Reaction Norms Research Articles

Phenotypic plasticity of the Cydalima perspectalis Walker life cycle stages development in the Crimea

The box tree moth ( Cydalima perspectalis Walker) is an invasive insect that has rapidly colonized the vast area of the European continent, damaging tonatural and ornamental box trees. In order to develop effective phytophagous control measures there are features of the local populations seasonal development that have been studied in the Crimea. It is determined that during the growing season in the green spaces of the Crimean parks there is a temporary overlapping of both development stages and generations of the C. perspectalis populations. An important seasonal adaptation of C. perspectalis to the habitat’s conditions is thermal sensitivity reduction and development acceleration of all life cycle stages in the second summer generation under the influence of photoperiod. This flexibility of ontogenetic requirements for the transition to diapause provides higher phenological variability in populations. There is identified the temperature and photoperiod impact to development rate of larvae and the influence of relative humidity to development rate of pupae. With identical thermal reaction norms for development of the overwintered larvae, for complete of life cycle of the one generation life cycle in the Southern coast of the Crimea conditions needed the sum of growing degrees-days are 80 °С higher than in the Foothill Crimea. It is identified relative constancy of growing degrees-days needed for complete of the second summer generation of C. perspectalis . It allows considering them as a tool for determining the timing of effective treatment of third-generation larvae before they cause severe damage. For the comparability of the research results with the available publications, it was proposed to use the temperature threshold of 9.5 °С when calculating the growing degrees-days.

Genome-based prediction of agronomic traits in spring wheat under conventional and organic management systems.

Using phenotype data of three spring wheat populations evaluated at 6-15 environments under two management systems, we found moderate to very high prediction accuracies across seven traits. The phenotype data collected under an organic management system effectively predicted the performance of lines in the conventional management and vice versa. There is growing interest in developing wheat cultivars specifically for organic agriculture, but we are not aware of the effect of organic management on the predictive ability of genomic selection (GS). Here, we evaluated within populations prediction accuracies of four GS models, four combinations of training and testing sets, three reaction norm models, and three random cross-validations (CV) schemes in three populations phenotyped under organic and conventional management systems. Our study was based on a total of 578 recombinant inbred lines and varieties from three spring wheat populations, which were evaluated for seven traits at 3-9 conventionally and 3-6 organically managed field environments and genotyped either with the wheat 90K SNP array or DArTseq. We predicted the management systems (CV0M) or environments (CV0), a subset of lines that have been evaluated in either management (CV2M) or some environments (CV2), and the performance of newly developed lines in either management (CV1M) or environments (CV1). The average prediction accuracies of the model that incorporated genotype × environment interactions with CV0 and CV2 schemes varied from 0.69 to 0.97. In the CV1 and CV1M schemes, prediction accuracies ranged from - 0.12 to 0.77 depending on the reaction norm models, the traits, and populations. In most cases, grain protein showed the highest prediction accuracies. The phenotype data collected under the organic management effectively predicted the performance of lines under conventional management and vice versa. This is the first comprehensive GS study that investigated the effect of the organic management system in wheat.

No evidence for short-term evolutionary response to a warming environment in Drosophila.

Adaptive evolution is key in mediating responses to global warming and may sometimes be the only solution for species to survive. Such evolution will expectedly lead to changes in the populations' thermal reaction norm and improve their ability to cope with stressful conditions. Conversely, evolutionary constraints might limit the adaptive response. Here, we test these expectations by performing a real-time evolution experiment in historically differentiated Drosophila subobscura populations. We address the phenotypic change after nine generations of evolution in a daily fluctuating environment with average constant temperature, or in a warming environment with increasing average and amplitude temperature across generations. Our results showed that (1) evolution under a global warming scenario does not lead to a noticeable change in the thermal response; (2) historical background appears to be affecting responses under the warming environment, particularly at higher temperatures; and (3) thermal reaction norms are trait dependent: although lifelong exposure to low temperature decreases fecundity and productivity but not viability, high temperature causes negative transgenerational effects on productivity and viability, even with high fecundity. These findings in such an emblematic organism for thermal adaptation studies raise concerns about the short-term efficiency of adaptive responses to the current rising temperatures.

Quantifying Glucocorticoid Plasticity Using Reaction Norm Approaches: There Still is So Much to Discover!

