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K. H. Low - One of the best experts on this subject based on the ideXlab platform.
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Design and Initial Testing of a Single-Motor-Driven Spatial Pectoral Fin Mechanism
2007 International Conference on Mechatronics and Automation, 2007Co-Authors: K. H. Low, Shiwu Zhang, Jie Yang, S. Prabu, Yonghua ZhangAbstract:This paper aims to study drag based labriform mode of locomotion in fishes and attempts to design and develop a prototype performing Pectoral Fin motions. The methodology involves Pectoral Fin mechanism concept generation, design, development, and performance analysis. For labriform mode drag based propulsion, the initial design makes use of a rotating disk on which a planet gear rotates around a fixed sun gear, conjunction with universal and spherical joints. The model is able to achieve Pectoral Fin motions rowing, flapping and feathering in an integrated manner, with a single motor. The unique feature of this prototype which makes it attractive from earlier designs is its capability to produce desired velocity by making use of a single power source. Initial studies carried out on the prototype's performance with respect to its potential to emulate actual Pectoral Fin movement gives promising results. It shows that the Pectoral Fin model can be incorporated into an autonomous underwater vehicle (AUV).
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Initial research on development of a flexible Pectoral Fin using shape memory alloy
2006 IEEE International Conference on Mechatronics and Automation ICMA 2006, 2006Co-Authors: Zhang Yonghua, He Jianhui, Yang Jie, K. H. LowAbstract:Crucians propel themselves through the water primarily either with their body and tail (axial-based locomotion) at high swimming speed or with their greatly expanded Pectoral Fins (Pectoral-Fin-based locomotion) at low swimming speed. They also use their Pectoral Fins to adjust stability in still motion. In this paper, we present recent experimental research on Pectoral Fin structure, Fin locomotion, Meanwhile consider a design of Pectoral Fin actuator based on shape memory alloy (SMA) composites composed of a couple of plates with the opposite functions. Both SMA plates, whose microstructure is either martensite or austenite, are individually arranged in parallel and operated as a bias to each other mimicking the morphological and kinematic characters of Pectoral Fin of crucian. We also use strain gauge sensors for deformation control. Finally an examination was carried out to test the relationship between the tip displacement of SMA plate and the output voltage signal of strain gauge as well as the relationship between Pulse Width Modulate(PWM) and bending angle(theta). The results give us a confidence on the possibility of imitating Pectoral Fin locomotion using shape memory alloy.
George V Lauder - One of the best experts on this subject based on the ideXlab platform.
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rajiform locomotion three dimensional kinematics of the Pectoral Fin surface during swimming in the freshwater stingray potamotrygon orbignyi
The Journal of Experimental Biology, 2012Co-Authors: Erin L Blevins, George V LauderAbstract:SUMMARY Rajiform locomotion in fishes is dominated by distinctive undulations of expanded Pectoral Fins. Unlike other fishes, which typically interact with the fluid environment via multiple Fins, undulating rays modulate a single control surface, the Pectoral disc, to perform pelagic locomotion, maneuvering and other behaviors. Complex deformations of the broad, flexible Pectoral Fins occur as the undulating wave varies in three dimensions; Pectoral Fin kinematics and changes in waveform with swimming speed cannot be fully quantified by two-dimensional analyses of the Fin margin. We present the first three-dimensional analysis of undulatory rajiform locomotion in a batoid, the freshwater stingray Potamotrygon orbignyi . Using three cameras (250 frames s −1 ), we gathered three-dimensional excursion data from 31 points on the Pectoral Fin during swimming at 1.5 and 2.5 disc lengths s −1 , describing the propulsive wave and contrasting waveforms between swimming speeds. Only a relatively small region of the Pectoral Fin (~25%) undulates with significant amplitude (>0.5 cm). Stingrays can maintain extreme lateral curvature of the distal Fin margin in opposition to induced hydrodynamic loads, ‘cupping’ the edge of the Pectoral Fin into the flow, with potential implications for drag reduction. Wave amplitude increases across both anteroposterior and mediolateral Fin axes. Along the anteroposterior axis, amplitude increases until the wave reaches mid-disc and then remains constant, in contrast to angulliform patterns of continuous amplitude increase. Increases in swimming speed are driven by both wave frequency and wavespeed, though multivariate analyses reveal a secondary role for amplitude.
