Biomed Central 2025 isPartOf:https://phaidra.vetmeduni.ac.at/o:605 doi:10.1186/s12915-025-02245-4 https://phaidra.vetmeduni.ac.at/o:4852 Pre- and post-copulatory traits are affected by experimental inbreeding, but they are not correlated It has been suggested that the expression of males’ secondary sexual traits provides reliable indicators of their sperm traits, predicting positive correlations between pre- and post-copulatory traits (Fertility Indicator Hypothesis). Yet, it has also been suggested that males face life-history tradeoffs between investing into primary versus secondary sexual traits, predicting negative correlations (Sexual Allocation Tradeoff Hypothesis). These two hypotheses are not mutually exclusive when males’ sexual traits are condition-dependent and high-quality males are better able to invest into both pre- and post-copulatory traits than low-quality males. To test these hypotheses, we manipulated the genetic quality of wild-derived male house mice by experimental inbreeding and first tested whether inbreeding affects primary or secondary sexual traits (condition-dependent expression). We then tested whether pre- and post-copulatory traits are correlated. We recorded courtship behavior and vocalizations of the males during female contact and measured males’ reproductive organs, sperm quality, and the expression of four genes associated with spermatogenesis. application/pdf Text journal article Text Wissenschaftlicher Artikel eng Copyright © 2025, The Author(s) open access Testo Articolo di rivista BMC Biology Doris Nicolakis Maria Adelaide Marconi Kerstin E. Auer Dustin J. Penn Sarah M. Zala Sexual Signals Inbreeding Depression Allocation Tradeoffs Ultrasonic Vocalizations Sperm Traits Wild House Mice Mus Musculus Musculus http://creativecommons.org/licenses/by/4.0/ issn:1741-7007