 5 4.7 - +++ MOR122-1 10.9 ± 4.6; n = 17 3.7 - ++++ MOR160-5 8.6 ± 7.5; n = 18 2.9 2.9 + MOR236-1 7.8 ± 3.3; n = 12 2.6 - ++ Category III MOR244-2 3.8 ± 1.8; n = 9 1.3 1.1 ++ MOR271-1 1.3 ± 2.1; n = 14 0.4 1.0 +++ MOR232-2 0.7 ± 0.8; n = 10 0.2 - +++ Category IV The following antisense RNA probes stained less than one cell per section, but their existence in the septal organ was confirmed by other means: MOR40-12 and MOR31-12 by genechips (both showed 2.6-fold increment as compared to the MOE) and specific RT-PCR; MOR13-6, MOR257-1, MOR103-15, MOR171-2, MOR279-2, MOR174-13 and MOR225-2 by cDNA cloning. Category V The following sequences were encountered only in one RNA sample in cDNA cloning, but their existence was not verified by in situ hybridization. MOR3-1; MOR9-2; MOR13-4; MOR14-4; MOR24-2; MOR29-1; MOR30-3; MOR31-4; MOR33-1; MOR33-2; MOR103-16; MOR132-1; MOR135-9; MOR135-13; MOR135-19; MOR135-20; MOR160-1; MOR161-5; MOR163-1; MOR164-1; MOR164-3; MOR171-6; MOR171-22; MOR171-23; MOR171-24; MOR171-43; MOR171-44; MOR172-2; MOR174-10; MOR174-12; MOR174-13; MOR174-15P; MOR174-18; MOR179-3; MOR185-7; MOR185-8; MOR187-1; MOR187-2; MOR188-3; MOR194-1; MOR203-1; MOR204-1; MOR204-23; MOR206-3; MOR206-4; MOR206-6; MOR208-5P; MOR209-1; MOR211-1; MOR224-4; MOR225-6P; MOR225-8P; MOR231-11; MOR232-5; MOR239-5; MOR256-12; MOR257-2; MOR262-5; MOR264-4; MOR274-1; MOR276-1; MOR277-1; MOR281-1; MOR284-1. -
The “NBT-BCIP positive cells” were counted and averaged (mean ± SD) from all the septal organ sections (n) stained by each RNA probe. NBT, Nitroblue tetrazolium; BCIP, 5-bromo-4-chloro-3-indolyl phosphate. The “percentage in OMP-positive cells” for MOR256-3 and MOR244-3 was obtained from double in situ hybridization, and the rest was estimated according to the MOR244-3 data generated in the two ways (see Results). The “fold-change (SO vs MOE) in genechips” was averaged from the two experiments, and a dash indicates “not detected.” The number of the plus signs under “cDNA cloning” indicates the number of RNA samples (of four) from which each sequence was encountered.
-
↵ a MOR0-2 was previously annotated as a pseudogene MOR0-2P in GenBank (accession number AY073944). Our sequencing data indicate this gene has an intact coding region; hence we use MOR0-2 with a new accession number (AY635588).
-
MOR gene Chromosome location Accession number Probe length (bp) Closest MOR (homology to the probe) Predicted cross-hybridization Counterpart in rat accession number Chromosome location Coding region homology (%) MOR256-3 Chr17 AY073026 520 MOR256-35 (38%) None AY639023 Chr20 94 MOR244-3 Chr14 AY073295 519 MOR244-2 (25%) None XM_344332 Chr15 95 MOR0-2 Chr6 AY635588 403 MOR266-2 (26%) None AY635589 Chr4 95 MOR235-1 Chr2 AY073623 485 MOR236-1 (74%) None XM_230271 Chr3 94 MOR160-2 Chr15 AY073641 497 MOR160-5 (74%) None AY635590 Chr7 93 MOR122-1 Chr15 AY073588 512 MOR204-5 (17%) None XM_235632 Chr7 92 MOR160-5 Chr15 AY073813 522 MOR160-2 (34%) None AY635591 Chr7 93 MOR236-1 Chr2 AY073890 484 MOR235-1 (76%) None XM_345395 Chr3 92 MOR244-2 Chr14 AY073294 484 MOR244-1 (91%) MOR244-1 XM_223999 Chr15 93 MOR271-1 Chr16 AY073019 496 MOR270-1 (98%) MOR270-1 AY635592 Chr11 91 MOR232-2 Chr2 AY073107 481 MOR231-2 (22%) None XM_230268 Chr3 94 -
The “Closest MOR” members were determined by BLAT (mouse genome) and BLAST (GenBank) search using the probe sequences (supplemental material, available at www.jneurosci.org).
-
Supplemental data
Files in this Data Supplement:
