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71.
Tony Robinet Eric Feunteun Philippe Keith Gérard Marquet Jean-Michel Olivier Elodie Réveillac Pierre Valade 《Environmental Biology of Fishes》2007,78(2):93-105
Anguillid eels were sampled from permanent rivers in the Réunion and Mauritius islands, western Indian Ocean, with a standardized
electrofishing method. A. marmorata was very dominant, corresponding to 91.7 and 90.7% of all the eels collected in Réunion and Mauritius, respectively. Three
other species (A. mossambica, A. bicolor bicolor and A. nebulosa labiata) were also present in both islands. A. marmorata showed a strong altitudinal gradient of densities from the lower to upper zones, especially in the younger stages (TL <250 mm),
while A. mossambica was only found in the upper zones and A. bicolor bicolor occurred only in the lower zones (A. nebulosa labiata was rare). The eel species composition in freshwaters of both islands is very similar because these two adjoining islands
are located in the same trail of drifting marine larvae. Mean estimated eel biomasses were noticeably low (11.1 and 22.2 kg ha−1 in Réunion and Mauritius islands, respectively), especially when compared to those of other tropical insular systems without
any eel fishery (Comoros or Polynesia, more than 100 kg ha−1). Nevertheless, the fluvial recruitment of A. marmorata seemed to be regular during the surveyed period, staggering from October to April. The obvious lack of large eels in Mauritius
but more significantly in Réunion suggests a high pressure from traditional fishery, and the local reproductive turnover is
uncertain. Because sexual maturation seems to occur at a large body size for A. marmorata, as for temperate species, the Réunion and Mauritius rivers may only have a weak contribution to the regional production
of spawners. However, the giant mottled eel population in the western Indian Ocean is believed to be panmictic at the regional
scale, and may not rely exclusively on these islands’ contribution. A comparison is made with those of freshwater systems
in other tropical islands. 相似文献
72.
Background
Introns, which constitute the largest fraction of eukaryotic genes and which had been considered to be neutral sequences, are increasingly acknowledged as having important functions. Several studies have investigated levels of evolutionary constraint along introns and across classes of introns of different length and location within genes. However, thus far these studies have yielded contradictory results. 相似文献73.
74.
Following the analysis of the biochemical and functional properties of the P. mirabilis extra cellular matrix performed in the first part of this study, the viscoelasticity of an actively growing colony was investigated in relation to water activity. The results demonstrate that the P. mirabilis colony exhibits a marked viscoelastic character likely due to both cell rafts and exoproduct H-bond networks. Besides, the water loss by evaporation during migration has been measured, whereas the experimental determination of the water diffusion coefficient in agar has allowed us to estimate the net water influx at the agar/colony interface. These data drive us to propose that a periodic increase of the water activity at the colony's periphery, mainly due to the drastic surface to volume ratio increase associated with swarming, causes the periodic and synchronous cessation of migration through the dissociation of exoproduct networks, which in turn strongly alters the matrix viscoelasticity. 相似文献
75.
Frantz Alain C. Viglino Andrea Wilwert Elodie Cruz Ana-Paula Wittische Julian Weigand Alexander M. Buijk Jacky Nyssen Pierrette Dekeukeleire Daan Dekker Jasja J.A. Horsburgh Gavin J. Schneider Simone Lang Mara Caniglia Romolo Galaverni Marco Schleimer Anna Bücs Szilárd-Lehel Pir Jacques B. 《Biodiversity and Conservation》2022,31(3):925-948
Biodiversity and Conservation - In the European Union, all bat species are strictly protected and member states must ensure their conservation. However, if populations are genetically structured,... 相似文献
76.
Effects of nutrients and warming on Planktothrix dynamics and diversity: a palaeolimnological view based on sedimentary DNA and RNA
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Olga Savichtcheva Didier Debroas Marie Elodie Perga Fabien Arnaud Clément Villar Emilie Lyautey Amy Kirkham Cécile Chardon Benjamin Alric Isabelle Domaizon 《Freshwater Biology》2015,60(1):31-49
77.
