Distinct genomic sequence of the CNR/Pcdhalpha genes in chicken.
CNR/Pcdhalpha family proteins have been first identified as a receptor family that corporate with Fyn, a family of the Src family of tyrosine kinase, and known as synaptic cadherins. Here we report the complete genomic sequence and organization of the chicken (Gallus gallus) CNR/Pcdhalpha The total length of chicken CNR/Pcdhalpha is 177kb. The chicken CNR/Pcdhalpha cluster encodes 12 variable and 3 constant exons. The genomic organizations of the chicken, rat, mouse, and human CNR/Pcdhalpha are basically orthologous. The constant-region exons (CP1, CP2, and CP3) are highly conserved between chicken and mammals, with percent identities of 90.9%, 90.7%, and 91.8% at the amino-acid level for chicken versus rat, mouse, and human, respectively. In contrast, the percent identities of the variable-region exons between chicken and mammals were lower: 51.8%, 51.3%, and 52.7%, on average, for chicken versus rat, mouse, and human, respectively, at the amino-acid level. Moreover, the chicken variable-region exons (from v1 to v12) are highly conserved paralogously (91.4%: nucleic acid, 92.4%: amino acid) in comparison with those of mammals. The CG content of each variable exon in the chicken (v1 to v12) is 74% on average and the CpG dinucleotide frequency in each variable-region exon is twice that of mammals. Due to the high CG content, chicken variable exons (from v1 to v12) encode 3 to 4 frame-shifted open reading frames, which span 1.5-3.0kb, in both the sense and anti-sense orientations.
Sugino
Hidehiko
H
Genome Information Research Center, Osaka University, 3-1, Yamadaoka Suita, Osaka 565-0871, Japan. sugino@fbs.osaka-u.ac.jp
Yanase
Hiroshi
H
Hamada
Shun
S
Kurokawa
Ken
K
Asakawa
Shuichi
S
Shimizu
Nobuyoshi
N
Yagi
Takeshi
T
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism; D002645:Chickens / Q000235:genetics*; D018899:CpG Islands; D005091:Exons; D016678:Genome; D006801:Humans; D007438:Introns; D051379:Mice; D005810:Multigene Family; D016366:Open Reading Frames; D010802:Phylogeny; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D017421:Sequence Analysis; D020506:Untranslated Regions
D015820:Cadherins; D011956:Receptors, Cell Surface; D020506:Untranslated Regions