DOI: 10.5061/dryad.z08kprr9k
title: The effect of baculum shape and mating behaviour on mating-induced Prolactin release in female house mice

description: Male genitalia are subject to rapid divergent evolution, and sexual
 selection is believed to be responsible for this pattern of evolutionary
 divergence. Genital stimulation during copulation is an essential feature
 of sexual reproduction. In mammals, the male intromittent genitalia
 induces a cascade of physiological and neurological changes in females
 that promote pregnancy. Previous studies of the house mouse have shown
 that the shape of the baculum (penis bone) influences male reproductive
 success and responds to experimentally imposed variation in sexual
 selection. Here, we test the hypothesis that the baculum is subject to
 sexual selection due to a stimulatory function during copulation. We
 selected male and female house mice (Mus musculus domesticus) from
 families with breeding values at the extremes of baculum shape and
 performed two series of experimental matings following which we examined
 the concentration of Prolactin in the blood of females either 15 (“early”)
 or 75 (“late”) minutes after ejaculation. Our results provide evidence of
 a mating-induced release of Prolactin in the female house mouse early
 after ejaculation, the level of which is dependent on an interaction
 between the shape of the baculum and male sexual behaviour. Our data
 thereby provide novel insight into the mechanism(s) of sexual selection
 acting on the mammalian baculum.
description: <strong>4thGeneration_BaculumLandmarks</strong>: TPS
 file with baculum raw landmarks for each specimen. Landmarks were placed
 around the periphery of the baculum (36 sliding, 4 fixed) and relative
 warps (RWs) and centroid size were extracted. Landmark placement conducted
 using tpsDig 232 developed by Rohlf. Specimen numbers/ID can be matched
 with ID at the excel spreadsheets
 (4thGenerationBaculum_Repeatibility_DATA; BaculumShapeVariation_DATA;
 EarlyGroup_DATA; LateGroup_DATA). 
 <strong>Experimental_BaculumLandmarks</strong>: TPS
 file with baculum raw landmarks for each specimen. Landmark data from
 fourth- generation laboratory-reared house mice used for
 <strong>both experimental groups</strong> (Early and Late
 group). Specimen number (ID) can be matched with ID in the excel
 spreadsheet from
 ExperimentalBaculum_ShapevariationDATA. 
 <strong>4thGenerationBaculum_Repeatibility_DATA: </strong>Excel spreadsheet containing data used for the analysis of the reliability of baculum landmark placement and repeatability of our measurements. <strong>BaculumShapeVariation_DATA: </strong>Excel spreadsheet containing male morphological data and identifiers of each individual for the fourth-generation laboratory-reared house mice. Dataset contains data used to check if 4<sup>th</sup> generation house mice aligned with the expected baculum shape extremes. <strong>ExperimentalBaculum_ShapeVariation_DATA: </strong>Excel spreadsheet containing the subset of the fourth-generation laboratory-reared house mice used to examine baculum and matinge behaviour effect on female mating-induced Prolactin release (Early and and Late group treatment males). Male identifiers (ID, genetic background extreme and family) and  male body weight are included in the spreadsheet.  <strong>Prolactin_Concentration_AllGroups: </strong>Excel spreadsheet containing female identifiers (ID, female genetic background extreme and Family), morphological data (Body weight) and, Prolactin concentration (ng/ml) data. Data used to conduct the statistical analysis to explore whether mating <em>per se</em> had an effect on the levels of circulating Prolactin across the different treatments (<em>Early Group; Late Group; Control Group</em>). <strong>Note:</strong> Female ID cells in<strong> red</strong> are individuals that were excluded from the statistical analysis after outlier examination (mean ± 2×sd).  <strong>Mating_Behavioural_DATA:</strong> Excel spreadsheet containing male identifiers (ID, genetic background extreme and Family) and mating behavioural data across treatment groups (Early, Late). Data used to conduct the a Principal component analysis (PCA), to reduce copulatory behaviour into fewer axis of variation.  <strong>EarlyGroup_DATA:</strong> Excel spreadsheet containing genital shape (RW1, RW2, Centroid size), mating behaviour (PC1) and Prolactin concentration (ng/ml) data and identifiers  of each individual from the Early group treatment (ID, genetic background extreme and family). Data used to conduct the statistical analysis on the <em>Early group experiment. </em> <strong>LateGroup_DATA: </strong>Excel spreadsheet containing genital shape (RW1, RW2, Centroid size), mating behaviour (PC1) and Prolactin concentration (ng/ml) data and identifiers  of each individual from the Early group treatment (ID, genetic background extreme and family). Data used to conduct the statistical analysis on the <em>Late group experiment.</em>