Validation of molecularly-defined olfactory bulb projection neurons targeting anterior or posterior brain areas

To validate different projection targets of already molecularly-defined olfactory bulb projection neurons we used viral targeting specifically into anterior or posterior cortical areas, Fluorescence Activated Nuclei Sorting (FANS) to enrich for olfactory bulb projection neurons, and single-nuclei RNA sequencing (sn-RNA seq) To isolate GFP-labelled nuclei, 1 individual replicate of AON or PCx-injected mice was used. Ipsilateral and controlateral sides were minced separately and placed into two different tubes. The minced tissue was gently homogenized in Nuclei PURE Lysis Buffer and 10% Triton X-100 using an ice-cold dounce and pestle, and filtered two times through a 40 μm cell strainer on ice. After centrifuging at 500 rpm for 5 min at 4 °C, the supernatant was aspirated and gently resuspended in 500 μl of cold buffer (1x of cold Hanks' Balanced Salt Solution HBSS, 1% nuclease-free BSA, RNasin Plus and 1/2000 DRAQ5). Our study identifies molecularly distinct subtypes of mitral cells projecting to anterior or posterior olfactory cortices. we used AAV viral targeting and Fluorescence Activated Nuclei Sorting (FANS) to enrich for olfactory bulb projection neurons, and single-nuclei RNA sequencing (10x Genomics)