Stages Of Ontogeny Research Articles

Electromagnetic radiation of low intensity as a factor of change of phenolic compounds content

The influence of low-intensity electromagnetic radiation (EMR) on the content of phenolic compounds (PC) in plants on different stages of ontogeny is discussed. A medicinal plant (Calendula officinalis L.) and agricultural crop Fagopyrum sagittatum G., diploid varieties and tetraploid varieties were chosen as objects of study. Microwave EMR in two frequency bands, 53.57-78.33 GHz (wide range mode) and 64.00-66.00 GHz (narrow range mode), has been selected to learn the physical effects on seeds, with a treatment exposure time of 20, 12, or 8 min. The experiments were conducted under laboratory and field conditions. Treated and control seeds were germinated by 100 pcs in a growth chamber on moistened filter paper at 22–24˚C in the dark and placed on the daylight from the third day. The level of PC in the seedlings was measured with the Folin-Ciocalteu reagent. It was found that in the EMR pretreated C. officinalis seedlings the level of PC is maximal on 14th day of germination. The wide mode treatment for 12 min results in a two-fold increase in the level of PC in juvenile shoots with respect to control. Different constitutional levels of phenolic compounds in the leaves of diploid and tetraploid varieties of F. sagittatum in the most critical phases of ontogeny were found. It is recommended to use EMR with a 12 min exposure time for C. officinalis. The narrow frequency mode with an exposure time of 20 min is preferable to use for most varieties of F. sagittatum.

INDICATORS OF DEVELOPMENT IN THE PRESHOOL PERIODAS A WAY TO PREDICT SCHOOL ADAPTATION OF FIRST-YEAR PRIMARY SCHOOL STUDENTS

The article is devoted to the analysis of the long-term consequences of the influence of unfavorable facts and situations in the preschool period on the success of the child's adaptation to school. The aim of the work was to study the relationship between the indicators of the preschool development period and the characteristics of the cognitive, emotional, behavioral components of the first-formers school adaptation. Methods. To identify the developmental features before the school and the characteristics of school adaptation 193 first-formers in Arkhangelsk were examined. Results. It is shown that as the child grows, the interrelation between the developmental features of the child and the components of school adaptation increases: if the indicators of the infant period are associated with the emotional component and the characteristics of the early childhood period (1-3 years) are associated with the emotional and behavioral characteristics, the characteristics of the pre-school development period (3-7 years) have high correlation with the cognitive, emotional and behavioral components of school adaptation. Conclusions. The findings suggest that the developmental features of a child aged 3 to 7 years, more than other previous stages of ontogeny, affect the ability of a first-year student to adapt to systematic learning activity. The construction of regression models revealed the key interrelationships between the investigated indicators of the child's preschool development and the components of school adaptation. The authors emphasize that the analysis of the child's developmental features before school makes it possible to get an idea of presence of dysontogenesis risk factors and to determine the focus in the corrective-developing work taking into account individual characteristics.

Metabolic response to elevated CO2 levels in Pinus pinaster Aiton needles in an ontogenetic and genotypic-dependent way

Global climate changes involve elevated atmospheric [CO2], fostering the carbon allocation to tree sink tissues, partitioning it into metabolic pathways. We use metabolomics analysis in adult and juvenile needles of four Pinus pinaster genotypes exposed to two levels of growth [CO2]: ambient (400 μmol mol−1) and enriched (800 μmol mol−1), to know if the metabolic responses are genotype-dependent and vary according to the stage of needle ontogeny. The eCO2-induced changes in the needle metabolomes are more significant in secondary metabolism pathways and especially meaningful in juvenile needles. The heteroblasty has important consequences in the expression of the metabolome, and on the plasticity to CO2, determining the level of specific metabolite accumulation, showing an interdependence between adult and juvenile needles. The P. pinaster needle metabolomes also show clear quantitative differences linked to genotype, as well as regarding the metabolic response to eCO2, showing both, common and genotype-specific biochemical responses. Thus, the changes in flavonol levels are mainly genotype-independent, while those in terpenoid and free fatty acids are mainly genotype-dependent, ratifying the importance of genotype to determine the metabolic response to eCO2. To understand the adaptation mechanisms that tree species can develop to cope with eCO2 it is necessary to know the genetically distinct responses within a species to recognize the CO2-induced changes from the divergent approaches, what can facilitate knowing also the possible interrelation of the physiological and metabolic responses. That could explain the controversial effects of eCO2 on the carbon-based metabolite in conifers, at the inter- and intra-specific level.

