title: Molecular basis of canalization in an ascidian species complex adapted to different thermal conditions.
abstract: Canalization is a result of intrinsic developmental buffering that ensures phenotypic robustness under genetic variation and environmental perturbation. As a consequence, animal phenotypes are remarkably consistent within a species under a wide range of conditions, a property that seems contradictory to evolutionary change. Study of laboratory model species has uncovered several possible canalization mechanisms, however, we still do not understand how the level of buffering is controlled in natural populations. We exploit wild populations of the marine chordate Ciona intestinalis to show that levels of buffering are maternally inherited. Comparative transcriptomics show expression levels of genes encoding canonical chaperones such as Hsp70 and Hsp90 do not correlate with buffering. However the expression of genes encoding endoplasmic reticulum (ER) chaperones does correlate. We also show that ER chaperone genes are widely conserved amongst animals. Contrary to previous beliefs that expression level of Heat Shock Proteins (HSPs) can be used as a measurement of buffering levels, we propose that ER associated chaperones comprise a cellular basis for canalization. ER chaperones have been neglected by the fields of development, evolution and ecology, but their study will enhance understanding of both our evolutionary past and the impact of global environmental change.
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.|Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.|Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, United Kingdom.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Sato
authors.affiliation: Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawashima
authors.affiliation: DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Fujie
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
authors.forename: Samantha
authors.initials: S
authors.lastname: Hughes
authors.affiliation: Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Satoh
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Shimeld
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000818:Animals; D005075:Biological Evolution; D002938:Ciona intestinalis / Q000145:classification / Q000502:physiology*; D005786:Gene Expression Regulation; D010802:Phylogeny; D012641:Selection, Genetic; D013312:Stress, Physiological; D013696:Temperature