Developmental Stability Research Articles

The effects of exposure to cold during incubation on developmental stability, fear, growth, and carcass traits in Japanese quails.

The aim of this study was to determine the effects of 6h/day cold (35.0°C) acclimatization between the 9th and 15th days of incubation of Japanese quail embryos on hatchability, livability, chick quality, developmental stability, fear response, live weight, and slaughter-carcass characteristics. Two homologous incubators and a total of 500 hatching eggs were used in the study. Randomly selected half of the eggs were exposed to cold according to the eggshell temperature. The cold acclimation of Japanese quail embryos had no adverse effects on all mentioned traits, except for chick quality. Chicks in the control group had higher Tona scores (99.46) than those exposed to cold (99.00) (P < 0.05). In addition, there were differences among the treatment groups in terms of the parameters of mature weight (β0), instantaneous growth rate (β2), and inflection point coordinates of the Gompertz growth model (P < 0.05 for all). It was found that exposing embryos to cold during the incubation changed the shape of the growth curve. As the development of embryos exposed to cold slows down, a compensatory growth occurs in the early posthatch period. Thus, the growth rate increased in the period before the inflection point of the growth curve.

Developmental Stability, Population Dynamics and Climate Change, with Particular Reference to the Common Shrew (&lt;i&gt;Sorex araneus&lt;/i&gt; L., 1758) in Central Siberia

We examine temporal variation in a measure of developmental stability, the degree of fluctuating asymmetry of the characters of skull morphology, of the common shrew (Sorex araneus L., 1758) in Central Siberia. Four-year cycles in this population in the last century were accompanied by significant changes in the level of developmental stability. Population fluctuations under the climate change conditions in this century commonly occur without essential changes in developmental stability. Deterioration of developmental stability takes place occasionally in case of adverse overpopulation impact in the year of peak population abundance that is beyond the certain threshold level increased due to the climate change.

The age at first reproduction as a potential mediator between facial fluctuating asymmetry and reproductive success in women

The level of fluctuating asymmetry is suggested as a putative signal of developmental stability, thus according to this theoretical framework more symmetric individuals should be in better biological condition and have greater reproductive potential. Here we hypothesize that women with more symmetric faces have more successful reproduction. Data were collected from 164 postmenopausal Polish women. Facial photographs were taken and the overall facial asymmetry (OFA) was calculated. The associations between the OFA and reproductive parameters were analyzed using multiple regression models. Furthermore, the mediation analysis was conducted to test for the indirect effects of the OFA on reproductive success. There was a statistically significant relationship between the OFA and the number of children born, which was mediated by the age at first reproduction (p = 0.03), however, the size of the effect was rather low. Women with more symmetric faces had an earlier age at first reproduction and, in consequence, a greater number of children. As fluctuating asymmetry is suggested to be established in utero, these findings shed light on the possible life-long importance of developmental conditions in shaping women's reproductive potential and performance.

The associative system of early-learned Hebrew verbs and body parts: a comparative study with American English

Abstract This paper compares the associative system of early-learned verbs and body parts in Hebrew with previously published data on American English (Maouene, Josita, Shohei Hidaka &amp; Linda B. Smith. 2008. Body parts and early-learned verbs. Cognitive Science 32(7). 1200–1216). Following the methodology of the former study, 51 Hebrew-speaking college students gave the first body part that came to mind for each of 103 early-learned Hebrew verbs, 81 of which were translational equivalents. Rate of convergence and divergence and underlying patterns were used to make inferences about the constraints at work. Overall convergence (92.3% of the Hebrew data and 93.7% of the English data) reveal similar entropy levels, comparable semantic field shapes of verbs organized by body parts and similar general cluster patterns of verbs by body parts. Most divergence lies in the infrequent responses (offered fewer than 1% of the time) which arise around body parts that are internal, very detailed, very general categorically, used in figurative language, uniquely provided and tend to be subject to cultural taboos. This is a new contribution, as previous work has not quantified the relative proportion of convergent to divergent associations. We discuss how these findings support neural and developmental continuity and stability in the verbal system with respect to the categorization of verbs by body parts cross-culturally.

