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Frontiers in Cell and Developmental... 2024Control mechanisms of spindle assembly and chromosome segregation are vital for preventing aneuploidy during cell division. The mammalian germ cells and embryos are...
Control mechanisms of spindle assembly and chromosome segregation are vital for preventing aneuploidy during cell division. The mammalian germ cells and embryos are prone to chromosome segregation errors, and the resulting aneuploidy is a major cause of termination of development or severe developmental disorders. Here we focused on early mouse embryos, and using combination of methods involving microinjection, immunodetection and confocal live cell imaging, we concentrated on the Spindle Assembly Checkpoint (SAC) and Anaphase Promoting Complex/Cyclosome (APC/C). These are two important mechanisms cooperating during mitosis to ensure accurate chromosome segregation, and assessed their activity during the first two mitoses after fertilization. Our results showed, that in zygotes and 2-cell embryos, the SAC core protein Mad1 shows very low levels on kinetochores in comparison to oocytes and its interaction with chromosomes is restricted to a short time interval after nuclear membrane disassembly (NEBD). Exposure of 2-cell embryos to low levels of spindle poison does not prevent anaphase, despite the spindle damage induced by the drug. Lastly, the APC/C is activated coincidentally with NEBD before the spindle assembly completion. This early onset of APC/C activity, together with precocious relocalization of Mad1 from chromosomes, prevents proper surveillance of spindle assembly by SAC. The results contribute to the understanding of the origin of aneuploidy in early embryos.
PubMed: 38544818
DOI: 10.3389/fcell.2024.1355979 -
Genes Feb 2024The glossiphoniid leech, , is an experimentally tractable member of the superphylum, Lophotrochozoa. Its large embryonic cells, stereotyped asymmetric cell divisions and...
The glossiphoniid leech, , is an experimentally tractable member of the superphylum, Lophotrochozoa. Its large embryonic cells, stereotyped asymmetric cell divisions and ex vivo development capabilities makes it a favorable model for studying the molecular and cellular events of a representative spiralian. In this study, we focused on a narrow developmental time window of ~6-8 h, comprising stages just prior to and immediately following zygote deposition. Employing RNA-Seq methodology, we identified differentially expressed transcripts at this fundamental ontogenic boundary, known as the maternal-to-zygotic transition (MZT). Gene expression changes were characterized by the massive degradation of maternal RNAs (~45%) coupled with the rapid transcription of ~5000 zygotic genes (~20% of the genome) in the first mitotic cell cycle. The latter transcripts encoded a mixture of cell maintenance and regulatory proteins that predictably influence downstream developmental events.
Topics: Zygote; Cell Division; Transcription Factors; Genome; Gene Expression Profiling
PubMed: 38540342
DOI: 10.3390/genes15030283 -
Genomics May 2024The CRISPR/Cas9 system can induce off-target effects in programmed gene editing, but there have been few reports on cleavage detection and their affection in embryo...
The CRISPR/Cas9 system can induce off-target effects in programmed gene editing, but there have been few reports on cleavage detection and their affection in embryo development. To study these events, sgRNAs with different off-target rates were designed and compared after micro-injected into mouse zygotes, and γH2AX was used for DNA cleavage sites analysis by immunostaining and CUT&Tag. Although the low off-target sgRNA were usually selected for production gene editing animals, γH2AX immunofluorescence indicated that there was a relative DSB peak at 15 h after Cas9 system injection, and the number of γH2AX foci at the peak was significantly higher in the low off-target sgRNA-injected group than in the control group. Further, the result of CUT&Tag sequencing analysis showed more double-strand breaks (DSBs) related sequences were detected in low off-target sgRNA-injected group than control and the distribution of DSB related sequences had no chromosome specificity. Gene Ontology (GO) annotation analysis of the DSB related sequences showed that these sequences were mainly concentrated at genes associated with some important biological processes, molecular functions, and cell components. In a conclusion, there are many sgRNA-sequence-independent DSBs in early mouse embryos when the Cas9 system is used for gene editing and the DSB related sequence could be detected and characterized in the genome. These results and method should also be considered in using or optimizing the Cas9 system.
Topics: Animals; Mice; CRISPR-Cas Systems; Embryo, Mammalian; DNA Breaks, Double-Stranded; Gene Editing; RNA, Guide, CRISPR-Cas Systems; DNA Cleavage; Zygote; Histones; Female
PubMed: 38537809
DOI: 10.1016/j.ygeno.2024.110836 -
Memorias Do Instituto Oswaldo Cruz 2024Malaria is an infectious disease caused by protozoan parasites belonging to the genus Plasmodium. Human-to-human transmission depends on a mosquito vector; thus, the...
