1996 Fiscal Year Final Research Report Summary
Interrelationships between neural crest cells and HoxB genes in the morphogenesis of pharyngeal arches
| Project/Area Number |
07838031
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 時限 |
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| Research Field |
咀嚼
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| Research Institution | Kagoshima University |
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Principal Investigator |
YASUI Kinya Dental School Kagoshima University Research Associate, 歯学部, 助手 (70191111)
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| Co-Investigator(Kenkyū-buntansha) |
UEMURA Masanori Dental School Kagoshima University Professor, 歯学部, 教授 (00034215)
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| Project Period (FY) |
1995 – 1996
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| Keywords | house shrew / whole embryo culture / pharyngeal arches / trigeminal nerve / Smtwist |
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| Research Abstract |
In this research project, we subjected to establish techniques to induce malformations of the pharyngeal arches in house shrew embryos using whole-embryo culture system and to reveal cell behavior, especially neural crest cells during the morphogenesis of pharyngeal metamerism.
Whole-embryo culture was performed changing the conditions of medium and supplying gas. When the culture was started from embryos with 1-5 somites, the best result was obtained in the following conditions. Culture medium was freshly prepared pure rat serum. The first gas flow was with 20% O_2 (50ml/min) balanced with CO_2 and 5% N_2 until 0.00 am and then changed to 60% O_2 (25-30 ml/min). It was kept for 12h, and changed gas flow to 50ml/min. The gas flow was further changed to 75ml/min at next 12h later.
The malformation of pharyngeal arches were induced with all-trans retinoic acid (RA) but not with Fertilysin (N,N'-Octamethylene-bis-2,2-dichloroacetamide). RA treatment showed dose-dependent and developmental stage-dependent effects. When RA was treated at 60ng/ml for embryos with 4-6 somites, it induced the malformation of the 1st and 2nd pharyngeal arches and the fusion of them. Similar results were obtained by the operation of scratch at the presumptive 1st-2nd pharyngeal arch region of embryos heving 4-6 somites with fine tungsten needle.
Until now, house shrew's orthologues of HoxB genes were not cloned but twist orthologue, Smtwist has been cloned from a cDNA library. We are constructing new cDNA library from house shrew embryos and preparing the analysis of Smtwist expression patterns in normal and treated embryos.
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