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IMGT reference sequences in FASTA format:

Nucleotide sequences with gaps

The FASTA header contains:
IMGT accession number | gene and allele name | species | functionality | exon name | domain name | domain type | alternative splicing (if it is) | partial (if it is) 
>AF411058|ICOS*01|Homo sapiens|F|EX1|
atgaagtcaggcctctggtatttctttctcttctgcttgcgcattaaagttttaacag
>AF411058|ICOS*01|Homo sapiens|F|EX2|[D]|V-LIKE|
gagaaatcaatggttctgccaattatgagatgtttatatttcacaacggaggtgtacaaa
ttttatgcaaatatcctgacattgtc.....................cagcaatttaaaa
tgcagttgctgaaa......ggggggcaaatactctgcgatctcactaagacaaaa...g
gaagtggaaacacagtgtccattaagagtctg............aaattctgccattctc
agttatccaacaacagtgtctctttttttctatacaacttggaccattctcatgccaact
attacttctgcaacctatcaatttttgatcctcctcctttt...aaagtaactcttacag
gaggatatttgcatatttatg
>AF411058|ICOS*01|Homo sapiens|F|EX3|
aatcacaactttgttgccagctgaagttctggttacccataggatgtgcagcctttgttg
tagtctgcattttgggatgcatacttatttgttggcttacaaaaaag
>AF411058|ICOS*01|Homo sapiens|F|EX4|
aagtattcatccagtgtgcacgaccctaacggtgaatacatgttcatgagagcagtgaac
acagccaaaaaatctagactcacag
>AF411058|ICOS*01|Homo sapiens|F|EX5|
atgtgaccctataa
>BC028006|ICOS*01|Homo sapiens|F|EX1|Splicing B|
atgaagtcaggcctctggtatttctttctcttctgcttgcgcattaaagttttaacag
>BC028006|ICOS*01|Homo sapiens|F|EX2|[D]|V-LIKE|Splicing B|
gagaaatcaatggttctgccaattatgagatgtttatatttcacaacggaggtgtacaaa
ttttatgcaaatatcctgacattgtc.....................cagcaatttaaaa
tgcagttgctgaaa......ggggggcaaatactctgcgatctcactaagacaaaa...g
gaagtggaaacacagtgtccattaagagtctg............aaattctgccattctc
agttatccaacaacagtgtctctttttttctatacaacttggaccattctcatgccaact
attacttctgcaacctatcaatttttgatcctcctcctttt...aaagtaactcttacag
gaggatatttgcatatttatg
>BC028006|ICOS*01|Homo sapiens|F|EX3|Splicing B|
aatcacaactttgttgccagctgaagttctggttacccataggatgtgcagcctttgttg
tagtctgcattttgggatgcatacttatttgttggcttacaaaaaagatg