Temperature until the 'eyed stage' of embryogenesis programmes the growth trajectory and muscle phenotype of adult Atlantic salmon.
We investigated how adult growth in Atlantic salmon (Salmo salar L.) was affected by changing embryonic temperature from fertilization until the completion of eye pigmentation. Fertilized eggs from several hundred families were divided between four temperature treatments (2, 5, 8 or 10 degrees C) and subsequently reared in identical conditions in replicated tanks. Fish exposed to 2 and 5 degrees C treatments were significantly smaller at smoltification than groups at higher temperatures, but showed substantial compensatory catch-up growth. Remarkably, temperature during this short window of embryogenesis dictated adult myogenic phenotype three years later with significant treatment effects on the muscle fibre final number (FFN), maximum diameter, nuclear density and size distribution. FFN was highest for the 5 degrees C treatment and was reduced at higher and lower treatment temperatures. Our results require direct temperature effects on embryonic tissues, such as the stem cell-containing external cell layer, in order to produce persistent effects on juvenile and adult growth.
Macqueen
Daniel J
DJ
School of Biology, University of St Andrews, St Andrews KY16 8LB, UK.
Robb
David H F
DH
Olsen
Tom
T
Melstveit
Linda
L
Paxton
Charles G M
CG
Johnston
Ian A
IA
D000704:Analysis of Variance; D000818:Animals; D016014:Linear Models; D024510:Muscle Development / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000196:embryology; D010641:Phenotype; D020317:Salmo salar / Q000196:embryology / Q000254:growth & development*; D013696:Temperature