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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) 
>AF327184|ICOS*01|Mus musculus|F|EX1|
atgaagccgtacttctgccgtgtctttgtcttctgcttcctaatcagacttttaacag
>AF327185|ICOS*01|Mus musculus|F|EX2|[D]|V-LIKE|
gagaaatcaatggctcggccgatcataggatgttttcatttcacaatggaggtgtacaga
tttcttgtaaataccctgagactgtc.....................cagcagttaaaaa
tgcgattgttcaga......gagagagaagtcctctgcgaactcaccaagaccaag...g
gaagcggaaatgcggtgtccatcaagaatcca............atgctctgtctatatc
atctgtcaaacaacagcgtctcttttttcctaaacaacccagacagctcccagggaagct
attacttctgcagcctgtccatttttgacccacctccttttcaagaaaggaaccttagtg
gaggatatttgcatatttatg
>AF327185|ICOS*01|Mus musculus|F|EX3|
aatcccagctctgctgccagctgaagctctggctacccgtagggtgtgcagctttcgttg
tggtactcctttttggatgcatacttatcatctggttttcaaaaaag
>AF327185|ICOS*01|Mus musculus|F|EX4|
aaatacggatccagtgtgcatgaccctaatagtgaatacatgttcatggcggcagtcaac
acaaacaaaaagtctagacttgcag
>AF327185|ICOS*01|Mus musculus|F|EX5|
gtgtgacctca
>AL645744|ICOS*01|Mus musculus|F|EX1|splicing B|
atgaagccgtacttctgccgtgtctttgtcttctgcttcctaatcagacttttaacag
>AL645744|ICOS*01|Mus musculus|F|EX2|[D]|V-LIKE|splicing B|
gagaaatcaatggctcggccgatcataggatgttttcatttcacaatggaggtgtacaga
tttcttgtaaataccctgagactgtc.....................cagcagttaaaaa
tgcgattgttcaga......gagagagaagtcctctgcgaactcaccaagaccaag...g
gaagcggaaatgcggtgtccatcaagaatcca............atgctctgtctatatc
atctgtcaaacaacagcgtctcttttttcctaaacaacccagacagctcccagggaagct
attacttctgcagcctgtccatttttgacccacctccttttcaagaaaggaaccttagtg
gaggatatttgcatatttatg
>AL645744|ICOS*01|Mus musculus|F|EX3|splicing B|
aatcccagctctgctgccagctgaagctctggctacccgtagggtgtgcagctttcgttg
tggtactcctttttggatgcatacttatcatctggttttcaaaaaag
>AL645744|ICOS*01|Mus musculus|F|EX4|splicing B|
aaatacggatccagtgtgcatgaccctaatagtgaatacatgttcatggcggcagtcaac
acaaacaaaaagtctagacttgcaggtacagctccccttacggctttggggagggaagaa
cacacttcatggttaagactggaattaatttgtttatttctattt
>AF257230|ICOS*02|Mus musculus|F|EX1|
atgaagccgtacttctgccatgtctttgtcttctgcttcctaatcagacttttaacag
>AF257230|ICOS*02|Mus musculus|F|EX2|[D]|V-LIKE|
gagaaatcaatggctcggccgatcataggatgttttcatttcacaatggaggtgtacaga
tttcttgtaaataccctgagactgtc.....................cagcagttaaaaa
tgcgattgttcaga......gagagagaagtcctctgcgaactcaccaagaccaag...g
gaagcggaaatgcggtgtccatcaagaatcca............atgctctgtctatatc
atctgtcaaacaacagcgtctcttttttcctaaacaacccagacagctcccagggaagct
attacttctgcagcctgtccatttttgacccacctccttttcaagaaaggaaccttagtg
gaggatatttgcatatttatg
>AF257230|ICOS*02|Mus musculus|F|EX3|
aatcccagctctgctgccagctgaagctctggctacccgtagggtgtgcagctttcgttg
tggtactcctttttggatgcatacttatcatctggttttcaaaaaag
>AF257230|ICOS*02|Mus musculus|F|EX4|
aaatacggatccagtgtgcatgaccctaatagtgaatacatgttcatggcggcagtcaac
acaaacaaaaagtctagacttgcag
>AF257230|ICOS*02|Mus musculus|F|EX5|
gtgtgacctca