SynopsisHormones are highly responsive internal signals that help organisms adjust their phenotype to fluctuations in environmental and internal conditions. Our knowledge of the causes and consequences of variation in circulating hormone concentrations has improved greatly in the past. However, this knowledge often comes from population-level studies, which generally tend to make the flawed assumption that all individuals respond in the same way to environmental changes. Here, we advocate that we can vastly expand our understanding of the ecology and evolution of hormonal traits once we acknowledge the existence of individual differences by quantifying hormonal plasticity at the individual level, where selection acts. In this review, we use glucocorticoid (GC) hormones as examples of highly plastic endocrine traits that interact intimately with energy metabolism but also with other organismal traits like behavior and physiology. First, we highlight the insights gained by repeatedly assessing an individual's GC concentrations along a gradient of environmental or internal conditions using a “reaction norm approach.” This study design should be followed by a hierarchical statistical partitioning of the total endocrine variance into the among-individual component (individual differences in average hormone concentrations, i.e., in the intercept of the reaction norm) and the residual (within-individual) component. The latter is ideally further partitioned by estimating more precisely hormonal plasticity (i.e., the slope of the reaction norm), which allows to test whether individuals differ in the degree of hormonal change along the gradient. Second, we critically review the published evidence for GC variation, focusing mostly on among- and within-individual levels, finding only a good handful of studies that used repeated-measures designs and random regression statistics to investigate GC plasticity. These studies indicate that individuals can differ in both the intercept and the slope of their GC reaction norm to a known gradient. Third, we suggest rewarding avenues for future work on hormonal reaction norms, for example to uncover potential costs and trade-offs associated with GC plasticity, to test whether GC plasticity varies when an individual's reaction norm is repeatedly assessed along the same gradient, whether reaction norms in GCs covary with those in other traits like behavior and fitness (generating multivariate plasticity), or to quantify GC reaction norms along multiple external and internal gradients that act simultaneously (leading to multidimensional plasticity). Throughout this review, we emphasize the power that reaction norm approaches offer for resolving unanswered questions in ecological and evolutionary endocrinology.

Dining in Blue Light Impairs the Appetite of Some Leaf Epiphytes.

Background: The phyllosphere is subjected to fluctuating abiotic conditions. This study examined the phenotypic plasticity (PP) of four selected non-phototrophic phyllosphere bacteria [control strain: Pseudomonas sp. DR 5-09; Pseudomonas agarici, Bacillus thuringiensis serovar israeliensis (Bti), and Streptomyces griseoviridis (SG)] regarding their respiration patterns and surfactant activity as affected by light spectrum and nutrient supply.Methods: The PP of the strains was examined under four light regimes [darkness (control); monochromatic light-emitting diodes (LED) at 460 nm (blue) and 660 nm (red); continuously polychromatic white LEDs], in the presence of 379 substrates and conditions.Results: Light treatment affected the studied bacterial strains regarding substrate utilization (Pseudomonas strains > SG > Bti). Blue LEDs provoked the most pronounced impact on the phenotypic reaction norms of the Pseudomonas strains and Bti. The two Gram-positive strains Bti and SG, respectively, revealed inconsistent biosurfactant formation in all cases. Biosurfactant formation by both Pseudomonas strains was supported by most substrates incubated in darkness, and blue LED exposure altered the surface activity profoundly. Blue and white LEDs enhanced biofilm formation in PA in highly utilized C-sources. Putative blue light receptor proteins were found in both Pseudomonas strains, showing 91% similarity with the sequence from NCBI accession number WP_064119393.Conclusion: Light quality–nutrient interactions affect biosurfactant activity and biofilm formation of some non-phototrophic phyllosphere bacteria and are, thus, crucial for dynamics of the phyllosphere microbiome.

