Zygote Formation Research Articles

Genomic Innovation in Early Life Cardiovascular Disease Prevention and Treatment.

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality globally. Although CVD events do not typically manifest until older adulthood, CVD develops gradually across the life-course, beginning with the elevation of risk factors observed as early as childhood or adolescence and the emergence of subclinical disease that can occur in young adulthood or midlife. Genomic background, which is determined at zygote formation, is among the earliest risk factors for CVD. With major advances in molecular technology, including the emergence of gene-editing techniques, along with deep whole-genome sequencing and high-throughput array-based genotyping, scientists now have the opportunity to not only discover genomic mechanisms underlying CVD but use this knowledge for the life-course prevention and treatment of these conditions. The current review focuses on innovations in the field of genomics and their applications to monogenic and polygenic CVD prevention and treatment. With respect to monogenic CVD, we discuss how the emergence of whole-genome sequencing technology has accelerated the discovery of disease-causing variants, allowing comprehensive screening and early, aggressive CVD mitigation strategies in patients and their families. We further describe advances in gene editing technology, which might soon make possible cures for CVD conditions once thought untreatable. In relation to polygenic CVD, we focus on recent innovations that leverage findings of genome-wide association studies to identify druggable gene targets and develop predictive genomic models of disease, which are already facilitating breakthroughs in the life-course treatment and prevention of CVD. Gaps in current research and future directions of genomics studies are also discussed. In aggregate, we hope to underline the value of leveraging genomics and broader multiomics information for characterizing CVD conditions, work which promises to expand precision approaches for the life-course prevention and treatment of CVD.

Development's Inaugural Outstanding Paper Prize.

Development's Inaugural Outstanding Paper Prize.

Significance of Complement Regulatory Protein Tetraspanins in the Male Reproductive System and Fertilization.

Fertilization is a very sophisticated and unique process involving several key steps resulting in a zygote's formation. Recent research has indicated that some immune system-related cell surface molecules (CD molecules from the tetraspanin superfamily) may have a role in fertilization. Extracellular vesicles are undeniably involved in a variety of cellular functions, including reproduction. Tetraspanin proteins identified in extracellular vesicles are now used mostly as markers; mounting evidence indicates that they also participate in cell targeting, cargo selection, and extracellular vesicle formation. Their significance and potential in mammalian reproduction are currently being studied extensively. Despite the fact that the current data did not establish any theory, the crucial function of tetraspanins in the fertilization process was not ruled out, and the specific role of tetraspanins is still unknown. In this review, we bring insight into the existing knowledge regarding the expression of tetraspanins in spermatozoa and seminal fluid and their role in gamete binding and fusion.

Male fertility in Pyricularia oryzae: Microconidia are spermatia.

Sexual reproduction in Ascomycetes is well described in several model organisms such as Neurospora crassa or Podospora anserina. Deciphering the biological process of sexual reproduction (from the recognition between compatible partners to the formation of zygote) can be a major advantage to better control sexually reproducing pathogenic fungi. In Pyricularia oryzae, the fungal pathogen causing blast diseases on several Poaceae species, the biology of sexual reproduction remains poorly documented. Besides the well-documented production of asexual macroconidia, the production of microconidia was seldom reported in P. oryzae, and their role as male gamete (i.e., spermatia) and in male fertility has never been explored. Here, we characterised the morphological features of microconidia and demonstrated that they are bona fide spermatia. Contrary to macroconidia, microconidia are not able to germinate and seem to be the only male gametes in P. oryzae. We show that fruiting body (perithecium) formation requires microconidia to get in contact with mycelium of strains of opposite mating type, to presumably fertilise the female gametes.

Successful heterozygous blastocyst formation of a 0PN zygote after ICSI - a case report

Background and Aim: Normal fertilisation is confirmed after the observation of a second polar body (PB) and two pronuclei (2PN). Zygotes that show no signs of pronuclei or second PB extrusion are usually considered unfertilised and discarded as they lack developmental potential and/or are at high risk of chromosomal aberrations due to potential parthenogenetic activation. Time-lapse culture systems have allowed embryologists to witness the successful formation of blastocysts from apronuclear zygotes; such embryos could potentially be considered for preimplantation genetic testing for aneuploidy (PGT-A).

