Reproductive Mechanisms Research Articles

Identification and expression analysis of a calmodulin gene in Phycocalida chauhanii (Rhodophyceae, Bangiales)

Calmodulin (CaM) plays an important regulatory role in plant growth and development. In this study, on the basis of previous transcriptomic annotation a homolog of CaM gene (Pc-CaM7) was identified from the red alga Phycocalida chauhanii (previously known as Porphyra chauhanii). It encoded a 151 amino acids protein with 4 EF-hand regions, which was the typical structure of calmodulin family proteins. Evolutionary analysis showed that Pc-CaM7 shared conserved orthologous relationships with CaMs from Neoporphyra haitanensis (formerly Pyropia haitanensis), Porphyra umbilicalis, and Gracilariopsis chorda. During the developmental period of P. chauhanii gametophytic germlings from 25- to 50-day-old, the asexual archeospores were continuedly released from the marginal region of blades, followed by the emergence of spermatangia from 40-day-old germlings. Based on quantitative real-time PCR analysis, it showed that expression trend of Pc-CaM7 was correlated with the rule of archeospores’ formation and release, whereas in N. haitanensis without archeospore characteristic, the expression pattern of the orthologous gene (Pha_00404) was different, which increased and reached a plateau during the same developmental period. These findings suggested that Pc-CaM7 may be involved in the process of archeospores formation and release, which may provide a foundation for understanding the molecular mechanisms of asexual reproduction in Bangiales.

Chemical conjugation of FITC to track silica nanoparticles in vivo and in vitro: An emerging method to assess the reproductive toxicity of industrial nanomaterials

Previous studies have demonstrated that silica nanoparticle (SiNP) exposure induces pulmonary and cardiovascular diseases, yet their transportation and degradation in vivo have not been fully elucidated. From the perspective of reproduction, this study was implemented to examine the uterine accumulation of SiNP and explore its reproductive toxicity and pathogenic mechanisms. First, we coupled FITC onto SiNPs and intratracheally instilled them into pregnant mice on the fifth gestational day, and the toxic effect of SiNP was evaluated in vitro and in vivo. It was found that SiNP penetrated the trophoblast membrane, leading to apoptosis and suppression of cell proliferation, tube formation, and invasion in a dose-dependent manner. Mechanistically, SiNP dysregulated the expression of Scd1, Slc27a1, and Cpt1a, and induced over synthesis and efflux obstruction of fatty acid through the PPARγ signaling pathway. The downregulation of Caspase-3 triggered apoptosis of trophoblast, which was causally associated with intracellular fatty acid accumulation as revealed by the correlation analysis. Besides, SiNP induced uterine inflammation in vivo, which aggravated with the observation prolongation within 24 h. Overall, SiNPs were visualized by coupling with FITC, and the uterine accumulation of SiNP induced fatty acid metabolic disorder, biological dysfunction, and trophoblast apoptosis, which were mediated in part by the PPARγ signaling pathway. These findings would contribute to understanding the environmental impacts of SiNP better, as well as the development of control measures for environmental pollution.

Igf3: a novel player in fish reproduction†.

As in other vertebrates, fish reproduction is tightly controlled by gonadotropin signaling. One of the most perplexing aspects of gonadotropin action on germ cell biology is the restricted expression of gonadotropin receptors in somatic cells of the gonads. Therefore, the identification of factors conveying the action of gonadotropins on germ cells is particularly important for understanding the mechanism of reproduction. Insulin-like growth factors (Igfs) are recognized as key factors in regulating reproduction by triggering a series of physiological processes in vertebrates. Recently, a novel member of Igfs called Igf3 has been identified in teleost. Different from the conventional Igf1 and Igf2 that are ubiquitously expressed in a majority of tissues, Igf3 is solely or highly expressed in the fish gonads. The role of Igf3 in mediating the action of gonadotropin through Igf type 1 receptor on several aspects of oogenesis and spermatogenesis have been demonstrated in several fish species. In this review, we will summarize existing data on Igf3. This new information obtained from Igf3 provides insight into elucidating the molecular mechanism of fish reproduction, and also highlights the importance of Igf system in mediating the action of gonadotropin signaling on animal reproduction.