Thinking of Fish Population Discrimination: Population Average Phenotype vs. Population Phenotypes

The genetic polymorphism and phenotypic variation are key in ecology and evolution. The morphological variability of the contour of fish otoliths has been extensively used for the delimitation of stocks. These studies are conventionally based on average phenotype using elliptic Fourier analysis and lineal discriminant analysis as classifier. Considering new analytical options, such as the wavelet transform and non-parametric algorithms, we here analyzed the otolith shape ofTrachurus picturatus(blue jack mackerel) from mainland Portugal, Madeira, and the Canaries. We explore the phenotypic variation throughout a latitudinal gradient, establish a hypothesis to explain this variability based on the reaction norms, and determine how the use of average phenotype and/or morphotypes influences in the delimitation of stocks. Four morphotypes were identified in all regions, with an increase of phenotypes in warmer waters. The findings demonstrated that stocks were clearly separated with classification rates over 90%. The use of morphotypes, revealed seasonal variations in their frequencies and per region. The presence of shared phenotypes in different proportions among fishing grounds may open new management approaches in migratory species. These results show the importance of the phenotypic diversity in fisheries management.

Modelling temperature-dependent dynamics of single and mixed infections in a plant virus

Multiple viral infection is an important issue in health and agriculture with strong impacts on society and the economy. Several investigations have dealt with the population dynamics of viruses with different dynamic properties, focusing on strain competition during multiple infections and the effects on viruses’ hosts. Recent interest has been on how multiple infections respond to abiotic factors such as temperature (T). This is especially important in the case of plant pathogens, whose dynamics could be affected significantly by global warming. However, few mathematical models incorporate the effect of T on parasite fitness, especially in mixed infections. Here, we investigate simple mathematical models incorporating thermal reaction norms (TRNs), which allow for quantitative analysis. A logistic model is considered for single infections, which is extended to a Lotka-Volterra competition model for mixed infections. The dynamics of these two models are investigated, focusing on the roles of T-dependent replication and competitive interactions in both transient and asymptotic dynamics. We determine the scenarios of co-existence and competitive exclusion, which are separated by a transcritical bifurcation. To illustrate the applicability of these models, we ran single- and mixed-infection experiments in plants growing at 20 ∘C and 30 ∘C using two strains of the plant RNA virus Pepino mosaic virus. Using a macroevolutionary algorithm, we fitted the models to the data by estimating the TRNs for both strains in single infections. Then, we used these TRNs to feed the mixed-infection model estimating the strength of competition. We found an asymmetrical pattern in which each strain dominated at different T values due to differences in their TRNs. We also identified that T can modify competition interference greatly for both isolates. The models proposed here can be useful for investigating the outcomes of multiple-infection dynamics under abiotic changes and have implications for the understanding of viral responses to global warming.

Genotype-environment interaction effects on weight gain in cattle using reaction norms

The existence of genotype-environment interaction (GEI) using reaction norm models and their impact on the genetic evaluation of Nellore sires for body weight at 120, 210, 365 and 450 days of age was verified. Three models were used: animal model (AM) that disregards GEI and the one-step reaction norm model with homogeneous and heterogeneous residual variance (1SRNMH_het). Bayes Inference via Gibbs Sampling was used to estimate the variance components. The AM model better fits to weights at 120 and 210 days of age, while 1SRNMH_het was more adequate for body weights at 365 and 450 days of age, suggesting the existence of GEI. The posterior means of direct heritability were 0.33±0.01 and 0.36±0.01 and maternal heritability of 0.21±0.01 and 0.19±0.01 for body weights at 120 and 210 days of age, respectively. For body weights at 365 and 450 days of age, posterior means of heritability varied along the environmental gradient, but the ranking of sires based on breeding values was not changed by different environmental gradients. All rank correlations were greater than 0.80, strongly suggesting a scale effect of GEI. Despite the evidence of GEI on post-weaning weight gain, it did not change the ranking of sires. Therefore, it did not have a relevant impact on the genetic evaluation of sires because they are robust to environmental changes.

Separating Paternal and Maternal Contributions to Thermal Transgenerational Plasticity

Climate change is rapidly altering the thermal environment in terrestrial and aquatic systems. Transgenerational thermal plasticity (TGP) – which occurs when the temperatures experienced by the parental generation prior to the fertilization of gametes results in a change in offspring reaction norms – may mitigate the effects of climate change. Although “maternal effects” have been widely studied, relatively little is known about TGP effects in vertebrates, particularly paternal contributions. We used artificial fertilization to cross sheepshead minnow (Cyprinodon variegatus) parents exposed to either low (26°C) or high (32°C) temperatures and measured growth rates of the offspring over the first 8 weeks of life at both low and high temperatures. A linear mixed effects model was employed to quantify the effects of maternal, paternal, and offspring temperatures on offspring growth and fecundity. We found that the offspring growth rate up to 63 days post-hatch was affected by both the temperature they experienced directly and parental temperatures prior to fertilization. Growth was lowest when neither parents’ temperature matched the offspring temperature, indicating a strong transgenerational effect. Notably, offspring growth was highest when all three (offspring, sire, and dam) temperatures matched [although the three-way interaction was found to be marginally non-significant (P = 0.155)], suggesting that TGP effects were additive across significant sire-offspring (P < 0.001) and dam-offspring interactions (P < 0.001). Transgenerational effects on fecundity (GSI) were suggestive for both maternal and paternal effects, but not significant. The finding that thermal TGP is contributed by both parents strongly suggests that it has an epigenetic basis.