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a biorobotic model of the sunfish Pectoral Fin for investigations of Fin sensorimotor control
Bioinspiration & Biomimetics, 2010Co-Authors: Chris Phelan, George V Lauder, James L. Tangorra, Melina E HaleAbstract:A comprehensive understanding of the control of flexible Fins is fundamental to engineering underwater vehicles that perform like fish, since it is the Fins that produce forces which control the fish's motion. However, little is known about the Fin's sensory system or about how fish use sensory information to modulate the Fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish Pectoral Fin, a biorobotic model of the Pectoral Fin and of the Fin's sensorimotor system was developed and used to investigate relationships between sensory information, Fin ray motions and propulsive forces. This robotic Fin is able to generate the motions and forces of the biological Fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the Pectoral Fin. Results support the idea that Fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a Fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of Fin ray motion will result from the integration of characteristics of many sensor modalities.
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low dimensional models and performance scaling of a highly deformable fish Pectoral Fin
Journal of Fluid Mechanics, 2009Co-Authors: Meliha Bozkurttas, George V Lauder, Rajat Mittal, Haibo Dong, Peter MaddenAbstract:The hydrodynamics of a highly deformable fish Pectoral Fin used by a bluegill sunfish (Lepomis macrochirus) during steady forward swimming are examined in detail. Low-dimensional models of the Fin gait based on proper orthogonal decomposition (POD) are developed, and these are subjected to analysis using an incompressible Navier- Stokes flow solver. The approach adopted here is primarily motivated by the quest to develop insights into the Fin function and associated hydrodynamics, which are specifically useful for the design of a biomimetic, Pectoral Fin propulsor. The POD analysis shows that the complex kinematics of the Pectoral Fin can be described by a few (<5) POD modes and that the first three POD modes are highly distinct. The significance of these modes for thrust production is examined by synthesizing a sequence of Fin gaits from these modes and simulating the flow associated with these gaits. We also conduct a scale study of the Pectoral Fin in order to understand the effect of the two key non-dimensional parameters, Reynolds number and Strouhal number, on the propulsive performance. The implications of the POD analysis and performance scaling on the design of a robotic Pectoral Fin are discussed.
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Low-dimensional models and performance scaling of a highly deformable fish Pectoral Fin
Journal of Fluid Mechanics, 2009Co-Authors: Meliha Bozkurttas, George V Lauder, Rajat Mittal, Haibo Dong, Peter MaddenAbstract:The hydrodynamics of a highly deformable fish Pectoral Fin used by a bluegill sunfish (Lepomis macrochirus) during steady forward swimming are examined in detail. Low-dimensional models of the Fin gait based on proper orthogonal decomposition (POD) are developed, and these are subjected to analysis using an incompressible Navier- Stokes flow solver. The approach adopted here is primarily motivated by the quest to develop insights into the Fin function and associated hydrodynamics, which are specifically useful for the design of a biomimetic, Pectoral Fin propulsor. The POD analysis shows that the complex kinematics of the Pectoral Fin can be described by a few (
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locomotion with flexible propulsors ii computational modeling of Pectoral Fin swimming in sunfish
Bioinspiration & Biomimetics, 2006Co-Authors: Rajat Mittal, George V Lauder, Meliha Bozkurttas, Haibo Dong, Peter MaddenAbstract:This paper describes a computational fluid dynamics (CFD) based investigation of the Pectoral Fin hydrodynamics of a bluegill sunfish. The Pectoral Fin of this fish undergoes significant shape-change during its abduction–adduction cycle and the effect of this deformation on the thrust performance remains far from understood. The current study is part of a combined experimental–numerical approach wherein the numerical simulations are being used to examine features and issues that are not easily amenable to the experiments. These numerical simulations are highly challenging and we briefly describe the computational methodology that has been developed to handle such flows. Finally, we describe some of the key computational results including wake vortex topologies and hydrodynamics forces.
