Project description:We report genome-wide gene expression changes in olfactory bulb cells, in the context of low, wild-type or high levels of local CRH signaling by local interneurons onto adult-born CRHR1+ granule neurons. To test the gene expression changes associated with altered local CRH signaling, we utilize the following animal models: CRHR1-/- mice whose bulbs were infected with a control AAV-flex-EGFP virus = low local CRH signaling, CRHR1-Cre mice whose bulbs were infected with AAV-flex-EGFP = pseudo-wild-type local CRH signaling, and CRHR1-Cre mice whose bulbs were infected with AAV-flex-(CA)CRHR1, which is a constitutively active variant of CRHR1 = high local CRH signaling. We find that, in response to changes in local CRH signaling in the bulb, the largest ontological category of transcription changes in the bulb that occurs reciprocally between low and high levels of CRH signaling are gene regulatory factors. To test the contributions of one of these factors, POU6f1, we perform loss- and gain-of-function analysis. We show that CRHR1 activation results in transcriptional activation of POU6f1 and that POU6f1 in turn influences synaptogenesis and dendritic patterning of adult-born neurons and olfactory circuit behavior.
Project description:The goal of this study is to profile NFIA DNA-binding properties in the adult mouse brain. We performed chromatin immunoprecipitation of NFIA in the hippocampus and olfactory bulb of wildtype mice, and samples were subjected to sequencing. We find that NFIA preferentially binds DNA in the hippocampus but not in the olfactory bulb as evidenced by the distinct lack of NFIA binding peaks in the olfactory bulb. Mass spectrometry results suggested that NFIA has a significantly higher binding affinity for NFIB in the olfactory bulb, potentially blocking NFIA’s ability to bind DNA. Virally induced siRNAs against NFIB or scramble were injected into the olfactory bulb of adult wildtype mice to knock down NFIB. We performed chromatin immunoprecipitation of NFIA in the olfactory bulb injected with siRNA-NFIB or siRNA-scramble. Subsequent sequencing revealed an increase of NFIA binding in the olfactory bulb upon the depletion of NFIB as compared to the siRNA-scramble and wildtype controls.
Project description:Emx2 is a homeobox transcription factor that plays a critical role in development. Olfactory sensory neuron axons from Emx2 knockout mice fail to innervate their target tissue, the olfactory bulb. Homeobox transcription factors may also play an important role in olfactory receptor expression. We used microarrays to analyze differences in mRNA abundance in the olfactory epithelium of Emx2 wildtype and knockout embryonic day 18.5 mice. Keywords: Knockout-Wildtype comparision
Project description:We conducted RNA-Seq and in situ hybridization to identify transcriptional profile changes in the Sp8/Sp9-DCKO olfactory bulb. Simultaneously, we did ChIP-Seq with homemade Sp9 antibody to identify Sp9 binding motifs and which changed genes might be the direct targets of transcription factor Sp9. We found that Sp9 directly binded to key genes which are required for olfactory bulb development. Transcription factors Sp8 and Sp9 belong to the same transcription factor family, so we think Sp8 and Sp9 have very similar binding sites of transcriptional regulation.
Project description:Purpose: The goal of this study is to investigate the effects of fine particulate matter (PM2.5) exposure on mouse olfactory bulb using next generation sequencing (NGS). Methods: After 28 days of 3 mg/kg/3 day and 10 mg/kg/3 day PM2.5 exposure, olfactory bulb mRNA profiles of 8-week-old wild-type (WT) male C57BL/6 mice were generated by deep sequencing, in 3-4 repeats, using Illumina NovaSeq 6000. For each sample, clean reads were obtained that mapped to mm10 using HISAT2 (hierarchical indexing for spliced alignment of transcripts) v2.0.477. Results: Our study revealed that PM2.5 treatment caused significant effects on the gene expression profilling of mouse olfactory bulb. Overall, the sequencing identified 34,745 transcripts, and two kinds of treatments obtained 60 and 138 differently expressed genes (DEGs) respectively, with a criteria of fold change >2 and q-value <0.5. Most biological events that DEGs involved were inflammation relevant. Conclusions: Our study revealed that PM2.5 treatment caused significant effects on the gene expression profiling of mouse olfactory bulb.