Phenotypic convergence in a natural Daphnia population acclimated to low temperature.

Fluidity of a given membrane decreases at lower ambient temperatures, whereas it rises at increasing temperatures, which is achieved through changes in membrane lipid composition. In consistence with homeoviscous adaptation theory, lower temperatures result in increased tissue concentrations of polyunsaturated fatty acids (PUFAs) in Daphnia magna, suggesting a higher PUFA requirement at lower temperatures. However, so far homeoviscous adaptation has been suggested for single or geographically separated Daphnia genotypes only. Here, we investigated changes in relative fatty acid (FA) tissue concentrations in response to a lower temperature (15°C) within a D. magna population. We determined juvenile growth rates (JGR) and FA patterns of 14 genotypes that were grown on Chlamydomonas klinobasis at 15°C and 20°C. We report significant differences of JGR and the relative body content of various FAs between genotypes at either temperature and between temperatures. Based on slopes of reaction norms, we found genotype‐specific changes in FA profiles between temperatures suggesting that genotypes have different strategies to cope with changing temperatures. In a hierarchical clustering analysis, we grouped genotypes according to differences in direction and magnitude of changes in relative FA content, which resulted in three clusters of genotypes following different patterns of changes in FA composition. These patterns suggest a lower importance of the PUFA eicosapentaenoic acid (EPA, C20:5ω3) than previously assumed. We calculated an unsaturation index (UI) as a proxy for membrane fluidity at 15°C, and we neither found significant differences for this UI nor for fitness, measured as JGR, between the three genotype clusters. We conclude that these three genotype clusters represent different physiological solutions to temperature changes by altering the relative share of different FAs, but that their phenotypes converge with respect to membrane fluidity and JGR. These clusters will be subjected to different degrees of PUFA limitation when sharing the same diet.

PSVII-27 Genetic analysis of disease resilience of nursery-to-finish pigs under a natural disease challenge model using reaction norms

Abstract Disease resilience is the ability of an animal to maintain performance across environments with different disease challenge loads (CL) and can be quantified using random regression reaction norm models that describe phenotype as a function of CL. Objectives of this study were to: 1) develop measures of CL using growth rate and clinical disease phenotypes under a natural disease challenge; 2) evaluate genetic variation in disease resilience. Data used were late nursery and finisher growth rates and clinical disease phenotypes, including medical treatment and mortality rates, and subjective health scores, collected on 50 batches of 60/75 crossbred (LRxY) barrows under a polymicrobial natural disease challenge. All pigs were genotyped using a 650K SNP panel. Different CL were derived from estimates of contemporary group effects and used as environmental covariates in reaction norm analyses of average daily gain (ADG) and treatment rate (TRT). The CL were compared based on model loglikelihoods and estimates of genetic variance, using both linear and cubic spline reaction norm models. Linear reaction norm models fitted the data significantly better than the standard genetic model and the cubic spline models fitted the data significantly better than the linear reaction norm model for most traits. CL based on early finisher ADG provided the best fit for nursery ADG, while CL based on clinical disease phenotypes was best for finisher ADG and TRT. With increasing CL, estimates of heritability for ADG initially decreased and then increased, while estimates of heritability for TRT generally increased with CL. Genetic correlations were low between ADG or TRT at high versus low CL but high for close CLs. Results can be used to select more resilient pigs across different CL levels, or high-performance animals at a given CL level, or a combination of these. Funded by Genome Canada, Genome Alberta, USDA-NIFA, and PigGenCanada.

