DOI: 10.5061/dryad.vdncjsz5n
title: Data from: Hybridization, reinforcement selection and sex-dependent reproductive character displacement of sperm and egg recognition proteins

description: The establishment of reproductive isolation between species via gametic
 incompatibility initially requires within-species selection for variation
 in reproductive compatibility. We investigate how the generation of
 within-species variation in sperm and egg recognition proteins,
 potentially via sexual conflict, influences reproductive isolation between
 two partially sympatric sea urchin species; the North American west coast
 Mesocentrotus franciscanus and the circumpolar Strongylocentrotus
 droebachiensis. Barriers to hybridization are stronger when eggs are given
 a choice of conspecific versus heterospecific sperm and the variation in
 hybridization among crosses can be explained by whether the sperm or egg
 protein variant is ancestral or derived. Derived proteins can be
 recognized as different and prevent hybridization. Examination of the
 allele frequencies of these proteins in M. franciscanus in and out of
 sympatry with S. droebachiensis along the west coast of North America
 reveals evidence of reinforcement selection and reproductive character
 displacement in eggs but not sperm, which likely reflects the differential
 cost of hybridization for males and females.
description: These data are the results of fertilization crosses between the
 sea urchins, Mesocentrotus franciscanus and Strongylocentrotus
 droebachiensis.  Tests were both choice (sperm from both males together)
 and no choice experiments. Data were analyzed as a function of the
 sire's sperm bindin genotype and the dame's EBR1 genotype. 
 Genotyping was conducted using PCR and Sangar sequencing.  Patterns of
 allele frequencies for these loci were investigated over the species range
 for M. franciscanus to investigate evidence of reproctive character
 displacement. These data files contain information of the genotypes of the
 parents in the cross and the fraction of eggs fertilized by conspecific or
 heterospecific sperm.  Fasta files of the haplotypes found for each locus
 are also presented.
description: # Data from: Hybridization, reinforcement selection and sex-dependent
 reproductive character displacement of sperm and egg recognition proteins
 Dataset DOI: [10.5061/dryad.vdncjsz5n](10.5061/dryad.vdncjsz5n) ##
 Description of the data and file structure The data presented here are
 from a study examining how gamete recognition proteins influence the
 likelihood of hybrid fertilization between two sea urchin species;
 *Mesocentrotus franciscanus* and *Strongylocentrotis droebachiensis*.
 Laboratory experiments examined crosses in which eggs had a choice between
 the sperm from these two species or in no-choice trials. The probability
 of hybridization was examined as a function of the sperm and egg
 recognition genotype of the two parents. In addition to these experiments
 a geographic survey of the allele frequencies of these sperm and egg
 proteins was examined in *M. franciscanus* along the west coast of North
 America in areas in sympatry with *S. droebachiensis* and in allopatry.
 The Excel file has all the data presented in the figures in the manuscript
 and what was used in the statistical analyses. Each sheet in the Excel
 file has the data for one figure with an explanation of the heading in
 each column. The text files have the sequence data, in fasta format, for
 all the *M. franciscanus* and *S. droebachiensis* alleles (and their
 frequencies) that comprised the haplotype networks presented in the
 paper's supplement. ### Files and variables #### File:
 M\_fran\_bindin\_alleles\_for\_haplotype.txt **Description:** text file in
 fasta format of the sperm bindin alleles used to generate the haplotype
 network in M. franciscanus ##### Variables * base pair identities ####
 File: M\_fran\_CUB7\_alleles\_for\_haplotype.txt **Description:** text
 file in fasta format of the EBR1 CUB7 alleles used to generate the
 haplotype network in *M. franciscanus* ##### Variables * base pair
 identities #### File: M\_fran\_TSP8\_alleles\_for\_haplotype.txt
 **Description:**  text file in fasta format of the EBR1 TSP8 alleles used
 to generate the haplotype network in *M. franciscanus* ##### Variables *
 base pair identities #### File:
 M\_fran\_TSP13\_alleles\_for\_haplotype.txt **Description:** text file in
 fasta format of the EBR1 TSP13 alleles used to generate the haplotype
 network in *M. franciscanus* ##### Variables * base pair identities ####
 File: M\_fran\_CUB1\_alleles\_for\_haplotype.txt **Description:** text
 file in fasta format of the EBR1 CUB1 alleles used to generate the
 haplotype network in *M. franciscanus* ##### Variables * Base pair
 identities #### File: S\_droeb\_CUB1\_alleles\_for\_haplotype.TXT
 **Description:** text file in fasta format of the EBR1 CUB1 alleles used
 to generate the haplotype network in *S. drobachiensis* Variables base
 pair identities #### File: S\_droeb\_CUB7\_alleles\_for\_haplotype.txt
 **Description:** text file in fasta format of the EBR1 CUB7 alleles used
 to generate the haplotype network in S. drobachiensis ##### Variables *
 Base pair identities #### File:
 Data\_for\_Evolution\_2025\_CSP\_paper\_author\_name\_removed.xlsx
 **Description:** Excel file for all the figures and statistical analyses
 presented in the paper. Fig 1 spreadsheet: This is the data used to
 generate Fig. 1 and evaluated in Supplemental Table 4. These are the
 results of laboratory crosses examining the proportion of eggs fertilized
 when eggs are not given a choice of sperm source. Column headings:
 “Species of eggs” is either *S. droebachiensis* or *M. franciscanus*;
 “Sperm concentration” is either low (sperm limited) or high (sperm
 saturated); “Type of cross” is either heterospecific (hybrid cross) or
 conspecific. Fig 2 spreadsheet: This is the data used to generate Fig. 2
 and test for the effects of sperm concentration and the ratio of *S.
