scholarly journals SWIMMING METABOLISM OF WILD-TYPE AND CLONED ZEBRAFISH BRACHYDANIO RERIO

1994 ◽  
Vol 194 (1) ◽  
pp. 209-223 ◽  
Author(s):  
I Plaut ◽  
M S Gordon
Keyword(s):  
Oxygen Consumption ◽  
Swimming Performance ◽  
Low Cost ◽  
Metabolic Cost ◽  
Routine Activity ◽  
Whole Body ◽  
Wild Type ◽  
Brachydanio Rerio ◽  
Consumption Rates ◽  
Homozygous Diploid

The availability of a gynogenetic isogenic homozygous diploid clonal strain (C) of the zebrafish (Brachydanio rerio), combined with the small adult body size of the species, made possible a study of the following two questions. (1) Is the genetic uniformity of a group of fish reflected in decreased variability of features of organismic performance physiology? (2) Is the metabolic cost of subcarangiform swimming significantly different in small fishes compared with large ones? Wild-type (WT) and C strain zebrafish maintained at 28 °C can all swim very rapidly [up to relative swimming speeds of 13 body lengths s-1 (BL s-1)] for extended periods (at least 2 h) without visibly tiring. Oxygen consumption rates were measured for both types at swimming speeds of 1.5­13 BL s-1. Whole-body lactate concentrations were also measured during routine activity and after prolonged exercise for both fish types. The slopes of the linear regressions between the logarithm of mass-specific oxygen consumption rates and relative swimming speeds for WT zebrafish were low (0.010­0.024) and were not significantly different from zero. Regression slopes were also low (0.009­0.026), but different from zero, for C zebrafish. Standard metabolic rates were 0.60­1.54 and 0.40­0.85 ml O2 g-1 h-1 for WT and C zebrafish respectively. Variances of slopes were significantly larger for WT than for C fish. Whole-body lactate concentrations and their variances were not significantly different between types and between rested and exercised fishes. The results demonstrate unusual swimming performance capacities, a remarkably low cost of swimming and some reductions in variability of C fish. Several possible explanations for the results are discussed.

Effects of fin size on swimming performance, swimming behaviour and routine activity of zebrafish Danio rerio

2000 ◽  
Vol 203 (4) ◽  
pp. 813-820 ◽  
Author(s):  
I. Plaut
Keyword(s):  
Danio Rerio ◽  
Swimming Performance ◽  
Activity Level ◽  
Routine Activity ◽  
Swimming Behaviour ◽  
Water Tunnel ◽  
Activity Levels ◽  
Wild Type ◽  
Caudal Fin ◽  
No Tail

The zebrafish Danio rerio exhibits substantial morphological variability in the sizes and shapes of the body and the caudal fin. The present study describes swimming performance, swimming behaviour and routine locomotor activity patterns in three of the major morphotypes: wild-type, long-finned and no-tail. Wild-type and long-finned differ in total length (TL), fork length (FL), caudal fin length (CFL) and caudal fin height (CFH). No-tail has no caudal fin and is significantly smaller in standard length (SL) than the other types. Critical swimming speeds (U(crit)) were measured at 28 degrees C in a modified Brett-type water tunnel. U(crit) of wild-type fish was 56.0+/−4.8 cm s(−1) or 15.5 SL s(−)(1) (mean +/− s.d., N=21), significantly faster than the U(crit) of long-finned fish (43.7+/−6.8 cm s(−1) or 12.5 SL s(−1), N=17); both were significantly faster than the U(crit) of no-tail fish (19. 8+/−4.7 cm s(−1) or 6.9 SL s(−1), N=15). When forced to swim in the water tunnel, zebrafish tended to turn and swim downstream for short periods at slow water velocities. Turning frequencies (turns per minute, f(T)) at the slowest velocity (4 cm s(−1)) were 10. 1+/−6.5 min(−)(1) (N=63) and 8.6+/−4.7 min(−1) (N=51) for wild-type and long-finned, respectively, significantly different from that of the no-tail fish, 4.7+/−2.8 min(−1) (N=45). These frequencies decreased below 1 min(−1) at 56%, 64% and 61% of U(crit) in wild-type, long-finned and no-tail fish, respectively. Activity levels of wild-type fish were generally significantly higher than those of long-finned fish, and the levels of both were significantly higher than those of no-tail fish. The pattern of differences in relative activity levels between types was similar to that for U(crit). The results show that the wild-type fish, on a size-scaled basis, is one of the fastest-swimming fishes ever measured, reaching the maximum predicted theoretical sustained swimming speed. U(crit) of long-finned fish was 22% lower than that of wild-type fish, and U(crit) of no-tail fish was 65% lower. Similar differences were found in turning frequencies and routine activity level.