High osmolarity glycerol response PtcB phosphatase is important for Aspergillus fumigatus virulence
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Lizziane K. Winkelströter Vinícius Leite Pedro Bom Patrícia Alves de Castro Leandra Naira Zambelli Ramalho Maria Helena S. Goldman Neil Andrew Brown Ranjith Rajendran Gordon Ramage Elodie Bovier Thaila Fernanda dos Reis Marcela Savoldi Daisuke Hagiwara Gustavo H. Goldman 《Molecular microbiology》2015,96(1):42-54
Aspergillus fumigatus is a fungal pathogen that is capable of adapting to different host niches and to avoid host defenses. An enhanced understanding of how, and which, A. fumigatus signal transduction pathways are engaged in the regulation of these processes is essential for the development of improved disease control strategies. Protein phosphatases are central to numerous signal transduction pathways. To comprehend the functions of protein phosphatases in A. fumigatus, 32 phosphatase catalytic subunit encoding genes were identified. We have recognized PtcB as one of the phosphatases involved in the high osmolarity glycerol response (HOG) pathway. The ΔptcB mutant has both increased phosphorylation of the p38 MAPK (SakA) and expression of osmo‐dependent genes. The ΔptcB strain was more sensitive to cell wall damaging agents, had increased chitin and β‐1,3‐glucan, and impaired biofilm formation. The ΔptcB strain was avirulent in a murine model of invasive pulmonary aspergillosis. These results stress the importance of the HOG pathway in the regulation of pathogenicity determinants and virulence in A. fumigatus. 相似文献
78.
I-Ching Sam Yvonne C. F. Su Yoke Fun Chan Siti Sarah Nor'E Ardalinah Hassan Faizatul Lela Jafar Udayan Joseph Rebecca A. Halpin Elodie Ghedin Poh Sim Hooi Mathieu Fourment Hamimah Hassan Sazaly AbuBakar David E. Wentworth Gavin J. D. Smith 《Journal of virology》2015,89(18):9689-9692
Influenza B virus causes significant disease but remains understudied in tropical regions. We sequenced 72 influenza B viruses collected in Kuala Lumpur, Malaysia, from 1995 to 2008. The predominant circulating lineage (Victoria or Yamagata) changed every 1 to 3 years, and these shifts were associated with increased incidence of influenza B. We also found poor lineage matches with recommended influenza virus vaccine strains. While most influenza B virus lineages in Malaysia were short-lived, one circulated for 3 to 4 years. 相似文献
79.
Lopes M Goupille O Saint Cloment C Lallemand Y Cumano A Robert B 《Development (Cambridge, England)》2011,138(14):3055-3066
Vessels are primarily formed from an inner endothelial layer that is secondarily covered by mural cells, namely vascular smooth muscle cells (VSMCs) in arteries and veins and pericytes in capillaries and veinules. We previously showed that, in the mouse embryo, Msx1(lacZ) and Msx2(lacZ) are expressed in mural cells and in a few endothelial cells. To unravel the role of Msx genes in vascular development, we have inactivated the two Msx genes specifically in mural cells by combining the Msx1(lacZ), Msx2(lox) and Sm22α-Cre alleles. Optical projection tomography demonstrated abnormal branching of the cephalic vessels in E11.5 mutant embryos. The carotid and vertebral arteries showed an increase in caliber that was related to reduced vascular smooth muscle coverage. Taking advantage of a newly constructed Msx1(CreERT2) allele, we demonstrated by lineage tracing that the primary defect lies in a population of VSMC precursors. The abnormal phenotype that ensues is a consequence of impaired BMP signaling in the VSMC precursors that leads to downregulation of the metalloprotease 2 (Mmp2) and Mmp9 genes, which are essential for cell migration and integration into the mural layer. Improper coverage by VSMCs secondarily leads to incomplete maturation of the endothelial layer. Our results demonstrate that both Msx1 and Msx2 are required for the recruitment of a population of neural crest-derived VSMCs. 相似文献
80.
The identification of a Sonic Hedgehog (Shh) signaling pathway in the adult vertebrate central nervous system has paved the way to the characterization of the functional roles of Shh signals in normal and diseased brain. This morphogen is proposed to play a key role in the establishment and maintenance of adult neurogenic niches and to modulate the proliferation of neuronal or glial precursors. Consistent with its role during embryogenesis, alteration of Shh signaling is associated with tumorigenesis while its recruitment in damaged neural tissue might be part of the regenerating process. We will discuss the most recent data of the Hedgehog pathway in the adult brain and its relevance as a novel therapeutic approach for brain diseases including brain tumors. 相似文献