Project description:Background: The goal of this study was to determine the transcriptional consequences of norepinephrine transporter (NET) gene deletion in noradrenergic neuron differentiation. The norepinephrine transporter (NET) is the target of powerful mind-altering substances, such as tricyclic antidepressants and the drug of abuse, cocaine. NET function in adult noradrenergic neurons of the peripheral and central nervous systems is that of a scavenger that internalizes norepinephrine from the synaptic cleft. By contrast, norepinephrine (NE) transport has a different role in embryogenesis. It promotes differentiation of neural crest cells and locus ceruleus progenitors into noradrenergic neurons, whereas NET inhibitors, such as the tricyclic antidepressant desipramine and the drug of abuse, cocaine, inhibit noradrenergic differentiation. While NET structure und regulation of NET function is well described, little is known about downstream targets of NE transport. Results: We have determined by long serial analysis of gene expression (LongSAGE) the gene expression profiles of in vitro differentiating wild type and norepinephrine transporter-deficient (NETKO) neural crest derivatives. Comparison analyses with the wild type library (GSM 105765) have identified a number of important differentially expressed genes, including genes relevant to noradrenergic neuron differentiation and to the phenotype of NETKO mice. Furthermore we have identified novel differentially expressed genes. Conclusions: Loss of NET function during embryonic development deregulates signaling pathways that are critically involved in neural crest formation and noradrenergic neuron differentiation. The library was constructed from total RNA of 60 neural crest culture at culture day 7. The neural tubes were dissected from E9.5 embryos that lack the norepinephrine transporter gene.
Project description:Background: The goal of this study was to determine the transcriptional consequences of norepinephrine transporter (NET) gene deletion in noradrenergic neuron differentiation. The norepinephrine transporter (NET) is the target of powerful mind-altering substances, such as tricyclic antidepressants and the drug of abuse, cocaine. NET function in adult noradrenergic neurons of the peripheral and central nervous systems is that of a scavenger that internalizes norepinephrine from the synaptic cleft. By contrast, norepinephrine (NE) transport has a different role in embryogenesis. It promotes differentiation of neural crest cells and locus ceruleus progenitors into noradrenergic neurons, whereas NET inhibitors, such as the tricyclic antidepressant desipramine and the drug of abuse, cocaine, inhibit noradrenergic differentiation. While NET structure und regulation of NET function is well described, little is known about downstream targets of NE transport. Results: We have determined by long serial analysis of gene expression (LongSAGE) the gene expression profiles of in vitro differentiating wild type and norepinephrine transporter-deficient (NETKO) neural crest derivatives. Comparison analyses with the wild type library (GSM 105765) have identified a number of important differentially expressed genes, including genes relevant to noradrenergic neuron differentiation and to the phenotype of NETKO mice. Furthermore we have identified novel differentially expressed genes. Conclusions: Loss of NET function during embryonic development deregulates signaling pathways that are critically involved in neural crest formation and noradrenergic neuron differentiation.
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in E9.0 mouse embryos.
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in anterior and posterior cranial regions of E9.25 mouse embryos.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.