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Here we provide experimental support for the direct phenotypic tradeoff between sexual activity and immunity by studying the antibacterial immune response in\n                    <jats:italic>Drosophila melanogaster<\/jats:italic>\n                    . Males exposed to more females showed a reduced ability to clear a bacterial infection, an effect that we experimentally link to changes in sexual activity. Our results suggest immunosuppression is an important cost of reproduction and that immune function and levels of disease susceptibility will be influenced by sexual selection.\n                  <\/jats:p>","DOI":"10.1073\/pnas.131216398","type":"journal-article","created":{"date-parts":[[2002,7,26]],"date-time":"2002-07-26T10:34:10Z","timestamp":1027679650000},"page":"7904-7909","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":232,"title":["Increased sexual activity reduces male immune function in\n                    <i>Drosophila melanogaster<\/i>"],"prefix":"10.1073","volume":"98","author":[{"given":"Kurt A.","family":"McKean","sequence":"first","affiliation":[{"name":"Department of Biology, University of California, Riverside, CA 92521"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonard","family":"Nunney","sequence":"additional","affiliation":[{"name":"Department of Biology, University of California, Riverside, CA 92521"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2001,6,19]]},"reference":[{"key":"e_1_3_3_1_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511629396"},{"key":"e_1_3_3_2_2","doi-asserted-by":"crossref","DOI":"10.1093\/oso\/9780195060584.001.0001","volume-title":"Evolution of Infectious Disease","author":"Ewald P W","year":"1994","unstructured":"P W Ewald Evolution of Infectious Disease (Oxford Univ. 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