Analysis of Gene Expression During Amphibian Tail Development (2006 JMU Biosymposium)

Talk given at the 2006 James Madison University Biosymposium on gene expression in Xenopus laevis and Hemidactylium scutatum tail development.

Transcript

1. Analysis of Gene Expression During Amphibian Tail Development Stephen Turner photo: www.herpsofnc.org JMU Biosymposium 2006
2. Tail Development 101 Vertebrates: Formation begins during embryogenesis. But in MOST vertebrates formation of new segments terminates. H. Scutatum adds new tail segments throughout larval, juvenile, and ADULT stages!
3. Somites photo: www.ulb.ac.be • Blocks of undifferentiated cells that arise from mesodermal tissue. • Blocks align down the anteroposterior axis flanking neural tube. • Cells in somite fated to become bone, muscle, or skin in trunk and tail segments. Bone Muscle Skin photo: www.animalpicturesarchive.com • First visible segmented structure in developing embryo.
4. Visualizing somites Somite 12-101 Antibody staining * * RNA in situ hybridization MyoD gene: expressed in somites Probe RNA mRNA in cell 12-101 ab 2° ab
5. 12-101 and MyoD Staining in Xenopus Antibody Staining 12-101 RNA in situ MyoD
6. 12-101 and MyoD Staining in H. scutatum Antibody Staining 12-101 RNA in situ: Using Xenopus MyoD probe Standard protocol used on Xenopus Reduced stringency
7. www.herpnet.net Xenopus laevis Hemidactylium scutatum Nieuwkoop and Faber Tail Development in Embryo, Larvae, Metamorphosis, and Adult
8. Tailbud genes Images from Linda K. Gont, et al. • Xbra & Xnot important in embryonic mesoderm patterning. • Xbra in particular is implicated in somitogenesis. • Previous research addresses embryonic expression. • When, and where are these genes expressed in post-embryonic tissues? Xbra: Xnot2:
9. Xbra expression in Xenopus laevis Stage 25 Stage 27 Stage 31 Stage 37 Stage 47
10. Stage 32 Stage 31 Xnot2 expression in Xenopus laevis Stage 27 Stage 47 Stage 40
11. Ongoing work & future directions • Examine expression of MyoD, Xbra, and Xnot2 in sections. • Modify 12-101 protocol for use in H. scutatum. • Modify my protocol to examine expression of these genes in late stage Xenopus (larval and metamorphosis stages). • Clone the H. scutatum homolog of these genes for in situ hybridization analysis of tail development in embryonic, larval, juvenile, and adult stages.
12. Acknoledgements Carol Hurney Sharon Babcock Also: Monroe Lab Temple Lab Seifert Lab Keller Lab (Xenopus laevis embryos) Grainger Lab (MyoD clone) De Robertis Lab (Xnot2 clone) Smith Lab (XBra clone) Teresa Pelletier (Pretty pictures)