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IMGT reference sequences in FASTA format:

Nucleotide sequences without 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) 
>AF142145|CTLA4*01|Mus musculus|F|EX1|
atggcttgtcttggactccggaggtacaaagctcaactgcagctgccttctaggacttgg
ccttttgtagccctgctcactcttcttttcatcccagtcttctctgaag
>AF142145|CTLA4*01|Mus musculus|F|EX2|[D]|V-LIKE|
ccatacaggtgacccaaccttcagtggtgttggctagcagccatggtgtcgccagctttc
catgtgaatattcaccatcacacaacactgatgaggtccgggtgactgtgctgcggcaga
caaatgaccaaatgactgaggtctgtgccacgacattcacagagaagaatacagtgggct
tcctagattaccccttctgcagtggtacctttaatgaaagcagagtgaacctcaccatcc
aaggactgagagctgttgacacgggactgtacctctgcaaggtggaactcatgtacccac
cgccatactttgtgggcatgggcaacgggacgcagatttatgtcattg
>AF142145|CTLA4*01|Mus musculus|F|EX3|
atccagaaccatgcccggattctgacttcctcctttggatccttgtcgcagttagcttgg
ggttgtttttttacagtttcctggtcactgctgtttctttgagcaagatg
>AF142145|CTLA4*01|Mus musculus|F|EX4|
ctaaagaaaagaagtcctcttacaacaggggtctatgtgaaaatgcccccaacagagcca
gaatgtgaaaagcaatttcagccttattttattcccatcaac
>CTLA4*01|Mus musculus|F|EX1-EX4|Splicing A|complete|
atggcttgtcttggactccggaggtacaaagctcaactgcagctgccttctaggacttgg
ccttttgtagccctgctcactcttcttttcatcccagtcttctctgaagccatacaggtg
acccaaccttcagtggtgttggctagcagccatggtgtcgccagctttccatgtgaatat
tcaccatcacacaacactgatgaggtccgggtgactgtgctgcggcagacaaatgaccaa
atgactgaggtctgtgccacgacattcacagagaagaatacagtgggcttcctagattac
cccttctgcagtggtacctttaatgaaagcagagtgaacctcaccatccaaggactgaga
gctgttgacacgggactgtacctctgcaaggtggaactcatgtacccaccgccatacttt
gtgggcatgggcaacgggacgcagatttatgtcattgatccagaaccatgcccggattct
gacttcctcctttggatccttgtcgcagttagcttggggttgtttttttacagtttcctg
gtcactgctgtttctttgagcaagatgctaaagaaaagaagtcctcttacaacaggggtc
tatgtgaaaatgcccccaacagagccagaatgtgaaaagcaatttcagccttattttatt
cccatcaactga