Examining the unique contributions and developmental stability of individual forms of relational reasoning to mathematical problem solving

Relational reasoning, a higher-order cognitive ability that identifies meaningful patterns among information streams, has been suggested to underlie STEM development. This study attempted to explore the potentially unique contributions of four forms of relational reasoning (i.e., analogy, anomaly, antinomy, and antithesis) to mathematical problem solving. Two separate samples, fifth graders (n = 254) and ninth graders (n = 198), were assessed on their mathematical problem solving ability and the different forms of relational reasoning ability. Linear regression analysis was conducted, with participants’ age, working memory, and spatial skills as covariates. The results showed that analogical and antithetical reasoning abilities uniquely predicted mathematical problem solving. This pattern demonstrated developmental stability across a four-year time frame. The findings clarify the unique significance of individual forms of relational reasoning to mathematical problem solving and call for a shift of research direction to reasoning abilities when exploring dissimilarity-based relations (opposites in particular).

Stability in gene expression and body-plan development leads to evolutionary conservation

BackgroundPhenotypic evolution is mainly explained by selection for phenotypic variation arising from factors including mutation and environmental noise. Recent theoretical and experimental studies have suggested that phenotypes with greater developmental stability tend to have a constant phenotype and gene expression level within a particular genetic and environmental condition, and this positively correlates with stronger evolutionary conservation, even after the accumulation of genetic changes. This could reflect a novel mechanism that contributes to evolutionary conservation; however, it remains unclear whether developmental stability is the cause, or whether at least it contributes to their evolutionary conservation. Here, using Japanese medaka lines, we tested experimentally whether developmental stages and gene expression levels with greater stability led to their evolutionary conservation.ResultsWe first measured the stability of each gene expression level and developmental stage (defined here as the whole embryonic transcriptome) in the inbred F0 medaka population. We then measured their evolutionary conservation in the F3 generation by crossing the F0 line with the distantly related Japanese medaka line (Teradomori), followed by two rounds of intra-generational crossings. The results indicated that the genes and developmental stages that had smaller variations in the F0 generation showed lower diversity in the hybrid F3 generation, which implies a causal relationship between stability and evolutionary conservation.ConclusionsThese findings suggest that the stability in phenotypes, including the developmental stages and gene expression levels, leads to their evolutionary conservation; this most likely occurs due to their low potential to generate phenotypic variation. In addition, since the highly stable developmental stages match with the body-plan-establishment stage, it also implies that the developmental stability potentially contributed to the strict conservation of animal body plan.

Forest Fragmentation and Developmental Stability of Wood Mice Apodemus sylvaticus: A Food-Mediated Effect?

Generalist mice are key species for the long-term dynamics of fragmented forests due to their dual role as seed dispersers or predators of the dominant trees. Wood mice, Apodemus sylvaticus, usually act as a net predator in woodlots due to higher winter densities and earlier winter reproduction than in forests. Here we analyze the recruitment expectations of young mice born in woodlots in relation to food availability through an index of developmental stability that combined values of fluctuating asymmetry (FA) for six traits of the lower mandibles. FA was measured in young and adult mice caught at the end of the winter in control woodlots, food-supplemented woodlots and in a nearby large forest. Despite low sample sizes (n = 9 for young and n = 74 for adults), FA in young mice born in control woodlots were significantly higher than in those from food-supplemented woodlots and the forest and in all adults. Food limitation in woodlots was thus associated with increased developmental instability of young mice, but it had no effect on adults. Instability likely reduced the survival prospects of young mice through increased mortality, and this should be compensated by yearly recolonization of woodlots by adults from the agricultural matrix in autumn and winter. Future work analyzing mechanisms suggested here but using non-lethal methods will be important to clarify the impacts of FA on the population dynamics of wood mice.