BACKGROUND
Malaria is an infectious disease caused by protozoan parasites belonging to the genus Plasmodium. Human-to-human transmission depends on a mosquito vector; thus, the interruption of parasite transmission from humans to mosquitoes is an important approach in the fight against malaria. The parasite stages infectious to mosquitoes are the gametocytes, sexual stages that are ingested by the vector during a blood meal and transform into male and female gametes in the midgut. Immunity against sexual stage antigens expressed by gametocytes, gametes, and the zygote formed after fertilisation can interrupt the parasite sexual cycle in the mosquito. This transmission blocking immunity is mediated by specific antibodies ingested during the mosquito blood feed, inhibiting the parasite development in the midgut. Merozoite thrombospondin related anonymous protein (MTRAP) is a merozoite and gametocyte surface protein essential for gamete egress from erythrocytes and for parasite transmission to mosquitoes.
OBJECTIVES
Here, we evaluated the potential of the P. berghei MTRAP to elicit antibodies with the ability to inhibit gamete fertilisation in vitro.
METHODS
We expressed a soluble recombinant PbMTRAP and used it to immunise BALB/c mice. The transmission blocking activity of the anti-rPbMTRAP antibodies was tested through in vivo challenge experiments followed by in vitro conversion assays.
FINDINGS
Immunisations with the rPbMTRAP induced a strong antibody response and the antibodies recognised the native protein by Western Blot and IFA. Anti-rPbMTRAP present in the blood stream of immunised mice partially inhibited gamete conversion into ookinetes.
CONCLUSION
Our results indicate that antibodies to PbMTRAP may reduce but are not sufficient to completely block transmission.
Topics: Male; Female; Humans; Animals; Mice; Protozoan Proteins; Plasmodium berghei; Merozoites; Malaria; Culicidae
PubMed: 38537036
DOI: 10.1590/0074-02760230217 -
Frontiers in Endocrinology 2024This study aims to evaluate the developmental potential of 0PN, 1PN, and 2PN zygotes in IVF cycles and compare their clinical outcomes.
PURPOSE
This study aims to evaluate the developmental potential of 0PN, 1PN, and 2PN zygotes in IVF cycles and compare their clinical outcomes.
METHODS
We conducted a retrospective cohort study involving IVF patients. Blastocyst formation rates were assessed with 0PN, 1PN, and 2PN zygotes. Subsequently, we collected clinical outcome data following the transfer of these zygotes.
RESULTS
The overall blastulation rate was similar between 0PN (29.6%) and 2PN (32.1%) zygotes, but 1PN zygotes exhibited a significantly lower blastulation rate (17.0%) compared to both 0PN and 2PN zygotes. Similarly, the overall rate of good-quality blastulation was comparable between 0PN (15.3%) and 2PN (17.5%) zygotes, while 1PN zygotes showed a significantly lower rate (7.0%) compared to both 0PN and 2PN. Clinical pregnancy, ectopic pregnancy, implantation, and live birth rates were similar among single blastocyst frozen embryo transfers (FET) of 0PN, 1PN, and 2PN. Additionally, no significant differences were observed between single- and double-blastocyst FET of 0PN and 2PN.
CONCLUSIONS
Our findings suggest that 0PN and 2PN zygotes have comparable developmental potential, while 1PN embryos exhibit lower developmental potential. Blastocyst FET outcomes appear similar among 0PN, 1PN, and 2PN zygotes.
Topics: Pregnancy; Female; Humans; Zygote; Fertilization in Vitro; Retrospective Studies; Embryo Transfer; Embryonic Development
PubMed: 38532894
DOI: 10.3389/fendo.2024.1361734 -
Clinical and Experimental Reproductive... Mar 2024This study compared the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in patients with polycystic ovarian syndrome...
Comparative analysis of conventional in vitro fertilization and intracytoplasmic sperm injection in patients with polycystic ovarian syndrome, tubal factor infertility, and unexplained infertility whose partners exhibit normal semen parameters: a retrospective study of sibling oocytes.
OBJECTIVE
This study compared the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in patients with polycystic ovarian syndrome (PCOS), tubal factor (TF) infertility, and unexplained infertility whose partners had normal semen parameters.
METHODS
This retrospective study included 360 couples diagnosed with infertility involving PCOS (n=157), unexplained infertility (n=140), and TF infertility (n=63). Sibling oocytes were randomly assigned to undergo ICSI or conventional IVF insemination. The fertilization rate and embryo morphology were evaluated as outcomes.