Molecular genetic mechanisms of ovarian organization and development

A review of the literature devoted to the analysis of conditions and development of the female reproductive gland. From the moment of the formation of urogenital scallops to the formation of a full gonad, at the different stages of ontogeny, a huge number of genes, factors and proteins are expressed, since in them the primary sex cells and in their surroundings render folliculogenesis and determine the reproductive health of a woman. Aberrant production of these factors can be the cause of ovarian dysfunction and disorders. Different points of view on the emergence of the problem of migration and colonization of germ cells in female gonads, as well as directions for further fundamental and practical research. The development and differentiation of the follicle is a succession of events that are tightly regulated by endocrine factors, intraocular regulators and intercellular interactions. The initial migration of germ cells and their multiplication within the urogenital scallop require regulation using integrated signals such as growth factors, transcription and differentiation, secreted oocytes, transforming growth factors, growth factor and differentiation-9, bone morphogenetic proteins, stem cell factor, basic growth factor of fibroblasts, tumor factor of Williams transcription, gene steroidogenesis, antimulylerovy hormone, meiosis-regulating genes and many others, as well as a contact these interactions of germ cells with extracellular matrix proteins and cellular substrates attract the developing gonads. Recent studies indicate the possibility of obtaining human gametes from the culture of stem cells, a distinct molecular genetic mechanism of the origin, migration and colonization of the sex cells. Consequently, the understanding that all the subtleties and molecular mechanisms at each stage of the bookmarking and development of the ovaries, germ cells and their environment, the death of gametes, can help in finding regulators and preventing pathological follicular depletion.

The Expression Profile of Connexin-30 and Connexin-32 in the Somatosensory and Visual Cortex of Rats during Early Postnatal Ontogeny

Many studies are focused on the mechanisms of CNS formation, especially on the molecular bases of CNS functioning at different stages of maturation. It is known that functional maturation of different parts of the neocortex occurs at different time points of postnatal ontogeny and gap junctions play an important role in this process. So far, it was not clear whether the expression of major proteins that form gap junctions, connexins, is uniform in the neocortex during its maturation. We compared the dynamics of mRNA level of connexin-30 (Cx30, gjb6) and connexin-32 (Cx32, gjb1) in the somatosensory and visual parts of the neocortex during period of early postnatal ontogeny. We measured the mRNA level of mentioned connexins using quantitative real-time PCR after reverse transcription in the samples of neocortex collected at postnatal days 5, 8, 10, 13, and 20. We found that the level of Cx30 mRNA progressively increased in the somatosensory neocortex from the 5th to 20th day of postnatal ontogeny. In contrast, the level of Cx30 mRNA in the visual cortex began to increase only after the 10th day of postnatal development. Analysis of Cx32 expression showed that its expression started to increase only after 10th day in the somatosensory cortex and after 13th day in the visual cortex. Taken together, our data suggest that the expression of Cx30 and Cx32 is more intense in the somatosensory than in the visual neocortex at early stages of ontogeny which may reflect different time course of maturation of these neocortical areas.

Effect of irradiation of Medicago Sativa L seeds by the radioactive elementCo On the development of plants in the initial stages of ontogeny

Effect of irradiation of Medicago Sativa L seeds by the radioactive elementCo On the development of plants in the initial stages of ontogeny

Morphological and histological description of small metoposaurids from Petrified Forest National Park, AZ, USA and the taxonomy of Apachesaurus

ABSTRACTMetoposaurids are Late Triassic temnospondyls that are abundant components of freshwater depositional settings. Although metoposaurids are represented by hundreds of specimens in collections around the world, the vast majority pertain to large-bodied, relatively mature individuals, and as a result, the early stages of ontogeny are still poorly characterised. Small-bodied metoposaurids from North America have traditionally been assigned to Apachesaurus gregorii, interpreted as a diminutive taxon, but this interpretation has not been rigorously tested. Here we provide a morphological description of two new small-bodied metoposaurid specimens from Petrified Forest National Park, AZ, USA. Both provide various anatomical details that improve our understanding of small-bodied metoposaurids and their taxonomic placement within Metoposauridae. Furthermore, we perform a histological analysis on associated intercentra of these specimens, which indicates that these are relatively immature individuals. These findings support the growing consensus that Apachesaurus is a juvenile metoposaurid, thereby providing additional data regarding the early stages of metoposaurid ontogeny and evidence of the persistence of large-bodied forms into the late Norian. Accordingly, these findings merit a reevaluation of the taxonomic validity and diagnosis of the taxon and of the previous interpretations of its paleobiology.

