Evolution of Vertebrate Solute Carrier Family 9B Genes and Proteins (SLC9B): Evidence for a Marsupial Origin for Testis Specific SLC9B1 from an Ancestral Vertebrate SLC9B2 Gene
- Corresponding Author:
- Roger S Holmes
Eskitis Institute for Drug Discovery and School of Natural Sciences
Griffith University, Nathan QLD 4111, Australia
Tel: +61 7 37356008
E-mail: [email protected]
Received date: May 18, 2016; Accepted date: June 03, 2016; Published date: June 10, 2016
Citation: Holmes RS, Spradling-Reeves KD, Cox LA (2016) Evolution of Vertebrate Solute Carrier Family 9B Genes and Proteins (SLC9B): Evidence for a Marsupial Origin for Testis Specific SLC9B1 from an Ancestral Vertebrate SLC9B2 Gene. J Phylogen Evolution Biol 4:167. doi:10.4172/2329-9002.1000167
Copyright: © 2016 Holmes RS, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
SLC9B genes and proteins are members of the sodium/lithium hydrogen antiporter family which function as solute exchangers within cellular membranes of mammalian tissues. SLC9B2 and SLC9B1 amino acid sequences and structures and SLC9B-like gene locations were examined using bioinformatic data from several vertebrate genome projects. Vertebrate SLC9B2 sequences shared 56-98% identity as compared with ~50% identities with mammalian SLC9B1 sequences. Sequence alignments, key amino acid residues and conserved predicted transmembrane structures were also studied. Mammalian SLC9B2 and SLC9B1 genes usually contained 11 or 12 coding exons with differential tissue expression patterns: SLC9B2, broad tissue distribution; and SLC9B1, being testis specific. Transcription factor binding sites and CpG islands within the human SLC9B2 and SLC9B1 gene promoters were identified. Phylogenetic analyses suggested that SLC9B1 originated in an ancestral marsupial genome from a SLC9B2 gene duplication event.