PSIV-5 Definition of environmental variables and critical periods to evaluate heat tolerance in maternal-line pigs based on single-step genomic reaction norms

Abstract Heat stress (HS) is a major welfare and economic issue in the swine industry. However, it is not a trivial task to appropriately quantify the environmental HS. Therefore, this study aimed to 1) define the critical periods and environmental descriptors (based on public weather station information) to evaluate heat tolerance (HT); and 2) estimate genetic parameters for HT in Large White pigs. The traits included in this study were: weaning weight (WW; kg), off-test weight (OTW; kg), total number of piglets born (TNB), number of piglets born alive (NBA), and number of piglets weaned (WN). The number of phenotypic records ranged from 6,059 (WN) to 172,984 (TNB), and genotypes were available for 8,686 animals. Seven climatic variables (maximum, minimum and average temperatures, average relative humidity, dew point, discomfort index and temperature-humidity index) based on public weather station records were compared based on three criteria [GxE estimate as measured by the slope term; theoretical accuracy of the genomic estimated breeding values (GEBV); deviation of GEBV per environmental value]. Relative humidity (for WN and WW) and maximum temperature (for OTW, TNB, and NBA) are the recommended environmental gradients for the studied traits. The acute HS (average of 30 days before measurement date) was the critical period recommended for OTW. For WN and WW, a period of 34 days prior to farrowing up to weaning is recommended. For TNB and NBA, the critical period of 20 days prior breeding to 30 days into gestation is recommended. In general, WN and WW were largely affected by the environment, while the remaining traits showed moderate correlations (OTW, TNB, and NBA). Heritabilities estimated for HT ranged from 0.08 (WW) to 0.25 (OTW). In summary, these results suggest that there is genotype-by-environment interaction for all traits analyzed, and genetic progress can be achieved through genetic selection.

Influence of cultivation background intensification on spring wheat productivity in the subtaiga zone of the Krasnoyarsk Territory, Russia

This paper presents the results of studying the role of cultivation background intensification in the formation of productivity and yield structure of spring wheat varieties Novosibirskaya 29, Novosibirskaya 41, Novosibirskaya 15 and Altayskaya 75 in the subtaiga zone of the Krasnoyarsk Territory, Russia. The influence rate of crop rotation steam link using a full range of modern means of protection and fertilization on the elements of the yield structure of soft spring wheat and its variations were determined. The cultivation background providing the greatest positive response in crop productivity formation was also established. New varieties, in comparison with previously zoned ones, are able to use moisture, and also the elements of mineral nutrition and other factors of plant life are more productively. However, there are no universal varieties that are equally suitable for all backgrounds and conditions. Therefore, the identification of the productivity potential, the norms of new variety reaction to intensification factors in modern conditions of climate change, is the most important condition for the development of varietal technologies, improving the techniques and methods of grain crop productivity management. Under the conditions of the subtaiga zone of the Krasnoyarsk Territory, with the intensification of the crop rotation steam link, such productivity elements as the length of the main plant, the length of an ear and the number of spikelets in an ear of the studied varieties of spring wheat vary within weak and medium limits. Their variation coefficient ranges from 2-6% to 16-17%. It is best to intensify such indicators as productive tillering (Cv 14-38%) and the amount of grain in an ear (Cv 11-28%) within this zone. These elements respond well to the control of the phytosanitary state of crops using herbicides, insecticides and fungicides. The varieties of spring soft wheat Altayskaya 75 and Novosibirskaya 41, with the use of pesticides and ammonium nitrate, can increase the grain content of an ear by 2 times (by 17.7 pieces), and the number of spikelets in an ear by 1.5 times (by 5.7 pieces). The varieties Novosibirskaya 15 and Novosibirskaya 29, when applying nitrogen fertilizers and a full range of protective equipment, increase the productive bushiness from 1.1 to 2.2.

