Project description:To elucidate molecular networks regulating important aspects of parasympathetic neuronal development, a genome-wide expression analysis was performed during multiple stages of avian ciliary ganglion (CG) development. The transcriptome data showed a well-defined sequence of events, starting from neuronal migration via neuronal fate cell determination, synaptic transmission, regulation of synaptic plasticity to growth factor associated signaling. Focusing on cell death-related changes in the transcriptome, we could characterize a series of events that starts with the activation of neuronal apoptotic processes at E7 via the cell death execution phase at E8 and E9 and ends with apoptotic cell clearance at E14. Moreover, we detected a transient up-regulation of the transcription factors TP53 and RARB that was linked to cell death. The expression of BID, a p53 target, was also found to be dynamically regulated. Using a virus-based RNAi knockdown approach, BID expression was shown to be crucial for the execution of ontogenetic programmed cell death (PCD). Therefore, this study for the first time provides a comprehensive analysis of CG neuron development on the transcriptome level, revealing a temporally well-controlled expression of genes regulating ontogenetic PCD, with BID being one of the most dynamically regulated genes during the cell death phase. The effect of BID silencing in vivo suggests an essential role of BID expression in neuronal development.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
Project description:The trigeminal ganglion is a critical structure in the peripheral nervous system, responsible for transmitting sensations of touch, pain, and temperature from craniofacial regions to the brain. Trigeminal ganglion development depends upon intrinsic cellular programming as well as extrinsic signals exchanged by diverse cell populations. With its complex anatomy and dual cellular origin from cranial placodes and neural crest cells, the trigeminal ganglion offers a rich context for examining diverse biological processes, including cell migration, fate determination, adhesion, and axon guidance. Avian models have, so far, enabled key insights into craniofacial and peripheral nervous system development. Yet, the molecular mechanisms driving trigeminal ganglion formation and subsequent nerve growth remain elusive. In this study, we performed RNA-sequencing at multiple stages of chick trigeminal ganglion development and generated a novel transcriptomic dataset that has been curated to illustrate temporally dynamic gene expression patterns. This publicly available resource identifies major pathways involved in trigeminal gangliogenesis, particularly with respect to the condensation and maturation of placode-derived neurons, thus inviting new lines of research into the essential processes governing trigeminal ganglion development.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola. To identify genes that are co-expressed with GATA3 at the striola reversal zone, we compared gene expression in cells micro-dissected from the sensory epithelia of the chick utricle striola to cells from the surrounding extra-striola. There are 2 biological samples and experiments include technical replicates as well as dye-switches for a total of 8 microarrays.
Project description:H5N1 subtype highly pathogenic avian influenza virus has been spreading to Asia, Eurasia and African coutries. An original or six of recombinant H5N1 subtype influenza viruses with varying survivability were infected to chickens for elucidating genes correlated with pathogenicity.
Project description:A minor population of M cells within the follicle-associated epithelium (FAE) of intestinal Peyer’s patches (PP) serves as a major portal for entry of exogenous antigens. Characterization of the mammalian M cells, including identification of M-cell surface molecules used for bacterial uptake, has been hampered by their relative rarity. In contrast, M cells constitute virtually all of the FAE cells in the avian bursa of Fabricius. We therefore performed comparative gene expression profiling of chicken and murine FAE to identify commonly expressed genes by M cells in both species. The comprehensive transcriptome analysis revealed that 28 genes were commonly up-regulated in FAE from both species. In situ hybridization (ISH) revealed that annexin A10 (Anxa10) mRNA was scattered in FAE, and co-localized with Ulex europaeus agglutinin-1(UEA-1) that binds to M cells. Whole-mount immunostaining also revealed that cellular prion protein (PrPC) was expressed on the luminal side of the apical plasma membrane of M cells, and co-localized with grycoprotein2 (GP2) that recognizes only M cells in murine PP. Taken together, we found new M-cell-specific molecules by using comprehensive transcriptome analysis. These molecules conserved in M cells from both species might play critical roles in M-cell function and/or differentiation.
Project description:H5N1 subtype highly pathogenic avian influenza virus has been spreading to Asia, Eurasia and African coutries. An original or six of recombinant H5N1 subtype influenza viruses with varying survivability were infected to chickens for elucidating genes correlated with pathogenicity. Two chickens were infected with each 10^6EID50/ head virus intranasally, and their lung was collected from infected chicken at 24 hours after infection.