碩士 / 東海大學 / 生命科學系 / 98 / The interrenal tissue of zebrafish is the counterpart of the mammalian adrenal cortex, and embedded at the anterior portion of head kidney in the adult. During early embryogenesis, the interrenal tissue arises as bilateral clusters of non-steroidogenic cells within pronephric primordia, and migrates out of the pronephric field at about 24.5 hpf. Meanwhile, the interrenal tissue is induced by endothelial signaling to undergo central migration and fusion to the right of the midline by 30 hpf. The mechanism that directs co-migration of the interrenal tissue and its neighboring endothelium remains unclear. An endodermless zebrafish mutant, casanova (cas), has been reported to show apparent defects in the heart, vasculature, blood and pronephric duct. Therefore, it has been postulated that the endoderm might provide signals that guide the morphogenesis of certain mesodermal tissues. We are interested to know whether the interrenal morphogenesis is defective in cas, where the endoderm development is abnormal. Our results showed that in the cas mutant and morphant, the central migration of the interrenal tissue and its associated midtrunk venous endothelium were disrupted simultaneously, while assembly of the dorsal aorta appeared normal. When we rescued the endoderm by knockdown of odd skipped related1 (osr1) expression in cas, central migration defects of interrenal and midtrunk venous endothelium were both recovered. Interestingly, a deletion of endothelium from the cas embryo led to the alleviation of interrenal migration defect. In addition, the extracellular matrix protein Fibronectin, which was defective in cas, did not seem to be required for the interrenal migration. We conclude from these data that the endoderm might pattern the morphology of endothelium, which in turn would attract interrenal cells and guide their migration to the midline. We will further study how tissue architecture around the interrenal tissue was altered in the endodermless or endothelium-free mutant, in order for us to understand the cellular mechanism that guides the interrenal migration.
| Identifer | oai:union.ndltd.org:TW/098THU00112010 |
| Date | January 2010 |
| Creators | Hsiao-Chu Hsu, 徐筱筑 |
| Contributors | Yi-Wen Liu, 劉薏雯 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 63 |
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