The Hegemon’s Perspective, Part I. On the inner source and morphology of world power and hegemony

The Hegemon’s Perspective, Part I. On the inner source and morphology of world power and hegemony

MiR-130a-3p regulates steroid hormone synthesis in goat ovarian granulosa cells by targeting the PMEPA1 gene

MicroRNAs (miRNAs) are key epigenomic regulators of proliferation, differentiation, and secretion in cells involved in follicular development. We here studied the functional role of one such molecule, miR-130a-3p, in goat ovarian granulosa cells (GCs). High expression of this miRNA was evident in goat GCs by fluorescence in situ hybridization and suppressed estradiol and progesterone secretion from these cells, as determined by ELISA. miR-130a-3p was predicted to have a binding site for the 3’ UTR of the prostate transmembrane protein androgen induced 1 gene (PMEPA1), and this was verified by a dual-luciferase reporter assay. PMEPA1 mRNA and protein expression were both found to be regulated by miR-130a-3p in GCs. Moreover, the overexpression or knockdown of PMEPA1 enhanced or suppressed estradiol and progesterone secretion from these cells, respectively. Furthermore, the secretion of estradiol and progesterone did not change significantly after the offsetting of PMEPA1 overexpression in GCs by miR-130a-3p. In summary, our present data indicate that miR-130a-3p inhibits the secretion of estradiol and progesterone in GCs by targeting PMEPA1. Our study thus provides seminal data and important new insights into the regulation of reproductive mechanisms in the nanny goat and other female mammals.

Brokers of international student mobility: The roles and processes of education agents in China

AbstractThe study on which this article reports explored the role of education agents in international student mobility, developing a better understanding of how they operate, behave and think when dealing with the admissions processes of universities overseas. The behaviours and reasoning, the modus operandi, and positioning of education agents are analysed using agency theory; specifically, the information‐asymmetric relations that they have with the principals they serve. The context analysed was characterised by two types of admissions practices: (a) direct admissions to the university without the need for any preparatory courses and (b) dual admissions involving enrolment in the host universities' preparatory language centres before university enrolment proper. Students and their families are principals in both types of admissions processes, whereas universities overseas serve as a principal in the dual admissions process. The findings demonstrate a mix of transparent practices and those that border to unethical practices in international university admissions services, as well as student dependence on service providing agents who operate free from accountability. Agents are identified as a cog in the machine of international higher education, which increasingly works as a mechanism of socioeconomic reproduction.

Combined effects of landscape composition and pesticide use on herbivore and pollinator functions in smallholder farms

BackgroundLandscape composition has the potential to foster regulating ecosystem services such as pollination and biocontrol in temperate regions. However, most landscape studies do not take pesticide use into account even though it is the main control strategy worldwide and has negative impacts on beneficial insects. Moreover, few studies have explored these combined effects in smallholder cropping system with diverse landscapes and small cultivated fields.MethodsWe assessed the effect of semi-natural cover and pesticide use on pollinator and herbivore abundances and functions in 9 fields in the Ecuadorian Andes through participatory experiments with smallholder farmers. We performed a path analysis to quantify the effects of landscape and pesticide use on herbivory, pollination and ultimately yield.ResultsPesticide use significantly reduced pollinator abundance but had no significant effect on pest abundance. Similarly, we found non-significant effects of landscape composition on either herbivory and pollination. The study also provides new information on understudied Andean lupine’s pests and pollinators, whose application for small farmers is discussed. Finally, we hypothesize that peculiarities of tropical smallholder cropping systems and landscapes could explain the non-significant landscape effects on insect-based processes, which calls for more research in places outside the well-studied temperate region.ConclusionsLandscape composition did not show any significant effect on pest and pollinator while pesticide use decreased the abundance pollinators, but with no significant effect on yield. This study also provides information about Andean lupine reproduction and overcompensation mechanisms that could be of interest for local farmers and researchers of this understudied crop.

