We describe the annual distribution of beluga whales (Delphinapterus leucas) in Bristol Bay, Alaska, using data from 31 satellite‐linked transmitters during 2002–2011. Bristol Bay has one of the largest and best studied Pacific salmon (Oncorhynchus spp.) fisheries in the world, allowing us to link the seasonal distribution of belugas to that of salmon. During salmon migrations, beluga movements were restricted to river entrances. Belugas generally did not relocate to different river entrances or change bays during peak salmon periods. However, the location of belugas was not related to the number of salmon passing counting towers, suggesting that belugas were either selecting locations that were good for catching salmon or there were simply more salmon than belugas needed to supply their nutritional needs. The distribution of belugas expanded after salmon runs ended, and was greatest in winter when belugas ranged beyond the inner bays, traveling as far west as Cape Constantine. Belugas continued to frequent the inner bays in winter whenever sea ice conditions allowed, e.g., when winds moved sea ice offshore; however, they were never located south of the southern ice edge in open water or outside of Bristol Bay. 相似文献
Movement is a trait of fundamental importance in ecosystems subject to frequent disturbances, such as fire‐prone ecosystems. Despite this, the role of movement in facilitating responses to fire has received little attention. Herein, we consider how animal movement interacts with fire history to shape species distributions. We consider how fire affects movement between habitat patches of differing fire histories that occur across a range of spatial and temporal scales, from daily foraging bouts to infrequent dispersal events, and annual migrations. We review animal movements in response to the immediate and abrupt impacts of fire, and the longer‐term successional changes that fires set in train. We discuss how the novel threats of altered fire regimes, landscape fragmentation, and invasive species result in suboptimal movements that drive populations downwards. We then outline the types of data needed to study animal movements in relation to fire and novel threats, to hasten the integration of movement ecology and fire ecology. We conclude by outlining a research agenda for the integration of movement ecology and fire ecology by identifying key research questions that emerge from our synthesis of animal movements in fire‐prone ecosystems. 相似文献
Chronic infection with hepatitis B virus (HBV) is associated with the majority of cases of hepatocellular carcinoma (HCC) in China. Despite this, there is no effective method for the early detection of HBV-induced liver cancer. Aberrant fucosylation is known to occur during the development of HCC. We, therefore, developed a method of applying matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to analyze the relationship between aberrant fucosylation, tumor genesis and progression of HBV-associated HCC, and to establish proteomic profiling of serum for early diagnosis of HCC. The MALDI-TOF MS was based on Lens culinaris agglutinin (LCA) lectin magnetic beads and their affinity for separation. The method was applied initially to a 'training' cohort of 111 serum samples obtained from subjects in China with no liver disease (n=26), chronic hepatitis B without cirrhosis (n=21), HBV-infected cirrhosis (n=32), or HBV-infected HCC (n=32). In contrast to previous findings, the results of our profiling analysis demonstrated defucosylation on some of the glycoproteins involved in HCC. HCC was then diagnostically classified in a 'blind test' cohort (n=96). In this group we demonstrated that, HCC could be distinguished from all serum samples, HBV-associated chronic liver disease, and HBV-associated cirrhosis with a sensitivity/specificity of 70%/70%, 78%/74%, and 81%/82%, respectively. When combined with serum alpha-fetoprotein detection (AFP>20 ng/mL), the sensitivity/specificity improved to 78%/88%, 85%/88%, and 89%/91%, respectively. In conclusion, serum glycoprotein fucosylation abnormalities have diverse forms in patients with HCC. MALDI-TOF MS profiling of aberrant serum fucosylated glycoproteins distinguished HCC from controls with high accuracy. 相似文献
Poliovirus (PV), like many positive-strand RNA viruses, subverts the macroautophagy/autophagy pathway to promote its own replication. Here, we investigate whether the virus uses the canonical autophagic signaling complex, consisting of the ULK1/2 kinases, ATG13, RB1CC1, and ATG101, to activate autophagy. We find that the virus sends autophagic signals independent of the ULK1 complex, and that the members of the autophagic complex are not required for normal levels of viral replication. We also show that the SQSTM1/p62 receptor protein is not degraded in a conventional manner during infection, but is likely cleaved in a manner similar to that shown for coxsackievirus B3. This means that SQSTM1, normally used to monitor autophagic degradation, cannot be used to accurately monitor degradation during poliovirus infection. In fact, autophagic degradation may be affected by the loss of SQSTM1 at the same time as autophagic signals are being sent. Finally, we demonstrate that ULK1 and ULK2 protein levels are greatly reduced during PV infection, and ATG13, RB1CC1, and ATG101 protein levels are reduced as well. Surprisingly, autophagic signaling appears to increase as ULK1 levels decrease. Overexpression of wild-type or dominant-negative ULK1 constructs does not affect virus replication, indicating that ULK1 degradation may be a side effect of the ULK1-independent signaling mechanism used by PV, inducing complex instability. This demonstration of ULK1-independent autophagic signaling is novel and leads to a model by which the virus is signaling to generate autophagosomes downstream of ULK1, while at the same time, cleaving cargo receptors, which may affect cargo loading and autophagic degradative flux. Our data suggest that PV has a finely-tuned relationship with the autophagic machinery, generating autophagosomes without using the primary autophagy signaling pathway.
