This Snakefile downloads IMGT's per-segment FASTA files for rhesus and human antibody genes and combines them into one CSV for Macaca mulatta and one CSV for Homo sapiens, parsing out details from the FASTA description lines (as described in the IMGT FASTA format). It also creates per-segment FASTA files for each species using ungapped sequences and modified sequence IDs for use with IgBLAST.