Axolotl MHC class II beta chain: predominance of one allele and alternative splicing of the beta1 domain.
The axolotl MHC is composed of multiple polymorphic class I loci linked to class II B loci. In this report, evidence of the existence of one class II B locus (Amme-DAB) that codes for two different transcripts is given. A 2.1-kb transcript is translated to a complete beta chain and a shorter transcript of 1.8 kb encodes a molecule lacking the beta1 domain. For two complete class II B mRNA synthesized, up to one mRNA devoid of the beta1 domain is synthesized. Alternative splicing involving a peptide binding domain at a class II B locus evidenced in axolotl (Ambystoma mexicanum) is also observed for A. tigrinum, the tiger salamander. Very little variability is found among various axolotl MHC class II B cDNA sequences, and the same allele is obtained from inbred and wild axolotls. The transcription of one MHC class B locus in two class II B isoforms in thymic cells and in splenic lymphocytes may shed new light on the well-known deficient immune responder state of the axolotl.
Laurens
V
V
CNRS-UMR 5548, Développement et Communication Chimique, Groupe Immunologie Comparée, Université de Bourgogne, Dijon, France. vlaurens@u-bourgogne.fr
Chapusot
C
C
del Rosario Ordonez
M
M
Bentrari
F
F
Padros
M R
MR
Tournefier
A
A
D000483:Alleles; D017398:Alternative Splicing; D000557:Ambystoma / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000032:analysis / Q000737:chemistry; D005802:Genes, MHC Class II; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000032:analysis
D018076:DNA, Complementary; D012333:RNA, Messenger