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National Science Review 2019年第6期6卷 1176-1188页

作者： Yuxin Chen Yang Shen Pei Lin Ding Tong Yixin Zhao Stefano Allesina Xu Shen Chung-I Wu School of Life Science Sun Yat-Sen University Target Discovery Research Boehringer Ingelheim Pharma Gmb H & Co KG Department of Biostatistics School of Public Health Yale University Department of Ecology and Evolution University of Chicago

Food web and gene regulatory networks(GRNs) are large biological networks, both of which can be analyzed using the May–Wigner theory. According to the theory, networks as large as mammalian GRNs would require dedicated gene products for stabilization. We propose that micro RNAs(mi RNAs) are those products. More than 30% of genes are repressed by mi RNAs, but most repressions are too weak to have a phenotypic consequence. The theory shows that(i) weak repressions cumulatively enhance the stability of GRNs, and(ii) broad and weak repressions confer greater stability than a few strong ones. Hence, the diffuse actions of mi RNAs in mammalian cells appear to function mainly in stabilizing GRNs. The postulated link between m RNA repression and GRN stability can be seen in a different light in yeast, which do not have mi RNAs. Yeast cells rely on non-specific RNA nucleases to strongly degrade m RNAs for GRN stability. The strategy is suited to GRNs of small and rapidly dividing yeast cells, but not the larger mammalian cells. In conclusion, the May–Wigner theory, supplanting the analysis of small motifs, provides a mathematical solution to GRN stability, thus linking mi RNAs explicitly to ’developmental canalization’.

关键词： micro RNAs network stability canalization May–Wigner theory systems biology RNA crosstalk

Predicting the dynamics of local adaptation in invasive species

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Journal of Arid Land 2013年第3期5卷 268-274页

作者： Erin K ESPELAND USDA-ARS Pest Management Research Unit Sidney MT 59270USA

An invasive plant species may restrict its spread to only one type of habitat, or, after some time, may continue to spread into a different, often stressful, secondary, habitat. The question of whether evolution is required for an invasive species to spread from one habitat to another is currently hotly debated. In order for local adaptation to occur, genetic variation must be present within invasive populations. In this paper, I focus on the effect of habitat on the maintenance of genetic variation during the lag phase, the phase of population stability prior to expansion. Genetic diversity in invasive plant populations accumulates through multiple introductions, gene flow, mutation, and hybridization, but diversity is maintained by population level processes influencing effective population size （Ne）. I show that when the plastic response to the environment results in little variation in reproductive output among indi- viduals, Ne is maximized and genetic variation is maintained. Established models of plant competition show that below-ground competition reduces the variation in reproductive output, whereas competition for light increases variation in reproductive output. The same environments that maintain high Ne also reduce the opportunity for se- lection and minimize the response to selection, and thus the effects of the environment are synchronized to prevent genetic purges. When the primary invasion habitat supports high Ne, conditions are ripe for local adaptation to a secondary habitat, particularly if the secondary habitat has high opportunity for selection. When the primary invasion habitat supports low Ne, genetic diversity is less likely to be sufficient for local adaptation to secondary habitat to occur.

关键词： canalization phenotypic plasticity population expansion secondary invasion

Overcoming maladaptive plasticity through plastic compensation

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Current Zoology 2013年第4期59卷 526-536页

作者： Matthew R.J. MORRIS Sean M. ROGERS Department of Biological Sciences University of Calgary Calgary AB Canada T2N 1N4

Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plas- ticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes （standing genetic variation, genetic compensation） and two of which do not （standing epigenetic variation, plastic compensation）. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for under- standing evolutionary change

关键词： Homeostasis canalization Ecological speciation Standing genetic variation Genetic compensation Countergradi-ent variation

Cell competition and its implications for development and cancer

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Journal of Genetics and Genomics 2011年第10期38卷 483-495页

作者： Yoichiro Tamori Department of Biological Science Florida State UniversityTallahasseeFL 32306-4370USA

Cell competition is a struggle for existence between cells in heterogeneous tissues of multicellular organisms. Loser cells, which die during cell competition, are normally viable when grown only with other loser cells, but when mixed with winner cells, they are at a growth disadvantage and undergo apoptosis. Intriguingly, several recent studies have revealed that cells bearing mutant tumor-suppressor genes, which show overgrowth and tumorigenesis in a homotypic situation, are frequently eliminated, through cell competition, from tissues in which they are surrounded by wild-type cells. Here, we focus on the regulation of cellular competitiveness and the mechanism of cell competition as inferred from two different categories of mutant cells：（1） slower-growing cells and （2） structurally defective cells. We also discuss the possible role of cell competition as an intrinsic homeostasis system through which normal cells sense and remove aberrant cells, such as precancerous cells, to maintain the integrity and normal development of tissues and organs.

