title: Influence of semicrystalline order on the second-harmonic generation efficiency in the anisotropic bands of myocytes.
abstract: The influence of semicrystalline order on the second-harmonic generation (SHG) efficiency in the anisotropic bands of Drosophila melanogaster sarcomeres from larval and adult muscle has been investigated. Differences in the semicrystalline order were obtained by using wild-type and mutant strains containing different amounts of headless myosin. The reduction in semicrystalline order without altering the chemical composition of myofibrils was achieved by observing highly stretched sarcomeres and by inducing a loss of viability in myocytes. In all cases the reduction of semicrystalline order in anisotropic bands of myocytes resulted in a substantial decrease in SHG. Second-harmonic imaging during periodic contractions of myocytes revealed higher intensities when sarcomeres were in the relaxed state compared with the contracted state. This study demonstrates that an ordered semicrystalline arrangement of anisotropic bands plays a determining role in the efficiency of SHG in myocytes.
authors.affiliation: University of Toronto at Mississauga, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Greenhalgh
authors.forename: Nicole
authors.initials: N
authors.lastname: Prent
authors.forename: Chantal
authors.initials: C
authors.lastname: Green
authors.forename: Richard
authors.initials: R
authors.lastname: Cisek
authors.forename: Arkady
authors.initials: A
authors.lastname: Major
authors.forename: Bryan
authors.initials: B
authors.lastname: Stewart
authors.forename: Virginijus
authors.initials: V
authors.lastname: Barzda
mesh_terms: D000818:Animals; D016880:Anisotropy; D002478:Cells, Cultured; D003461:Crystallography; D004331:Drosophila melanogaster; D008856:Microscopy, Fluorescence / Q000379:methods*; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology* / Q000648:ultrastructure*; D012518:Sarcomeres / Q000502:physiology* / Q000648:ultrastructure*