10.1371/journal.pone.0147549 Qiang Huang Qiang Huang Yan Ping Chen Yan Ping Chen Rui Wu Wang Rui Wu Wang Shang Cheng Shang Cheng Jay D. Evans Jay D. Evans Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees Public Library of Science 2016 SNP positions ceranae strains infection period Nosema ceranae parasitism reactive mitochondrial oxygen species modulator 1 parasite genome Honey Bees time period parasite mRNAs honey bee cells 1122 parasite genes data support reproduction cycle 4 expression patterns honey bee host Microsporidian Parasite hypothesis Purifying Selection 2016-02-03 12:31:36 Dataset https://plos.figshare.com/articles/dataset/Host_Parasite_Interactions_and_Purifying_Selection_in_a_Microsporidian_Parasite_of_Honey_Bees/2577763 <div><p>To clarify the mechanisms of <i>Nosema ceranae</i> parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of <i>N</i>. <i>ceranae</i> strains might be dominating infection.</p></div>