Pax 7 Gene for Spinal Cord - Brain and Neural Crest - myassignmenthelp

Question: Discuss about thePax 7 Gene for Spinal Cord, Brain and Neural Crest. Answer: Introduction The development of skeletal muscle, spinal cord, brain and neural crest is largely influenced ny Pax 7 gene. The entire brain consists of Pax 7 gene transcripts in a subset of cells at the initial stage. However, in the later life, the expression of the gene is restricted only to mesencephalon. Pax 7 gene is a sequence-specific DNA binding factor, the functional role played by the gene during development is mediated by the selection of the target gene (Xu et al., 2013). Describing the gene Pax7 gene is one of the significant developmental control genes and is a member of thepaired box of transcription factors. The major functions of the Pax7 gene is the contribution of the gene in the neural development in order to establish dorsal polarity of the neural tube. Additionally, the Pax7 gene helps in continuous refinement of its expression to the brain nuclei thereby, ensuring regional identity. Pax7 gene is plays a significant role in human diseases and cancers. Homology and encode protein The Pax7 gene is highly conserved within a paired box sequence and encodes for a paired DNA binding domain. This suggest that the Pax7 gene plays a significant role in the transcriptional factor by influencing the binding and regulating downstream target genes. The Pax7 gene is categorized by the presences of 128 amino acid DNA with paired binding DNA with two subunits. The two subunits are the N terminal (PAI) domain and the C terminal (RED) domain. Mechanism action of protein One of the significant function of the Pax7 gene is its function in the early neural development in order to establish dorsal polarity of the neural tube along with continuous refinement of the expression. The continuous refinement of the expression helps the Pax7 gene to express regional identity to the brain nuclei, particularly in the superior colliculus. The Pax7 gene also contributes in the development and regeneration of the skeletal muscles. Pax7 are also helps in building the muscle satellite cells along with regulating the proliferation of the satellite cells thereby, regulating the entry into the myogenic differentiation program (Gunther et al., 2013). Pax7 expressional action Pax7 gene is generally expressed during the development of the brain along with the ectodermal cells including the nasal olfactory epithelim and neural tube. The expression of Pax7 gene is also noticed at the lining between the mid brain and the hind brain along with regions close to the mesencephalon and pons. Overlapping of the Pax7 gene and the Pax3 gene is noticed in the neural crest , CNS and the somites. In the initial stages of the embryonic development, the expression of the Pax7 gene is noticed in the neural folds that later develops into neural tube. The dorsal sensory neurons are developed from dorsal neural tube. Pax7 gene has huge influence in activating the target genes that regulates the entry of the satellite cells in the myogenic development program along with determining the survival of the cells. The satellite cells develop into stem cells that regulate the maintenance and repair of the skeletal muscles. The expression of the paired box transcription factor of Pax7 gene influences the satellite cells (Wen et al., 2012). Mutation of Pax7 gene and evidence The activation of some genes are dependent when some of the DNA segments of one chromosome are switched with another. This process generally occurs during mitosis process. For example, during cancer, a small portion of chromosome 2 or chromosome 1 is switched with chromosome 13. As a result, the Pax3 gene moves next to the gene named FOXO1. During the embryonic development, Pax7 genes plays a significant role is promoting the growth of the cells and embryonic tissue. However, after the completion of the process, the genes are automatically deactivated. FOXO1 gene helps in activating the functions of other genes. Therefore, simultaneous movement helps in activating the Pax gene thereby, resulting in the formation of tumour and a functional transcriptional activator. The striated muscle consists of a highly malignant tumour, Rhabdomyosarcoma, that is formed from the primitive mesenchymal cells along with differentiation wthin the rhabdomyoblastic lines. Rhabdomyosarcoma is mostly found in children and is one of the soft tissue cancers. Rhabdomyosarcoma develops in four forms: botryoidal rhabdomyosarcomas , alveolar, embryonal and pleomorphic. In the case of paediatric cancer alveolar rhabdomyosarcoma, the Pax7 gene fuses with FKHR by the variant (1:13) (p36:q14). Therefore, it can be said that the development of paediatric cancer alveolar rhabdomyosarcoma is due to the rearrangement of Pax7 gene on chromosome and fusion to FKHR on chromosome 13 (Missiaglia et al., 2012). References Gnther, S., Kim, J., Kostin, S., Lepper, C., Fan, C. M., Braun, T. (2013). Myf5-positive satellite cells contribute to Pax7-dependent long-term maintenance of adult muscle stem cells. Cell stem cell, 13(5), 590-601. Missiaglia, E., Williamson, D., Chisholm, J., Wirapati, P., Pierron, G., Petel, F., ... Delattre, O. (2012). PAX3/FOXO1 fusion gene status is the key prognostic molecular marker in rhabdomyosarcoma and significantly improves current risk stratification. Journal of Clinical Oncology, 30(14), 1670-1677. Wen, Y., Bi, P., Liu, W., Asakura, A., Keller, C., Kuang, S. (2012). Constitutive Notch activation upregulates Pax7 and promotes the self-renewal of skeletal muscle satellite cells. Molecular and cellular biology, 32(12), 2300-2311. Xu, Y., Liu, J., Lan, X., Zhang, Y., Lei, C., Zhang, C., ... Chen, H. (2013). Consistent effects of single and combined SNP (s) within bovine paired box 7 gene (Pax7) on growth traits. Journal of genetics, 92(2), 53-57.