Flower Type Affects the Timing of Embryo Development in Native Primula Vulgaris

In this study, pin and thrum flowered wild primrose (Primula vulgaris= Syn: Primula acaulis) populations, which are naturally distributed in Black Sea Region in Türkiye, were cultivated and their pollen viability, pollen tube growth and embryo development stages were investigated. As a result of the study, pollen viability in pollen of the pin flower type was 83.10%, while the in vitro germination rate was 69.43%. The viability and in vitro germination rates of pollen of thrum flower type were 84.91% and 67.92%, respectively. As a result of the squash preparation examinations, it was observed that the pollen tubes of both types started to germinate on the stigma on the 1 DAP (Day after pollination). On 4 DAP, it was determined that pollen tubes penetrated to the ovule. Embryo developmental stages examinations showed that, zygote formation occurred on 6 DAP in the pin flower type; while on the 20 DAP, the embryo was in the heart stage and finally on the 40 DAP, it was seen that it formed a mature cotyledonary stage embryo. Endosperm in the thrum type started to develop faster than the pin type and formed on the 6 and 7 DAP. In the thrum flower type, the proembryo formed on 10 DAP, but embryo formation could only be seen on 30 DAP. In the ovary examinations performed on the 40 DAP, some embryos were in the cotyledon stage while some were still in the globular or heart stage. It was also determined that no embryos were found in some ovules.

Monoclonal antibodies for reducing malaria transmission

In 2020, 241 million malaria cases and 627 000 deaths were reported globally by WHO, 95% of which occurred in sub-Saharan Africa. 1 WHOWorld malaria report 2021. World Health Organization, Geneva2021 Google Scholar The maintenance of the malaria parasite within humans is reliant on the transmission of the gametocyte stage from infected humans to female Anopheles vectors during blood feeding. Gametocytes develop in humans through formation and maturation in five morphologically recognisable stages. 2 Bousema T Drakeley C Determinants of malaria transmission at the population level. Cold Spring Harb Perspect Med. 2017; 7a025510 Crossref PubMed Scopus (21) Google Scholar Early-stage gametocytes are sequestered and only mature stage V gametocytes circulate in peripheral blood. Once ingested by mosquitoes, the fusion of gametes results in the formation of zygotes that develops further into motile ookinetes and oocysts. The oocysts release sporozoites that render the mosquito infectious. To date, no effective broad treatments or preventative immune-based interventions are available to interrupt malaria transmission. Safety, tolerability, and Plasmodium falciparum transmission-reducing activity of monoclonal antibody TB31F: a single-centre, open-label, first-in-human, dose-escalation, phase 1 trial in healthy malaria-naive adultsTB31F is a well tolerated and highly potent monoclonal antibody capable of completely blocking transmission of P falciparum parasites from humans to mosquitoes. In areas of seasonal transmission, a single dose might cover an entire malaria season. Full-Text PDF Open Access

Effects of photoperiod and temperature on ecophysiological responses of Ericaria barbatula (Phaeophyceae): a long-term study

Abstract The photoperiod alone or in combination with temperature may affect macroalgal growth, reproduction, and development. This study aimed to investigate the responses of Ericaria barbatula, a perennial fucalean species collected from Kavala Gulf, Greece, to photoperiod and temperature. Maximum quantum yield (F v /F m ), wet biomass (g), relative growth rate (day−1), and reproduction (receptacles and zygote formation) were monitored in two laboratory experiments, the first one in two consecutive phases (A and B), that lasted at least seven months. While in Experiment 1, phase A, specimens were cultivated under long-day (LD) and short-day (SD) conditions at a constant temperature, in Experiment 1, phase B, they were cultivated at a seasonally changing temperature. The results indicated that E. barbatula reproduced in both phases under SD conditions and grew better in winter to early spring under seasonally changing temperatures. The cultivation under night-break (NB) daylength and seasonally changing temperatures (Experiment 2) indicated that E. barbatula is a facultative (quantitative) SD plant, a result that needs further examination. However, the induction of reproductive organs under SD conditions has been confirmed. It secures the release of zygotes and the germlings’ growth in the field from April to June/July under non-stressful Mediterranean Sea temperatures.