Glutamine Synthetase-Containing Cells of the Dorsal Root Ganglion at Different Stages of Rat Ontogeny

In the present study, formation, location, and morphological features of glutamine synthetaseimmunopositive cells of the dorsal root ganglion (DRG) at different stages of prenatal and postnatal development of the rat was examined. It was demonstrated that small differentiating satellite cells containing glutamine synthetase were observed in the DRG close to sensory neurons on embryonic day 18. On embryonic day 19, the forming immunopositive glial cells were located around developing neurons of the DRG in accordance with topography, which is observed in newborn and adult animals. The averaged number of satellite cells per sensory neuron in mature and aging rats was calculated and it was found that this index did not change during aging.

Local Population of Eritrichium caucasicum as an Object of Mathematical Modelling. II. How Short Does the Short-Lived Perennial Live?

In the previous publication (Logofet et al., 2017), we reported on constructing a matrix model for a local population of Eritrichium caucasicum at high altitudes of north-western Caucasus. The model described the population structure according to the stages of ontogeny and field data for 6 years of observation. Calibrated from the data, the matrices, L(t), of stage-specific vital rates, which projected the population vector at time t (t = 2009, 2010, …, 2013) to the next year, were dependent on t and naturally different, reflecting indirectly the temporal differences in habitat conditions that occurred during the observations. Therefore, the model turned out to be non-autonomous. In addition to the range of variations in the adaptation measure λ1(L), we also obtained certain “age traits from a stage-structured model,” such as the average stage duration and the life expectancy for each stage. Those traits were uniquely determined for each given matrix L by a known (from the English literature) VAMC (virtual absorbing Markov chain) technique, while their variations for different years t pointed out the need to solve a mathematical problem of finding the geometric mean (G) of five matrices L(t) with a fixed pattern. The problem has no exact solution, whereas the best approximate one (presented here) results in the estimate of life expectancy as 3.5 years and that of the mean age at first flowering as 12 years. Given the data of 6-year observations, the forecast of whether the local population increases/declines in the long term draws on the range of possible variations in the measure λ1(G) under reproductive uncertainty, and this range localizes entirely to the right of 1, though very close to λ1 = 1 meaning a stable population.

Polymorphism in promoter of SIX4 gene shows association with its transcription and body measurement traits in Qinchuan cattle

The sine oculis homeobox homolog 4 (SIX4) gene belongs to the SIX gene family, which plays a critical role in muscle regeneration and early stages of ontogeny. This study aimed to detect promoter variations of bovine SIX4 genes in Qinchuan cattle, and to evaluate the effect of transcription regulations and body measurement traits. Quantitative real-time PCR (qPCR) results showed that the mRNA expression levels of SIX4 gene were found significantly highest in longissimus thoracis tissue and individual before attaining the stage of physiological maturity. Using sequencing technology on a total of 428 Qinchuan cattle, seven single nucleotide polymorphisms (SNPs) were identified in the promoter region of SIX4, and seven haplotypes representing 18 potential transcription factor compositions of polymorphic potential cis-acting elements. Association analysis indicated that the H3-H3 diplotype performed greater withers height, chest depth, chest circumference, back fat thickness and ultrasound loin muscle area (P < 0.05) than H5-H6, which were consistent with the promoter activity of Hap3 haplotype was higher than the Hap5 and Hap6 haplotype in vitro. These potential transcription factor information and combined genotypes H3-H3 of the SIX4 gene can be used as a molecular marker for selection of economic traits in Qinchuan cattle.