Melina E Hale - One of the best experts on this subject based on the ideXlab platform.
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Pectoral Fin kinematics and motor patterns are shaped by Fin ray mechanosensation during steady swimming in scarus quoyi
The Journal of Experimental Biology, 2020Co-Authors: Brett R Aiello, Mark W. Westneat, Aaron M Olsen, Chris E Mathis, Melina E HaleAbstract:For many fish species, rhythmic movement of the Pectoral Fins, or forelimbs, drives locomotion. In terrestrial vertebrates, normal limb-based rhythmic gaits require ongoing modulation with limb mechanosensors. Given the complexity of the fluid environment and dexterity of fish swimming through it, we hypothesize that mechanosensory modulation is also critical to normal Fin-based swimming. Here, we examined the role of sensory feedback from the Pectoral Fin rays and membrane on the neuromuscular control and kinematics of Pectoral Fin-based locomotion. Pectoral Fin kinematics and electromyograms of the six major Fin muscles of the parrotfish, Scarus quoyi, a high-performance Pectoral Fin swimmer, were recorded during steady swimming before and after bilateral transection of the sensory nerves extending into the rays and surrounding membrane. Alternating activity of antagonistic muscles was observed and drove the Fin in a figure-of-eight Fin stroke trajectory before and after nerve transection. After bilateral transections, Pectoral Fin rhythmicity remained the same or increased. Differences in Fin kinematics with the loss of sensory feedback also included Fin kinematics with a significantly more inclined stroke plane angle, an increased angular velocity and Fin beat frequency, and a transition to the body-caudal Fin gait at lower speeds. After transection, muscles were active over a larger proportion of the Fin stroke, with overlapping activation of antagonistic muscles rarely observed in the trials of intact fish. The increased overlap of antagonistic muscle activity might stiffen the Fin system in order to enhance control and stability in the absence of sensory feedback from the Fin rays. These results indicate that Fin ray sensation is not necessary to generate the underlying rhythm of Fin movement, but contributes to the specification of Pectoral Fin motor pattern and movement during rhythmic swimming.
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a biorobotic model of the sunfish Pectoral Fin for investigations of Fin sensorimotor control
Bioinspiration & Biomimetics, 2010Co-Authors: Chris Phelan, George V Lauder, James L. Tangorra, Melina E HaleAbstract:A comprehensive understanding of the control of flexible Fins is fundamental to engineering underwater vehicles that perform like fish, since it is the Fins that produce forces which control the fish's motion. However, little is known about the Fin's sensory system or about how fish use sensory information to modulate the Fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish Pectoral Fin, a biorobotic model of the Pectoral Fin and of the Fin's sensorimotor system was developed and used to investigate relationships between sensory information, Fin ray motions and propulsive forces. This robotic Fin is able to generate the motions and forces of the biological Fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the Pectoral Fin. Results support the idea that Fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a Fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of Fin ray motion will result from the integration of characteristics of many sensor modalities.
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Neural development of the zebrafish (Danio rerio) Pectoral Fin
The Journal of comparative neurology, 2007Co-Authors: Dean H. Thorsen, Melina E HaleAbstract:The innervation and actuation of limbs have been major areas of research in motor control. Here we describe the innervation of the Pectoral Fins of the larval zebrafish (Danio rerio) and its ontogeny. Imaging and genetic tools available in this species provide opportunities to add new perspectives to the growing body of work on limbs. We used immunocytological and gross histological techniques with confocal microscopy to characterize the pattern of Pectoral Fin nerves. We retrogradely labeled Fin neurons to describe the distributions of the Pectoral Fin motor pool in the spinal cord. At 5 days postfertilization, four nerves innervate the Pectoral Fins. We found that the rostral three nerves enter the Fin from the dorsal side of the Fin base and service the dorsal and middle Fin regions. The fourth nerve enters the Fin from the ventral Fin base and innervates the ventral region. We found no mediolateral spatial segregation between adductor and abductor cell bodies in the spinal cord. During the larval stage Pectoral Fins have one adductor and one abductor muscle with an endoskeletal disc between them. As the skeleton and muscles expand and differentiate through postlarval development, there are major changes in Fin innervation including extensive elaboration to the developing muscles and concentration of innervation to specific nerves and Fin regions. The pattern of larval Fin innervation recorded is associated with later muscle subdivision, suggesting that Fin muscles may be functionally subdivided before they are morphologically subdivided.
