title: Expression and functionality of transient receptor potential melastatin 4 (TRPM4)-like channels during development of the zebrafish.
abstract: Calcium signaling, from localized spikes to coordinated waves, are linked to cleavage, patterning, differentiation, and growth during embryonic development. The basis for control of these Ca(2+) signals is poorly defined. In this study, the expression and functionality of the transient receptor potential melastatin 4 protein (TRPM4), an ion channel that controls Ca(2+) entry into cells, was examined in the zebrafish embryo and adult. Originating with the human TRPM4 gene, Ensembl ortholog, NCBI BLAST, and Homologene searches identified a zebrafish TRPM4 "like" gene encoding a predicted protein of 1199 amino acids and sharing a 42-43% sequence identity with the mouse, rat, and human. Custom-designed zebrafish primers identified TRPM4 transcripts throughout the 0-123h period of embryonic development with greatest and lowest relative expression at 12 and 123h post-fertilization, respectively. Perforated patch clamp recordings in 27h embryonic cells revealed Ca(2+)-activated currents with the characteristics of those described for mammalian TRPM4. Similarly, TRPM4-like expression and functionality was observed in brain and liver cells from adult fish. These findings suggest that a TRPM4-like channel is available for Ca(2+) regulation during early development of the zebrafish.
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. Electronic address: hcheng@lsu.edu.
authors.forename: Henrique
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA. Electronic address: Jaaellis@utmb.edu.
authors.forename: Jayne
authors.initials: J
authors.lastname: Ellis
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. Electronic address: kklein7@lsu.edu.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Kleinow
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D050053:TRPM Cation Channels / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism
chemical_list: D050053:TRPM Cation Channels; D002118:Calcium
keywords: Ca(2+); Embryonic development; Gene expression; Patch clamp; TRPM4; Zebrafish