Domestication reduces phenotypic plasticity in chaya (<em>Cnidoscolus aconitifolius</em> (Mill.) I.M. Johnst)

Background: Natural selection optimizes phenotypic plasticity in plants found in environmentally variable habitats. However, it is unclear how artificial selection has affected the phenotypic plasticity of crops. Reduced plasticity in crop yield is often considered a desirable feature in cultivated plants; however, limited phenotypic plasticity in this and other traits may also affect the ability of crops to cope with environmental variation. Study species: Wild and domesticated chaya (Cnidoscolus aconitifolius (Mill.) I.M. Johnst). Question: How domestication has affected the phenotypic plasticity of vegetative traits in response to the light environment? Methods: Leaf area, leaf perimeter, leaf specific area, leaf production, trichome density, stem elongation, growth in stem diameter and slenderness were measured in clones of wild and domesticated plants. These clones were allocated to two contrasting light treatments: fully exposed to sun vs. placement beneath a shade cloth. The phenotypic traits and reaction norms were compared between the genotypes of wild and domesticated plants. Results: Lower plasticity in leaf production and slenderness was observed in the domesticated compared to the wild plants. Leaf production and slenderness are associated with the shade avoidance syndrome, which was evident in wild plants but not manifested in domesticated plants. Reduced plasticity in leaf production also suggests yield stability. Conclusion: Artificial selection reduces phenotypic plasticity in the yield of chaya and in its response to variation in light availability.

Spatial and temporal variation in phenotypes and fitness in response to developmental thermal environments

AbstractPhenotypic variation within populations is influenced by the environment via plasticity and natural selection. How phenotypes respond to the environment can vary among traits, populations and life stages in ways that can influence fitness.Plastic responses during early development are particularly important because they can affect components of fitness throughout an individual's life. Consequently, how natural selection shapes developmental plasticity could be influenced by fitness consequences across different life stages. Moreover, spatial variation in selection pressures could generate differences in plastic responses among populations.To gain insight into sources of variation in phenotypes and survival, we used a laboratory egg incubation experiment using brown anole lizardsAnolis sagreifrom mainland (ancestral) and island (descendent) populations, combined with a mark–release–recapture experiment in the field. Our study was designed to (a) quantify the effects developmental temperature on embryo development and offspring morphology, (b) assess how developmental temperature influences offspring survival across different life stages and (c) quantify how thermal reaction norms vary among ancestral and descendant populations.Developmental temperature influenced offspring morphology, but thermal reaction norms of embryos showed little variation among populations. Developmental temperature influenced offspring survival, but the patterns differed between embryo and hatchling stages; the optimal temperature for embryos was about 5℃ lower than that for hatchlings. High temperatures were thermally stressful to embryos, but they reduced incubation duration and led to early hatching. In turn, earlier hatching increased the probability of survival to adulthood. Moreover, the effect of developmental temperature on hatchling survival was most pronounced for offspring that hatched late in the season.The difference in optimal developmental temperatures between life stages may be driven by physiological tolerance for embryos and by ecological factors for hatchlings. Moreover, the fitness consequences of the developmental environment depend on the phenology of hatching. Overall, these results highlight how the developmental environment can differentially affect fitness across life stages and show that temporal thermal heterogeneity can influence survival of embryos, but the consequences on post‐hatching stages may vary at different times of the season.A freePlain Language Summarycan be found within the Supporting Information of this article.

Соматометрическая оценка недоношенных детей в сенситивный период развития

Aim. To establish the features of somatometric maturity of premature infants in the sensitive period of development. Material and methods. The somatometric method of the study was used to examine 124 children aged 7 years, who were divided into control and main groups. The control group included boys and girls with a history of traditional gestation periods. Boys and girls of the main group had all the signs of anatomical and physiological prematurity. Somatometric studies were carried out according to the traditional method, which included measurements of the overall dimensions of the body. On the basis of somatometric indicators, the indices of proportionality and harmony of the physique were calculated. The body types of children were determined according to the recommendations of V. G. Nikolaev (2007). To perform calculations of individual components of body weight, the manual of E. G. Martirosov (2010). Results. Somatometric studies have established sexual and intergroup differences in the physique of children aged 7 years. The analysis of the obtained data revealed the following feature: the longitudinal, transverse and girth dimensions in children of the control group are characterized by a significantly high increase by the age of 7. In children of the main group, the value of somatometric indicators is significantly lower, which is reflected in the lower massiveness and strength of the body of children of this group. It can be assumed that somatometric measurements revealed the features of growth processes in the physical development of children of the main and control groups. Somatometric studies can serve as objective criteria for the physical health of children and allow a more differentiated approach to the assessment of growth processes, as well as to predict possible deviations in a timely manner. Our study showed that the component composition of body weight has a significant impact on the formation of somatotypological features that reflect the degree of reactivity and resistance of the body of children at certain stages of development. The magnitude of endomorphy, mesomorphy and ectomorphy is characterized by sexual and intergroup differences that have a significant impact on the body shape and strength of the physique. Conclusion. Somatometric studies of the body of children aged 7 years allowed us to establish the features of growth processes in children of the main and control groups, which represent the norm of a biological reaction aimed at the optimal development of the child’s body. The revealed features in the morphofunctional status of children have established the mechanisms of compensatory and adaptive reactions that contribute to the formation of a certain morphotype. The structural and functional specificity of children is determined, which provides a certain reactivity and resistance of the body at the age of 7 years. Somatometric differences in the physical status of children are an objective criterion for the sanitary and hygienic well-being of the younger generation, and the data obtained allow us to identify deviations in a timely manner and carry out corrective measures.