Influence of river water quality on homeostasis characteristics of cypriniform and perciform fish

Within an integrated ecosystem approach, it is preferable to evaluate the effects of pollution of surface waters through research on the organisms of fish. The aim of this study was to analyse the impact of a set of water quality indicators on the homeostasis of fish, in order to determine the response of a hydro-ecosystem to the impact of human activity. Fish samples were obtained from control catches in 16 control sites located in the rivers of Rivne Oblast which differ in intensity of anthropogenic load. The researchers observed that increased concentrations of phosphates and suspended substances, heavy metals, iron, fluorides and nitrogen compounds have violated the environmental state of the examined hydro-ecosystems. Parameters of the morphological homeostasis were assessed by the levels of the fluctuating asymmetry of the meristic signs of fish.The scientists recorded significant impairments (within IV points of body stability) in case of roach and bleak in the majority of the control sites. We carried out the analysis of cytogenetic parameters of fish homeostasis using a micronuclear test of blood erythrocytes.The investigation revealed a significant excess of spontaneous mutagenesis (1.1–1.7 times) in such species as roach, bleak and perch, and this is certainly a clear indicator of unfavourable ecological conditions of the water environment in seven areas of hydro-ecosystems. Given the results of the analysis, the authors found that different ecological groups of fish have their own complex and multifactorial processes of morphological and cytogenetic homeostasis formation. Furthermore, the regression dependences set out in the paper indicated the decisive impact of the oxygen regime of the water environment (COD, BOD5, О2), pollutants (Cu2+, Zn2+, Mn2+), and substances of biogenic group (NH4+, NO2–, PO4‑) upon fish homeostasis. differences in scope of homeostasis characteristics of different fish species were complemented by the differences in the composition of the regression equations. In particular, in case of species that had signs of homeostasis violation, the equation consisted of a greater number of members. The dependences for morphological and cytogenetic homeostasis of bleak and roach appeared to multifactorial. This finding suggests that these species are sensitive local indicators of the water environment both at early and late stages of ontogeny . Finally, as an outcome of the research we obtained prognostic forms of the relationship between water quality indicators and fish homeostasis that may form the basis of an environmental assessment method in which fish characteristics are used to assess the health of hydro-ecosystems.

RENIN-ANGIOTENSIN SYSTEM IN REGULATION OF HEMATOPOIESIS

The renin-angiotensin system (RAS) has long been known as the endocrine system involved in the regulation of arterial pressure and waterelectrolyte balance. Local (tissue) RAS can influence cellular activity, tissue damage and regeneration. In the bone marrow there are active ligands of peptides, mediators, receptors and signaling pathways of the RAS. Local RAS can influence the growth, production, proliferation and differentiation of hematopoietic cells and participate in the regulation of both normal and pathological hematopoiesis. Angiotensin-converting enzyme (ACE) CD143 plays a key role in the classical RAS. After differentiation from hemangioblast, hematopoietic progenitor cells constantly express ACE in human embryonic, fetal and adult hematopoietic tissues, as well as at all stages of hematopoietic ontogeny. The ACE cleaves the C-terminal dipeptide and thus forms the octapeptide Angiotensin II. In addition to angiotensin II, ACE also regulates a group of biologically active peptides, such as substance P, ac-SDKP and angiotensin 1–7. Local RAS is also one of the most important components in the tumor microenvironment, affecting tumor growth and metastasis by autocrine and paracrine pathways, modulating numerous carcinogenic events such as angiogenesis, apoptosis, cell proliferation, immune responses, and extracellular matrix formation. The purpose of this review is to describe the known functions of local RAS in the hematopoiesis regulation. More detailed study of the RAS components mechanisms of action will expand therapy approaches in the neoplastic diseases and in bone marrow transplantation.

Plant organ senescence - regulation by manifold pathways.