Selected Uterine Immune Events Associated With the Establishment of Pregnancy in the Dog.

In the dog, implantation takes place at approximately 17 days of embryonal life and, while exposed to relatively high circulating progesterone concentrations, embryos presence is required for the formation of decidua. Furthermore, a balance between pro- and anti-inflammatory responses in conceptus-maternal communication is crucial for the onset of pregnancy. Strikingly, the understanding of such immune mechanisms in canine reproduction is still elusive. Here, canine uterine samples from pre-implantation (day 10–12, E+) and corresponding non-pregnant controls (E–), implantation (day 17, Imp) and post-implantation (day 18–25, Post-Imp) stages of pregnancy were used to investigate the expression and localization of several immune-related factors. The most important findings indicate increased availability of CD4, MHCII, NCR1, IDO1, AIF1, CD25, CCR7, and IL6 in response to embryo presence (E+), while FoxP3 and CCL3 were more abundant in E– samples. Implantation was characterized by upregulated levels of FoxP3, IL12a, ENG, and CDH1, whereas CD4, CCR7, IL8, and -10 were less represented. Following implantation, decreased transcript levels of TNFR1, MHCII, NCR1, TLR4, CD206, FoxP3, and IL12a were observed concomitantly with the highest expression of IL6 and IL1β. MHCII, CD86, CD206, CD163, TNFα, IDO1, and AIF1 were immunolocalized in macrophages, CD4 and Nkp46 in lymphocytes, and some signals of IDO1, AIF1, and TNF-receptors could also be identified in endothelial cells and/or uterine glands. Cumulatively, new insights regarding uterine immunity in the peri-implantation period are provided, with apparent moderated pro-inflammatory signals prevailing during pre-implantation, while implantation and early trophoblast invasion appear to be associated with immunomodulatory and rather anti-inflammatory conditions.

Genetic Diversity and Connectivity in Plant Species Differing in Clonality and Dispersal Mechanisms in Wetland Island Habitats.

In plants, long-distance dispersal is both attenuated and directed by specific movement vectors, including animals, wind, and/or water. Hence, movement vectors partly shape metapopulation genetic patterns that are, however, also influenced by other life-history traits such as clonal growth. We studied the relationship between area, isolation, plant-species richness, reproduction, and dispersal mechanisms with genetic diversity and divergence in 4 widespread wetland plant-species in a total of 20 island-like kettle-hole habitats surrounded by an intensive agricultural landscape. Our results showed that genetic parameters reflect the reproduction strategies with the highest genetic diversity being observed in the non-clonal, outcrossing Oenanthe aquatica compared to the clonal Lycopus europaeus, Typha latifolia, and Phragmites australis. Lycopus showed a positive relationship between genetic diversity and kettle-hole area, but a negative relationship with the number of neighboring kettle holes (less isolation). Genetic diversity increased with plant-species richness in the clonal species Phragmites and Lycopus; while it decreased in the non-clonal Oenanthe. Finally, genetic divergence and, therefore, connectivity differed between alternative dispersal strategies, where wind-dispersed Typha and Phragmites had a higher gene flow between the analyzed kettle holes compared with the insect-pollinated, hydrochorous Lycopus and Oenanthe. Our study provides information on genetic patterns related to reproduction and dispersal mechanisms of 4 common wetland species contributing to the understanding of the functioning of plant metacommunities occurring in kettle holes embedded in agricultural landscapes.

