A comprehensive analysis of germline and expressed immunoglobulin repertoire in the horse.
Based on the recently released horse genome, we have characterized the genomic organization of the horse Ig gene loci. The horse IgH locus in genomic scaffold Un0011 contains 40 D(H) segments, 8 J(H) segments and 50 V(H) segments. The Igkappa locus contains only a single C(kappa) gene, 5 J(kappa) segments and a 60 V(kappa) segments, whereas the Iglambda locus contains 7 C(lambda) genes each preceded by a J(lambda) gene segment. A total of 110 V(lambda) segments with the same transcriptional polarity as J(lambda)-C(lambda) were identified upstream of the J(lambda)-C(lambda) cluster. However, 34 V(lambda) segments locating downstream of the J(lambda)-C(lambda) cluster showed an opposite transcriptional polarity. Our results reveal that the horse germline V repertoires were more complex than previously estimated. By analyzing the cloned IgH/L cDNA, we further showed that several selected V subgroups were utilized in the expressed V(H), V(kappa), or V(lambda) and a high frequency of nucleotide deletions and insertions were introduced by somatic hypermutation in these expressed V genes.
Sun
Yi
Y
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
Wang
Chunyan
C
Wang
Yating
Y
Zhang
Tianyi
T
Ren
Liming
L
Hu
Xiaoxiang
X
Zhang
Ran
R
Meng
Qingyong
Q
Guo
Ying
Y
Fei
Jing
J
Li
Ning
N
Zhao
Yaofeng
Y
D000595:Amino Acid Sequence; D000818:Animals; D002999:Clone Cells; D016678:Genome; D006736:Horses / Q000235:genetics* / Q000276:immunology*; D007136:Immunoglobulins / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
D007136:Immunoglobulins