Mitochondrial DNA Copy Number in Cleavage Stage Human Embryos—Impact on Infertility Outcome

A retrospective case control study was undertaken at the molecular biology department of a private center for reproductive medicine in order to determine whether any correlation exists between mitochondrial DNA (mtDNA) content of cleavage-stage preimplantation embryos and their developmental potential. A total of 69 couples underwent IVF treatment (averaged women age: 36.5, SD 4.9) and produced a total of 314 embryos. A single blastomere was biopsied from each embryo at the cleavage stage (day-3 post-fertilization) subjected to low-pass next generation sequencing (NGS), for the purpose of detecting aneuploidy. For each sample, the number of mtDNA reads obtained after analysis using NGS was divided by the number of reads attributable to the nuclear genome. The mtDNA copy number amount was found to be higher in aneuploid embryos than in those that were euploid (mean mtDNA ratio ± SD: 6.3 ± 7.5 versus 7.1 ± 5.8, p < 0.004; U Mann–Whitney test), whereas no statistically significant differences in mtDNA content were seen in relation to embryo morphology (6.6 ± 4.8 vs. 8.5 ± 13.6, p 0.09), sex (6.6 ± 4.1 vs. 6.2 ± 6.8, p 0.16), maternal age (6.9 ± 7.8 vs. 6.7 ± 4.5, p 0.14) or its ability to implant (7.4 ± 6.6 vs. 5.1 ± 4.6, p 0.18). The mtDNA content cannot serve as a useful biomarker at this point in development. However, further studies investigating both quantitative and qualitative aspects of mtDNA are still required to fully evaluate the relationship between mitochondrial DNA and human reproduction.

TOLERANCE FOR AMBIGUITY IN THE STRUCTURE OF THE PERSONAL COMPONENT OF SITUATIONS RELATED WITH PEDAGOGICAL PROBLEMS

Statement of the problem. Improving the quality of resolving difficult situations associated with teachers’ professional activity is possible only by studying those personal and situational variables that a) affect the resolution of difficult situations, b) are included in the personal structure and are available for comprehension. Tolerance for ambiguity (TA), being an intersubjective personality parameter, has all the necessary characteristics and can be considered when developing socio-psychological programs for teachers. However, its contribution to the resolution of difficult situations is currently not well understood. The purpose of the article is to show the place of TA in the structure of the personal component of situations related with pedagogical difficulties based on experimental data. Review of scientific literature on the problem. TA has many interpretations and is considered by researchers as a personality trait, as a metacognitive characteristic, as a socio-psychological attitude. Currently, without denying the multidimensionality of the concept, the emotional, cognitive and perceptual components of TA are considered. This means a return, at a new level, to the original idea of E. Frenkel-Brunswik, author of this psychological concept, who defined TA as an emotional-cognitive personality variable associated with the ambivalence of experiencing negative and positive properties of objects of reality. Sharing the views of E. Lehtinen and K. Merenluoto, we consider TA not as a stable, but as a dynamic characteristic. However, we have to admit that in this aspect the problem has been studied least of all. Therefore, studying the structure of the personal component of situations related with pedagogical difficulties, we consider as a separate task of studying TA as a structural component that develops in personal and situational interaction. Materials and methods. The research methodology is built in accordance with the idea of ​​L.S. Vygotsky and K. Levin, according to which any objective characteristic with which a person interacts becomes subjective through experience. The second foundation is understanding of the personality in the existential and humanistic approach as the leading instance that mediates any interaction with the world and oneself. The third foundation is a situational approach. The study involved 111 practicing teachers, who were offered five problem-solving tasks. Self-reports were processed using content analysis, the results were correlated with the data of personality techniques, including S. Badner’s TA test, and were subjected to factorization. Research results. The paper proves that TA refers to intersubjective parameters that affect the relationship between the personality and the situation. The TA factor turned out to be significant for all three groups of open, closed, and mixed models of interaction in difficult situations and is included in the structure of the personal component of situations related with pedagogical difficulties along with such factors as autonomy, communication, cognitive interest, openness, and creativity. Conclusion. The idea of ​K. Dahlbert that TA is most of all connected with the time factor was confirmed. During the study, it was found out that entering into different combinations within the personality structure, the TA parameter forms different configurations. Combined with the “orientation in time” factor, TA promotes an open type of interaction, while intolerance is associated with categoricalness and a closed type of communication in a situation of difficulty. Temporal competence enhances the personality ability to resolve a situation of difficulty through time resource management. At the same time, expectation of easiness and categoricalness lower the developmental potential of interaction in a situation of difficulty. In general, the high weight of TA in the structure of the personality component of situations related with pedagogical difficulties allows us to consider TA as a task and condition in the development of socio-psychological programs for practicing teachers.

