Differential expression and intrachromosomal evolution of the sghC1q genes in zebrafish (Danio rerio).

The secreted globular head C1q (sghC1q) genes can be characterized as a family of genetic loci encoding signal peptides followed by single complement component 1q globular (gC1q) motifs. Members of this family have been referred to as precerebellin-like (Cblnl), C1q-like or ovary specific C1q-like factors, and are transcribed in response to infection and/or during early development. This study was primarily undertaken to identify the zebrafish sghC1q (or DrsghC1q) genes that increase their transcription in response to infection and to examine their transcriptional patterns during early development. Twenty sghC1q genes were found in the zebrafish (Danio rerio) genome (Zv9). Two of the examined twenty genes showed significant up-regulation within 24h of infection with the fish pathogen Streptococcus iniae, and eleven of the examined twenty were expressed during early development. Due to the clustered nature of these genes on chromosomes two and seven, intrachromosomal duplication events are hypothesized and explored.