To overcome the limitations that accompanied traditional transgenesis using pronuclear injections, multiple methods have been employed to target a single copy of a transgenic sequence to a chosen location in the genome. One of which is the introduction of a construct as a single copy, in a known orientation, upstream of the hprt (hypoxanthine phosphoribosyl transferase) gene. The present study is designed to characterize the influence this locus could impose on the expression capability of the docked sequence. / Consistent ectopic expression of reporter constructs bearing different Myelin Basic Protein (mbp) regulatory elements and docked at the hprt locus was noted in cardiomyocytes and major CNS blood vessels; two sites in which mbp is not thought to be expressed. This ectopic expression originated from endogenous hprt enhancer activity as similar mbp reporter constructs, randomly inserted, did not reproduce the same expression phenotypes. / In addition, this work also unraveled aspects of the complex nature of mbp gene regulation. The results obtained from this study reveal that reporter constructs containing mbp enhancer elements docked in hprt locus expressed ectopically in the cartilagenous cells of the vertebral bodies during the mouse mid-fetal development period. / Finally, analysis of the "enhancer trap" construct exposed additional ectopic expression in the muscles of the back and tongue uncovering further hprt enhancer activity. Surprisingly, when mbp enhancer sequences were added to the "enhancer trap" construct, marked reduction in muscle expression was noted.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.80256 |
| Date | January 2003 |
| Creators | El-Gouhary, Inas |
| Contributors | Peterson, A. C. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Human Genetics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002032429, proquestno: AAIMQ98625, Theses scanned by UMI/ProQuest. |
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