RESULTS
Retrieved cumulus-oocyte complexes from patients with PCOS (2,974), unexplained infertility (1,843), and TF infertility (844) were split and inseminated by conventional IVF and ICSI respectively. In comparison to the ICSI method, the conventional IVF approach was linked to a significantly higher fertilization rate in groups with PCOS (68.81% vs. 77.49%), unexplained infertility (67.62% vs. 78.84%), and TF issues (69.23% vs. 78.63%) (p<0.05). The proportion of embryos with grade A produced by the conventional IVF method was significantly higher than that produced using the ICSI method in the PCOS and unexplained infertility groups (p<0.05). Additionally, the percentage of grade B embryos produced with the ICSI method was significantly higher than that produced with the conventional IVF method in PCOS patients (p=0.002).
CONCLUSION
Our results indicated that the conventional IVF method was associated with higher zygote production and a higher proportion of grade A embryos when all infertile groups were evaluated together. Thus, ICSI is not suggested for patients with these causes of infertility if their partner has normal semen parameters.
PubMed: 38525518
DOI: 10.5653/cerm.2023.06408 -
Biological Research Mar 2024Extracellular vesicles (EVs) and their cargoes, including MicroRNAs (miRNAs) play a crucial role in cell-to-cell communication. We previously demonstrated the...
BACKGROUND
Extracellular vesicles (EVs) and their cargoes, including MicroRNAs (miRNAs) play a crucial role in cell-to-cell communication. We previously demonstrated the upregulation of bta-mir-148b in EVs from oviductal fluid of cyclic cows. This miRNA is linked to the TGF-β pathway in the cell proliferation. Our aim was to verify whether miR-148b is taken up by embryos through gymnosis, validate its target genes, and investigate the effect of miR-148b supplementation on early embryo development and quality.
METHODS
Zygotes were cultured in SOF + 0.3% BSA (Control) or supplemented with: 1 µM miR-148b mimics during: D1-D7 (miR148b) or D1-D4 (miR148b-OV: representing miRNA effect in the oviduct) or D4-D7 (miR148b-UT: representing miRNA effect in the uterus) or 1 µM control mimics was used during: D1-D7 (CMimic). Embryos at ≥ 16-cells and D7 blastocysts (BD7) were collected to examine the mRNA abundance of transcripts linked to the TGF-β pathway (TGFBR2, SMAD1, SMAD2, SMAD3, SMAD5, BMPR2, RPS6KB1, POU5F1, NANOG), total cell number (TC), trophectoderm (TE), and inner cell mass (ICM) were also evaluated. One-way ANOVA was used for all analyses.
RESULTS
We demonstrated that miR-148b can be taken up in both 16-cell embryos and BD7 by gymnosis, and we observed a decrease in SMAD5 mRNA, suggesting it's a potential target of miR-148b. Cleavage and blastocysts rates were not affected in any groups; however, supplementation of miR-148b mimics had a positive effect on TC, TE and ICM, with values of 136.4 ± 1.6, 92.5 ± 0.9, 43.9 ± 1.3 for miR148b and 135.3 ± 1.5, 92.6 ± 1.2, 42.7 ± 0.8, for miR148b-OV group. Furthermore, mRNA transcripts of SMAD1 and SMAD5 were decreased (P ≤ 0.001) in 16-cell embryos and BD7 from miR148b and miR148b-OV groups, while POU5F1 and NANOG were upregulated (P ≤ 0.001) in BD7 and TGFBR2 was only downregulated in 16-cell embryos. pSMAD1/5 levels were higher in the miR148b and miR148b-OV groups.
CONCLUSIONS
Our findings suggest that supplementation of bta-miR-148b mimics during the entire culture period (D1 - D7) or from D1 - D4 improves embryo quality and influences the TGF-β signaling pathway by altering the transcription of genes associated with cellular differentiation and proliferation. This highlights the importance of miR-148b on embryo quality and development.
Topics: Humans; Female; Cattle; Animals; Transforming Growth Factor beta; Receptor, Transforming Growth Factor-beta Type II; MicroRNAs; Oviducts; Extracellular Vesicles; RNA, Messenger
PubMed: 38520036
DOI: 10.1186/s40659-024-00488-z -
Scientific Reports Mar 2024Hydatidiform moles are abnormal conceptuses. Many hydatidiform moles are diploid androgenetic, and of these, most are homozygous in all loci. Additionally, most...
