Transcriptional studies of a novel family of "short C1q" domain proteins in zebrafish.

The genes for the "short C1q" family of proteins exist in most vertebrates and possibly in some invertebrates. At least one "short C1q" protein is expressed in teleosts during the inflammatory response (zebrafish, trout and catfish), and other members of this family of proteins have been detected at the transcriptional level during early zebrafish development. The objective of this study was to quantitatively characterize the differential expression of putative "short C1q" paralogs in zebrafish during early development and the inflammatory response. To this end, quantitative real time PCR (qRT-PCR) was performed using RNA extracted at 12 hour time intervals during these two events to quantify transcript levels. In a parallel effort to track the differential expression of the paralogs; reporter constructs were injected into embryos and transfected into a zebrafish liver cell line infected with the bacterial fish pathogen Streptococcus iniae. This story is furthered by bioinformatic analyses of the zebrafish genome displaying the likelihood of intrachromosomal gene duplications involving these genes. The "short C1q" genes identified as responsive during the inflammatory response will be further studied for their possible direct interaction with the pathogen S. iniae by using fluorescently labeled bacteria and protein. [ABSTRACT FROM AUTHOR]