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This article demonstrates two modalities to acquire information on cardiac function in larval Drosophila Melanogaster:
in-vivo imaging and heartbeat monitoring. To achieve these goals a dedicated imaging instrument able to provide
simultaneous en-face Optical Coherence Tomography (OCT) and Laser Scanning Confocal Microscopy (LSCM) images
has been developed. With this dual imaging system, the heart can easily be located and visualised within the specimen
and the change of the heart shape in a cardiac cycle monitored. The system can easily be switched to a stethoscopic
regime, simply by interrupting the scanning of the light beam across the sample, after selecting the point of interest in the
imaging regime. Here we have used targeted gene expression to knockdown the myospheroid (mys) gene in the larval
heart using a specific RNAi construct. By knocking down a β integrin subunit encoded by mys we have recorded an
enlarged heart chamber in both diastolic and systolic states. Also, the fraction of reduction of the chamber diameter was
smaller in the knockdown heart. These phenotypic differences indicate that impaired cardiac contractility occurs in the
heart where the integrin gene express level is reduced. As far as we are aware, this is for the first time when it is shown
in Drosophila that integrins have a direct relationship to a dilated heart defect, and conseqThis article demonstrates two modalities to acquire information on cardiac function in larval Drosophila Melanogaster:
in-vivo imaging and heartbeat monitoring. To achieve these goals a dedicated imaging instrument able to provide
simultaneous en-face Optical Coherence Tomography (OCT) and Laser Scanning Confocal Microscopy (LSCM) images
has been developed. With this dual imaging system, the heart can easily be located and visualised within the specimen
and the change of the heart shape in a cardiac cycle monitored. The system can easily be switched to a stethoscopic
regime, simply by interrupting the scanning of the light beam across the sample, after selecting the point of interest in the
imaging regime. Here we have used targeted gene expression to knockdown the myospheroid (mys) gene in the larval
heart using a specific RNAi construct. By knocking down a β integrin subunit encoded by mys we have recorded an
enlarged heart chamber in both diastolic and systolic states. Also, the fraction of reduction of the chamber diameter was
smaller in the knockdown heart. These phenotypic differences indicate that impaired cardiac contractility occurs in the
heart where the integrin gene express level is reduced. As far as we are aware, this is for the first time when it is shown
in Drosophila that integrins have a direct relationship to a dilated heart defect, and consequently we demonstrate the
utility of Drosophila as model for the study of vertebrate heart disease. By monitoring the heartbeat we also
demonstrated a reduction of the heart rate in Tropomyosin mutant compared to the wild type larva.uently we demonstrate the
utility of Drosophila as model for the study of vertebrate heart disease. By monitoring the heartbeat we also
demonstrated a reduction of the heart rate in Tropomyosin mutant compared to the wild type larva.
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