TY - JOUR
T1 - Patterns of nuclear genetic variation in the poecilogonous polychaete Streblospio benedicti
AU - Rockman, Matthew V.
N1 - Funding Information:
This work was supported by startup funds from New York University. The symposium was sponsored by the United States National Science Foundation (IOS-1157279), the Company of Biologists, Ltd., the American Microscopical Society, and the Society for Integrative and Comparative Biology, including SICB divisions DEDB, DEE, and DIZ.
PY - 2012/7
Y1 - 2012/7
N2 - The evolution of marine larvae is replete with transitions in trophic mode, but little is known about how, at the genetic level, these transitions are achieved. Basic parameters, including the number of underlying loci, their molecular characteristics, and the population-genetic processes that drive transitions remain unknown. Streblospio benedicti, an abundant benthic polychaete with heritable poecilogony, provides a unique genetically tractable system for addressing these issues. Individuals of S. benedicti vary in diverse aspects of development. Some females produce small, planktotrophic larvae, whereas others produce large, yolky larvae capable of settling without feeding. Here, I present estimates of basic features of nuclear genetic variation in S. benedicti to lay the foundations for subsequent efforts to understand the genetic basis of poecilogony. Sequence of ∼20kb of random nuclear DNA indicates that the nucleotide composition, at 62.1 A+T, is typical of lophotrochozoan genomes. Population-genetic data, acquired by sequencing two loci (∼2500 bp) in multiple animals of each developmental morph, indicate that the morphs exhibit very little differentiation at random loci. Nucleotide heterozygosity (θ̂π) is ∼0.5-1 per site, and linkage disequilibrium decays within a few kilobases (ρ̂∼3× 10-3 per site). These data suggest that genetic mapping by association will require a high density of markers, but linkage mapping and identification of regions of elevated inter-morph differentiation hold great promise.
AB - The evolution of marine larvae is replete with transitions in trophic mode, but little is known about how, at the genetic level, these transitions are achieved. Basic parameters, including the number of underlying loci, their molecular characteristics, and the population-genetic processes that drive transitions remain unknown. Streblospio benedicti, an abundant benthic polychaete with heritable poecilogony, provides a unique genetically tractable system for addressing these issues. Individuals of S. benedicti vary in diverse aspects of development. Some females produce small, planktotrophic larvae, whereas others produce large, yolky larvae capable of settling without feeding. Here, I present estimates of basic features of nuclear genetic variation in S. benedicti to lay the foundations for subsequent efforts to understand the genetic basis of poecilogony. Sequence of ∼20kb of random nuclear DNA indicates that the nucleotide composition, at 62.1 A+T, is typical of lophotrochozoan genomes. Population-genetic data, acquired by sequencing two loci (∼2500 bp) in multiple animals of each developmental morph, indicate that the morphs exhibit very little differentiation at random loci. Nucleotide heterozygosity (θ̂π) is ∼0.5-1 per site, and linkage disequilibrium decays within a few kilobases (ρ̂∼3× 10-3 per site). These data suggest that genetic mapping by association will require a high density of markers, but linkage mapping and identification of regions of elevated inter-morph differentiation hold great promise.
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U2 - 10.1093/icb/ics083
DO - 10.1093/icb/ics083
M3 - Article
C2 - 22659203
AN - SCOPUS:84863439113
SN - 1540-7063
VL - 52
SP - 173
EP - 180
JO - Integrative and Comparative Biology
JF - Integrative and Comparative Biology
IS - 1
ER -