The objective development mechanism of agriculture in the Russian Federation: theory, methodology, and practice

The problem of determination of the the objective mechanism of social reproduction of agriculture is yet to be resolved. Its cognition furnishes the clue ti the rational solution of a range of socioeconomic, environmental, scientific-technological, ideological, political, and practical tasks for successful development of the sector and its branches in the Russian Federation. The existing domestic and foreign experience proves the inadequacy of the used theories, methodologies and practices, which give only a partial representation in the conditions of considerable uncertainty. The modern theories, methodologies, and practices are incapable of determining the objective mechanism for agricultural development in relation to social reproduction, and thus, ensure the development of agriculture in the current context of sanctions and increased competition in the world market. The author offers an alternative approach with a fundamentally new scientific base, systemic and comprehensive methodology, an adequate theory that fully reflects all aspects of the objective reproduction mechanism on all economic levels. The pivotal link in transformation in the strategy of agricultural development of the Russian Federation is the drastic change in the socioeconomic ideology and state policy aimed at improvement of living conditions for all members of the society based on the legislative consolidation, which via state coercion, ensures the increase in the share of advantageous  spending and reduction of disadvantageous, harmful spending within the budget structure of a social worker and spare time of each person or society in nature. Successful transition of agriculture to an innovative type of reproduction becomes possible only in terms of the accelerated (5-7 years) second Industrialization of the Russian Federation in all production sectors.

Experimental increase in fecundity causes upregulation of fecundity and body maintenance genes in the fat body of ant queens.

In most organisms, fecundity and longevity are negatively associated and the molecular regulation of these two life-history traits is highly interconnected. In addition, nutrient intake often has opposing effects on lifespan and reproduction. In contrast to solitary insects, the main reproductive individual of social hymenopterans, the queen, is also the most long-lived. During development, queen larvae are well-nourished, but we are only beginning to understand the impact of nutrition on the queens' adult life and the molecular regulation and connectivity of fecundity and longevity. Here, we used two experimental manipulations to alter queen fecundity in the ant Temnothorax rugatulus and investigated associated changes in fat body gene expression. Egg removal triggered a fecundity increase, leading to expression changes in genes with functions in fecundity such as oogenesis and body maintenance. Dietary restriction lowered the egg production of queens and altered the expression of genes linked to autophagy, Toll signalling, cellular homeostasis and immunity. Our study reveals that an experimental increase in fecundity causes the co-activation of reproduction and body maintenance mechanisms, shedding light on the molecular regulation of the link between longevity and fecundity in social insects.

Autonomous apomixis in Praxelis clematidea (Asteraceae: Eupatorieae), an invasive alien plant.

Understanding the reproductive mechanisms of invasive alien species can lay the foundation for effective control measures. Praxelis clematidea is a triploid neotropical Asteraceae species that is invasive in China and other countries. However, few studies have focused on its reproductive biology. In this study, flow cytometric seed screening (FCSS) was used to identify and confirm the reproductive mode of the species. The development of ovules, anthers, and mega- and microgametophytes was observed using a clearing method and differential interference contrast microscopy. Pollen viability was measured using the Benzidine test and Alexander’s stain. Pollen morphology was observed via fluorescence microscopy after sectioning the disk florets and staining with water-soluble aniline blue or 4′6-diamidino-2-phenylindole nuclei dyes. Controlled pollination experiments were conducted on four populations in China to examine the breeding system and to confirm autonomous apomixis. The reproductive mode was found to be autonomous apomixis without pseudogamy, according to FCSS. Megaspore mother cells developed directly into eight-nucleate megagametophytes without meiosis, conforming to Antennaria-type diplospory. The unreduced egg cells developed into embryos through parthenogenesis, while the endosperm was formed by the fusion of two unreduced polar nuclei. Pollen viability was very low (0.82 ± 0.57 % and 0.36 ± 0.44 %) as measured by the Benzidine test and Alexander’s stain, respectively. The majority of the pollen grains were empty and had neither cytoplasm nor nuclei. The seed set was >90 % for all treatments of open pollination, bagging and emasculated capitula. Mature cypselae developed in capitula that were emasculated before flowering, which confirmed that the breeding system of P. clematidea was autonomous apomixis. The present study is the first report of autonomous apomixis in P. clematidea in China. Antennaria-type autonomous apomixis in P. clematidea greatly increases the probability of successful colonisation and dispersal of P. clematidea into new areas, which likely contributes to its high invasion potential. Effective control measures should be implemented to prevent autonomous (pollen-independent) seed production.

