title: Micro-magnetic resonance imaging study of live quail embryos during embryonic development.
abstract: Eggs containing live Japanese quail embryos were imaged using micro-magnetic resonance imaging (μMRI) at 24-h intervals from Day 0 to 8, the period during which the main body axis is being laid down and organogenesis is taking place. Considerable detail of non-embryonic structures such as the latebra was revealed at early stages but the embryo could only be visualized around Day 3. Three-dimensional (3D) changes in embryo length and volume were quantified and also changes in volume in the extra- and non-embryonic components. The embryo increased in length by 43% and nearly trebled in volume between Day 4 and Day 5. Although the amount of yolk remained fairly constant over the first 5 days, the amount of albumen decreases significantly and was replaced by extra-embryonic fluid (EEF). ¹H longitudinal (T₁) and transverse (T₂) relaxation times of different regions within the eggs were determined over the first 6 days of development. The T₂ measurements mirrored the changes in image intensity observed, which can be related to the aqueous protein concentrations. In addition, a comparison of the development of Day 0 to 3 quail embryos exposed to radiofrequency (rf) pulses, 7 T static magnetic fields and magnetic field gradients for an average of 7 h with the development of control embryos did not reveal any gross changes, thus confirming that μMRI is a suitable tool for following the development of live avian embryos over time from the earliest stages.
authors.affiliation: Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, DD1 5EH Dundee, UK. s.duce@dundee.ac.uk
authors.forename: Suzanne
authors.initials: S
authors.lastname: Duce
authors.forename: Fiona
authors.initials: F
authors.lastname: Morrison
authors.forename: Monique
authors.initials: M
authors.lastname: Welten
authors.forename: Glenn
authors.initials: G
authors.lastname: Baggott
authors.forename: Cheryll
authors.initials: C
authors.lastname: Tickle
mesh_terms: D000818:Animals; D003370:Coturnix; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology*; D047108:Embryonic Development / Q000502:physiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization; D011784:Quail / Q000033:anatomy & histology* / Q000196:embryology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity