Metabolic and Organ Mass Responses to Selection for High Growth Rates in the Domestic Chicken (Gallus domesticus)

2000 ◽  
Vol 73 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Marek Konarzewski ◽  
Amanda Gavin ◽  
Regina McDevitt ◽  
Ian R. Wallis
2021 ◽  
Author(s):  
Silvia Kollerova ◽  
Lionel Jouvet ◽  
Julia Smelkova ◽  
Ulrich Karl Steiner

Tolerance and persistence are states that allow non-genetically resistant bacterial cells to survive periods of bactericidal concentrations. Compared to resistance, tolerance and persistence appear to be more diverse in their mechanisms but are less studied. Here we report, using a high throughput microfluidic single-cell microfluidic device, selection for and phenomenological characteristics of cells exposed to recurring exposure to antibiotics. We find a high fraction of tolerant cells, these cells reduce their growth rate but do not go into slow growth or growth arrest, a characteristic previously reported on. Here, tolerance is induced by antibiotic exposure and not caused by a stochastic switch or predetermined state. The tolerance state only weakly depends on the applied concentration of the antibiotic and post-antibiotic exposure there is no fast resumption of growth contrasting again with previous studies. Tolerant cells remain susceptible to antibiotic exposure suggesting recurrent selection for tolerance. Selection also did not act primarily on cells showing relatively high growth rates, as often assumed under exposure to a β-lactam antibiotic. The cells with relatively high growth rates, but still reduced growth compared to prior antibiotic exposure conditions, showed equal mortality risk than cells that were in growth arrest or shrank, slowly growing cells showed the lowest mortality risk. Relatively fast-growing cells and non-growing or shrinking cells exhibited less robust growth patterns compared to slowly, but constantly, growing cells. Our findings suggest a type of tolerance that differs from previously described tolerance and persister characteristics. The high frequency of such tolerant cells, in combination with the fact that they do not arise from growth arrested cells and do not go into growth arrest under antibiotic exposure, suggest that they might play an important role for the evolution to resistance and for antibiotic treatment failure of recurring infections.


Heredity ◽  
1995 ◽  
Vol 75 (5) ◽  
pp. 518-529 ◽  
Author(s):  
Torbjörn von Schantz ◽  
Måns Tufvesson ◽  
Görgen Göransson ◽  
Mats Grahn ◽  
Martin Wilhelmson ◽  
...  

Author(s):  
Saule Zhangirovna Asylbekova ◽  
Kuanysh Baibulatovich Isbekov ◽  
Vladimir Nickolaevich Krainyuk

Pike-perch is an invader for the water basins of Central Kazakhstan. These species have stable self-reproductive populations in the regional waters. Back calculation method was used to investigate pike-perch growth rates in reservoirs of K. Satpayev’s channel. For comparison, the data from the other water bodies (Vyacheslavsky and Sherubay-Nurinsky water reservoirs) were used, as well as literature data. Pike-perch species from the investigated waters don’t show high growth rates. The populations from the reservoirs of K. Satpayev’s channel have quite similar growth rates with populations from the Amur river, from a number of reservoirs in the Volga river basin and from the reservoir in Spain. Sexual differences in growth have not been observed. Evaluating possible influence of various abiotic and biotic factors on the growth rate of pike-perch in the reservoirs of K. Satpayev’s channel was carried out. It has been stated that the availability of trophic resources cannot play a key role in growth dynamics because of their high abundance. Morphology of water bodies also does not play a role, as well as chromaticity, turbidity and other optical water indicators. It can be supposed that the main factor influencing growth of pike perch is the habitat’s temperature. This factor hardly ever approaches optimal values for the species in reservoirs of K. Satpaev’s channel. The possible influence of fishing selectivity on pike-perch growth rates was also evaluated. Currently, there has been imposed a moratorium on pike-perch catch. However, pike-perch is found in by-catches and in catches of amateur fishermen. It should be said that such seizures have an insignificant role in the dynamics of growth rates.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 519
Author(s):  
Shajahan Ferosekhan ◽  
Serhat Turkmen ◽  
Cathaysa Pérez-García ◽  
Hanlin Xu ◽  
Ana Gómez ◽  
...  

Genetic selection in gilthead seabream (GSB), Sparus aurata, has been undertaken to improve the growth, feed efficiency, fillet quality, skeletal deformities and disease resistance, but no study is available to delineate the effect of genetic selection for growth trait on GSB reproductive performance under mass spawning condition. In this study, high growth (HG) or low growth (LG) GSB broodstock were selected to evaluate the sex steroid hormones, sperm, egg quality and reproductive performance under different feeding regime of commercial diet or experimental broodstock diet containing either fish oil (FO) or vegetable oil (VO) based diet. Under commercial diet feeding phase, broodstock selected for either high growth or low growth did not show any significant changes in the egg production per kg female whereas egg viability percentage was positively (p = 0.014) improved by the high growth trait broodstock group. The experimental diet feeding results revealed that both growth trait and dietary fatty acid composition influenced the reproductive performance of GSB broodstock. In the experimental diet feeding phase, we observed high growth trait GSB males produced a higher number of sperm cells (p < 0.001) and also showed a higher sperm motility (p = 0.048) percentage. The viable egg and larval production per spawn per kg female were significantly improved by the broodstock selected for high growth trait and fed with fish oil-based diet. This present study results signifies that gilthead seabream broodstock selected on growth trait could have positive role in improvement of sperm and egg quality to produce viable progeny.


1967 ◽  
Vol 24 (12) ◽  
pp. 2573-2594 ◽  
Author(s):  
David G. Patriquin

Gadus morhua L. occurs in Ogac Lake, a salt, meromictic lake on Baffin Island that receives influxes of seawater only during the highest summer tides. Cod of the order of 10,000 of lengths 25 cm and greater and 500 of lengths greater than 60 cm were present. The size ranges for various ages far exceeded those of oceanic populations. Feeding conditions were poor, and sea urchins predominated in the diet. Large cod (greater than 50 cm) were highly cannibalistic, and it was estimated that they consume of the order of 3500 fish of 20–40 cm annually. Maturation occurred at the unusually large size of 85 cm in females, and at about 65 cm in males. Apparently many of the cod never reach these sizes. Spawning was from late May to early July in 1962, and initiation of spawning appeared to be related to light. The hatching of cod larvae coincided with the appearance of the nauplii of the dominant copepod in the lake. Egg size was highly variable and exhibited a curious bimodalism. Variation in vertebral and fin-ray counts was slight in spite of high environmental variability, and thus appears largely genetically controlled. Possibly the first inhabitants came from Greenland stocks, which have high growth rates similar to the faster growing cod in the lake, and similar high length at maturity. Meristic characters also suggest affinity with Greenland rather than Labrador cod. The hydrography of the area and the possibilities of larval drift or adult migration into the lake are discussed. Cannibalism must exert continuing selection for high growth rates, but very poor feeding conditions and hierarchial dominance effects probably prevent general attainment of high growth rates.


2000 ◽  
Vol 266-269 ◽  
pp. 450-454 ◽  
Author(s):  
Yoram Lubianiker ◽  
Yanyang Tan ◽  
J.David Cohen ◽  
Gautam Ganguly

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.


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