Molecular cloning and analysis of zebrafish voltage-gated sodium channel beta subunit genes: implications for the evolution of electrical signaling in vertebrates

Table 1 Comparative genomics of the sodium channel β1 gene in zebrafish and mammals.

gene	Genbank accession number	gene location	cDNA	exon1	exon2	exon 3	exon 4	exon 5	exon6	protein	%ID (%SIM)	topology
zβ1A	DQ489722	Chr 16	1411	219 (52)	167	238	142	645 (31)	-	209	47.5% (57.0%)	IG(V): 37–149 TM: 164–185
zβ1B	DQ489723	Chr 16	1054	219 (52)	167	238	142	28	260 (9)	211	49.8% (59.6%)	IG(V): 37–149 TM: 164–185
zβ1C	DQ489724	Chr 16	574	219 (52)	355 (266)	-	-	-	-	105	13.0% (17.5%)	IG(V): none TM: none
zβ1D	DQ489725	Chr 16	1320	219 (52)	167	238	142	72 (67)	482 (0)	221	53.4% (63.7%)	IG(V): 37–149 TM: 164–185
hβ1	NM_001037	Chr 19	1521	231 (40)	167	241	142	72 (67)	668 (0)	218	100% (100%)	IG(V): 33–146 TM: 161–182
rβ1A	AF182949	Chr 1	850	40	167	643 (615)	-	-	-	273	55.1% (59.1%)	IG(V): 33–146 TM: 216–234
hβ1B	NM_199037	Chr 19	1170	231 (40)	167	772 (600)	-	-	-	268	58.0% (60.2%)	IG(V): 33–146 TM: 244–263

Gene: z = zebrafish, h = human, r = rat, and letters A-D refer to different splice variants. Accession numbers are identifiers for nucleotide sequences in NCBI GenBank. Values for cDNA and exons represent number of nucleotides. (Parentheses) indicate nucleotides within the open reading frame (difference = untranslated sequence or UTR). Protein values represent amino acid number with signal peptide intact. %ID (%SIM) refers to percentage identity and similarity with the human β1 protein sequence as determined by alignment. Zebrafish β subunit topology was determined as described in Methods. IG(V) = V-type immunoglobulin domain and TM = transmembrane domain. Numbering refers to β1 protein sequence with signal peptide intact. IG(V) domain and transmembrane regions for human β1 and human/rat splice variants were annotated based on previous reports [10, 14, 43, 49, 50].

ISSN: 2730-7182