Senescence is the final stage of plant ontogeny before death. Senescence may occur naturally because of age or may be induced by various endogenous and exogenous factors. Despite its destructive character, senescence is a precisely controlled process that follows a well-defined order. It is often inseparable from programmed cell death (PCD), and a correlation between these processes has been confirmed during the senescence of leaves and petals. Despite suggestions that senescence and PCD are two separate processes, with PCD occurring after senescence, cell death responsible for senescence is accompanied by numerous changes at the cytological, physiological and molecular levels, similar to other types of PCD. Independent of the plant organ analysed, these changes are focused on initiating the processes of cellular structural degradation via fluctuations in phytohormone levels and the activation of specific genes. Cellular structural degradation is genetically programmed and dependent on autophagy. Phytohormones/plant regulators are heavily involved in regulating the senescence of plant organs and can either promote [ethylene, abscisic acid (ABA), jasmonic acid (JA), and polyamines (PAs)] or inhibit [cytokinins (CKs)] this process. Auxins and carbohydrates have been assigned a dual role in the regulation of senescence, and can both inhibit and stimulate the senescence process. In this review, we introduce the basic pathways that regulate senescence in plants and identify mechanisms involved in controlling senescence in ephemeral plant organs. Moreover, we demonstrate a universal nature of this process in different plant organs; despite this process occurring in organs that have completely different functions, it is very similar. Progress in this area is providing opportunities to revisit how, when and which way senescence is coordinated or decoupled by plant regulators in different organs and will provide a powerful tool for plant physiology research.

Effect of etoksidol against sulfur-containing gas induced reduction in bone marrow microcirculation in different stages of ontogenesis in rats

Objective: To investigate the state of femoral red bone marrow microvasculature of nonlinear white male rats in the course of an acute experiment. Materials and Methods: The ontogenesis of experimental animals were between 36 and 730 days: Intact ones, those subjected to the action of subtoxic doses of sulfur-bearing gas, and those receiving a protector-drug “Etoksidol”. The data on microcirculation were obtained using laser Doppler flowmetry. The industrial sulfur-containing natural gas of the Astrakhan gas condensate field was used as a toxic agent. It was revealed that the reducing intensity of blood microcirculation in the red bone marrow of intact rats is statistically more significance in the presenile period of ontogenesis compared with the earlier periods. Results: The use of “Etoksidol” along with the influence of sulfur-containing pollutant on the experimental animals of different age groups led to improvement of microcirculation in the bone marrow at all the studied stages of ontogeny. However, such improvement was statistically highly significant (P < 0.01) in the mature age I, very close to significant in the mature age II, and was not statistically significant in the young and presenile age. Conclusions: As a result, the following findings were obtained: The toxic effect greatly reduces the intensity of the microcirculation in the bone marrow, which is most pronounced in younger animals; the experimental results suggest that the drug “Etoksidol,” with an antihypoxic and antioxidant action, has a positive effect on red bone marrow microvasculature.

ПСИХОЛОГІЯ ФЕМІНІННОЇ САМОАКЦЕПТАЦІЇ НА ПІДЛІТКОВОМУ ЕТАПІ ОНТОГЕНЕЗУ: ТЕОРЕТИКО-ЕМПІРИЧНИЙ РАКУРС

ПСИХОЛОГІЯ ФЕМІНІННОЇ САМОАКЦЕПТАЦІЇ НА ПІДЛІТКОВОМУ ЕТАПІ ОНТОГЕНЕЗУ: ТЕОРЕТИКО-ЕМПІРИЧНИЙ РАКУРС

Ontogenetic change in determinants of social network position in the spotted hyena

Social development is crucial in the ontogeny of animals living in complex societies and has lasting consequences in adulthood. Spotted hyenas (Crocuta crocuta) live in fission-fusion societies as complex as those of cercopithecine primates. The social positions adult hyenas hold within their groups are complex and varied, but little is known about how those positons emerge and change over the course of development. Using social network analysis (SNA), we tested predictions of hypotheses suggesting that sex and dominance status affect the social network positions of young hyenas across three stages of ontogeny: (1) while living at the communal den, (2) den independent but pre-reproductive, and (3) early adulthood. By examining rates at which hyenas were found alone and their association networks, aggression networks, and affiliation networks, we observed striking changes in individuals’ network positions across ontogeny, as well as pronounced sex differences. With the exception of rates at which individuals were found alone, which increased over ontogeny, most social network position metrics decreased greatly from infancy to adulthood. However, females showed considerably more rank-related variation in this trajectory than did males. Overall, social rank had stronger effects on the development of social network positions in females than males. Thus, females and males have different social development trajectories that appear to prepare them for their different respective futures of integrating into their natal clan or dispersing to a new one. Social development is difficult to study, particularly in long-lived gregarious mammals, so little is known about the variables shaping the emergence during ontogeny of social roles played by adults. We used social network analysis to investigate how sex and rank affect the social positions of maturing spotted hyenas as their positions change across ontogenetic development. Females develop more complex social positions than males early in life, with strategies that vary with their dominance status. Although males are just as well connected to group-mates as females when they are cubs, they generally disengage from the natal clan as they mature; males clearly do not disperse because they are aggressively expelled from their natal group. Our data suggest for the first time that social development appears to prepare females and males for their alternative futures of philopatry or dispersal.

