Elsevier

Gene Expression Patterns

Volume 7, Issue 3, 2 January 2007, Pages 318-322
Gene Expression Patterns

Isolation and expression of zebrafish zinc-finger transcription factor gene tsh1

https://doi.org/10.1016/j.modgep.2006.08.004Get rights and content

Abstract

We report the expression patterns of tsh1, a zebrafish homologue of the Drosophila homeotic gene teashirt. Expression of tsh1 is first detected at the 2-somite stage (10 h post-fertilization, hpf) at the anterior end of the spinal cord. Expression expands toward the posterior spinal cord, and by the prim-5 stage (24 hpf) tsh1 transcripts are detected throughout spinal cord. Between the 14- and 25-somite stage (16–24 hpf), spinal cord expression shows a clear anterior boundary at the rostral margin of rhombomere 7. Around the prim-25 stage (36 hpf), while the spinal expression of tsh1 decreases, new expression is detected in the pectoral fin buds and dorsal forebrain. By the long-pec stage (48 hpf), spinal cord expression is undetectable, but strong expression is observed in the rhombencephalon, telencephalon, tectum opticum, midbrain–hindbrain boundary, in the first pharyngeal arch and in the eyes. This expression persists at least until the larval stages. Retinoic acid signaling influences tsh1 expression. Zebrafish tsh1 expression was induced in the anterior neural tube in embryos treated briefly with exogenous retinoic acid. Furthermore, tsh1 expression was down-regulated in the spinal cord in the zebrafish neckless mutant in which RA signaling is disrupted due to a missense mutation in the gene encoding retinaldehyde dehydrogenase type 2.

Section snippets

Results

The Drosophila transcription factor teashirt (tsh) is involved in trunk segmentation, midgut morphogenesis and proximal leg formation (Alexandre et al., 1996, de Zulueta et al., 1994, Erkner et al., 1999, Mathies et al., 1994, Roder et al., 1992). Tsh functions in parallel with other homeotic proteins such as those encoded by the HOM-C complex genes (de Zulueta et al., 1994). In addition, tsh is required for transcriptional repression mediated by the Wingless signaling pathway (Gallet et al.,

Zebrafish husbandry

Wild-type zebrafish AB strains and neckless (nlsi26) (Begemann et al., 2001) were raised at 28.5 °C according to (Westerfield, 2000). Embryos were produced by pair-mating and staged as described (Kimmel et al., 1995).

RNA isolation and cDNA subtraction

Total RNA was isolated using TRIZOL RNA isolation kit (Gibco). mRNA was purified from total RNA using PolyA Tract-1000 system (Promega). cDNA subtraction was performed using Repressive Subtractive Hybridization Kit (Clontech).

Amplification of 5′ end of tsh1

The 5′ end of tsh1 was amplified by PCR using Smart RACE

Acknowledgements

We thank Lucille Joly for technical assistance and Dr. Marie-Andrée Akimenko for helpful discussions. The project was partly funded by Grant MOP-14460 from the Canadian Institutes of Health Research to M.E., Grants from NIH (1P20RR17703-04) and the Whitehall foundation (2002-12-103) to H.W., and the Cornell Vertebrate Functional Genomics Initiative fund to Q.L.

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Cited by (5)

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Present address: Laboratory of Molecular Genetics, National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD 20892, USA.

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