Fluctuating Asymmetry as a Measure of Stress in Natural Populations of Woody Plants: Influence of Ecological and Geographical Factors on Developmental Stability

Fluctuating asymmetry is a sensitive indicator of favorable conditions during the period of individual development. The influence of climatic factors, biotopic conditions, latitude, altitude, and age of plants from the natural populations of the silver birch Betula pendula Roth was analyzed. The material consisted of 13,000 leaves of the silver birch from 11 regions of north-eastern Siberia. The influence of 23 climatic factors and six integrated coefficients characterizing the general suitability of the climate, as well as summer, winter, spring, and autumn was analyzed. The developmental stability of woody plants and, consequently, the level of the FA of the lamina in natural biotopes can vary in a wide range. We found that climatic factors, mainly conditions in the warm season, have a significant impact. We also noted the influence of the age, biotope, and light conditions. For Betula pendula, an increase in FA was registered on the ecological periphery of its range, i.e., on the edge of the forest belt in the north and in the mountains. The data obtained demonstrate the high influence of natural stress-inducing factors on development stability in plants.

The Evolutionary Principles of the Attractiveness of Symmetry and Their Possible Sustainability in the Context of Research Ambiguities

Symmetry belongs to one of the basic principles of the beauty of human and non-human objects since antiquity. Even though its significance has been verified by numerous theories and research studies, there is a number of papers suggesting that this principle may be false. The study identifies five major evolutionary principles, in the context of new approaches and research ambiguities based mainly on neuroscience and evolutionary psychology, that support the thesis that highlights the significance of symmetry in the perception and assessment of attractiveness: 1. symmetry as an honest signal of various health characteristics; 2. symmetry as proof of developmental stability; 3. effectiveness; 4. comprehensibility; 5. predictability. In the context of the mechanisms described above it also seeks possible explanations for the existence of contradictory research results related to the attractiveness of symmetry. The outcome of the study is the postulation of three hypotheses: 1. the naturalness hypothesis (symmetry is only attractive to the same degree that it naturally occurs in the subject); 2. the accent hypothesis (minor asymmetries do not disprove the principles of symmetry, they make them more visible); 3. the ecology hypothesis (the attractiveness of symmetry is conditioned by the situation and depends on the type of subject assessed) that allow us to integrate both past and contemporary (and putatively contradictory) research findings. The paper also provides proposals for the verification of the postulated hypotheses.

School bullying and its risk and protective factors in Chinese early adolescents: A latent transition analysis.

Bullying perpetration and victimization are common and problematic occurrences during adolescence. Typically, bullying incidents involve different bullying roles. However, little is known about the developmental stability and changes in these roles. In the present study, we aimed to assess the stability and changes in bullying roles and examine risk and protective factors associated with bullying involvement. A total of 1711 Chinese early adolescents (47.4% girls, Mage = 11.99) participated in the study at two time points approximately 6months apart. Three subgroups of bullying were identified: bully-victims, victims, and the uninvolved. In terms of stability and changes, the uninvolved were the most stable over time, while victims and bully-victims tended to become the uninvolved. Bully-victims also tended to become victims. Early adolescents with higher levels of parental psychological control and depression symptoms were more likely to be victims or bully-victims. Higher levels of depression symptoms increased the risk of transitioning from being the uninvolved or bully-victims to becoming victims. Higher levels of friendship quality were associated with higher odds of being the uninvolved or transitioning from being victims or bully-victims to becoming the uninvolved. Our findings indicate that bullying roles were relatively stable, with some changes over time. The results also highlight the important function that parental psychological control, friendship quality, and depression symptoms can play in preventing and intervening in bullying.

Selection on an extreme-yet-conserved larval life-history strategy in a tapeworm.

Evolutionary stasis characterizes many phenotypes, even ones that seem suboptimal. Among tapeworms, Schistocephalus solidus and its relatives have some of the shortest developmental times in their first intermediate hosts, yet their development still seems excessively long considering they can grow faster, larger, and safer in the next hosts in their complex life cycles. I conducted 4 generations of selection on the developmental rate of S. solidus in its copepod first host, pushing a conserved-but-counterintuitive phenotype toward the limit of known tapeworm life-history strategies. Faster parasite development evolved and enabled earlier infectivity to the stickleback next host, but low heritability for infectivity moderated fitness gains. Fitness losses were more pronounced for slow-developing parasite families, irrespective of selection line, because directional selection released linked genetic variation for reduced infectivity to copepods, developmental stability, and fecundity. This deleterious variation is normally suppressed, implying development is canalized and thus under stabilizing selection. Nevertheless, faster development was not costly; fast-developing genotypes did not decrease copepod survival, even under host starvation, nor did they underperform in the next hosts, suggesting parasite stages in successive hosts are genetically decoupled. I speculate that, on longer time scales, the ultimate cost of abbreviated development is reduced size-dependent infectivity.