Hybridization Assays in Strawberry Tree toward the Identification of Plants Displaying Increased Drought Tolerance

Arbutus unedo L. is a small Ericaceae tree with a circum-Mediterranean distribution. It has a huge ecological impact on southern Europe forests and a great economic importance as a source of phytochemicals with bioactive properties and for fruit production. On the foreseen climate change context, breeding toward drought tolerance is necessary in order to ameliorate plant performance. Therefore, the aim of this work was to study the reproduction mechanisms of the strawberry tree, obtain new genetic combinations by hybridization, and select genotypes more tolerant to drought stress. A morphological analysis of flowers and pollen was carried out, and controlled pollinations were performed both in vitro and ex vitro. The very first approach on strawberry tree breeding by means of hybridization is also presented. Several physiological parameters were evaluated on 26 genotypes submitted to a water-deficit regime. Plant behavior under drought greatly varied among genotypes, which showed high phenotype plasticity. Three genotypes that were able to cope with water restriction without compromising net CO2 assimilation were identified as highly tolerant to drought stress. The results obtained elucidate the reproduction mechanisms of the strawberry tree and open the way for a long-term breeding program based on the selection of drought-tolerant plants.

Did climate change induce infiltration of composite thrips Microcephalothrips abdominalis sexual populations in Central Europe?

Alien and invasive thrips (Thysanoptera) species from tropical and subtropical regions are spread into temperate countries by human activities and by shifting their natural range as a result of global climate change. The presence of glasshouses with suitable host plants may contribute to the survival of these species and provide overwintering sites necessary for establishment of outdoor populations. Sampling the first male of Microcephalothrips abdominalis in Slovakia has given the reason to discuss on climate change induced infiltration of this alien species in Central Europe and consider its possible reproduction mechanisms as well as colonization strategies.

Dificuldades de leitura, escrita e numeramento na educação superior: discussões acerca da reprodução das desigualdades sociais

Este artigo objetiva compreender como as desigualdades sociais originam dificuldades de leitura, escrita, aritmética e como essas questões de ordem social são transformadas em supostos diagnósticos clínico-biológicos em estudantes da Educação Superior. Os contornos metodológicos envolvem um estudo de caso de uma estudante encaminhada para a clínica fonoaudiológica para avaliação clínica. Os dados demonstram que as dificuldades acadêmicas da universitária são consideradas como “alterações de cunho patológico” por que refletem mecanismos de manutenção e reprodução de desigualdades sociais. A Universidade, por sua vez, não consegue fazer com que o apoio pedagógico institucional dê conta das dificuldades da acadêmica, devido às especificidades do curso de graduação. A partir disso, conclui-se que um possível caminho a ser construído no contexto da Educação Superior seja (trans)formar os cursos a partir da perspectiva do Desenho Universal para a Aprendizagem (DUA).

A Path-Dependent Approach to Communal Transformation

Cognitive views claim that ethnic, national, and racial communities are malleable and constantly transforming, while more structural accounts consider these collective communities highly static. This article considers communal transformations at the population level, combines aspects of cognitive and structural perspectives, and uses path dependence to explain why collective communities are transformative in some instances but much more rigid in others. It claims that communal boundaries are usually relatively static because communal structures reinforce them through three main mechanism of reproduction, all of which can reproduce communal frameworks through inclusion and exclusion: cost, power, and socialization. In turn, the article describes how two types of critical juncture create openings for more punctuated and extensive communal transformations. Constructive critical junctures occur prior to the existence of powerful mechanisms of communal reproduction and make possible the construction of new communal frameworks. Alternatively, transformative critical junctures are openings for change that result from the weakening or breakdown of extant mechanisms of reproduction and generally promote transformations in preexisting communal frameworks. To clarify and support the argument, the article provides a variety of examples and an analysis of transformations in the Quebecois collective community.