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Pectoral Fin coordination and gait transitions in steadily swimming juvenile reef fishes
The Journal of Experimental Biology, 2006Co-Authors: Melina E Hale, Dean H. Thorsen, Ryan D Day, Mark W. WestneatAbstract:A common feature of animal locomotion is its organization into gaits with distinct patterns of movement and propulsor use for specific speeds. In terrestrial vertebrates, limb gaits have been extensively studied in diverse taxa and gait transitions have been shown to provide efficient locomotion across a wide range of speeds. In contrast, examination of gaits in fishes has focused on axial gaits and the transition between synchronous paired Fin locomotion and axial propulsion. Because many fishes use their Pectoral Fins as their primary propulsors, we aimed to examine more broadly the use of Pectoral Fin gaits in locomotion. We used juvenile reef fishes in these experiments because their swimming could be recorded readily across a wide range of Reynolds numbers, which we thought would promote gait diversity. Based on previous work in larval fishes, we hypothesized that juveniles have alternating Pectoral Fin movements rather than the synchronous, or in-phase, coordination pattern of adults. In flow tank swim studies, we found that juvenile sapphire damselfish Pomacentrus pavo used two Fin gaits during steady swimming. Below approximately 3 BL s-1, P. pavo primarily swam with alternating Fin strokes 180° out of phase with one another. At speeds in the range of 3-4 BL s-1, they performed a gait transition to synchronous Fin coordination. Between approximately 4 and 8 BL s-1, P. pavo primarily beat their Fins synchronously. At around 8 BL s-1 there was another gait transition to body-caudal Fin swimming, in which the Pectoral Fins were tucked against the body. We suggest that the transition from alternating to synchronous Fin coordination occurs due to mechanical limits of gait performance rather than to energy efficiency, stability or transitions in hydrodynamic regime. To determine whether this gait transition was species-specific, we surveyed Pectoral Fin locomotion in juveniles from 11 species in three reef fish families (Pomacentridae, Labridae and Scaridae). We found that this gait transition occurred in every species examined, suggesting that it may be a common behavior of juvenile reef fishes. Greater inclusion of early life history stages in the study of Fin-based locomotion should significantly enhance and inform the growing body of work on these behaviors.
Jie Yang - One of the best experts on this subject based on the ideXlab platform.
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Design and Implementation of a Lightweight Bioinspired Pectoral Fin Driven by SMA
Mechatronics, IEEE/ASME Transactions on, 2014Co-Authors: Shiwu Zhang, Kin Huat Low, Qin Yan, Bo Liu, Lei Wang, Jie YangAbstract:Pectoral Fins play an important role in the fish swimming performance, especially in maneuverability underwater. This paper presents the swimming propulsion by means of a flexible and lightweight Pectoral Fin inspired by a Koi Carp. The Fin is driven by embedded shape memory alloy (SMA) wires. In this paper, the kinematics of a Pectoral Fin from a live Koi Carp fish is first studied. The motion of Fin rays is analyzed, in which four basic patterns are extracted from the motion of the Pectoral Fin captured experimentally, especially the motion in retreating and hovering. Inspired by the Fin motion of the live fish, an SMA-driven Fin ray providing a two-degree-of-freedom bending motion is proposed. The detailed design of the bioinspired Pectoral Fin driven by SMA-driven rays is then presented. The basic unit is an SMA-driven plate with two SMA wires embedded on the two opposite sides of a plastic plate. The SMA-driven plate can bend by a pulse width modulation current delivered through SMA wires. An assembled SMA Fin ray is next formed by two SMA plates, which are placed in series with their cross sections perpendicular to each other. As a result, a lightweight bioinspired Pectoral Fin is constructed by placing radially multiple SMA Fin rays. The integrated Pectoral Fin is able to exhibit four patterns extracted in the biological kinematic study. The simulation and experimental optimization on the SMA-driven plate are presented in the Final part of this paper. The diameter of SMA wires is optimized and the oscillation angle of SMA plate is obtained. The experiment is also conducted to evaluate the motions of the bioinspired Pectoral Fin. The result demonstrates that the SMA-based Fin is effective in driving the bioinspired Fin. Moreover, the bioinspired Pectoral Fin is able to perform complex motions that can contribute to the maneuverability of fish robots.
