title: Thermal acclimation of heart rates in reptilian embryos.
abstract: In many reptiles, the thermal regimes experienced by eggs in natural nests vary as a function of ambient weather and location, and this variation has important impacts on patterns of embryonic development. Recent advances in non-invasive measurement of embryonic heart rates allow us to answer a long-standing puzzle in reptilian developmental biology: Do the metabolic and developmental rates of embryos acclimate to local incubation regimes, as occurs for metabolic acclimation by post-hatching reptiles? Based on a strong correlation between embryonic heart rate and oxygen consumption, we used heart rates as a measure of metabolic rate. We demonstrate acclimation of heart rates relative to temperature in embryos of one turtle, one snake and one lizard species that oviposit in relatively deep nests, but found no acclimation in another lizard species that uses shallow (and hence, highly thermally variable) nests. Embryonic thermal acclimation thus is widespread, but not ubiquitous, within reptiles.
authors.affiliation: Hangzhou Key Laboratory for Animal Science and Technology, Hangzhou Normal University, Hangzhou, People's Republic of China. dwghz@126.com
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Du
authors.forename: Hua
authors.initials: H
authors.lastname: Ye
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Warner
authors.forename: Richard
authors.initials: R
authors.lastname: Shine
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015509:Developmental Biology / Q000379:methods; D004625:Embryo, Nonmammalian / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology; D004734:Energy Metabolism; D006339:Heart Rate; D006358:Hot Temperature; D010101:Oxygen Consumption; D012104:Reptiles / Q000196:embryology*; D013696:Temperature; D014426:Turtles / Q000196:embryology