Rapid Selective Proliferation of Mitochondria during Zygote Maturation in the Uniparental Inheritance of <i>Physarum polycephalum</i>

Mitochondrial DNA (mtDNA) is uniparentally inherited in most sexual eukaryotes called maternal/uniparental inheritance. It is well known that selective elimination of paternal mitochondria and digestion of paternal mtDNA are important to this process. However, little is known about the control of maternal mitochondrial proliferation. In the isogamous Physarum polycephalum, haploid myxamoebae act as gametes. When two myxamoebal strains with different mating types are mated, mtDNA is inherited from only one strain, defined as the maternal strain. Here, we developed a method to distinguish uniparental mitochondria in zygotes of P. polycephalum by chemical staining and investigated the proliferation of maternal and paternal mitochondria during the selective digestion of mitochondrial nucleoids (mt-nucleoids) in paternal mitochondria. We stained the myxamoebae with MitoTracker Red CMXRos (MTR) or MitoTracker Green FM (MTG). MTG-stained mitochondria more specifically than MTR. When the AI35 strain was crossed with the MTG-stained DP246 strain and mtDNA was stained with N-aryl pyrido cyanine 3, mt-nucleoids in mitochondria derived from DP246 became shorter in the zygotes 3 h after crossing. There was no significant difference in the number of mitochondria derived from both AI35 and DP246 in early zygotes, but the number of mitochondria derived from AI35 proliferated 1.7-fold from 3 to 5 h after crossing. Similar results were obtained when MTG-stained AI35 crossed with DP246. These results indicate that the proliferation of mitochondria derived from AI35 rapidly occurred after the initiation of digestion of mt-nucleoids derived from DP246. Our results suggest the possibility of controlling the mechanism of the selective proliferation of maternal mitochondria during zygote formation for uniparental inheritance.

Calcium Ionophore Supplementation in In vitro Fertilization Medium towards Fertilization Rates of Kacang Goats (Capra hircus)

In vitro fertilization is assisted reproduction technology that can overcome infertility problems. This method can produce embryos with high quality in large quantities. In its application, the success rate of IVF is still relatively low. This is due to the poor quality of oocytes and spermatozoa, which can cause IVF failure. The absence of oocyte activation during fertilization also results in failure of fertilization. Calcium ionophore is known to be able to increase the oocyte activation process. This study aims to prove that Calcium Ionophore can increase the rate of fertilization in goat oocytes in vitro. This study was divided into two groups: the control group was fertilized oocytes using a medium without Calcium ionophore supplementation, the treatment group was fertilized oocytes using a medium supplemented with Calcium ionophore at a dose of 5.2 µl/ml. Fertilization rates are observed based on the formation of zygote or two pronuclear (2PN) in the cytoplasm of oocytes and observed under an inverted microscope. The data obtained were analyzed using the T test. The results of the study after being analyzed statistically showed that there were significant differences between the control group and the treatment group (P<0.05). Fertilization rates in the treatment group (93.12±13.7) showed higher results than the control group (65.96±28.36). Based on these results it can be concluded that calcium ionophore supplementation at a dose of 5.2 µl/ml in the fertilization medium can increase oocyte activation thereby increasing the rate of oocyte fertilization of the goat nuts.

Characterization of PSOP26 as an ookinete surface antigen with improved transmission-blocking activity when fused with PSOP25

