Profile the immunoglobulin heavy chain repertoires by high-throughput sequencing

NGS has established itself as a highly useful platform in studying several aspects of genomics research. One such area is the expressed Ig repertoire. Smaller model organisms that contain fewer cells in total and, of course, fewer immune cells, can provide a better starting point from which to maximize sequenced Ig sequences. Torafugu has the earliest recognizable adaptive immune system and more importantly one of the smallest genomes (~400 Mb) among vertebrates, which, makes it an ideal model system for studying the Ig repertoire. In this study, we sought to describe the baseline diversity of V, D, J, and CDR-H3 repertoires in torafugu using multiplex PCR and Illumina sequencing. Three torafugu immunoglobulin heavy chain repertoires were sequenced. Highly diversified CDR-H3 repertoire and unequal usage of V, D, and J gene segments across individuals were observed.