碩士 / 國立海洋大學 / 水產養殖學系 / 90 / Abstract
The heart, the first functional organ in the developing embryo arises from paired regions of dorsolateral mesoderm. Most of congenital heart diseases were the defect of cell differentiation at the embryo developmental stage and these developmental defect most were appeared in the atrium and ventricle. dHAND (dextral Heart、Autonomic nervous system、Neural crest-derived cell types、Deciduum) gene is mainly expressed in the lateral plate mesoderm, right ventricle, heart tube of neural crest-divided, and aortic arch arteries. In human, mice, chicken and zebrafish (Danio rerio) which dHAND had been cloned and characterized as a basic Helix-Loop-Helix transcription factor. The N-terminal b-HLH region a dHAND gene is high conserved within those species. This transcription factor can promote the development of ventricle and aortic arch in zebrafish. The long term goal of this project is to study the molecular mechanism of dHAND on early developmental process in lower vertebrates; i.e. zebrafish. To fulfill this long term goal, a series of short term goals were developed: 1) Gene expression pattern of dHAND gene during embryonic stages, 2) The impacts of dHAND gene expression on early heart development. 3) The influence of dHAND gene on heart-vessel formation during early embryonic development. The results of whole mount in situ hybridization indicated that the dHAND gene was expressed at lateral plate mesoderm (lpm) at 12 hpf and at heart and aortic arch areas after 24hpf as well. However, the expression of dHAND gene was only detected in heart area but not in aortic arch at 72hpf. When dHAND morpholino antisense RNA was injected into the embryonic yolk, the expression of dHAND gene can not be detected at lpm in 12hpf but only a little dHAND mRNA can be detected at developmental heart region but not in aortic arch area by 24hpf. By 24hpf, the heart beating and heart formation cannot be detected in 24hpf and most of the dHAND gene knockdown embryos died at 24hpf. Microangiography data showed that aortic arch and branchial arch was absent at 48hpf on those survived injected embryos. These results subjected that dHAND antisense RNA might cause abnormal heart development in those survived individuals, Interestingly, it was found that the heart development can be restored in some dHAND gene knockdown injected embryos, but with abnormal pericardium edema. All these results indicated that dHAND play an important role in heart formation and heart-vessel development at zebrafish embryonic stage.
| Identifer | oai:union.ndltd.org:TW/090NTOU0086019 |
| Date | January 2002 |
| Creators | Chen-Hsien Yang, 楊承憲 |
| Contributors | J.K. Lu, 陸振岡 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 0 |
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