Histogenetic morphotypes of rats respiratory system at the stages of early and late fetogenesis

Aim. Morphological analysis of the deployment of histogenetic information of pulmonary parenchyma at the stages of late embryogenesis and fetogenesis in laboratory rats within the limits of the norm of reaction with verification according to morphometric criteria of individual morphotypes.Materials and methods. Comparative morphological study of histogenesis of endodermal derivatives of the lungs of rats at critical periods of intrauterine development – late embryogenesis (day 14 of gestation), and late fetogenesis (day 20 of gestation) was performed using morphometric identification of plane parameters and a complex of plane form factors of epithelial structures of the lung. Morphometric studies were carried out in the Morphometer program on semi-thin sections of the rat lung.Results. Two critical stages of histogenesis of entodermal beginnings of fetal lungs are described – pseudoglandular and canalicular. The options of discordance of individual development within the response norm are justified. The lungs of the fetus at the pseudoglandular stage and the canalicular stage show significant fluctuations in the plane values of the pulmonary parenchyma, the presence in different individuals of variants of the plane values of entodermal derivatives, which indicated individual morphotypes of the development of the rat lung. At the pseudoglandular stage, in fetus with type I, called “compact”, the total area of the tubular system and the total perimeter are significantly inferior (p<0.001) to the same indicators of the lung II morphotype, designated as “air”. The values of one tubule (the outer perimeter, its area, the dimensions of the X-projection and Y-projection, the length of the epithelial tubes) in type I, on the contrary, are significantly larger than in type II (p<0.01). Among form factors, reliable differences have elongation (FE), squareness (FQ) and equivalent radius (FR) (p<0.01), less significant compactness (FF) and roundness (FC) (p<0.05). The discordance of development is established by a number of reliable values at the stage of late fetogenesis: the area of the tubule (p<0.01), the area of the epithelium of the preacinar department (p<0.001), the value of the outer perimeter of the tubule, the length and, to a lesser extent, the width of the tubule (p<0.05) significantly exceed such type II indicators. In this regard, the dimensions of X- and Y-projections for type I are also increased (p<0.05).Conclusion. As a result of morphological studies, the development of entodermal derivatives of pulmonary parenchyma at the pseudoglandular stage (day 14 of gestation) and the canalicular stage (day 20 of gestation) in rat fetus was verified; morphometric criteria for assessing the histogenesis of entodermal parenchyma units at critical stages of development have been introduced; comparative analysis of morphometric indices of different individuals in gestation dynamics; individual variants of two morphotypes are objectified – “compact-I” and “air-II” in the process of histogenesis of the fetal lungs.

TH80. CLUSTERING OF SCHIZOPHRENIA CASES BASED ON COMMON GENETIC VARIANTS

Due to the discrepancy of the high energy demand for rapidly increasing milk production and limited feed intake in the transition period around parturition, dairy cows require considerable metabolic adaptations. We hypothesize that some cows are genetically less suited to cope with these metabolic needs than others, leading to adverse follow-up effects on longevity. To test this, we designed a reaction norm model in which functional lifetime was linked to the metabolic challenge in the beginning of the first lactation. As challenge variables, we used either the sum of milk yield or the accumulated fat-to-protein ratio of the first 3 test-days (<120 d in milk), pre-adjusted for herd-test-day variance. We defined a random regression sire model, in which a random slope was estimated for each sire to assess whether a bull had robust (neutral or positive slopes) or non-robust (negative slopes) daughters. We fitted the model to data of ∼580,000 daughters of ∼5,000 Brown Swiss bulls with suitable observations available (≥10 daughters per bull). To validate our proposed model and assess the reliability of the estimated (co)variance components, we conducted an extensive bootstrap approach. For both challenge variables, we found the sire variance for the slope of the random regression to be significantly different from zero, suggesting a genetic component for metabolic adaptability. The results of the study show that the ability to cope with metabolic stress in the transition period has a genetic component, which can be used to breed metabolically robust dairy cows.

