Expression data from testes of zebra finch males artificially selected for long or short sperm

Male zebra finches of a captive population in the University of Sheffield were artificially selected for long or short sperm based on their breeding values for three generations. We used Affymetrix microarrays to examine gene expression differences between testes of selection line male birds. At third generation, males with extreme values of total sperm lengths were selected and their testes on both sides were collected for RNA extraction and hybridization on Affymetrix microarrays. After quality control and normalization, 69 testes from 42 males were retained for further analyses.