scholarly journals Social recognition in wild fish populations

2007 ◽  
Vol 274 (1613) ◽  
pp. 1071-1077 ◽  
Author(s):  
Ashley J.W Ward ◽  
Michael M Webster ◽  
Paul J.B Hart
Keyword(s):  
Spatial Resolution ◽  
Gasterosteus Aculeatus ◽  
Social Recognition ◽  
Wild Populations ◽  
Recognition Mechanism ◽  
Temporal Flexibility ◽  
Social And Physical Environment ◽  
Focal Fish ◽  
High Degree ◽  
Recent Laboratory

The ability of animals to gather information about their social and physical environment is essential for their ecological function. Odour cues are an important component of this information gathering across taxa. Recent laboratory studies have revealed the importance of flexible chemical cues in facilitating social recognition of fishes. These cues are known to be mediated by recent habitat experience and fishes are attracted to individuals that smell like themselves. However, to be relevant to wild populations, where animals may move and forage freely, these cues would have to be temporally flexible and allow spatial resolution. Here, we present data from a study of social recognition in wild populations of three-spined sticklebacks ( Gasterosteus aculeatus ). Focal fish preferentially associated with conspecifics from the same habitat as themselves. These preferences were changed and updated following translocation of the focal fish to a different site. Further investigation revealed that association preferences changed after 3 h of exposure to different habitat cues. In addition to temporal flexibility, the cues also allowed a high degree of spatial resolution: fish taken from sites 200 m apart produced cues that were sufficiently different to enable the focal fish to discriminate and associate with fish captured near their own home site. The adaptive benefits of this social recognition mechanism remain unclear, though they may allow fish to orient within their social environment and gain current local information.

Evolution of stickleback spines through independent cis-regulatory changes at HOXDB

2021 ◽  
Author(s):  
Julia I Wucherpfennig ◽  
Timothy R Howes ◽  
Jessica N Au ◽  
Eric H Au ◽  
Garrett A Roberts Kingman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Evolutionary Biology ◽  
Gasterosteus Aculeatus ◽  
Molecular Mechanisms ◽  
Wild Populations ◽  
Gene Variation ◽  
Regulatory Changes ◽  
Fundamental Goal ◽  
Apeltes Quadracus ◽  
Genetic Mechanisms

Understanding the genetic mechanisms leading to new traits is a fundamental goal of evolutionary biology. We show that HOXDB regulatory changes have been used repeatedly in different stickleback fish species to alter the length and number of bony dorsal spines. In Gasterosteus aculeatus, a variant HOXDB allele is genetically linked to shortening an existing spine and adding a spine. In Apeltes quadracus, a variant allele is associated with lengthening an existing spine and adding a spine. The alleles alter the same conserved non-coding HOXDB enhancer by diverse molecular mechanisms, including SNPs, deletions, and transposable element insertions. The independent cis-acting regulatory changes are linked to anterior expansion or contraction of HOXDB expression. Our findings support the long-standing hypothesis that natural Hox gene variation underlies key morphological patterning changes in wild populations and illustrate how different mutational mechanisms affecting the same region may produce opposite gene expression changes with similar phenotypic outcomes.

scholarly journals Two different epigenetic pathways detected in wild three-spined sticklebacks are involved in salinity adaptation

2019 ◽  
Author(s):  
Melanie J. Heckwolf ◽  
Britta S. Meyer ◽  
Robert Häsler ◽  
Marc P. Höppner ◽  
Christophe Eizaguirre ◽  
...  
Keyword(s):  
Natural Selection ◽  
Gasterosteus Aculeatus ◽  
Natural Populations ◽  
Wild Populations ◽  
Epigenetic Marks ◽  
Transgenerational Plasticity ◽  
The Face ◽  
Adaptation Processes ◽  
Methylation Patterns ◽  
Rapid Emergence

AbstractWhile environmentally inducible epigenetic marks are discussed as one mechanism of transgenerational plasticity, environmentally stable epigenetic marks emerge randomly. When resulting in variable phenotypes, stable marks can be targets of natural selection analogous to DNA sequence-based adaptation processes. We studied both postulated pathways in natural populations of three-spined sticklebacks (Gasterosteus aculeatus) and sequenced their methylomes and genomes across a salinity cline. Consistent with local adaptation, populations showed differential methylation (pop-DMS) at genes enriched for osmoregulatory processes. In a two-generation experiment, 62% of these pop-DMS were insensitive to salinity manipulation, suggesting that they could be stable targets for natural selection. Two-thirds of the remaining inducible pop-DMS became more similar to patterns detected in wild populations from the corresponding salinity, and this pattern accentuated over consecutive generations, indicating a mechanism of adaptive transgenerational plasticity. Natural DNA methylation patterns can thus be attributed to two epigenetic pathways underlying the rapid emergence of adaptive phenotypes in the face of environmental change.