BackgroundThe Plasmodium zygote-to-ookinete developmental transition is an essential step for establishing an infection in the mosquito vector, and antigens expressed during this stage are potential targets for transmission-blocking vaccines (TBVs). The secreted ookinete protein 26 (PSOP26) is a newly identified ookinete surface protein. The anti-PSOP26 serum has moderate transmission-blocking activity, indicating the benefit of further investigating this protein as a target for TBVs.MethodsThe function of psop26 was analyzed by targeted gene disruption. A chimeric PSOP25-PSOP26 protein was expressed in the Escherichia coli system. The PSOP25-PSOP26 fusion protein, along with mixed (PSOP25 + PSOP26) or single proteins (PSOP26 or PSOP25), were used for the immunization of mice. The antibody titers and immunogenicity of individual sera were analyzed by enzyme-linked immunoassay (ELISA), indirect immunofluorescence assay (IFA), and Western blot. The transmission-blocking activity of sera from different immunization schemes was assessed using in vitro and in vivo assays.ResultsPSOP26 is a surface protein expressed in Plasmodium gametes and ookinetes. The protein is dispensable for asexual blood-stage development, gametogenesis, and zygote formation, but is essential for the zygote-to-ookinete developmental transition. Specifically, both the prevalence of infections and oocyst densities were decreased in mosquitoes fed on psop26-null mutants. Mixtures of individual PSOP25 and PSOP26 fragments (PSOP25 + PSOP26), as well as chimeras (PSOP25-PSOP26), elicited high antibody levels in mice, with no immunological interference. Antisera against the mixed and fusion proteins elicited higher transmission-reducing activity (TRA) than antisera against the single PSOP26 antigen, but comparable to antisera against PSOP25 antigen alone.ConclusionsPSOP26 plays a critical role in the zygote-to-ookinete developmental transition. PSOP25 is a promising TBV candidate that could be used alone to target the ookinete stage.

How does maternal age affect genomic stability in the offspring?

In high‐income countries, women tend to give birth at increasingly advanced ages. Despite its physiological, developmental, and medical consequences, why this tendency significantly affects genetic stability of the offspring remains largely unresolved. Accumulating evidence indicates that the higher the age of the mother at fertilization, the more intense the activity of transposable elements causing insertional mutations in functional DNA stretches in her oocyte involved in zygote formation.

Pheromone Guidance of Polarity Site Movement in Yeast.

Cells’ ability to track chemical gradients is integral to many biological phenomena, including fertilization, development, accessing nutrients, and combating infection. Mating of the yeast Saccharomyces cerevisiae provides a tractable model to understand how cells interpret the spatial information in chemical gradients. Mating yeast of the two different mating types secrete distinct peptide pheromones, called a-factor and α-factor, to communicate with potential partners. Spatial gradients of pheromones are decoded to guide mobile polarity sites so that polarity sites in mating partners align towards each other, as a prerequisite for cell-cell fusion and zygote formation. In ascomycetes including S. cerevisiae, one pheromone is prenylated (a-factor) while the other is not (α-factor). The difference in physical properties between the pheromones, combined with associated differences in mechanisms of secretion and extracellular pheromone metabolism, suggested that the pheromones might differ in the spatial information that they convey to potential mating partners. However, as mating appears to be isogamous in this species, it is not clear why any such signaling difference would be advantageous. Here we report assays that directly track movement of the polarity site in each partner as a way to understand the spatial information conveyed by each pheromone. Our findings suggest that both pheromones convey very similar information. We speculate that the different pheromones were advantageous in ancestral species with asymmetric mating systems and may represent an evolutionary vestige in yeasts that mate isogamously.

Elhik’s Metamathematics and the robot Philia: Internet Communication Protocol Modelling of Observeds according to Observers

Like all robot and IoT oriented mathematical studies this study is also transdisciplinary however most of the study remains in the field of mathematics and philosophy of mathematics due to the aim of mathematical modelling of the observations: a) protein synthesis by the information encoded in DNA and b) communication protocols of hacking software with encryption of IP of computers c) the process of DNA duplication to offspring formation in asexual and sexual reproduction. The ultimate mathematical aim of this study is providing a metamathematical approach for different types of mathematics to be utilized in information sciences by forced or free choice of artificial intelligence driven technological beings and computational systems. This study is biomathematically inspired from protein synthesis, cellular reproduction, DNA duplication, bacterial simple cell division, bacterial sex and zygote formation in human and mammalian fertilization; and all are modelled as moving pieces of quantized information. The ultimate robotic aim is finding an algorithm for data off-springs, thus the formation of the data-offspring in the form of living being off-springs’ DNA is chosen to be mathematically described. For this purpose, a new mathematics with new mathematical operations and a definition to mathematics are postulated, together with twelve postulations about the real-life observations. The introduced Aydan operation is synthesizing fuzzy logic based mathematical existence possibilities into abstract formal logic based abstract mathematical categories to be analyzed with additional color codes for each object, whereas deAydan operation is doing the opposite by analyzing a given synthesis. There is a coexistence of mathematical objects and operators in the biological cells. The co-existence of objects and mathematical operations in a given mathematics M, are axiomatically chosen to be a satisfiability rule for M to be accepted as mathematics in the form of a universal set isolated from other universal sets. Aydan function can be used for hacking other AI by deviating its results by merging them with forced formal logic based analytic input by another hacking software, and deAydan function can be used as anti-hack in the opposite direction. The metamathematical existence degree of a given mathematics is shown to be between zero and infinite dimensions. ELHIK is an abbreviation of the words El Harizmi and Immanuel Kant.

