Project description:How species-specific developmental timing is controlled is largely unknown. By following human embryonic stem cell (hESC) and mouse stem cell (mESC) differentiation to motor neurons through detailed RNA-sequencing time courses, we wish to find if there is a global scaling factor between species
Project description:The motor neuron (MN)–hexamer complex consisting of LIM homeobox 3, Islet-1, and nuclear LIM interactor is a key determinant of motor neuron specification and differentiation. To gain insights into the transcriptional network in motor neuron development, we performed a genome-wide ChIP-sequencing analysis and found that the MN–hexamer directly regulates a wide array of motor neuron genes by binding to the HxRE (hexamer response element) shared among the target genes. Interestingly, STAT3-binding motif is highly enriched in the MN–hexamer–bound peaks in addition to the HxRE. We also found that a transcriptionally active form of STAT3 is expressed in embryonic motor neurons and that STAT3 associates with the MN–hexamer, enhancing the transcriptional activity of the MN–hexamer in an upstream signal-dependent manner. Correspondingly, STAT3 was needed for motor neuron differentiation in the developing spinal cord. Together, our studies uncover crucial gene regulatory mechanisms that couple MN–hexamer and STAT-activating extracellular signals to promote motor neuron differentiation in vertebrate spinal cord. To explain our experimental scheme briefly, we are interested in finding target sites for the dimer of transcription factors Isl1 and Lhx3. To mimic the biological activity of Isl1/Lhx3 dimer, we made Isl1-Lhx3 fusion and found that Isl1-Lhx3 has a potent biological activity in multiple systems (i.e. generation of ectopic motor neurons). Then we made ES cell line that induces Flag-tagged Isl1-Lhx3 expression upon Dox treatment. These *mouse* ES cells differentiate to motor neurons (iMN-ESCs) when treated with Dox following EB formation. To identify genomic binding sites of Isl1-Lhx3 (Flag-tagged), we performed ChIP with Flag antibody (pull down of Flag-Isl1-Lhx3) in ES cells treated with Dox. ChIP with Flag antibody in ES cells treated with vehicle (no Dox) was done as a negative control in parallel, and sequenced along with +Dox sample. We have done these experiments twice (two sets).
Project description:How species-specific developmental timing is controlled is largely unknown. By following human embryonic stem cell (hESC) and mouse stem cell (mESC) differentiation to motor neurons through detailed RNA-sequencing time courses, we wish to find if there is a global scaling factor between species
Project description:The motor neuron (MN)–hexamer complex consisting of LIM homeobox 3, Islet-1, and nuclear LIM interactor is a key determinant of motor neuron specification and differentiation. To gain insights into the transcriptional network in motor neuron development, we performed a genome-wide ChIP-sequencing analysis and found that the MN–hexamer directly regulates a wide array of motor neuron genes by binding to the HxRE (hexamer response element) shared among the target genes. Interestingly, STAT3-binding motif is highly enriched in the MN–hexamer–bound peaks in addition to the HxRE. We also found that a transcriptionally active form of STAT3 is expressed in embryonic motor neurons and that STAT3 associates with the MN–hexamer, enhancing the transcriptional activity of the MN–hexamer in an upstream signal-dependent manner. Correspondingly, STAT3 was needed for motor neuron differentiation in the developing spinal cord. Together, our studies uncover crucial gene regulatory mechanisms that couple MN–hexamer and STAT-activating extracellular signals to promote motor neuron differentiation in vertebrate spinal cord.
Project description:To determine what kind of genes are involved in vocal learning ability, we performed microarray experiments using 3 vocal learning species (zebra finch, budgerigar, Anna's hummingbird) and 2 non-vocal learning species(ring dive, and Japanese quail) from the bird group. All of the animals are male adults. They were isolated over night and had 1hour light exposure at morning. Birds who did not sing were used in this experiment. We used 2-3 animals each species. We used the 12th motor neuron for both vocal learners and non-vocal learners. We used the Supra Spinal motor neuron (ssp) as control area for both groups.
Project description:Mouse spinal motor neurons are specified in the embryo on embrynic day 9.5 (E9.5), but motor function doesn't fully mature till the third week of postnatal life (P14-P21) and the degenerative disease Amyotrophic Lateral Sclerosis only affects motor neurons in adulthood (age of onset differs between models). In order to better understand motor neuron maturation, we have generated a temporal map of motor neuron transcriptional states at E10.5, E13.5, P4, P13, P21, P56, 2yr. In addition we have also profiled stem cell derived motor neurons that were co-cultured with astrocytes at DIV0, DIV7, DIV28.