关键词： Cell competition canalization Competition-dependent cell death Drosophila models Cellular proliferation Cellular growth Tumor-suppressor genes

Multivariate analyses of skull morphology inform the taxonomy and evolution of geomyoid rodents

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Current Zoology 2023年第4期69卷 456-474页

作者： Lily A.Noftza Jonathan J.M.Calede aBiology Program The Ohio State University at Marion1459 Mount Vernon AvenueMarionOH 43302USA Department of Evolution Ecologyand Organismal BiologyThe Ohio State University318 W.12th Ave.ColumbusOH 43210USA.

Morphological analyses are critical to quantify phenotypic variation,identify taxa,inform phylogenetic relationships,and shed light on evolutionary *** work is particularly important in groups that display great morphological *** is the case in geomyoid rodents,a group that includes 2 of the most species-rich families of rodents in North America:the Geomyidae(pocket gophers)and the Heteromyidae(kangaroo rats,pocket mice,and their relatives).We assessed variation in skull morphology(including both shape and size)among geomyoids to test the hypothesis that there are statistically significant differences in skull measurements at the family,genus,and species *** sample includes 886 specimens representing all geomyoid genera and 39 *** used the geometric mean to compare size across *** used 14 measurements of the cranium and lower jaw normalized for size to compare shape among and within *** results show that skull measurements enable the distinction of geomyoids at the family,genus,and species *** is a larger amount of size variation within Geomyidae than within *** phylomorphospace analysis shows that the skull shape of the common ancestor of all geomyoids was more similar to the common ancestor of heteromyids than that of *** skulls display negative allometry whereas heteromyid skulls display positive *** heteromyids,dipodomyines,and non-dipodomyines show significantly different allometric *** analyses including fossils will be necessary to test our evolutionary hypotheses.

关键词： canalization convergent evolution Geomyidae Heteromyidae morphometrics phylomorphospace

Master of one trade:Arbutus unedo relies on plasticity to persist under habitats differing in water availability

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Journal of Plant Ecology 2017年第5期10卷 869-881页

作者： Xabier Santiso Rubén Retuerto Área de Ecología Facultad de BiologíaCampus VidaUniversidade de Santiago de Compostela15782 Santiago de CompostelaSpain

Aims the limited water supply in the Mediterranean Basin will be exacerbated in the immediate future as result of severe drought ***,the study of the intraspecific variability in functional traits of plant species is important,because such variability modulates species’***,we aimed to analyse the variability in plasticity of physiological and structural traits of Arbutus unedo *** response to water availability and to determine whether the levels of phenotypic plasticity varied in plants of different *** We kept two sets of plants under contrasted water regimes(high water and low water)and calculated a phenotypic plasticity index to determine the plastic response to water *** compared the response among kind of traits and *** also per-formed analysis of variance to assess the trait and provenance *** Findings We found that biomass and key physiological traits decrease under drought conditions,while the water use efficiency *** differed between groups of traits,being higher in structural and gas exchange parameters,but the provenance did not account for signifi-cant variation in *** has evolved a‘good saver’strat-egy,involving decreasing growth and water use-when this resource is unavailable-together with the dissipation of excess of radiation that it cannot *** homogeneous response between provenances may be the result of a canalization *** strategy,based on a high degree of plasticity,is a probable determining factor in the success of the species over its wide range of environmental conditions and will be critical to withstand the ongoing environmental changes.

关键词： adaptation canalization contrasted provenances drought global change phenotypic plasticity

Early social context does not influence behavioral variation at adulthood in ants

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Current Zoology 2022年第3期68卷 335-344页

作者： Iago SANMARTÍN-VILLAR Raphaël JEANSON Centre de Recherches Sur la Cognition Animale Centre de Biologie IntégrativeUniversitéde ToulouseCNRSUPSToulouseFrance Universidade de Vigo ECOEVO LabEscola de Enxeñaría ForestalCampus A XunqueiraPontevedraSpain

Early experience can prepare offspring to adapt their behaviors to the environment they are likely to encounter later in life. In several species of ants, colonies show ontogenic changes in the brood-to-worker ratio that are known to have an impact on worker morphology. However, little information is available on the influence of fluctuations in the early social context on the expression of behavior in adulthood. Using the ant Lasius niger, we tested whether the brood-to-worker ratio during larval stages influenced the level of behavioral variability at adult stages. We raised batches of 20 or 180 larvae in the presence of 60 workers until adulthood. We then quantified the activity level and wall-following tendency of callow workers on 10 successive trials to test the prediction that larvae reared under a high brood-to-worker ratio should show greater behavioral variations. We found that manipulation of the brood-to-worker ratio influenced the duration of development and the size of individuals at emergence. We detected no influence of early social context on the level of between- or within-individual variation measured for individual activity level or on wall-following behavior. Our study suggests that behavioral traits may be more canalized than morphological traits.

关键词： brood care canalization locomotion metamorphosis ontogeny variability