scholarly journals Correlation between spatial resolution and ball distortion rate of panoramic radiography

2020 ◽  
Author(s):  
Han-Gyeol Yeom ◽  
Sam-Sun Lee ◽  
Jo-Eun Kim ◽  
Kyung-Hoe Huh ◽  
Won-Jin Yi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Spatial Resolution ◽  
Panoramic Radiography ◽  
Reference Value ◽  
Vertical Line ◽  
Line Pair ◽  
Horizontal Line ◽  
Student’S T ◽  
High Degree ◽  
Distortion Rate

Abstract BackgroundThe purpose of this study was to analyze the correlation between spatial resolution and ball distortion rate of panoramic radiography and to elucidate the minimum criterion for ball distortion rate, which is very relevant to clinical readability.MethodsHorizontal and vertical spatial resolution and ball distortion rates were calculated in the same position, such as the incisor, premolar, molar, and temporomandibular joint area with various object depths corresponding to 48 mm. Three devices were evaluated. A region showing spatial resolution above the reference standard was selected, and the ball distortion rate corresponding to the same region was divided into horizontal and vertical phantom groups.The mean and standard deviation of the obtained ball distortion rates were calculated. Student’s t-test was used to statistically analyze the mean difference in ball distortion rates between vertical and horizontal phantom groups.ResultsIn all devices, the horizontal line pair phantom, but not the vertical line pair phantom, was readable in all areas measured at the line pair value of at least 1.88 lp/mm. The line pair value tended to be higher toward the center and lower toward the outside. The ball distortion rate tended to decrease closer to the center and increased further away. In addition, ball distortion rates could not be measured at some areas as they were not recognized as balls due to the high degree of distortion at the outermost and innermost sides. The number of balls satisfying the reference value using the horizontal line pair phantom was 102 (mean of ball distortion rates, 20.98; standard deviation, 15.25). The number of balls satisfying the reference value using the vertical line pair phantom was 49 (mean of ball distortion rates, 16.33; standard deviation, 14.25). However, mean ball distortion rate was not significantly different between the two groups.ConclusionsFocal layer of panoramic radiography could be evaluated by the spatial resolution using horizontal and vertical line pair phantoms and by assessing ball distortion rates through a ball-type panorama phantom. A ball distortion rate of 20% could be used as a threshold to evaluate the focal layer of panoramic radiography.

High degree of genetic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus)

2013 ◽  
Vol 22 (18) ◽  
pp. 4811-4828 ◽  
Author(s):  
Jacquelin DeFaveri ◽  
Takahito Shikano ◽  
Yukinori Shimada ◽  
Juha Merilä
Keyword(s):  
Genetic Differentiation ◽  
Gasterosteus Aculeatus ◽  
High Degree

scholarly journals Recent Laboratory Contributions to the Control of Yellow Fever

1933 ◽  
Vol 27 (2) ◽  
pp. 203-210
Author(s):  
Edward Hindle
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Early Stage ◽  
Immune Serum ◽  
Long Duration ◽  
Laboratory Infection ◽  
Sources Of Infection ◽  
High Degree ◽  
Improved Methods ◽  
Recent Laboratory

The most important recent laboratory contributions to the control of yellow fever will be briefly summarized under three headings: (1) Methods of diagnosis, (2) Transmission, and (3) Protection. (1) Methods of diagnosis.—The development of improved methods of identification, in particular by immunity tests, has made it possible to diagnose yellow fever with much greater certainty. Moreover, since the immunity following an attack of the disease is usually of life-long duration, it is possible to determine what proportion of any particular population has been infected and also how long any district has been free from infection. The application of immunity tests to the delimitation of endemic zones, especially in West Africa, has led to a great increase in our knowledge, and yellow fever has been found to have a much wider distribution than was previously suspected. Among other methods of recognizing the disease may be mentioned complement-fixation tests and also in post-mortem material the histopathology of the liver. (2) Methods of transmission. Indirect.—The main factors in the transmision of the disease by mosquitoes have been elucidated, and the relations between the course of the infection in monkeys (and also presumably in man) and the infectivity of these animals to mosquitoes. It is found that the blood becomes infective at a very early stage, before febrile symptoms develop, and that infectivity usually disappears three to four days after the onset of fever, owing to the presence of immune bodies in the blood. It is evident that any yellow fever patient must be considered to have been capable of infecting mosquitoes before showing any signs of the disease. Many other species of mosquitoes in addition to the Aëdes ægypti have now been shown capable of transmitting yellow fever. Direct.—It is now known that it is possible to acquire yellow fever in the absence of mosquitoes, through handling infected material. Many cases of laboratory infection have now been recorded in which other sources of infection can be definitely excluded. (3) Protection.—The most important advance in this direction has been the development of practicable methods of vaccination. The use of attenuated virus was followed by the use of virus and immune serum. The development of the latter has depended mainly on the discovery that when yellow fever virus is inoculated intracerebrally into mice, after a few passages it acquires neurotropic affinities and loses to a great extent its capacity for producing a general infection. The use of such virus, combined with human or animal immune serum, has been found to result in the development of a high degree of immunity comparable in intensity with that following an attack of the disease.