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Fluid-Structure Interaction study on a flexible robotic Pectoral Fin
2012 IEEE International Conference on Mechatronics and Automation, 2012Co-Authors: Min Xu, Lei Wang, Jie Yang, Shiwu ZhangAbstract:Interested by the phenomenon that flexible structures of living creatures have better performance than the artificial rigid propeller, a study on Fluid-Structure Interaction (FSI), which solves the coupling between solid structure and fluid, is conducted to investigate the stiffness effect of the Pectoral Fin. Firstly, a three dimension computational Fin model based on the Pectoral Fin of Koi Carp is adopted and three cases are investigated which are rigid case, flexible case and flexible variable stiffness case, respectively. With this approach, their hydrodynamic force and fluid field are compared, and it is discovered that flexible cases have better hydrodynamic force and special fluid field, and there is a delay-response in the flexible structure. The flexible variable stiffness case exhibits the best performance in our experiment. Moreover, corresponding robotic Pectoral Fin experiments are carried out and the results Coincide with those of the simulation. The results will be a useful inspiration for the design of flexible underwater propeller and understanding of fish swimming mechanism.
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Initial implementation of basic actuated unit of a flexible Pectoral Fin driven by SMA
2010 IEEE International Conference on Mechatronics and Automation, 2010Co-Authors: Qin Yan, Shiwu Zhang, Jie YangAbstract:Fish are capable of remarkable locomotor performance through the complex 3D motions and the cooperation of different Fins. Specially, Pectoral Fins play an important role to provide thrust, maneuverability and balance ability. In this paper, a novel design of a flexible Pectoral Fin capable of 3D motions actuated by Shape Memory Alloy (SMA) is proposed. The flexible Pectoral Fin can perform five basic gestures of real Pectoral Fins: Relaxed, Expansion, Bending, Cupping and Undulation. First, we present the mechanical design of the flexible Pectoral Fin, and then put forward two effective designs (Plate Mode and Wire Embedded Mode) of Fin ray, the basic actuated unit of the Pectoral Fin, capable of bending in two mutually orthogonal directions. Second, we conduct theoretical analysis of the SMA Fin ray respectively based on the two designs. Finally, a series of experiments are conducted to investigate the performance of the two designs, meanwhile, the comparison between the two is given out.
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Design and Initial Testing of a Single-Motor-Driven Spatial Pectoral Fin Mechanism
2007 International Conference on Mechatronics and Automation, 2007Co-Authors: K. H. Low, Shiwu Zhang, Jie Yang, S. Prabu, Yonghua ZhangAbstract:This paper aims to study drag based labriform mode of locomotion in fishes and attempts to design and develop a prototype performing Pectoral Fin motions. The methodology involves Pectoral Fin mechanism concept generation, design, development, and performance analysis. For labriform mode drag based propulsion, the initial design makes use of a rotating disk on which a planet gear rotates around a fixed sun gear, conjunction with universal and spherical joints. The model is able to achieve Pectoral Fin motions rowing, flapping and feathering in an integrated manner, with a single motor. The unique feature of this prototype which makes it attractive from earlier designs is its capability to produce desired velocity by making use of a single power source. Initial studies carried out on the prototype's performance with respect to its potential to emulate actual Pectoral Fin movement gives promising results. It shows that the Pectoral Fin model can be incorporated into an autonomous underwater vehicle (AUV).
