title: O father where art thou? Paternity analyses in a natural population of the haploid-diploid seaweed Chondrus crispus.
abstract: The link between life history traits and mating systems in diploid organisms has been extensively addressed in the literature, whereas the degree of selfing and/or inbreeding in natural populations of haploid-diploid organisms, in which haploid gametophytes alternate with diploid sporophytes, has been rarely measured. Dioecy has often been used as a proxy for the mating system in these organisms. Yet, dioecy does not prevent the fusion of gametes from male and female gametophytes originating from the same sporophyte. This is likely a common occurrence when spores from the same parent are dispersed in clumps and recruit together. This pattern of clumped spore dispersal has been hypothesized to explain significant heterozygote deficiency in the dioecious haploid-diploid seaweed Chondrus crispus. Fronds and cystocarps (structures in which zygotes are mitotically amplified) were sampled in two 25 m(2) plots located within a high and a low intertidal zone and genotyped at 5 polymorphic microsatellite loci in order to explore the mating system directly using paternity analyses. Multiple males sired cystocarps on each female, but only one of the 423 paternal genotypes corresponded to a field-sampled gametophyte. Nevertheless, larger kinship coefficients were detected between males siring cystocarps on the same female in comparison with males in the entire population, confirming restricted spermatial and clumped spore dispersal. Such dispersal mechanisms may be a mode of reproductive assurance due to nonmotile gametes associated with putatively reduced effects of inbreeding depression because of the free-living haploid stage in C. crispus.
authors.affiliation: 1] CNRS, UPMC University Paris 06, Sorbonne Universités, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, Roscoff, France [2] Departamento de Ecología, Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: S A
authors.initials: SA
authors.lastname: Krueger-Hadfield
authors.affiliation: CNRS, UPMC University Paris 06, Sorbonne Universités, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, Roscoff, France.
authors.forename: D
authors.initials: D
authors.lastname: Roze
authors.affiliation: Departamento de Ecología, Center of Applied Ecology and Sustainability, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: J A
authors.initials: JA
authors.lastname: Correa
authors.affiliation: CNRS, UPMC University Paris 06, Sorbonne Universités, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, Roscoff, France.
authors.forename: C
authors.initials: C
authors.lastname: Destombe
authors.affiliation: CNRS, UPMC University Paris 06, Sorbonne Universités, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, Roscoff, France.
authors.forename: M
authors.initials: M
authors.lastname: Valero
mesh_terms: D044723:Chondrus / Q000235:genetics* / Q000502:physiology; D004171:Diploidy; D005828:Genetics, Population; D005838:Genotype; D055993:Germ Cells, Plant / Q000254:growth & development*; D006238:Haploidy; D006720:Homozygote; D007178:Inbreeding; D008969:Molecular Sequence Data; D012098:Reproduction / Q000235:genetics