Growth Regulation in the Larvae of the Lepidopteran Pieris brassicae: A Field Study.

Size and shape are important determinants of fitness in most living beings. Accordingly, the capacity of the organism to regulate size and shape during growth, containing the effects of developmental disturbances of different origin, is considered a key feature of the developmental system. In a recent study, through a geometric morphometric analysis on a laboratory-reared sample of the lepidopteran Pieris brassicae, we found evidence of regulatory mechanisms able to restrain size and shape variation, including bilateral fluctuating asymmetry, during larval development. However, the efficacy of the regulatory mechanism under greater environmental variation remains to be explored. Here, based on a field-reared sample of the same species, by adopting identical measurements of size and shape variation, we found that the regulatory mechanisms for containing the effects of developmental disturbances during larval growth in P. brassicae are also effective under more natural environmental conditions. This study may contribute to better characterization of the mechanisms of developmental stability and canalization and their combined effects in the developmental interactions between the organism and its environment.

Insulin-like peptide 8 (Ilp8) regulates female fecundity in flies.

Introduction: Insulin-like peptides (Ilps) play crucial roles in nearly all life stages of insects. Ilp8 is involved in developmental stability, stress resistance and female fecundity in several insect species, but the underlying mechanisms are not fully understood. Here we report the functional characterization of Ilp8s in three fly species, including Bactrocera dorsalis, Drosophila mercatorum and Drosophila melanogaster. Methods: Phylogenetic analyses were performed to identify and characterize insect Ilp8s. The amino acid sequences of fly Ilp8s were aligned and the three-dimensional structures of fly Ilp8s were constructed and compared. The tissue specific expression pattern of fly Ilp8s were examined by qRT-PCR. In Bactrocera dorsalis and Drosophila mercatorum, dsRNAs were injected into virgin females to inhibit the expression of Ilp8 and the impacts on female fecundity were examined. In Drosophila melanogaster, the female fecundity of Ilp8 loss-of-function mutant was compared with wild type control flies. The mutant fruit fly strain was also used for sexual behavioral analysis and transcriptomic analysis. Results: Orthologs of Ilp8s are found in major groups of insects except for the lepidopterans and coleopterans, and Ilp8s are found to be well separated from other Ilps in three fly species. The key motif and the predicted three-dimensional structure of fly Ilp8s are well conserved. Ilp8 are specifically expressed in the ovary and are essential for female fecundity in three fly species. Behavior analysis demonstrates that Ilp8 mutation impairs female sexual attractiveness in fruit fly, which results in decreased mating success and is likely the cause of fecundity reduction. Further transcriptomic analysis indicates that Ilp8 might influence metabolism, immune activity, oocyte development as well as hormone homeostasis to collectively regulate female fecundity in the fruit fly. Discussion: Our findings support a universal role of insect Ilp8 in female fecundity, and also provide novel clues for understanding the modes of action of Ilp8.

Three methods testing the asymmetry of the leaf blades of the small-leaved lime

Three methods were used to determine the fluctuating asymmetry (FA) of leaf blades and the developmental stability of smallleaved linden (Tilia cordata Mill): the normalizing difference method, the sample normalization method, and the two-factor analysis method (FA10). The collection of leaf blades took place along the latitudinal zonality gradient from north to south in five cities from Murmansk (68°58′ N) to Mozhaisk (55°30′ N), including the cities of Apatity, Petrozavodsk and Saint Petersburg. In all analyses, the highest FA value was obtained in the population of Petrozavodsk, the lowest in the population of Mozhaisk. In other cities, the FA indices differed, except for the populations in Apatity and Petrozavodsk with FA10 indices, respectively, 0.02 (p=0.02) and 0.03 (p=0.01). In the northernmost population (Murmansk), no decrease in developmental stability was noted. The stability of the development of Tilia cordata was more strongly influenced by the climatic and geographical conditions of the area and the technogenic state of the environment than by the geographic latitude. The authors note that a non-parametric sample distribution is advisable to use the two-factor analysis of variance, since normality difference and normalization lead to a non-equivalent deviation of the results. Bonferroni’s adjustments for measurement error were convenient for accurately distributing FA values at significance level.