Respiration of the Atlantic Cod

1963 ◽  
Vol 20 (2) ◽  
pp. 373-386 ◽  
Author(s):  
Richard L. Saunders
Keyword(s):  
Oxygen Consumption ◽  
Size Effect ◽  
Atlantic Cod ◽  
Metabolic Cost ◽  
Unit Weight ◽  
Respiratory Volume ◽  
Ambient Oxygen ◽  
Consumption Rates ◽  
Rate Of Oxygen Consumption

Measurements of routine and standard rates of oxygen consumption of various sized cod at temperatures between 3 and 15 °C revealed a well-marked size effect; small cod consume oxygen at a greater rate per unit weight than do large ones. Increases in temperature raise oxygen consumption in starved and fed fish. The increase in rate of oxygen consumption of starved fish between 3 and 10° is proportionately greater than that between 10 and 15 °C. Feeding of cod which have previously been starved increases the rate of oxygen consumption by 40–90%. The rate subsides to the starvation level in 4–7 days depending on temperature and amount of food eaten. Handling cod causes them to increase their rate of oxygen consumption; rates return to normal levels in 3–5 hours. Crowding reduces the rate of oxygen consumption apparently by reducing the space for movement and thus restricting activity. Reducing the ambient oxygen from about 10 to 3 mg/l lowers the rate of oxygen consumption slightly, but the respiratory volume (volume of water pumped over the gills per unit time) is markedly increased. This suggests there is added stress because the increased metabolic cost of irrigating the gills is not met by increased rates of oxygen consumption.

The Metabolic Cost of Swimming in Ducks

1970 ◽  
Vol 53 (3) ◽  
pp. 763-777 ◽  
Author(s):  
HENRY D. PRANGE ◽  
KNUT SCHMIDT-NIELSEN
Keyword(s):  
Oxygen Consumption ◽  
Swimming Speed ◽  
Swimming Performance ◽  
Water Channel ◽  
Minimum Cost ◽  
Metabolic Cost ◽  
Power Input ◽  
Cost Of Transport ◽  
Overall Efficiency ◽  
The Cost

1. The metabolic cost of swimming was studied in mallard ducks (Anas platyrhynchos) which had been trained to swim steadily in a variable-speed water channel. 2. At speeds of from 0.35 to 0.50 m/sec the oxygen consumption remained relatively constant at approximately 2.2 times the resting level. At speeds of 0.55 m/sec and higher the oxygen consumption increased rapidly and reached 4.1 times resting at the maximum sustainable speed of 0.70 m/sec. 3. The maximum sustainable swimming speed of the ducks coincided with the limit predicted from hydrodynamic considerations of the water resistance of a displacement-hulled ship of the same hull length as a duck (0.33 m). 4. The cost of transport (metabolic rate/speed) reached a minimum of 5.77 kcal/kg km at a swimming speed of 0.50 m/sec. Ducks swimming freely on a pond were observed to swim at the speed calculated in experimental trials to give minimum cost of transport. 5. Drag measurements made with model ducks indicated a maximum overall efficiency (power output/power input) for the swimming ducks of about 5%. Ships typically have maximum efficiencies of 20-30%. Because of the difficulty in delimiting the cost of swimming activity alone from the other bodily functions of the duck, overall efficiency may present an incorrect description of the swimming performance of the duck relative to that of a ship. An hydrodynamic parameter such as speed/length ratio [speed/(hull length)½] whereby a duck excels conventional ships may present a more appropriate comparison.

scholarly journals Association between Oxygen Consumption and Surface Electromyographic Amplitude and Its Variation within Individual Calf Muscles during Walking at Various Speeds

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1748
Author(s):  
Kohei Watanabe ◽  
Shideh Narouei
Keyword(s):  
Oxygen Consumption ◽  
Spatial Variation ◽  
Metabolic Response ◽  
Correlation Coefficients ◽  
Surface Emg ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Young Males ◽  
Emg Amplitude ◽  
Calf Muscles