Abbreviations: ACTB - actin beta; ATG13 - autophagy related 13; ATG14 - autophagy related 14; ATG101 - autophagy related 101; BECN1 - beclin 1; CVB3 - coxsackievirus B3; DMV - double-membraned vesicles; EM - electron microscopy; EMCV - encephalomyocarditis virus; EV-71 - enterovirus 71; FMDV - foot and mouth disease virus; GFP - green fluorescent protein; MAP1LC3B/LC3B - microtubule associated protein 1 light chain 3 beta; MOI - multiplicity of infection; MTOR - mechanistic target of rapamycin kinase; PIK3C3 - phosphatidylinositol 3-kinase catalytic subunit type 3; PRKAA2 - protein kinase AMP-activated catalytic subunit alpha 2; PSMG1 - proteasome assembly chaperone 1; PSMG2 - proteasome assembly chaperone 2PV - poliovirus; RB1CC1 - RB1 inducible coiled-coil 1; SQSTM1 - sequestosome 1; ULK1 - unc-51 like autophagy activating kinase 1; ULK2 - unc-51 like autophagy activating kinase 2; WIPI1 - WD repeat domain, phosphoinositide interacting 1 相似文献
Saccharomyces bayanus var. uvarum plays an important role in the fermentation of red wine from the D.O. Ribera del Duero. This is due to the special organoleptic taste that this yeast gives the wines and their ability to ferment at low temperature. To determine the molecular factors involved in the fermentation process at low temperature, a differential proteomic approach was performed by using 2D‐DIGE, comparing, qualitatively and quantitatively, the profiles obtained at 13 and 25°C. A total of 152 protein spots were identified. We detected proteins upregulated at 13°C that were shown to be related to temperature stress, the production of aromatic compounds involved in the metabolism of amino acids, and the production of fusel alcohols and their derivatives, each of which is directly related to the quality of the wines. To check the temperature effects, an aromatic analysis by GC–MS was performed. The proteomic and “aromatomic” results are discussed in relation to the oenological properties of S. bayanus var. uvarum. 相似文献
The mitotic checkpoint (also called spindle assembly checkpoint, SAC) is a signaling pathway that safeguards proper chromosome segregation. Correct functioning of the SAC depends on adequate protein concentrations and appropriate stoichiometries between SAC proteins. Yet very little is known about the regulation of SAC gene expression. Here, we show in the fission yeast Schizosaccharomyces pombe that a combination of short mRNA half‐lives and long protein half‐lives supports stable SAC protein levels. For the SAC genes mad2+ and mad3+, their short mRNA half‐lives are caused, in part, by a high frequency of nonoptimal codons. In contrast, mad1+ mRNA has a short half‐life despite a higher frequency of optimal codons, and despite the lack of known RNA‐destabilizing motifs. Hence, different SAC genes employ different strategies of expression. We further show that Mad1 homodimers form co‐translationally, which may necessitate a certain codon usage pattern. Taken together, we propose that the codon usage of SAC genes is fine‐tuned to ensure proper SAC function. Our work shines light on gene expression features that promote spindle assembly checkpoint function and suggests that synonymous mutations may weaken the checkpoint. 相似文献
Age and sex need to be considered in the establishment of reference intervals (RIs), especially in early life when there are dynamic physiological changes. Since data for important biomarkers in healthy neonates and infants are limited, particularly in Iranian populations, we have determined age‐specific RIs for 7 laboratory biochemical parameters. This cross‐sectional study comprised a total of 344 paediatric participants (males: 158, females: 186) between the ages of 3 days and 30 months (mean age: 12.91 ± 7.15 months). Serum levels of creatinine, urea, uric acid, calcium, phosphate, vitamin D and high‐sensitivity C‐reactive protein (hs‐CRP) were measured using an Alpha classic‐AT plus auto‐analyser. We determined age‐specific RIs using CLSI Ep28‐A3 and C28‐A3 guidelines. No sex partitioning was required for any of the biomarkers. Age partitioning was required for kidney function tests and phosphate. The serum concentration of urea and creatinine increased with age, while phosphate and uric acid decreased with age. Age partitioning was not required for serum calcium, vitamin D, and hs‐CRP, which remained relatively constant throughout the age range. Age‐specific RIs for 7 routine biochemical markers were determined to address critical gaps in RIs in early life to help improve clinical interpretation of blood test results in young children, including neonates. Established age partitions demonstrate the biochemical changes that take place during child growth and development. These novel data will ultimately better disease management in the Iranian paediatric population and can be of value to clinical and hospital laboratories with similar populations. 相似文献