Developmental change and stability of social anxiety from toddlerhood to young adulthood: A three-level meta-analysis of longitudinal studies

Developmental change and stability of social anxiety from toddlerhood to young adulthood: A three-level meta-analysis of longitudinal studies

Cytokinins

The extraordinary variety that characterizes the living world in terms of forms and structures is the result of natural selection that allows an organism to be in perfect harmony with its environmental niche. Once a specific shape is acquired, many different factors act together to guarantee phenotypic robustness and developmental stability of the organism. Among these factors, hormones play a key role in the regulation and coordination of growth - they control the activity of a single cell, the progression to tissue organization, the development of specific organs, ending with the development of the entire body. In plants, hormones acquire yet another important role - plants, due to their sessile nature, along with the quest for robust development, rely on plastic development to adapt growth to a changing environment. Plant hormones play a crucial role in sensing and responding to different environmental stimuli, translating these inputs into specific developmental changes that adapt the plant body to the environment. Here, we will focus on cytokinins - a unique class of plant hormones - giving clues on their metabolism, on how they are perceived by cells and how cells change their activity in response to it. Most of the data presented have been derived by studies conducted on Arabidopsis thaliana, a plant used as a model system in plant science.

Analysis of the fluctuating asymmetry of bilateral traits in the Russian sturgeon grown in fish farms of various types

The aim of our work was to determine the influence of the Russian sturgeon breeding conditions on its phenotypic variability in the process of ontogenesis. The phenotypic variability identification work was carried out on the Russian sturgeon fingerlings and juveniles grown in three different fish farms: Sturgeon fish hatchery Bertyulskiy with an intensive pond type of breeding, Fish hatchery of Elektrogorsk SDPS named after R.E. Klasson with an intensive cage type of breeding and Mozhaisk production and experimental fish hatchery with an industrial use of RAS. In the first two farms, the fishes were studied postmortally, and in the third farm, the fishes were examined in vivo, by studying the fluctuating asymmetry of traits recorded on previously taken photographs. In the course of our study, it was found that the smallest impact on the organism development stability, estimated by the value of the average frequency of the asymmetric manifestations for trait (0.6), was found in the fish farms with an intensive method of reproduction in small ponds, as in the BSFH enterprise. The highest impact (0.8) was found in the farms using an industrial reproduction in RAS as organized in MPEFH. In the Elektrogorsk SDPS fish hatchery, an average value between the three compared farms, 0.7, was recorded, which is explained by the minimal temperature fluctuations of water due to the discharge of warm water into the cooling pond where the fishes are bred. Also, during the determination of the developmental stability level, estimated by the magnitude of the variance of the fluctuating asymmetry of bilateral traits, it was found that it depends on the temperature regime stability in the fish farms. It has also been established that the temperature changes in the spring-summer period lead to the formation of the physiological deviations in fishes, expressed by the fluctuating asymmetry of bilateral traits, mainly by the number of lateral and ventral scutes, as well as the number of rays of pectoral and ventral fins. The obtained data has high reliability at the level of Pі0.01 when comparing the above results.

Phenotypic Variation in a Species Range: Another Look (Developmental Stability Study of the Meristic Variation in the Sand Lizard Lacerta agilis)

Variation of the meristic characteristics of pholidosis in the sand lizard, Lacerta agilis, was studied both in laboratory experiments and in natural populations. The total phenotypic variability was assessed by the variation of the sum of the number of scales on the left and on the right sides of the body (l + r), while the measure of developmental stability, providing insight into the degree of fluctuating asymmetry, or developmental variability, was assessed by the variation of the difference in the character values on the left and on the right (l − r). Experimental incubation of eggs at different temperatures demonstrates that the minimal level of both kinds of variability corresponds to a certain temperature, which can be characterized as an optimal one, increasing both with an increase and with a decrease in the temperature from this regime. The data demonstrate the crucial role of the temperature impact for the phenotypic variation under study. An increase in the level of developmental variability to the north and to the south from the center part of the species range, in the absence of an obvious trend in geographic variation of the level of total phenotypic variability, assumes an increase in the role of developmental variability in the observed phenotypic diversity at the periphery of the species range. The results obtained indicate the importance of a population phenogenetic approach, based on the developmental stability study in natural populations, to provide certain information supposing the possible nature of phenotypic diversity in a species range.

