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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) 
>AY293285|BTLA*01|Mus musculus|F|EX1|L-REGION|
atgaagacagtgcctgccatgcttgggactcctcggttatttagggaattcttcatcctc
catctgggcctctggagcatcctttgtgagaaagctactaagaggaatg
>AY293285|BTLA*01|Mus musculus|F|EX2|[D]|C-LIKE|
atgaagagtgtgaagtgcaacttaatattaagaggaattccaaacactctgcctggacag
gagagttatttaaaattgaatgtcctgtgaaatactgtgttcatagacctaatgtgactt
ggtgtaagcacaatggaacaatctgggtaccccttgaagttggtcctcagctatacacta
gttgggaagaaaatcgatcagttccggtttttgttctccattttaaaccaatacatctca
gtgataacgggtcgtatagctgttctacaaacttcaattctcaagttattaatagccatt
cagtaaccatccatgtgagag
>AY293285|BTLA*01|Mus musculus|F|EX3|CO|
aaaggactcaaaactcttcagaacacccactaataa
>AY293285|BTLA*01|Mus musculus|F|EX4|CO+TM+CY|
cagtatctgacatcccagatgccaccaatgcctcaggaccatccaccatggaagagaggc
caggcaggacttggctgctttacaccttgcttcctttgggggcattgcttctgctccttg
cctgtgtctgcctgctctgctttctgaaaaggatccaag
>AY293285|BTLA*01|Mus musculus|F|EX5|CY|
ggaaagaaaagaagccttctgacttggcaggaagggacactaacctg
>AY293285|BTLA*01|Mus musculus|F|EX6|CY|
gttgatattccagccagttccaggacaaatcaccaagcactgccatcaggaactggaatt
tatgataatgatccctggtctagcatgcaggatgaatctgaattgacaattagcttgcaa
tcagagagaaacaaccagggcattgtttatgcttctttgaaccattgtgttattggaagg
aatccaagacaggaaaacaacatgcaggaggcacccacagaatatgcatccatttgtgtg
agaagt
>BTLA*01|Mus musculus|F|EX1-6|
atgaagacagtgcctgccatgcttgggactcctcggttatttagggaattcttcatcctc
catctgggcctctggagcatcctttgtgagaaagctactaagaggaatgatgaagagtgt
gaagtgcaacttaatattaagaggaattccaaacactctgcctggacaggagagttattt
aaaattgaatgtcctgtgaaatactgtgttcatagacctaatgtgacttggtgtaagcac
aatggaacaatctgggtaccccttgaagttggtcctcagctatacactagttgggaagaa
aatcgatcagttccggtttttgttctccattttaaaccaatacatctcagtgataacggg
tcgtatagctgttctacaaacttcaattctcaagttattaatagccattcagtaaccatc
catgtgagagaaaggactcaaaactcttcagaacacccactaataacagtatctgacatc
ccagatgccaccaatgcctcaggaccatccaccatggaagagaggccaggcaggacttgg
ctgctttacaccttgcttcctttgggggcattgcttctgctccttgcctgtgtctgcctg
ctctgctttctgaaaaggatccaagggaaagaaaagaagccttctgacttggcaggaagg
gacactaacctggttgatattccagccagttccaggacaaatcaccaagcactgccatca
ggaactggaatttatgataatgatccctggtctagcatgcaggatgaatctgaattgaca
attagcttgcaatcagagagaaacaaccagggcattgtttatgcttctttgaaccattgt
gttattggaaggaatccaagacaggaaaacaacatgcaggaggcacccacagaatatgca
tccatttgtgtgagaagttaa