 droebachiensis*/*M. franciscanus* sperm. There are the results of
 laboratory crosses where *S. droebachiensis* eggs were tested against a
 mixture of sperm from both species and the proportion of hybrid embyros
 produced. Column headings: “Proportion of *S. droebachiensis* sperm” is
 the proportion of the total sperm consisting of *S. droebachiensis* sperm;
 “Sperm concentration” is either saturating (sat) or limiting (lim);
 “Proportion of hybrid embryos” is the proportion of embryos genotyped as
 being sired by *M. franciscanus* sperm. Fig 3 spreadsheet: This is the
 data used to generate Fig. 3 and the analysis presented in Supplemental
 Table 5. These are the results of laboratory crosses testing a 90%/10%
 mixture of *M. franciscanus* sperm/*S. droebachieneis* sperm on *S.
 droebachiensis* eggs as a function of protein variants in sperm and egg
 recognition proteins. The proportion of embryo produced by *M.
 franciscanus* sperm (hybrids) were assigned via PCR or species-specific
 primers. Column headings: “*M. franciscanus* bindin sites 16 and 38” is
 the genotype (amino acid code at those sites) of the sire at the sperm
 bindin locus;” S.droeb CUB1_17” is the genotype (amino acid code) of the
 dame at the CUB1 repeat in the EBR1 gene; S.droeb CUB7_44” is the genotype
 (amino acid code) of the dame at the CUB7 repeat in the EBR1 gene;
 “Proportion hybrid” is the proportion of hybrids produced in each cross.
 Fig 4 spreadsheet: This is the data for Fig. 4 and analysis presented in
 Supplemental Table 6. These were laboratory crosses testing the proportion
 of *M. franciscanus *eggs fertilized by *S. droebachiensis *sperm as a
 function of sperm concentration and the genotype of the four variable EBR1
 repeats in *M. franciscanus* females. Dots indicate missing data. Column
 headings: “Date” is the date of the experimental cross; “TSP8_31” is the
 genotype (amino acid code) of the dame at the TSP8 repeat in the EBR1
 gene; “TSP13_27” is the genotype (amino acid code) of the dame at the
 TSP13 repeat in the EBR1 gene; CUB1_27” is the genotype (amino acid code)
 of the dame at the CUB1 repeat in the EBR1 gene; “CUB7_51 is the genotype
 (amino acid code) of the dame at the TCUB7 repeat in the EBR1 gene; “droe
 sperm” is the sperm concentration (sperm/mL); “Prop” is the proportion of
 eggs fertilized in that cross. Fig5 spreadsheet: This is the data for Fig.
 5 and analysis presented in Supplemental Table 7. These data are the
 allele frequencies of the four variable EBR1 repeats and sperm bindin gene
 in *M. franciscanus* at sites in (north) and out (south) of sympatry with
 *S. droebachiensis*. Column headings: “site” name of site; “Lat” is the
 latitude of the site; following 11 columns are the allele frequencies for
 each repeat; 14th column is whether the site is north or south of Point
 Conception, CA, USA; Last column is the average test diameter of the sea
 urchin in the sample.