A New Method for Detection and Quantification of Heartbeat Parameters in Drosophila, Zebrafish, and Embryonic Mouse Hearts

Abstract

The genetic basis of heart development is remarkably conserved from Drosophila to mammals, and insights from flies have greatly informed our understanding of vertebrate heart development. Recent evidence suggests that many aspects of heart function are also conserved and the genes involved in heart development also play roles in adult heart function. We have developed a Drosophila heart preparation and movement analysis algorithm that allows quantification of functional parameters. Our methodology combines high-speed optical recording of beating hearts with a robust, semi-automated analysis to accurately detect and quantify, on a beat-to-beat basis, not only heart rate but also diastolic and systolic intervals, systolic and diastolic diameters, percent fractional shortening, contraction wave velocity, and cardiac arrhythmicity. Here, we present a detailed analysis of hearts from adult Drosophila, 2–3-day-old zebrafish larva, and 8-day-old mouse embryos, indicating that our methodology is potentially applicable to an array of biological models. We detect progressive age-related changes in fly hearts as well as subtle but distinct cardiac deficits in Tbx5 heterozygote mutant zebrafish. Our methodology for quantifying cardiac function in these genetically tractable model systems should provide valuable insights into the genetics of heart function.

Tinman/Nkx2-5 acts via miR-1 and upstream of Cdc42 to regulate heart function across species

“…Image analysis and M-mode traces on semi-intact fly preparations Procedures used were as described previously (Ocorr et al, 2007;Fink et al, 2009). In brief, flies were anesthetized and the head, ventral thorax, and fashion in the adult is limited.…”

Pathologies et vieillissement cardiaque

“…Pour l'analyse du rythme et de la contractilité, une meilleure précision est obtenue avec des préparations semi-intactes dans lesquelles le coeur de la mouche nettoyé du corps gras, baigne dans une solution physiologique oxygénée. À partir de films réalisés à haute vitesse et à haute résolution [12], est créée une image globale, similaire aux M-modes 2 qui sont générés en échographie cardiaque, qui décrit les mouvements des bords du tube cardiaque au cours du temps (Figure 2). Ainsi, le coeur de la mouche est-il devenu un modèle génétique non seulement des cardiomyopathies congénitales -résultant de défauts survenus au cours du développement -mais aussi pour comprendre des anomalies structurelles et fonctionnelles telles que les cardiomyopathies et les arythmies dont certains aspects seront décrits plus en détail dans cette synthèse.…”

Real-time optical gating for three-dimensional beating heart imaging

“…17 Very similar metrics have been used by other authors for motion detection in brightfield heart images, see for example. 18 For two frames f and g each consisting of n pixels f i and g i , the metrics are defined as follows:…”