title: Computational identification of genes modulating stem height-diameter allometry.
abstract: The developmental variation in stem height with respect to stem diameter is related to a broad range of ecological and evolutionary phenomena in trees, but the underlying genetic basis of this variation remains elusive. We implement a dynamic statistical model, functional mapping, to formulate a general procedure for the computational identification of quantitative trait loci (QTLs) that control stem height-diameter allometry during development. Functional mapping integrates the biological principles underlying trait formation and development into the association analysis of DNA genotype and endpoint phenotype, thus providing an incentive for understanding the mechanistic interplay between genes and development. Built on the basic tenet of functional mapping, we explore two core ecological scenarios of how stem height and stem diameter covary in response to environmental stimuli: (i) trees pioneer sunlit space by allocating more growth to stem height than diameter and (ii) trees maintain their competitive advantage through an inverse pattern. The model is equipped to characterize 'pioneering' QTLs (piQTLs) and 'maintaining' QTLs (miQTLs) which modulate these two ecological scenarios, respectively. In a practical application to a mapping population of full-sib hybrids derived from two Populus species, the model has well proven its versatility by identifying several piQTLs that promote height growth at a cost of diameter growth and several miQTLs that benefit radial growth at a cost of height growth. Judicious application of functional mapping may lead to improved strategies for studying the genetic control of the formation mechanisms underlying trade-offs among quantities of assimilates allocated to different growth parts.
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Meixia
authors.initials: M
authors.lastname: Ye
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
authors.forename: Minren
authors.initials: M
authors.lastname: Huang
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.|Center for Statistical Genetics, The Pennsylvania State University, Hershey, PA, USA.
authors.forename: Rongling
authors.initials: R
authors.lastname: Wu
mesh_terms: D005838:Genotype; D008962:Models, Theoretical; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics
keywords: functional mapping; height-diameter allometry; mathematical equation; quantitative trait loci