Do genetic differences in growth thermal reaction norms maintain genetic variation in timing of diapause induction?

AbstractAn optimal timing for diapause induction through the sexual production of dormant propagules is expected in organisms with temporary populations. Yet, empirical studies often find high within‐population genetic variation in the sexual production of such propagules, suggesting that this is a common feature of such organisms.Here, we hypothesize that genetic variation in the propensity to produce dormant propagules,Pd, is maintained by a genotype‐by‐environment interaction in clonal reproductive rates, where fast‐growing genotypes within an environment should delay diapause relative to slow‐growing genotypes. From this, we derive two predictions. First, if reaction norms of clonal reproduction cross between two environments, the genetic correlation ofPdbetween these environments should be negative. Second, the correlation between plasticity values of clonal reproduction andPdshould be negative.We tested these predictions by quantifying ephippia production in genotypes of a population of the facultative sexual cladoceranDaphnia magnaat two temperatures. The population biomass at the onset of ephippia production was used as a measure ofPd, whereas juvenile somatic growth rate was used as a proxy for clonal reproductive rate. Plasticity for both measurements was derived from thermal reaction norms.Our results did not support either prediction, as neither the genetic correlation ofPdbetween environments, nor the correlation between plasticity values of growth andPdwere found to be significant.Our results suggest that genetic variation in the timing of diapause is not maintained by genetic differences in thermal clonal reproduction reaction norms. We propose as an alternative hypothesis that if there is variation across years in how the environment deteriorates over a season, fluctuating selection may favor genotypes with differentPdbetween years.

Plasticity and flexibility in the anti-predator responses of treefrog tadpoles

Tadpoles can respond to perceived predation risk by adjusting their life history, morphology, and behavior in an adaptive way. Adaptive phenotypic plasticity can evolve by natural selection only if there is variation in reaction norms and if this variation is, at least in part, heritable. To provide insights into the evolution of adaptive phenotypic plasticity, we analyzed the environmental and parental components of variation in predator-induced life history (age and size at metamorphosis), morphology (tail depth), and behavior of Italian treefrog tadpoles (Hyla intermedia). Using an incomplete factorial design, we raised tadpoles either with or without caged predators (dragonfly larvae, gen. Aeshna) and, successively, we tested them in experimental arenas either with or without caged predators. Results provided strong evidence for an environmental effect on all three sets of characters. Tadpoles raised with caged predators (dragonfly larvae, gen. Aeshna) metamorphosed earlier (but at a similar body size) and developed deeper tails than their fullsib siblings raised without predators. In the experimental arenas, all tadpoles, independent of their experience, flexibly changed their activity and position, depending on whether the cage was empty or contained the predator. Tadpoles of the two experimental groups, however, showed different responses: those raised with predators were always less active than their predator-naive siblings and differences slightly increased in the presence of predators. Besides this strong environmental component of phenotypic variation, results provided evidence also for parental and parental-by-environment effects, which were strong on life-history, but weak on morphology and behavior. Interestingly, additive parental effects were explained mainly by dams. This supports the hypothesis that phenotypic plasticity might mainly depend on maternal effects and that it might be the expression of condition-dependent mechanisms.Significance statementAnimals, by plastically adjusting their phenotypes to the local environments, can often sensibly improve their chances of survival, suggesting the hypothesis that phenotypic plasticity evolved by natural selection. We test this hypothesis in the Italian treefrog tadpoles, by investigating the heritable variation in the plastic response to predators (dragonfly larvae). Using an incomplete factorial common-garden experiment, we showed that tadpoles raised with predators metamorphosed earlier (but at similar body size), developed deeper tails, and were less active than their siblings raised without predators. The plastic response varied among families, but variation showed a stronger maternal than paternal component. This suggests that plasticity might largely depend on epigenetic factors and be the expression of condition-dependent mechanisms.