Transcript abundance measured for any gene on a microarray can be considered as a quantitative trait. If the transcription profile of a sufficient number of individuals from a segregating progeny is generated by microarrays, it allows mapping of genomic regions regulating variation in transcript abundance using traditional methods of QTL analysis. We generated transcript level profiles of wood forming tissue (differentiating xylem) collected from 91 individuals from a <I>E. grandis</I> x <I>E. globulus</I> F1 hybrid x <I>E. grandis</I> backcross population, using microarrays containing 2608 cDNAs. Least-square means estimates of transcript abundance were generated for each individual and cDNA, and mapped as QTLs in two single-tree linkage maps (hybrid paternal and <I>E. grandis</I> maternal) using composite interval mapping. QTLs were identified for 811 genes in the <I>Eucalyptus</I> hybrid map, displaying in most cases a simple genetic architecture, with a single QTL controlling up to 70% of the transcript level variation. A more complex genetic architecture was detected in one third of the genes, where up to five QTLs could be identified for three genes. QTL hotspots were identified in both maps, typically for genes encoding several enzymes of specific metabolic pathways, suggesting coordinated genetic regulation. Transcript level QTLs were co-localized to QTLs detected previously in this family for wood quality and growth traits and candidate genes were identified by the analysis of correlation between gene expression and phenotypic variation.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-01042004-175350 |
| Date | 08 January 2004 |
| Creators | Kirst, Matias |
| Contributors | Barry Goldfarb, Ross W. Whetten, Edward S. Buckler, Trudy F.C. Mackay, Ronald R. Sederoff |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-01042004-175350/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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