Otolith microstructure and otolith size analyses have been important research tools in the study of the early life history of cod, Gadus morhua L., since 1980. This review of the literature covers 41 ...years (1980–2021) of publications in this research category. Most articles were published in the 1990s and 2000s, while in the past ten years, only four articles were published, and most focused on juvenile specimens. As this review indicates, during the larval period, the lapillus was used more often in age analyses than was the sagitta, while in studies on juvenile specimens, the sagitta was used more frequently. Age estimated from otolith microstructures most frequently served as basic data for analyses of somatic growth, otolith growth, and hatch dates, while it was used less commonly for analyses of age validation, age prediction, and juvenile settlement. Since the otoliths of cod are relatively difficult to read, it is worth noting that the topic of the effect of reader experience on the accuracy and precision of age determination was addressed in one of the articles. The purpose of the otolith microstructure analysis of larval and juvenile cod did not change significantly among the years reviewed with regard to these main categories, and only age validation was conducted notably more frequently in the first 20 years of the period analyzed than in the last 20 years, which seems logical. Undoubtedly, otolith size and microstructure analyses have contributed significantly to the knowledge of larval and juvenile cod ecology, and this review could be a good starting point for any researcher interested in using otolith techniques to explore the early life history of cod.
•Literature covering period from 1981 to 2021 was reviewed.•Otolith microstructure analysis is frequently applied in the research on early life history of cod.•Lapillus is used more often for larvae, and sagittae for juveniles.•Otolith microstructures analysis mostly serves for research on somatic and otolith growth, and hatch dates.
is a primary cause of biofilm-mediated infections in humans due to adherence to foreign bodies. A major staphylococcal biofilm accumulation molecule is polysaccharide intracellular adhesin (PIA), ...which is synthesized by enzymes encoded by the
operon. Expression of PIA is highly variable among clinical isolates, suggesting that PIA expression levels are selected in certain niches of the host. However, the mechanisms that govern enhanced
transcription and PIA synthesis in these isolates are not known. We hypothesized that enhanced PIA synthesis in these isolates was due to function of IcaR and/or TcaR. Thus, two
isolates (1457 and CSF41498) with different
transcription and PIA expression levels were studied. Constitutive expression of both
and
demonstrated that both repressors are functional and can completely repress
transcription in both 1457 and CSF41498. However, it was found that IcaR was the primary repressor for CSF41498 and TcaR was the primary repressor for 1457. Further analysis demonstrated that
transcription was repressed in 1457 in comparison to CSF41498, suggesting that TcaR functions as a repressor only in the absence of IcaR. Indeed, DNase I footprinting suggests IcaR and TcaR may bind to the same site within the
intergenic region. Lastly, we found mutants expressing variable amounts of PIA could rapidly be selected from both 1457 and CSF41498. Collectively, we propose that strains producing enhanced PIA synthesis are selected within certain niches of the host through several genetic mechanisms that function to repress
transcription, thus increasing PIA synthesis.
is a commensal bacterium that resides on our skin. As a commensal, it protects humans from bacterial pathogens through a variety of mechanisms. However, it is also a significant cause of biofilm infections due to its ability to bind to plastic. Polysaccharide intercellular adhesin is a significant component of biofilm, and we propose that the expression of this polysaccharide is beneficial in certain host niches, such as providing extra strength when the bacterium is colonizing the lumen of a catheter, and detrimental in others, such as colonization of the skin surface. We show here that fine-tuning of
transcription, and thus PIA synthesis, is mediated via two transcriptional repressors, IcaR and TcaR.
The ages of 8 to 23·5 cm total length (LT) round goby Neogobius melanostomus collected monthly during 2006 and 2007 in the Gulf of Gdańsk (Baltic Sea) ranged from 2 to 6 years, with age class 4+ ...years dominant. Males were larger at age than females. The fastest growth occurred in the first 2 years of life in both sexes. Females were heavier at a given LT than males, but only for fish > c. 15 cm. A strong relationship between N. melanostomus otolith size and fish size was found, with no difference between males and females, and a significant relationship between fish growth rate and otolith growth rate, which enabled backcalculation of growth rates. Marginal increment width analysis confirmed the periodicity of annual ring formation in otoliths and showed that the most intense opaque zone formation occurs in July to August, while hyaline zone formation starts as early as September to October. It was concluded that the N. melanostomus that have colonized the southern Baltic Sea exhibit the largest size and longest life span ever recorded for this species.
