10.1371/journal.pcbi.1006174.g002 Mary M. Rorick Mary M. Rorick Edward B. Baskerville Edward B. Baskerville Thomas S. Rask Thomas S. Rask Karen P. Day Karen P. Day Mercedes Pascual Mercedes Pascual An approach to identifying functional groups within the multi-copy <i>var</i> genes. Public Library of Science 2018 sample var DBL α sequence types var gene diversity approach recombining var antigenic gene family malaria parasite Plasmodium falciparum recombining parts recombining antigenic var genes multi-copy gene families 2018-06-13 17:54:15 Figure https://plos.figshare.com/articles/figure/An_approach_to_identifying_functional_groups_within_the_multi-copy_i_var_i_genes_/6512681 <p><b>(A)</b> Graphical representation of a stochastic block model for the normalized co-occurrence matrix <b>Z</b>, for nine homology blocks divided into three functional groups (HB functional groups 1–3). The blocks within the matrix of a single color represent the <i>z</i>-scores between pairs of HB functional groups, which are assumed to be drawn from the same normal distribution. <b>(B)</b> Homology blocks recombine to form <i>var</i> gene sequences, so after homology blocks are classified into functional groups (7 shown here, represented by distinct colors), <i>var</i> functional types can be defined as unique combinations of homology block functional groups (HBFG types). Viewing <i>var</i> sequences as HBFG types reduces diversity by over two orders of magnitude.</p>