The particularities of the growth of Siberian fir (Abies sibirica Ledeb.) in the first stages of ontogeny in conifer forests (Ufa plateau, Pre-Ural)

Fir undergrowth under forest canopy forms the xylorhizome, which allows a long time to exist in pessimal conditions and to compete with nemoral species. This work is devoted to studying features of Siberian fir (Abies sibirica Ledeb.) in the first stages of ontogeny in different forest conditions. We have shown that in determining biological (exact) age of the plant, researchers should consider the xylorhizome formation. While studying the growth dynamics of the shoot, we identified three periods of accelerated growth, which correspond to increased competition from different layers of grassy vegetation. The change in fir growth rates was associated with the growth of the lateral and pseudo-whorl shoots, leading to the increased assimilating surface of the needles. These regularities of growth and development of fir in the first stages of ontogeny reflect specific adaptations of fir that allow this species to compete with understory nemoral species. The xylorhizome formation is one of the structural–functional adaptations for the ontogeny protection, allowing to fir undergrowth a long time exist in pessimal conditions under the forest canopy.

The Origin of Cladocera (Crustacea, Branchiopoda): A New Understanding of an Old Hypothesis

Comparative analysis of the ontogeny of representatives of two sister taxa (Cladocera and Cyclestherida) showed that the paedomorphic morphology of cladocerans (the small number of thoracic segments and segments of branches of antennae II, and the reduction of the carapace) was caused by the cessation of development of the somatic structures at early larval stages of ontogeny. It is demonstrated that this stop is not associated with the accelerated development of the reproductive system (progenesis), since it takes place long prior to the beginning of reproduction. In accordance with this fact, the past hypotheses that cladocerans evolved from the reproducing larvae of the ancestral form or that they are early maturing metanauplii should be recognized as erroneous. Cyclestheria. The origin of Cladocera from a Cyclestheria-like ancestor should be regarded as neotenic, taking into consideration the extended interpretation of this term.

Female lizards choose warm, moist nests that improve embryonic survivorship and offspring fitness

AbstractThe fitness consequence of maternal nest‐site choice has attracted increasing scientific attention, but field studies identifying the long‐term effects of nest‐site choice on offspring survival and reproductive success are still rare in vertebrates.To investigate the consequences of nest‐site choice in lizards, we quantified the thermal and hydric conditions of nest sites that were chosen by female toad‐headed agama (Phrynocephalus przewalskii) in the desert steppe of northern China. We also determined the effect of nest‐site choice on embryonic development and survival and on offspring growth, survival and maturity by comparing the embryos and offspring from maternally and randomly chosen nest sites.We found that female toad‐headed agama chose warm and moist nest sites that improved the developmental rate and survivorship of embryos and promoted the post‐hatching growth, sexual maturity, reproduction and fitness of offspring, thereby improving their reproductive success.Such studies on short‐lived lizards across multiple stages of embryonic and postembryonic ontogeny are critical for fully understanding the fitness consequences of nest‐site choice.Aplain language summaryis available for this article.

Cauline domatia of the ant-plant Humboldtia brunonis (Fabaceae)

We examined the morphology of the cauline domatia of the semi-myrmecophyte Humboldtia brunonis at different stages of ontogeny. We observed that the hollow chamber in H. brunonis is spontaneously formed by the plant, and suggest this to be a collective effect of both schizogeny and lysogeny, following acropetal lignification of the pith cells as the domatium internode swells up. Unlike some other cauline domatia, there is a self-opening slit that provides access to the domatium chamber. We investigated the micro-structure of the inner wall of the domatia using scanning electron microscopy, and observed that cells that form the inner lining of the domatia cavity have canaliculated, lignified sclerenchyma with numerous plasmodesmata, as reported for the true myrmecophyte Leonardoxa africana, which could explain the observed nutrient flux from domatia-dwelling invertebrates into the host plant. We also observed fungal mycelia in ant-occupied domatia, though the role of fungi in this ant–plant system awaits further investigation.