Otolith growth rates of the early life stages of herring Clupea harengus (n= 472) and smelt Osmerus eperlanus (n= 348) collected in the Vistula Lagoon (Baltic Sea) during 1997–1999 were analysed. The ...larvae and early juveniles were not only collected in the same geographical area they were also of the same size (range 15–43 mm standard length, LS), similar ages and were collected during the same seasons (May to July). Although the two clupeid species experienced very similar environmental conditions, there were significant discrepancies in the analysed relationships. The otolith growth of larval and juvenile smelt was very strongly related to somatic growth while temperature had a minor effect. In herring, the effect of somatic growth, although clearly visible and statistically highly significant, was of less importance than temperature. Furthermore, variation in the otolith size and LS relationship was affected by temperature and somatic growth in both species, but the variance of otolith size at LS was higher for herring than for smelt. Although growth backcalculation from otoliths can presently be recommended as an appropriate method for use with both smelt and herring (despite possibly lower precision and accuracy with the latter), other methods referring directly to short‐term increment width changes (e.g. marginal increment analysis) are recommended for smelt but not for herring.
Abstract
The Gene Ontology resource (GO; http://geneontology.org) provides structured, computable knowledge regarding the functions of genes and gene products. Founded in 1998, GO has become widely ...adopted in the life sciences, and its contents are under continual improvement, both in quantity and in quality. Here, we report the major developments of the GO resource during the past two years. Each monthly release of the GO resource is now packaged and given a unique identifier (DOI), enabling GO-based analyses on a specific release to be reproduced in the future. The molecular function ontology has been refactored to better represent the overall activities of gene products, with a focus on transcription regulator activities. Quality assurance efforts have been ramped up to address potentially out-of-date or inaccurate annotations. New evidence codes for high-throughput experiments now enable users to filter out annotations obtained from these sources. GO-CAM, a new framework for representing gene function that is more expressive than standard GO annotations, has been released, and users can now explore the growing repository of these models. We also provide the ‘GO ribbon’ widget for visualizing GO annotations to a gene; the widget can be easily embedded in any web page.
Francisella tularensis subsp. holarctica is widely disseminated in North America and the boreal and temperate regions of the Eurasian continent. Comparative genomic analyses identified a 1.59-kb ...genomic deletion specific to F. tularensis subsp. holarctica isolates from Spain and France. Phylogenetic analysis of strains carrying this deletion by multiple-locus variable-number tandem repeat analysis showed that the strains comprise a highly related set of genotypes, implying that these strains were recently introduced or recently emerged by clonal expansion in France and the Iberian Peninsula.
We describe here a previously unknown, dominantly inherited, late-onset basal ganglia disease, variably presenting with extrapyramidal features similar to those of Huntington's disease (HD) or ...parkinsonism. We mapped the disorder, by linkage analysis, to 19q13.3, which contains the gene for ferritin light polypeptide (FTL). We found an adenine insertion at position 460-461 that is predicted to alter carboxy-terminal residues of the gene product. Brain histochemistry disclosed abnormal aggregates of ferritin and iron. Low serum ferritin levels also characterized patients. Ferritin, the main iron storage protein, is composed of 24 subunits of two types (heavy, H and light, L) which form a soluble, hollow sphere. Brain iron deposition increases normally with age, especially in the basal ganglia, and is a suspected causative factor in several neurodegenerative diseases in which it correlates with visible pathology, possibly by its involvement in toxic free-radical reactions. We found the same mutation in five apparently unrelated subjects with similar extrapyramidal symptoms. An abnormality in ferritin strongly indicates a primary function for iron in the pathogenesis of this new disease, for which we propose the name 'neuroferritinopathy'.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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