Project description:Deprivation of peripheral nerve input by cochlear removal in young mice results in dramatic neuron death in the cochlear nucleus (CN). The same manipulation in older mice does not result in significant loss. The molecular basis of this critical period of vulnerability remains largely unknown. Here we identified genes regulated at early time points after cochlear removal at ages when neurons are vulnerable (postnatal day (P)7) or invulnerable (P21) to this challenge. Afferent deprivation regulated very different sets of genes at P7 and P21. These genes showed a variety of functions at both ages, but surprisingly there was no net increase in pro-apoptotic genes at P7. A large set of upregulated immune-related genes was identified at P21. Experiment Overall Design: Mice received unilateral cochlear removals. At 6, 12, 24, and 48 hours after surgery, the CN ipsilateral and contralateral were removed, and RNA isolated from separate pools of tissue for each replicate. Deafferented CN were compared to age-matched and time-matched contralateral, control CN to identify genes regulated by cochlear removal at age P7 and P21.
Project description:Deprivation of peripheral nerve input by cochlear removal in young mice results in dramatic neuron death in the cochlear nucleus (CN). The same manipulation in older mice does not result in significant loss. The molecular basis of this critical period of vulnerability remains largely unknown. Here we identified genes regulated at early time points after cochlear removal at ages when neurons are vulnerable (postnatal day (P)7) or invulnerable (P21) to this challenge. Afferent deprivation regulated very different sets of genes at P7 and P21. These genes showed a variety of functions at both ages, but surprisingly there was no net increase in pro-apoptotic genes at P7. A large set of upregulated immune-related genes was identified at P21. Keywords: Time Course after Cochlear Removal, Age Comparison
Project description:Developmental differences in gene expression in the postnatal mouse cochlear nucleus was analyzed at two or three ages using two different array platforms, the Affymetrix Mouse 430A GeneChip or the NIA 15K mouse cDNA microarray. These ages, P7, P14, and P21 parallel a critical period of neuron survival dependent on input from the auditory nerve. Keywords: parallel sample
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other