Surface electromyography (EMG) has been used to estimate muscle work and physiological burden of the whole body during human movements. However, there are spatial variations in surface EMG responses within individual muscles. The aim of this study was to investigate the relation between oxygen consumption and surface EMG responses of lower leg muscles during walking at various speeds and to quantify its spatial variation within an individual muscle. Nine young males walked on a treadmill at four speeds: preferred minus 1 km/h, preferred, preferred plus 1 km/h, and preferred plus 2 km/h, and the metabolic response was measured based on the expired gas. High-density surface EMG of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles was performed using 64 two-dimensional electrode grids. Correlation coefficients between oxygen consumption and the surface EMG amplitude were calculated across the gait speeds for each channel in the electrode grid and for individual muscles. Mean correlation coefficients across electrodes were 0.69–0.87 for the four individual muscles, and the spatial variation of correlation between the surface EMG amplitude and oxygen consumption within an electrode grid was significantly greater in MG muscle than in TA muscle (Quartile deviations: 0.24 for MG and 0.02 for TA, p < 0.05). These results suggest that the physiological burden of the whole body during gait at various speeds can be estimated from the surface EMG amplitude of calf muscles, but we need to note its spatial distribution within the MG muscle.

scholarly journals Using a simple rope-pulley system that mechanically couples the arms, legs, and treadmill reduces the metabolic cost of walking

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Daisey Vega ◽  
Christopher J. Arellano
Keyword(s):  
Metabolic Cost ◽  
Metabolic Energy ◽  
Metabolic Effects ◽  
Whole Body ◽  
Walking Ability ◽  
Arm Swing ◽  
Pulley System ◽  
Young Subjects ◽  
Walking Recovery ◽  
Set Up

Abstract Background Emphasizing the active use of the arms and coordinating them with the stepping motion of the legs may promote walking recovery in patients with impaired lower limb function. Yet, most approaches use seated devices to allow coupled arm and leg movements. To provide an option during treadmill walking, we designed a rope-pulley system that physically links the arms and legs. This arm-leg pulley system was grounded to the floor and made of commercially available slotted square tubing, solid strut channels, and low-friction pulleys that allowed us to use a rope to connect the subject’s wrist to the ipsilateral foot. This set-up was based on our idea that during walking the arm could generate an assistive force during arm swing retraction and, therefore, aid in leg swing. Methods To test this idea, we compared the mechanical, muscular, and metabolic effects between normal walking and walking with the arm-leg pulley system. We measured rope and ground reaction forces, electromyographic signals of key arm and leg muscles, and rates of metabolic energy consumption while healthy, young subjects walked at 1.25 m/s on a dual-belt instrumented treadmill (n = 8). Results With our arm-leg pulley system, we found that an assistive force could be generated, reaching peak values of 7% body weight on average. Contrary to our expectation, the force mainly coincided with the propulsive phase of walking and not leg swing. Our findings suggest that subjects actively used their arms to harness the energy from the moving treadmill belt, which helped to propel the whole body via the arm-leg rope linkage. This effectively decreased the muscular and mechanical demands placed on the legs, reducing the propulsive impulse by 43% (p < 0.001), which led to a 17% net reduction in the metabolic power required for walking (p = 0.001). Conclusions These findings provide the biomechanical and energetic basis for how we might reimagine the use of the arms in gait rehabilitation, opening the opportunity to explore if such a method could help patients regain their walking ability. Trial registration: Study registered on 09/29/2018 in ClinicalTrials.gov (ID—NCT03689647).

scholarly journals SEC3 Mutations Are Synthetically Lethal With Profilin Mutations and Cause Defects in Diploid-Specific Bud-Site Selection

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 495-510 ◽  
Author(s):  
B K Haarer ◽  
A Corbett ◽  
Y Kweon ◽  
A S Petzold ◽  
P Silver ◽  
...  
Keyword(s):  
Site Selection ◽  
Secretory Pathway ◽  
Wild Type ◽  
Synthetic Lethal ◽  
Abnormal Growth ◽  
Colony Color ◽  
Synthetically Lethal ◽  
Homozygous Diploid ◽  
Bud Site ◽  
Wild Type Yeast

Abstract Replacement of the wild-type yeast profilin gene (PFY1) with a mutated form (pfy1-111) that has codon 72 changed to encode glutamate rather than arginine results in defects similar to, but less severe than, those that result from complete deletion of the profilin gene. We have used a colony color-sectoring assay to identify mutations that cause pfy1-111, but not wild-type, cells to be inviable. These profilin synthetic lethal (psl) mutations result in various degrees of abnormal growth, morphology, and temperature sensitivity in PFY1 cells. We have examined psl1 strains in the most detail. Interestingly, these strains display a diploid-specific defect in bud-site selection; haploid strains bud normally, while homozygous diploid strains show a dramatic increase in random budding. We discovered that PSL1 is the late secretory gene, SEC3, and have found that mutations in several other late secretory genes are also synthetically lethal with pfy1-111. Our results are likely to reflect an interdependence between the actin cytoskeleton and secretory processes in directing cell polarity and growth. Moreover, they indicate that the secretory pathway is especially crucial for maintaining budding polarity in diploids.

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