Conserved Non-Coding Element m2de3 Directed Gene Expression During Development

Meis genes are well known for their important roles in gene regulation and development, in combination with other transcription factors such as the Hox and Pbx families. The primary purpose of this study is to gain a better understanding of the genetic mechanisms that control the expression of meis genes during development. The Zerucha lab identified four highly conserved non-coding elements, named m2de1-m2de4 (for meis2 downstream element) that we hypothesize regulate expression of the meis2 gene. I have characterized the m2de3 element to determine if this element is able to direct spatial and temporal gene expression consistent with meis2 expression patterns over different stages of development. Zebrafish (Danio rerio) were used in combination with a Tol2 injection cassette to introduce gene expression constructs containing murine m2de3 through microinjection at single cell stage. In primary transgenic embryos, m2de3 directed expression was observed in a punctate expression pattern along the notochord, within motor neurons along the notochord, around the heart and in developing muscle fibers along the trunk of zebrafish embryos. In addition, a stable m2de3 transgenic zebrafish genetic line was generated through fin clip genome analysis. This transgenic line demonstrates the expression pattern in the heart and along the entire notochord.