CHARACTERISTICS OF ARTISTIC AND ACTIVITY CRITERION OF FORMATION OF CREATIVITY OF A CHILD OF PRESCHOOL AGE BY MEANS OF A MODERN ARTISTPLAYER

The article analyzes the contemporaneity and relevance of the point of creation of preschool children. In the framework of scientific and pedagogical research, creativity considers as a qualitative change in human ability that corresponds to the psychophysical and psycho-emotional processes of the preschool period of personality formation. With the help of the conducted experimental work based on children’s preschool institutions of Poltava region, the art-activity criterion of creativity of children of 5-7 years with the involvement of modern art-game material has been revealed. Particular attention has been paid to modern scientific research, which is devoted to the matter of children’s creativity, which is developing in creative activities. As a result of experimental work, we identified indicators of artistic and creative criteria of creativity of preschool children, namely the indicator of artistic and game literacy, the indicator of artistic and playful actions, and the indicator of improvisation and creative activity.Special attention should be paid to identifying the levels of indicators of artistic and creative criteria of creativity of preschool children with the involvement of contemporary art and game material in the experiment - high, medium, and low levels of creativity, their features, and quality examples. Our article contains a diagnosis of the problems faced by preschool children when playing, as a leading activity or when getting acquainted with the developmental potential of modern art and game material from the standpoint of an artistic and creative criterion of creativity. Prospects for further development in the direction of forming the creativity of preschool children using modern art and game material are aimed at preparing a curriculum in this thematic area.

The effects of vitrification on oocyte quality

Vitrification, is an ultra-rapid, manual cooling process that produces glass-like (ice crystal free) solidification. Water is prevented from forming intercellular and intracellular ice crystals during cooling as a result of oocyte dehydration and the use of highly concentrated cryoprotectant. Though oocytes can be cryopreserved without ice crystal formation through vitrification, it is still not clear whether the process of vitrification causes any negative impact (temperature change/chilling effect, osmotic stress, cryoprotectant toxicity, and/or phase transitions) on oocyte quality that translate to diminished embryo developmental potential or subsequent clinical outcomes. In this review, we attempt to assess the technique’s potential effects and the consequence of these effects on outcomes.

Transcriptome Analysis of mRNAs and Long Non-Coding RNAs During Subsequent Embryo Development of Porcine Cloned Zygotes After Vitrification

Cryopreservation of porcine cloned zygotes has important implications for biotechnology and biomedicine research; however, lower embryo developmental potential remains an urgent problem to be resolved. For exploring the sublethal cryodamages during embryo development, this study was designed to acquire the mRNA and long non-coding RNA (lncRNA) profiles of 2-cells, 4-cells and blastocysts derived from vitrified porcine cloned zygotes using transcriptome sequencing. We identified 167 differentially expressed (DE) mRNAs and 516 DE lncRNAs in 2-cell stage, 469 DE mRNAs and 565 lncRNAs in 4-cell stage, and 389 DE mRNAs and 816 DE lncRNAs in blastocyst stage. Functional enrichment analysis revealed that the DE mRNAs during embryo development were involved in many regulatory mechanisms related to cell cycle, cell proliferation, apoptosis, metabolism and others. Moreover, the target genes of DE lncRNAs in the three embryonic stages were also enriched in many key GO terms or pathways such as “defense response”, “linoleic acid metabolic process”, “embryonic axis specification”, “negative regulation of protein neddylation”, etc., In conclusion, the present study provided comprehensive transcriptomic data about mRNAs and lncRNAs for the vitrified porcine cloned zygotes during different developmental stages, which contributed to further understand the potential cryodamage mechanisms responsible for impaired embryo development.