Robert M. Tombes - One of the best experts on this subject based on the ideXlab platform.
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tbx5 mediated expression of ca2 calmodulin dependent protein kinase ii is necessary for zebrafish cardiac and Pectoral Fin morphogenesis
Developmental Biology, 2009Co-Authors: Sarah C. Rothschild, Charles A. Easley, Ludmila Francescatto, James A. Lister, Deborah M. Garrity, Robert M. TombesAbstract:Abstract Mutations in the T-box transcription factor, TBX5, result in Holt–Oram syndrome (HOS), a human condition in which cardiac development is defective and forelimbs are stunted. Similarly, zebrafish tbx5 morphants and mutants (heartstrings; hst) lack Pectoral Fins and exhibit a persistently elongated heart that does not undergo chamber looping. Tbx5 is expressed in the developing atrium, ventricle and in Pectoral Fin fields, but its genetic targets are still being uncovered. In this study, evidence is provided that Tbx5 induces the expression of a specific member of the CaMK-II (the type II multifunctional Ca2+/calmodulin-dependent protein kinase) family; this CaMK-II is necessary for proper heart and Fin development. Morphants of β2 CaMK-II (camk2b2), but not the β1 CaMK-II (camk2b1) paralog, exhibit bradycardia, elongated hearts and diminished Pectoral Fin development. Normal cardiac phenotypes can be restored by ectopic cytosolic CaMK-II expression in tbx5 morphants. Like tbx5, camk2b2 is expressed in the Pectoral Fin and looping heart, but this expression is diminished in both tbx5 morphant and hst embryos. Conversely, the introduction of excess Tbx5 into zebrafish embryos and mouse fibroblasts doubles CaMK-II expression. We conclude that β CaMK-II expression and activity are necessary for proper cardiac and limb morphogenesis. These Findings not only identify a morphogenic target for Ca2+ during heart development, but support implied roles for CaMK-II in adult heart remodeling.
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Tbx5-mediated expression of Ca2+/calmodulin-dependent protein kinase II is necessary for zebrafish cardiac and Pectoral Fin morphogenesis
Developmental Biology, 2009Co-Authors: Sarah C. Rothschild, Charles A. Easley, Ludmila Francescatto, James A. Lister, Deborah M. Garrity, Robert M. TombesAbstract:Abstract Mutations in the T-box transcription factor, TBX5, result in Holt–Oram syndrome (HOS), a human condition in which cardiac development is defective and forelimbs are stunted. Similarly, zebrafish tbx5 morphants and mutants (heartstrings; hst) lack Pectoral Fins and exhibit a persistently elongated heart that does not undergo chamber looping. Tbx5 is expressed in the developing atrium, ventricle and in Pectoral Fin fields, but its genetic targets are still being uncovered. In this study, evidence is provided that Tbx5 induces the expression of a specific member of the CaMK-II (the type II multifunctional Ca2+/calmodulin-dependent protein kinase) family; this CaMK-II is necessary for proper heart and Fin development. Morphants of β2 CaMK-II (camk2b2), but not the β1 CaMK-II (camk2b1) paralog, exhibit bradycardia, elongated hearts and diminished Pectoral Fin development. Normal cardiac phenotypes can be restored by ectopic cytosolic CaMK-II expression in tbx5 morphants. Like tbx5, camk2b2 is expressed in the Pectoral Fin and looping heart, but this expression is diminished in both tbx5 morphant and hst embryos. Conversely, the introduction of excess Tbx5 into zebrafish embryos and mouse fibroblasts doubles CaMK-II expression. We conclude that β CaMK-II expression and activity are necessary for proper cardiac and limb morphogenesis. These Findings not only identify a morphogenic target for Ca2+ during heart development, but support implied roles for CaMK-II in adult heart remodeling.