Mitochondrial DNA patterns among endemic stickleback from the Queen Charlotte Islands: a preliminary survey

1989 ◽  
Vol 67 (5) ◽  
pp. 1324-1328 ◽  
Author(s):  
M. H. Gach ◽  
T. E. Reimchen
Keyword(s):  
Mitochondrial Dna ◽  
Gasterosteus Aculeatus ◽  
Size Variation ◽  
Sequence Divergence ◽  
Isolated Populations ◽  
Base Pairs ◽  
Queen Charlotte Islands ◽  
Freshwater Habitats ◽  
Unique Restriction ◽  
High Degree

Mitochondrial DNA (mtDNA) restriction fragments were analyzed in 30 individuals from four populations of Gasterosteus aculeatus from the Queen Charlotte Islands, British Columbia. Two morphologically divergent endemic freshwater populations (Boulton Lake, Drizzle Lake), a typical stream form, and a brackish form were sampled. mtDNA size variation of 70 to 180 base pairs was noted among individuals from all populations, and 1.1 and 5.0 kilobase duplications were observed in mtDNAs from two individuals. Analysis of 75 mtDNA fragments produced by five restriction endonucleases revealed seven clones differing by less than 1.0% sequence divergence. While the high degree of genetic similarity is consistent with a postglacial origin of these populations, the presence of a unique restriction site among geographically isolated populations suggests that these endemics may have had a common freshwater ancestor that inhabited periglacial freshwater habitats rather than being independently derived from marine forms.

Some requirements for the study of the organization of cellular processes

1954 ◽  
Vol 142 (907) ◽  
pp. 137-140 ◽  
Keyword(s):  
Spatial Resolution ◽  
Biological Activities ◽  
Living Systems ◽  
Cellular Processes ◽  
The Subject ◽  
High Degree ◽  
Electrical Activities ◽  
Difficult Word ◽  
The Way

The subject of this discussion is the organization of enzymic processes within cells. Organization is a difficult word; perhaps a distasteful one to many biochemists, who often wonder whether people who ask them to study organization mean anything precise. Yet if biological activities are to be treated in chemical terms it is necessary to study not only individual enzymic processes but also the way that these are related to each other (Peters 1930; Hopkins 1935). One of the chief difficulties in doing this is that in living systems diverse processes go on very close to each other and yet in separate compartments. This may indeed be a large part of the secret of the synthetic feats performed by enzymic action. To study the relation of these various nearby processes in the cell we require above all methods providing a high degree of resolution in space. Any discussion of the subject is bound to be concerned largely with how to obtain this resolution. It can probably only be achieved by microscopy, including its recent refinements. The microscope provides a power of spatial resolution much greater than can be obtained, in most cases, by such methods as extraction or isolation or the study of electrical activities, valuable though these are in their proper places.

Unusual ascospore germination in Hypoxylon fragiforme: first seps in the establishment of an endophytic symbiosis

1990 ◽  
Vol 68 (12) ◽  
pp. 2571-2575 ◽  
Author(s):  
I. H. Chapela ◽  
O. Petrini ◽  
L. E. Petrini
Keyword(s):  
Germ Tube ◽  
Initial Step ◽  
Wall Layer ◽  
Flexible Structure ◽  
Specific Factor ◽  
Recognition Mechanism ◽  
Ascospore Germination ◽  
Host Fungus ◽  
High Degree ◽  
Rigid Shell