Capturing Pluripotency and Beyond

During the development of a multicellular organism, the specification of different cell lineages originates in a small group of pluripotent cells, the epiblasts, formed in the preimplantation embryo. The pluripotent epiblast is protected from premature differentiation until exposure to inductive cues in strictly controlled spatially and temporally organized patterns guiding fetus formation. Epiblasts cultured in vitro are embryonic stem cells (ESCs), which recapitulate the self-renewal and lineage specification properties of their endogenous counterparts. The characteristics of totipotency, although less understood than pluripotency, are becoming clearer. Recent studies have shown that a minor ESC subpopulation exhibits expanded developmental potential beyond pluripotency, displaying a characteristic reminiscent of two-cell embryo blastomeres (2CLCs). In addition, reprogramming both mouse and human ESCs in defined media can produce expanded/extended pluripotent stem cells (EPSCs) similar to but different from 2CLCs. Further, the molecular roadmaps driving the transition of various potency states have been clarified. These recent key findings will allow us to understand eutherian mammalian development by comparing the underlying differences between potency network components during development. Using the mouse as a paradigm and recent progress in human PSCs, we review the epiblast’s identity acquisition during embryogenesis and their ESC counterparts regarding their pluripotent fates and beyond.

MiR-290 family maintains developmental potential by targeting p21 in mouse pre-implantation embryos

The miR-290 family is a mouse-specific microRNA cluster, which maintains mouse embryonic stem cells (ESCs) pluripotency by increasing OCT3/4 and C-MYC expression. However, its functions in mouse pre-implantation embryos remain unclear, especially during zygotic genome activation (ZGA). In this study, miR-290 family expression increased from the two-cell embryo stage through the blastocyst stage. Inhibition of miR-294-3p/5p did not affect ZGA initiation or embryo development, whereas pri-miR-290 knockdown decreased ZGA gene expression and slowed embryonic development. In addition, pluripotency decreased in ESCs derived from pri-miR-290 knockdown blastocysts. To clarify the mechanism of action, 33 candidate miR-294-3p target genes were screened from three databases, and miR-294-3p directly targeted the 3′-untranslated region of Cdkn1a (p21) mRNA. Similar to pri-miR-290 knockdown, P21 overexpression impeded embryonic development, whereas simultaneous overexpression of P21 and pri-miR-290 partially rescued embryonic development. The results indicate that the miR-290 family participates in promoting ZGA process and maintaining developmental potency in embryos by targeting p21.

The reaggregation of normal granulosa-cumulus cells and mouse oocytes with polycystic ovarian syndrome in vitro: An experimental study

Background: The dialogue between oocytes and their surrounding cells plays a major role in the progress of oocyte meiosis and their developmental potential. Objective: This study aimed to evaluate the effect of co-culture of normal granulosa-cumulus cells (GCCs) with oocytes from polycystic ovarian syndrome (PCOS) mice. Materials and Methods: Normal GCCs were collected from 10 virgin adult Naval Medical Research Institute female mice (30-35 gr, 7-8 wk old), and were cultured in an alpha-minimum essential medium supplemented with 5% fetal calf serum for 24-48 hr (1×106 cells/well). Then, germinal-vesicle oocytes from PCOS mice were cultured in the presence of cultured normal GCCs (experimental group) and without GCCs (control group). The maturation rate and quality of the PCOS oocytes were examined by evaluating TFAM and Cx43 gene expression (real-time PCR) and the connection among PCOS oocytes and normal GCCs after 24 hr of culture. Results: The co-culture of normal GCCs and PCOS oocytes in the experimental group led to the formation of a complex called a PCOS oocyte-normal GCCs complex. The maturation rate of these complexes was significantly increased compared to that of the control group (p ≤ 0.001). A significant difference was also found in the expression of Cx43 (p ≤ 0.001) and TFAM (p < 0.05) genes in the experimental group compared with the control group. The connection between PCOS oocytes and normal GCCs was observed in the scanning electron microscope images. Conclusion: Co-culture with normal GCCs improves the capacity of PCOS oocytes to enter meiosis, which may result in the promotion of assisted reproduction techniques. Key words: PCOS, Co-culture, Granulosa-cumulus cells, IVM, Cx43.