The genetics of cranial sensory ganglia development and evolution
<p>Vertebrates perceive the world through sensory neurons of their cranial nerves that connect primary sensory receptors to the brain. The bodies of these neurons are organized in cranial sensory ganglia (CSG) in the head. CSG are considered a vertebrate novelty and they develop from neurog...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2020
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| _version_ | 1797077571544809472 |
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| author | Papadogiannis, V |
| author2 | Shimeld, S |
| author_facet | Shimeld, S Papadogiannis, V |
| author_sort | Papadogiannis, V |
| collection | OXFORD |
| description | <p>Vertebrates perceive the world through sensory neurons of their cranial nerves that connect primary sensory receptors to the brain. The bodies of these neurons are organized in cranial sensory ganglia (CSG) in the head. CSG are considered a vertebrate novelty and they develop from neurogenic placodes and neural crest. The genetic network underlying their early development has been relatively well studied and placodal cell homologs have been suggested in other chordates. However, knowledge has been lacking on the evolution of different ganglia and their neurons. Undertaking a comparative approach, cyclostomes and tunicates are used here to look into the molecular identity and evolution of CSG sensory cells. First, conserved pan-vertebrate markers of the ganglia are identified by exploring the expression and specificity of candidate genes in lamprey embryos. Two of these marker gene families are the starting ground for a comparative investigation of sensory cell types between vertebrates and other chordates. Conserved expression and regulation of the estrogen related receptor (ERR) between lamprey and gnathostomes is presented. It is revealed that a single ERR homolog acquired a role in the development of the vestibuloacoustic ganglion in early vertebrates. Invertebrate sensory expression highlights ERR as an ancient sensory cell marker in bilaterian animals, suggesting a mode of evolution at cell type level. The Hmx homeobox gene family is then identified to ubiquitously mark all CSG and possess conserved genomic architecture across vertebrates. A unique enhancer pair is reported, derived by tandem duplication, connected to ancestral regulation of expression in the central and peripheral nervous systems. Hmx expression and function in Ciona embryos, combined with vertebrate data, provide evidence of homology between CSG and tunicate sensory neurons. Finally, a review is carried out, discussing how placodal and CSG components gradually evolved and assembled under new genomic organization and control in vertebrates.</p> |
| first_indexed | 2024-03-07T00:20:01Z |
| format | Thesis |
| id | oxford-uuid:7c3642d4-982a-424a-87af-59ff4038884c |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:20:01Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | oxford-uuid:7c3642d4-982a-424a-87af-59ff4038884c2022-03-26T20:55:37ZThe genetics of cranial sensory ganglia development and evolutionThesishttp://purl.org/coar/resource_type/c_db06uuid:7c3642d4-982a-424a-87af-59ff4038884cEnglishORA Deposit2020Papadogiannis, VShimeld, S<p>Vertebrates perceive the world through sensory neurons of their cranial nerves that connect primary sensory receptors to the brain. The bodies of these neurons are organized in cranial sensory ganglia (CSG) in the head. CSG are considered a vertebrate novelty and they develop from neurogenic placodes and neural crest. The genetic network underlying their early development has been relatively well studied and placodal cell homologs have been suggested in other chordates. However, knowledge has been lacking on the evolution of different ganglia and their neurons. Undertaking a comparative approach, cyclostomes and tunicates are used here to look into the molecular identity and evolution of CSG sensory cells. First, conserved pan-vertebrate markers of the ganglia are identified by exploring the expression and specificity of candidate genes in lamprey embryos. Two of these marker gene families are the starting ground for a comparative investigation of sensory cell types between vertebrates and other chordates. Conserved expression and regulation of the estrogen related receptor (ERR) between lamprey and gnathostomes is presented. It is revealed that a single ERR homolog acquired a role in the development of the vestibuloacoustic ganglion in early vertebrates. Invertebrate sensory expression highlights ERR as an ancient sensory cell marker in bilaterian animals, suggesting a mode of evolution at cell type level. The Hmx homeobox gene family is then identified to ubiquitously mark all CSG and possess conserved genomic architecture across vertebrates. A unique enhancer pair is reported, derived by tandem duplication, connected to ancestral regulation of expression in the central and peripheral nervous systems. Hmx expression and function in Ciona embryos, combined with vertebrate data, provide evidence of homology between CSG and tunicate sensory neurons. Finally, a review is carried out, discussing how placodal and CSG components gradually evolved and assembled under new genomic organization and control in vertebrates.</p> |
| spellingShingle | Papadogiannis, V The genetics of cranial sensory ganglia development and evolution |
| title | The genetics of cranial sensory ganglia development and evolution |
| title_full | The genetics of cranial sensory ganglia development and evolution |
| title_fullStr | The genetics of cranial sensory ganglia development and evolution |
| title_full_unstemmed | The genetics of cranial sensory ganglia development and evolution |
| title_short | The genetics of cranial sensory ganglia development and evolution |
| title_sort | genetics of cranial sensory ganglia development and evolution |
| work_keys_str_mv | AT papadogiannisv thegeneticsofcranialsensorygangliadevelopmentandevolution AT papadogiannisv geneticsofcranialsensorygangliadevelopmentandevolution |