An unusual germination mechanism in ascospores of Hypoxylon fragiforme is described and illustrated. In this xylariaceous, endophytic fungus, germination always involved the emergence of a bivalved, flexible structure from an outer rigid shell, formed by a differentiated transparent wall layer, and resulted in the exposure of the cell body. The series of fast movements leading to the emergence of activated ascospores from their shells was termed spore eclosion. Eclosion was a necessary initial step of germination, but eclosion without germ-tube production could be obtained by cycloheximide treatment. Major changes involved in eclosion occurred within a few seconds, some minutes after discharge of ascospores onto the host material (Fagus sylvatica). We postulate the existence of a host-derived, diffusible, specific factor eliciting those changes. This sophisticated recognition mechanism indicates a high degree of specialization of H. fragiforme to its endophytic symbiosis with beech trees. Key words: eclosion, tree, Fagus, Hypoxylon, host–fungus recognition.

scholarly journals Investigation of Inter- and Intratumoral Heterogeneity of Glioblastoma Using TOF-SIMS

2020 ◽  
Vol 19 (6) ◽  
pp. 960-970 ◽  
Author(s):  
Samvel K. Gularyan ◽  
Alexander A. Gulin ◽  
Ksenia S. Anufrieva ◽  
Victoria O. Shender ◽  
Michail I. Shakhparonov ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Intratumoral Heterogeneity ◽  
Clinical Samples ◽  
Normal Brain ◽  
Pathological Feature ◽  
Caveolin 1 ◽  
Tof Sims ◽  
High Degree

Glioblastoma (GBM) is one of the most aggressive human cancers with a median survival of less than two years. A distinguishing pathological feature of GBM is a high degree of inter- and intratumoral heterogeneity. Intertumoral heterogeneity of GBM has been extensively investigated on genomic, methylomic, transcriptomic, proteomic and metabolomics levels, however only a few studies describe intratumoral heterogeneity because of the lack of methods allowing to analyze GBM samples with high spatial resolution. Here, we applied TOF-SIMS (Time-of-flight secondary ion mass spectrometry) for the analysis of single cells and clinical samples such as paraffin and frozen tumor sections obtained from 57 patients. We developed a technique that allows us to simultaneously detect the distribution of proteins and metabolites in glioma tissue with 800 nm spatial resolution. Our results demonstrate that according to TOF-SIMS data glioma samples can be subdivided into clinically relevant groups and distinguished from the normal brain tissue. In addition, TOF-SIMS was able to elucidate differences between morphologically distinct regions of GBM within the same tumor. By staining GBM sections with gold-conjugated antibodies against Caveolin-1 we could visualize border between zones of necrotic and cellular tumor and subdivide glioma samples into groups characterized by different survival of the patients. Finally, we demonstrated that GBM contains cells that are characterized by high levels of Caveolin-1 protein and cholesterol. This population may partly represent a glioma stem cells. Collectively, our results show that the technique described here allows to analyze glioma tissues with a spatial resolution beyond reach of most of other omics approaches and the obtained data may be used to predict clinical behavior of the tumor.

scholarly journals Two different epigenetic information channels in wild three-spined sticklebacks are involved in salinity adaptation

2020 ◽  
Vol 6 (12) ◽  
pp. eaaz1138 ◽  
Author(s):  
Melanie J. Heckwolf ◽  
Britta S. Meyer ◽  
Robert Häsler ◽  
Marc P. Höppner ◽  
Christophe Eizaguirre ◽  
...  
Keyword(s):  
Gasterosteus Aculeatus ◽  
Epigenetic Inheritance ◽  
Genomic Variation ◽  
Direct Selection ◽  
Salinity Adaptation ◽  
Wild Populations ◽  
Epigenetic Marks ◽  
Transgenerational Plasticity ◽  
Information Channels ◽  
Methylation Patterns

Epigenetic inheritance has been proposed to contribute to adaptation and acclimation via two information channels: (i) inducible epigenetic marks that enable transgenerational plasticity and (ii) noninducible epigenetic marks resulting from random epimutations shaped by selection. We studied both postulated channels by sequencing methylomes and genomes of Baltic three-spined sticklebacks (Gasterosteus aculeatus) along a salinity cline. Wild populations differing in salinity tolerance revealed differential methylation (pop-DMS) at genes enriched for osmoregulatory processes. A two-generation experiment demonstrated that 62% of these pop-DMS were noninducible by salinity manipulation, suggesting that they are the result of either direct selection or associated genomic divergence at cis- or trans-regulatory sites. Two-thirds of the remaining inducible pop-DMS increased in similarity to patterns detected in wild populations from corresponding salinities. The level of similarity accentuated over consecutive generations, indicating a mechanism of transgenerational plasticity. While we can attribute natural DNA methylation patterns to the two information channels, their interplay with genomic variation in salinity adaptation is still unresolved.

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