Plasmodium falciparum Cysteine Rich Secretory Protein uniquely localizes to one end of male gametes

Fertilization is a central event during the life cycle of most eukaryotic organisms and involves gamete recognition and fusion, ultimately resulting in zygote formation. Gamete fertilization in the malaria-causing Plasmodium parasites occurs inside the mosquito midgut and represents a major bottleneck in the life cycle. Cysteine Rich Secretory Proteins (CRISPs) are key molecules involved in fertilization in vertebrates and the presence of a CRISP ortholog in human malaria infective Plasmodium falciparum suggested a possible role in fertilization. Strikingly, P. falciparum CRISP exhibited a unique terminal localization in the male microgamete. Parasites with a CRISP gene deletion (P. falciparum crisp−) proliferated asexually similar to wildtype NF54 parasites and differentiated into gametocytes. Further analysis showed that Plasmodium falciparum crisp− gametocytes underwent exflagellation to form male gametes and no apparent defect in transmission to the mosquito vector was observed. These data show that P. falciparum CRISP is a marker for the apical end of the microgamete and that it might only have an ancillary or redundant function in the male sexual stages.

Three classes of epigenomic regulators converge to hyperactivate the essential maternal gene deadhead within a heterochromatin mini-domain

The formation of a diploid zygote is a highly complex cellular process that is entirely controlled by maternal gene products stored in the egg cytoplasm. This highly specialized transcriptional program is tightly controlled at the chromatin level in the female germline. As an extreme case in point, the massive and specific ovarian expression of the essential thioredoxin Deadhead (DHD) is critically regulated in Drosophila by the histone demethylase Lid and its partner, the histone deacetylase complex Sin3A/Rpd3, via yet unknown mechanisms. Here, we identified Snr1 and Mod(mdg4) as essential for dhd expression and investigated how these epigenomic effectors act with Lid and Sin3A to hyperactivate dhd. Using Cut&Run chromatin profiling with a dedicated data analysis procedure, we found that dhd is intriguingly embedded in an H3K27me3/H3K9me3-enriched mini-domain flanked by DNA regulatory elements, including a dhd promoter-proximal element essential for its expression. Surprisingly, Lid, Sin3a, Snr1 and Mod(mdg4) impact H3K27me3 and this regulatory element in distinct manners. However, we show that these effectors activate dhd independently of H3K27me3/H3K9me3, and that dhd remains silent in the absence of these marks. Together, our study demonstrates an atypical and critical role for chromatin regulators Lid, Sin3A, Snr1 and Mod(mdg4) to trigger tissue-specific hyperactivation within a unique heterochromatin mini-domain.

Human embryonic development: from peri-implantation to gastrulation.

The basic body plan of the mammalian embryo is established through gastrulation, a pivotal early postimplantation event during which the three major germ layers (endoderm, ectoderm, and mesoderm) are specified with cellular and spatial diversity. Despite its basic and clinical importance, human embryo development from peri-implantation to gastrulation remains shrouded in mystery. Recent advances in the elongated in vitro culture of rodent and non-primate embryos and the construction of embryo-like structures have helped to improve understanding of the mechanisms of human early embryonic development. Here, we review the recent advances and possible future directions in the development of in vitro models to better understand human embryogenesis from peri-implantation to gastrulation.