Hydatidiform moles are abnormal conceptuses. Many hydatidiform moles are diploid androgenetic, and of these, most are homozygous in all loci. Additionally, most hydatidiform moles are euploid. Using Single Nucleotide Polymorphism (SNP) array analysis, in two studies a higher frequency of aneuploidy was observed in diploid androgenetic heterozygous conceptuses, than in their homozygous counterparts. In the Danish Mole Project, we analyze conceptuses suspected to be hydatidiform moles due to the clinical presentation, using karyotyping and Short Tandem Repeat (STR) analysis. Among 278 diploid androgenetic conceptuses, 226 were homozygous in all loci and 52 (18.7%) were heterozygous in several loci. Among 142 triploid diandric conceptuses, 141 were heterozygous for paternally inherited alleles in several loci. Here we show that the frequencies of aneuploidy in diploid androgenetic heterozygous and triploid diandric heterozygous conceptuses were significantly higher than the frequency of aneuploidy in diploid androgenetic homozygous conceptuses. In diploid androgenetic and triploid diandric conceptuses that are heterozygous for paternally inherited alleles, the two paternally inherited sets of genomes originate in two spermatozoa. Each spermatozoon provides one pair of centrioles to the zygote. The presence of two pairs of centrioles may cause an increased risk of aneuploidy.
Topics: Male; Pregnancy; Female; Humans; Diploidy; Triploidy; Hydatidiform Mole; Heterozygote; Aneuploidy; Uterine Neoplasms
PubMed: 38519579
DOI: 10.1038/s41598-024-57465-5 -
Frontiers in Molecular Biosciences 2024Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are anchored at the outer phospholipid layer of eukaryotic plasma membranes exclusively by a glycolipid. GPI-APs...
Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are anchored at the outer phospholipid layer of eukaryotic plasma membranes exclusively by a glycolipid. GPI-APs are not only released into extracellular compartments by lipolytic cleavage. In addition, certain GPI-APs with the glycosylphosphatidylinositol anchor including their fatty acids remaining coupled to the carboxy-terminus of their protein components are also detectable in body fluids, in response to certain stimuli, such as oxidative stress, radicals or high-fat diet. As a consequence, the fatty acid moieties of GPI-APs must be shielded from access of the aqueous environment by incorporation into membranes of extracellular vesicles or into micelle-like complexes together with (lyso)phospholipids and cholesterol. The GPI-APs released from somatic cells and tissues are transferred via those complexes or EVs to somatic as well as pluripotent stem cells with metabolic consequences, such as upregulation of glycogen and lipid synthesis. From these and additional findings, the following hypotheses are developed: i) Transfer of GPI-APs via EVs or micelle-like complexes leads to the induction of new phenotypes in the daughter cells or zygotes, which are presumably not restricted to metabolism. ii) The membrane topographies transferred by the concerted action of GPI-APs and interacting components are replicated by self-organization and self-templation and remain accessible to structural changes by environmental factors. iii) Transfer from mother cells and gametes to their daughter cells and zygotes, respectively, is not restricted to DNA and genes, but also encompasses non-genetic matter, such as GPI-APs and specific membrane constituents. iv) The intergenerational transfer of membrane matter between mammalian organisms is understood as an epigenetic mechanism for phenotypic plasticity, which does not rely on modifications of DNA and histones, but is regarded as molecular mechanism for the inheritance of acquired traits, such as complex metabolic diseases. v) The missing interest in research of non-genetic matter of inheritance, which may be interpreted in the sense of Darwin's "Gemmules" or Galton's "Stirps", should be addressed in future investigations of the philosophy of science and sociology of media.
PubMed: 38516184
DOI: 10.3389/fmolb.2024.1347397 -
MicroPublication Biology 2024In the early stage of the nematode embryogenesis, the zygote divides asymmetrically into a symmetric fast lineage and an asymmetric slow lineage, producing 16 and 8...
In the early stage of the nematode embryogenesis, the zygote divides asymmetrically into a symmetric fast lineage and an asymmetric slow lineage, producing 16 and 8 cells respectively almost at the same time, followed by the onset of gastrulation. It was recently reported that this cell division pattern is optimal for rapid cell proliferation. In this work, we compare the cell lineages of 9 nematode species, revealing that this pattern is conserved for >60 million years. It further suggests that such lineage design has an important functional role and it might speed up embryonic development in the nematode kingdom, not limited to , and independent of the maternal-zygotic transition dynamics.
PubMed: 38505394
DOI: 10.17912/micropub.biology.001006