碩士 / 國立彰化師範大學 / 生物學系 / 97 / Crustacean hyperglycemic hormone (Crustacean hyperglycemic hormone1, CHH1) is a neurohormone originally identified in the X-organ sinus gland (XO-SG) of the eyestalk ganglia. According to the combined data from our previous and this studies, at least six CHH transcripts were present in the crayfish (Procambarus clarkii) : CHH1, CHH1-L (CHH1- like), t-CHH1 (truncated-CHH1), CHH2, CHH2-L (CHH2- like), t-CHH2 (truncated-CHH2). I studied the structural organization of CHH1 gene and CHH2 gene. The results from genomic PCR and sequence analyses revealed a CHH1 gene that generated CHH1, CHH1-L transcripts, and CHH2 gene generated CHH2, CHH2-L, and t-CHH2 by cis- splicing. Moreover, t-CHH1 is generated by trans- splicing of CHH1gene and Hem-CHH1 Untranslated region Gene (HUG gene). CHH2-L transcripts were widely expressed in many tissue (hemocyte, eyestalk ganglia, cerebral ganglia, circum-oesophageal nerve, thoracic ganglia, abdominal ganglia, gut, heart, and muscle), but CHH2 transcripts are only detected in eyestalks. However, except CHH1, CHH1-L, CHH2 peptides, which have been purified from tissues by another study of our lab, the existence of other CHH peptides (CHH2-L, t-CHH1, and t-CHH2) have not been validated. CHH2, CHH2-L, t-CHH1, and t-CHH2 transcripts contain destabilizing elements (i. e., AU rich elements) in 3’UTR, which presumably increase their degradation rates. Moreover, characteristics of the sequence adjacent to the initiator codon of these CHH transcripts are not typical of Kozak’s rule, implying CHHs are translated at very low levels or not at all. Efforts attempting to confirm if any the CHH transcript RNA molecules might act as microRNA precursor do not resulted in positive data. The combined results not only show that the unique CHH variants to the existing repertoire of CHH molecular polymorphism, but also speculate these that CHHs may have regulatory functions differ from CHH1.
| Identifer | oai:union.ndltd.org:TW/097NCUE5112010 |
| Date | January 2009 |
| Creators | 宮珮真 |
| Contributors | 李奇英 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 119 |
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