Molecular approaches for identification of the apomictic/sexual reproductive mechanism and genetic variability in buffel grass (Cenchrus spp.) accessions

Cenchrus spp. encompasses forage grasses that are especially important for drylands. Thus, information on their reproductive mechanism and genetic diversity is needed. The Active Germplasm Bank (AGB) of the Embrapa Semi?rido (Tropical semiarid research center) has 115 accessions of Cenchrus spp. that were not molecularly characterized. Therefore, the objective of this work was to evaluate the genetic diversity of Cenchrus spp. accessions in the AGB, and identify their reproductive mechanisms using DNA markers. Specific SCAR markers Q8H, UGT197, and PCAB10, in addition to the SCAR marker 4HS

Декаплинг как механизм обеспечения воспроизводства природно-ресурсного капитала в агропроизводственной сфере

Natural resource capital is the most important tool in the process of reproduction activity of both enter-prises and all sectors of national economy. Therefore, the impact of the economic component, which ensures the formation of an effective mechanism for the reproduction of such resource capital is of crucial importance in the overall system of socio-economic development of the country. The dynamism of this process is about the progressive development of economy which must ensure the increasing role of natural resource capital in the formation of effective activities of all sectors of the national economy as a whole, including every individual enterprise, regardless the emerging forms of owner-ship. In this regard, the influence of decupling on the formation of a mechanism for the effective reproduction of natural resource capital in the specific agricultural sector becomes extremely important.

УСЛОВИЯ ДЛЯ ЭФФЕКТИВНОГО ВОСПРОИЗВОДСТВА МАШИННО-ТРАКТОРНОГО ПАРКА

In agriculture, the downsizing of the machinery fl eet is still underway, which leads to a violation of the agrotechnical terms of technical operations, incomplete yields, and loss of products. Reproduction of the machine and tractor fl eet in agriculture is possible provided there are fi nancial sources: own (depreciation, profi t) or borrowed funds. Based on the analysis of statistical data of Rosstat, the Ministry of Agriculture of Russia, publications in scientifi c journals, etc. the author established that the share of investments in machinery and equipment in the total volume of investments in fi xed assets in agriculture in 2017-2019 was 30% less than in the Russian economy as a whole. In the structure of investment fi nancing, the share of own funds was more than 50%, including the depreciation share of about 20%, which indicates that the reproduction mechanism does not work eff ectively enough. The volume of profi t is also insuffi cient. In 2019, the share of enterprises with a profi tability rate of more than 10% (making the reproduction process feasible) amounted to 55%. The high debt on loans (about 7% of the total revenue of agricultural organizations, 136% of the profi t in 2019) makes it necessary to provide state support for the acquisition and search for ways to operate the reproduction mechanism more eff ectively.

Environmental Import Substitution in the System of Sustainable Development of the "Green" Economy

Currently, the economic systems of developed countries are undergoing structural transformations associated with the deployment of a new environmentally oriented industrial sector on a new technological environmentally friendly basis. For technologically catching-up countries, including those focused on the extraction of natural resources, the task is to critically understand the modification of this trend, since the deindustrialization processes led to the loss of many modern manufacturing industries, which resulted in a deep import dependence on resource-saving technologies and equipment. This results in the wasteful use of the resource base of the economy and the lack of recycling, in increasing pollution and lagging behind in terms of environmental industrial technologies. Ineffective institutions and international financial and technological restrictions reduce the effect of stimulating environmental import substitution by the state, hinder the development of its reproductive mechanisms that can provide a positive trend in economic dynamics. Therefore, the development of environmental import substitution, integrating the resource availability of the economy and environmental imperatives, technologies for the careful use of resources and their recycling, determines the prospects for sustainable development of the economy as a whole.