Data from: Multiple post-mating barriers to hybridisation in field crickets

Cryptic advantages to conspecific sperm may be very widespread and have been identified based on the observations of higher paternity of conspecifics in several species. However, a relationship between the fate of sperm from two species within the female and paternity has never been demonstrated. We use competitive microsatellite PCR to show that in two hybridising cricket species, Gryllus bimaculatus and G. campestris, sequential cryptic reproductive barriers are present.

In competition with heterospecifics, more sperm from conspecific males is stored by females. Additionally, sperm from conspecific males has a higher fertilisation probability. This reveals that conspecific sperm precedence can occur through processes fundamentally under the control of females, providing avenues for females to evolve multiple mating as a defence against hybridization, with the counterintuitive outcome that promiscuity reinforces isolation and may promote speciation.

Usage notes

Tyler_et_al_genemapper_samples Genemapper output for spermathecal and offspring samples from each triad. Female.ID: A unique ID number given to each female, here used to identify triads. Sample.type: For each triad DNA from the spermatheca and offspring were extracted.

These are given as ‘sperm’ or ‘nymph’, respectively. Plex: Samples were screened with either individual markers or as plexes (details of microsatellite screening conditions are given in the supporting information ‘S2_Suppinfo’). Dye: The dyes used in the microsatellite screening.

Blue (B), Green (G) or Yellow (Y). Allele1 / Allele2: The unique allele identified for each male in the triad. Size1 / Size2: Peak height of an allele.

Area1 / Area2: Peak area of an allele. Tyler_et_al_genemapper_standards Genemapper output for the standards used to create a standard curve for each triad. Female.ID: A unique ID number given to each female, here used to identify triads.

Plex: Samples were screened with either individual markers or as plexes (details of microsatellite screening conditions are given in the supporting information ‘S2_Suppinfo’). Dye: The dyes used in the microsatellite screening. Blue (B), Green (G) or Yellow (Y).

Allele1 / Allele2: The unique allele identified for each male in the triad. Size1 / Size2: Peak height of an allele. Area1 / Area2: Peak area of an allele.

Standard: The percentage of DNA from the focal male added to the mix of DNA from both males. Tyler_et_al_standard_curves Detail of the standard curves calculated from the Genemapper output. Female.ID: A unique ID number given to each female, here used to identify triads.

Equation: The equation describing the fit of the curve through the standards for each triad. R-squared: The R-squared value for each standard curve. Tyler_et_al_triad_data Detail of the individuals used in mating trials, male success in sperm storage and siring offspring, the number of eggs laid, and the percentage of nymphs that hatched.