Meeting Abstract
P1.44 Tuesday, Jan. 4 Tissue distribution of akirin genes in several vertebrate species, including fish and rodents. CHARGING, M. J.*; BILLING, S. R.; BIGA, P. R.; North Dakota State University; North Dakota State University; North Dakota State University matthew.charging@ndsu.edu
Akirin was recently identified in Drosophila melanogaster and shown to be an essential nuclear protein in the immune deficiency (Imd) pathway. The akirin gene is conserved in vertebrates as two homologues have been identified in several vertebrate species and named akirin1 and akirin2. In mice, akirin2 functions as part of the signaling pathway regulating the transcription of several immune-response genes. Akirin1 was recently demonstrated to be a down-stream target of myostatin, a negative regulator of muscle growth. In this study we evaluated the tissue distribution pattern of both akirin genes and all known isoforms for each gene in rainbow trout (Oncorhynchus mykiss) and several strains of mice (Mus musculus). Several genome duplication events within salmonids resulted in the rainbow trout possessing four isoforms of each akirin gene. Liver, lung or gill, blood cells, adipose, brain, intestine, heart, skeletal muscle, kidney, spleen, and skin cells were used in this analysis. Total RNA was isolated from each tissue or cell type and reverse transcribed to cDNA. Semi-quantitative PCR was utilized to analyze relative abundance of each akirin isoform and gene. In rainbow trout, all eight isoforms were expressed in all tissues and cells with the exception of blood cells. For each akirin gene, the akirin1/2 2a and 2b isoforms exhibited increased expression in red versus white muscle. In mice, akirin2 was expressed constitutively and interestingly found in blood cells. In contrast, akirin1 expression appears to be predominately confined to liver and skeletal muscle. These results suggest an interesting and complex expression pattern conserved within the vertebrate lineage. In addition, the fairly constitutive expression of the akirin genes might suggest diversity in functions between the various isoforms identified in salmonids.