Mind-mindedness in new mothers and fathers: Stability and discontinuity from pregnancy to toddlerhood.

This study examined the development of caregiver mind-mindedness-defined as the propensity to see one's child as an agent with an independent mind-across the first 1,000 days of life. At four time-points (i.e., third trimester of pregnancy, 4, 14, and 24 months postpartum), 384 first-time mothers (Mage = 32.55, SD = 3.63 years) and fathers (Mage = 33.96, SD = 4.40 years) gave 5-minute speech samples about their infant that were coded for mind-mindedness (Meins & Fernyhough, 2015). Reflecting the local population, the 192 heterosexual couples were highly educated (84.6% of mothers, 77.1% of fathers had a degree) and ethnically homogenous (92.7% of mothers, 94.8% of fathers identified as White British). Results showed significant variability in mind mindedness within both expectant mothers and expectant fathers, with no mean group difference. Auto-regressive models demonstrated modest positive associations between prenatal and postnatal mind-mindedness. Latent change score models showed gains in mean mind-mindedness over time that, on average, were stronger for mothers than for fathers. For fathers, gains in mind-mindedness were positively associated with having an infant daughter and infant surgency. For mothers, higher socioeconomic status and more equal childcare were associated with greater gains in mind-mindedness across toddlerhood. Within-couple associations were evident for changes in mind-mindedness, but not for initial (prenatal) scores. We apply the relational account of mind-mindedness to frame our discussion of these findings that, by highlighting both developmental stability and change in mind-mindedness, suggest fruitful avenues for future research. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Mother-Fetus Immune Cross-Talk Coordinates "Extrinsic"/"Intrinsic" Embryo Gene Expression Noise and Growth Stability.

Developmental instability (DI) is thought to be inversely related to a capacity of an organism to buffer its development against random genetic and environmental perturbations. DI is represented by a trait’s inter- and intra-individual variabilities. The inter-individual variability (inversely referred to as canalization) indicates the capability of organisms to reproduce a trait from individual to individual. The intra-individual variability reflects an organism’s capability to stabilize a trait internally under the same conditions, and, for symmetric traits, it is expressed as fluctuating asymmetry (FA). When representing a trait as a random variable conditioned on environmental fluctuations, it is clear that, in statistical terms, the DI partitions into “extrinsic” (canalization) and “intrinsic” (FA) components of a trait’s variance/noise. We established a simple statistical framework to dissect both parts of a symmetric trait variance/noise using a PCA (principal component analysis) projection of the left/right measurements on eigenvectors followed by GAMLSS (generalized additive models for location scale and shape) modeling of eigenvalues. The first eigenvalue represents “extrinsic” and the second—“intrinsic” DI components. We applied this framework to investigate the impact of mother–fetus major histocompatibility complex (MHC)-mediated immune cross-talk on gene expression noise and developmental stability. We showed that “intrinsic” gene noise for the entire transcriptional landscape could be estimated from a small subset of randomly selected genes. Using a diagnostic set of genes, we found that allogeneic MHC combinations tended to decrease “extrinsic” and “intrinsic” gene noise in C57BL/6J embryos developing in the surrogate NOD-SCID and BALB/c mothers. The “intrinsic” gene noise was negatively correlated with growth (embryonic mass) and the levels of placental growth factor (PLGF), but not vascular endothelial growth factor (VEGF). However, it was positively associated with phenotypic growth instability and noise in PLGF. In mammals, the mother–fetus MHC interaction plays a significant role in development, contributing to the fitness of the offspring. Our results demonstrate that a positive impact of distant MHC combinations on embryonic growth could be mediated by the reduction of “intrinsic” gene noise followed by the developmental stabilization of growth.