The Association of Oxidative Stress and Reactive Oxygen Species Modulator 1 (ROMO1) with Infertility: A Mini Review.

Infertility is one of the disorders that worries many couples around the world, although novel and molecular methods can be used to cure this disease in different stages. One of the factors that causes infertility in men and women is the increased oxidative stress within the cells, which can lead to damage in zygote formation. ROMO1 is one of the most important proteins in the production of reactive oxygen species. This protein can enhance oxidative stress in the cells and body through cellular pathways, such as TNF-α and NF-κB routes, which will eventually lead to many diseases, especially infertility. We engage several international databases by using keywords; ROMO1, Infertility, and Reactive Oxygen Species, and gained a great quantity of information about ROMO1, Infertility, and Oxidative Stress. Although not proven, it is hypothesized that ROMO1 might elevate oxidative stress by activating NF-κB pathway in the cells, furthermore, TNF-α can arouse ROMO1 that can end up with apoptosis and cell death, which consequently can have a lot of disturbing effects on the body, especially the reproductive system. To sum up, revealing the exact cellular and molecular mechanisms of ROMO1-dependent TNF-α and NF-κB pathways in the pathogenesis of infertility might find interesting therapeutic and management strategies for this disorder.

Resetting of the 24-nt siRNA landscape in rice zygotes.

The zygote, a totipotent stem cell, is crucial to the life cycle of sexually reproducing organisms. It is produced by the fusion of two differentiated cells—the egg and sperm, which in plants have radically different siRNA transcriptomes from each other and from multicellular embryos. Owing to technical challenges, the epigenetic changes that accompany the transition from differentiated gametes to totipotent zygote are poorly understood. Because siRNAs serve as both regulators and outputs of the epigenome, we characterized small RNA transcriptomes of zygotes from rice. Zygote small RNAs exhibit extensive maternal carryover and an apparent lack of paternal contribution, indicated by absence of sperm signature siRNAs. Zygote formation is accompanied by widespread redistribution of 24-nt siRNAs relative to gametes, such that ∼70% of the zygote siRNA loci do not overlap any egg cell siRNA loci. Newly detected siRNA loci in zygote are gene-proximal and not associated with centromeric heterochromatin, similar to canonical siRNAs, in sharp contrast to gametic siRNA loci that are gene-distal and heterochromatic. In addition, zygote but not egg siRNA loci are associated with high DNA methylation in the mature embryo. Thus, the zygote begins transitioning before the first embryonic division to an siRNA profile that is associated with future RdDM in embryogenesis. These findings indicate that, in addition to changes in gene expression, the transition to totipotency in the plant zygote is accompanied by resetting of the epigenetic reprogramming that occurred during gamete formation.

Identification and Analysis of Genes Involved in Double Fertilization in Rice.

Double fertilization is a key determinant of grain yield, and the failure of fertilization during hybridization is one important reason for reproductive isolation. Therefore, fertilization has a very important role in the production of high-yield and well-quality hybrid of rice. Here, we used RNA sequencing technology to study the change of the transcriptome during double fertilization with the help of the mutant fertilization barrier (feb) that failed to finish fertilization process and led to seed abortion. The results showed that 1669 genes were related to the guided growth of pollen tubes, 332 genes were involved in the recognition and fusion of the male–female gametes, and 430 genes were associated with zygote formation and early free endosperm nuclear division. Among them, the genes related to carbohydrate metabolism; signal transduction pathways were enriched in the guided growth of pollen tubes, the genes involved in the photosynthesis; fatty acid synthesis pathways were activated by the recognition and fusion of the male–female gametes; and the cell cycle-related genes might play an essential role in zygote formation and early endosperm nuclear division. Furthermore, among the 1669 pollen tube-related genes, it was found that 7 arabinogalactan proteins (AGPs), 1 cysteine-rich peptide (CRP), and 15 receptor-like kinases (RLKs) were specifically expressed in anther, while 2 AGPs, 7 CRPs, and 5 RLKs in pistil, showing obvious unequal distribution which implied they might play different roles in anther and pistil during fertilization. These studies laid a solid foundation for revealing double fertilization mechanism of rice and for the follow-up investigation.