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EMANUELE SUSANA CHIARA PAPETTI FEDERICA BARBISAN ERICA BORTOLOTTO SIMONA BUCCOLI TOMASO PATARNELLO LORENZO ZANE 《Molecular ecology resources》2007,7(5):791-793
We characterized eight polymorphic microsatellites in the Scotia icefish Chaenocephalus aceratus (Perciformes, Notothenioidei, Channichthyidae) that is endemic of Southern Ocean waters surrounding the tip of the Antarctic Peninsula. Microsatellites were isolated from a partial genomic library enriched for an AC motif. The number of alleles ranged from two to 19 with a mean observed hererozygosity of 0.71. Loci were in Hardy–Weinberg equilibrium and no evidence for linkage disequilibrium was found. These molecular markers will be useful to investigate Scotia icefish genetic structure, possibly providing insights on its effective population size and demographic history. 相似文献
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Thomas Desvignes Jason Sydes Jerme Montfort Julien Bobe John H Postlethwait 《Molecular biology and evolution》2021,38(8):3308
MicroRNAs (miRNAs) are important gene expression regulators implicated in many biological processes, but we lack a global understanding of how miRNA genes evolve and contribute to developmental canalization and phenotypic diversification. Whole-genome duplication events likely provide a substrate for species divergence and phenotypic change by increasing gene numbers and relaxing evolutionary pressures. To understand the consequences of genome duplication on miRNA evolution, we studied miRNA genes following the teleost genome duplication (TGD). Analysis of miRNA genes in four teleosts and in spotted gar, whose lineage diverged before the TGD, revealed that miRNA genes were retained in ohnologous pairs more frequently than protein-coding genes, and that gene losses occurred rapidly after the TGD. Genomic context influenced retention rates, with clustered miRNA genes retained more often than nonclustered miRNA genes and intergenic miRNA genes retained more frequently than intragenic miRNA genes, which often shared the evolutionary fate of their protein-coding host. Expression analyses revealed both conserved and divergent expression patterns across species in line with miRNA functions in phenotypic canalization and diversification, respectively. Finally, major strands of miRNA genes experienced stronger purifying selection, especially in their seeds and 3′-complementary regions, compared with minor strands, which nonetheless also displayed evolutionary features compatible with constrained function. This study provides the first genome-wide, multispecies analysis of the mechanisms influencing metazoan miRNA evolution after whole-genome duplication. 相似文献
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Winnard P Cashon RE Sidell BD Vayda ME 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2003,134(4):651-667
Creatine kinase (CK) was isolated from the white muscle of the Antarctic icefish Chaenocephalus aceratus, which is deficient in glycolytic capacity. C. aceratus white myotomal creatine kinase (MMCK) displayed an apparent Km at 0.5 °C of 0.06 mM for ADP and 17 mM for Phosphocreatine. These Km values are similar to those reported for other vertebrate MMCKs at their physiologically relevant body temperatures. C. aceratus MMCK exhibited optimal activity at pH of 7.6–7.7 at 0.5 °C, in contrast to rabbit MMCK which had optimum activity at pH 6.2 at 30 °C. The apparent Vmax of C. aceratus MMCK at 0.5 °C is 94±4 S.D. (n=9) μmol ATP/min/mg (i.e. U/mg), which is comparable to rabbit MMCK assayed at 20 °C and 8-fold greater than rabbit MMCK measured at 0.5 °C. DEAE chromatography of C. aceratus white muscle CK resolved two distinct activity peaks. Cloning and sequencing of C. aceratus CK cDNAs confirmed that two muscle-specific isoforms of CK were expressed that were distinct from the mitochondrial and brain isoforms. Icefish MMCK was sensitive to transient temperature elevation, and the DEAE-fractionated forms were highly unstable. These results indicate that C. aceratus MMCK displays significant activity at physiological temperature and intracellular pH of icefish muscle that could contribute to sustaining energy charge during burst-swimming. 相似文献
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Chiara Papetti Emanuele Susana Mario La Mesa Karl-Hermann Kock Tomaso Patarnello Lorenzo Zane 《Polar Biology》2007,30(12):1605-1613
Chaenocephalus aceratus is one of the most abundant Antarctic icefish species in the Atlantic sector and has been a by-catch species in the fishery
for mackerel icefish, Champsocephalus gunnari, between the mid-1970s and mid-1980s at South Georgia, South Orkney, and South Shetland Islands. The species became the target
of the fishery in particular seasons, such as at South Georgia in 1977/78. In our paper, we report results on genetic differentiation
for 11 microsatellite loci in C. aceratus samples collected at the South Shetlands and Elephant Island. This study represents the first report on microsatellite variability
of an icefish species. Our results support the evidence from previous studies on differences in infestation patterns of parasites
that a single panmictic population of C. aceratus exists, spanning the two sampling sites separated by about 100 km. Moreover, our study indicates the presence of a significant
genetic differentiation between individual year-classes pointing out the existence of dynamic processes acting at the population
genetic level, according to recent results for broadly distributed marine species. Both small effective population size and
immigration from unsampled differentiated stocks may be at the base of the differentiation found in C. aceratus.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Peter Vilhelm Skov Peter G. Bushnell Bjørn Tirsgaard John Fleng Steffensen 《Polar Biology》2009,32(2):215-223
The present work was performed to test the hypothesis that Antarctic teleosts rely mostly on cholinergic inhibition for autonomic
modulation of the heart. The effects of adrenaline on the inotropic properties on paced, isometrically contracting muscle
strips were examined in two distinct Antarctic teleosts, the haemoglobinless icefish Chaenocephalus aceratus and the red-blooded Notothenia coriiceps. All tissues examined revealed a negative force-frequency relationship. Under baseline conditions C. aceratus contracted with a force twice as great as that of N. coriiceps. While the degree to which ventricular tissues responded to adrenaline varied between species, adrenergic stimulation significantly
increases myocyte contraction force in this group of fishes. Contraction and relaxation times were not significantly affected
by adrenaline concentration while absolute rates of contraction were. Adrenergic stimulation does not enable tissues to achieve
higher contraction frequencies, but is shown to be a potent modulator of contraction force. 相似文献
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