Expressed IgH μ and τ transcripts share diversity segment in ranched Thunnus orientalis.
It is now appreciated that in addition to the immunoglobulin (Ig)M and D isotypes fish also make the mucosal IgT. In this study we sequenced the full length of Ig τ as well as μ in the commercially important Thunnus orientalis (Pacific bluefin tuna), the first molecular analysis of these two Ig isotypes in a member of the order Perciformes. Tuna IgM and IgT are each composed of four constant (CH) domains. We cloned and sequenced 48 different variable (VH) domain gene rearrangements of tuna immunoglobulins and grouped the VH gene sequences to four VH gene segment families based on 70% nucleotide identity. Three VH gene families were used by both IgM and IgT but one group was only found to be used by IgM. Most interestingly, both μ and τ clones appear to use the same diversity (DH) segment, unlike what has been described in other species, although they have dedicated IgT and IgM joining (JH) gene segments. We complemented this repertoire study with phylogenetic and tissue expression analysis. In addition to supporting the development of humoral vaccines in this important aquaculture species, these data suggest that the DH-JH recombination rather than the VH-DH recombination may be instructive for IgT versus IgM/D bearing lymphocyte lineages in some fish.
Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: smashoof@cvm.tamu.edu.
Sara
S
Mashoof
Department of Wildlife and Fisheries Sciences, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: cpohlenz@tamu.edu.
Camilo
C
Pohlenz
Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: pchen@cvm.tamu.edu.
Patricia L
PL
Chen
Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: tdeiss@cvm.tamu.edu.
Thaddeus C
TC
Deiss
Department of Wildlife and Fisheries Sciences, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: dgatlin@nature.tamu.edu.
Delbert
D
Gatlin
Schillinger Genetics, 4401 Westown Parkway Suite 225, West Des Moines, IA 50266, USA. Electronic address: abuentello@schillgen.com.
Alejandro
A
Buentello
Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA. Electronic address: mcriscitielllo@cvm.tamu.edu.
Michael F
MF
Criscitiello
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D029941:Fish Proteins; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D056724:Immunity, Humoral / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D007075:Immunoglobulin M / Q000235:genetics / Q000378:metabolism*; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007136:Immunoglobulins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012689:Sequence Homology, Nucleic Acid; D059467:Transcriptome; D014413:Tuna / Q000276:immunology*; D014612:Vaccines
D029941:Fish Proteins; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D007136:Immunoglobulins; D014612:Vaccines; C569864:immunoglobulin T, teleost
Evolution; IgZ/T; Immunoglobulin; Isotype exclusion; Tuna