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Theriogenology Oct 2023Early cleavage (EC) influences the development of the pre-implantation and post-implantation embryo. Symmetric cleavage (Sym) and asymmetric cleavage (Asy) have been...
Early cleavage (EC) influences the development of the pre-implantation and post-implantation embryo. Symmetric cleavage (Sym) and asymmetric cleavage (Asy) have been observed in EC, but its molecular mechanism remains unclear. This study was designed to pick out the key candidate genes and signaling pathway between Sym and Asy embryos by applying Smart-seq2 technique. In in-vitro fertilization (IVF) 2-cell embryos, Sym embryos and Asy embryos accounted for 62.55% and 37.45%, respectively. The 2-cell rate, blastocyst rate and total blastocyst cells of Sym group were significantly higher than those of Asy group (31.38% vs 18.79%, 47.55% vs 29.5%, 71.33 vs 33.67, P < 0.05). The 2-cell rate, blastocyst rate and total blastocyst cell number in parthenogenetic activation (PA) embryos in Sym group were significantly higher than those in Asy group (40.61% vs 23.64%, 63.15% vs 30.11%, 50.75 vs 40.5, P < 0.05). A total of 216 differentially expressed genes (DEGs) incorporating 147 genes up-regulated and 69 genes down-regulated genes were screened under the p-value <0.05 and |log2 (fold change)| ≥ 1 when compared with Sym group. Further Gene Ontology (GO) analysis showed that these DEGs were related to the regulation of metabolic process, cell cycle, chromosome segregation, centromeric region and microtubule cytoskeleton. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEGs were mainly enriched to oocyte meiosis, cell cycle, p53 and Hippo signaling pathways. We concluded that asymmetric cleavage is a consequence of altered gene expression. Atg4c, Sesn2, Stk11ip, Slc25a6, Cep19 and Cep55 associated with mitochondrial function and cytoskeletal structure were probably the key candidate genesto determine the zygote cleavage pattern.
Topics: Animals; Swine; Embryonic Development; Parthenogenesis; Fertilization in Vitro; Embryo Implantation; Zygote; Blastocyst
PubMed: 37540954
DOI: 10.1016/j.theriogenology.2023.07.029 -
Genomics, Proteomics & Bioinformatics Oct 2023During mammalian preimplantation development, a totipotent zygote undergoes several cell cleavages and two rounds of cell fate determination, ultimately forming a mature... (Review)
Review
During mammalian preimplantation development, a totipotent zygote undergoes several cell cleavages and two rounds of cell fate determination, ultimately forming a mature blastocyst. Along with compaction, the establishment of apicobasal cell polarity breaks the symmetry of an embryo and guides subsequent cell fate choice. Although the lineage segregation of the inner cell mass (ICM) and trophectoderm (TE) is the first symbol of cell differentiation, several molecules have been shown to bias the early cell fate through their inter-cellular variations at much earlier stages, including the 2- and 4-cell stages. The underlying mechanisms of early cell fate determination have long been an important research topic. In this review, we summarize the molecular events that occur during early embryogenesis, as well as the current understanding of their regulatory roles in cell fate decisions. Moreover, as powerful tools for early embryogenesis research, single-cell omics techniques have been applied to both mouse and human preimplantation embryos and have contributed to the discovery of cell fate regulators. Here, we summarize their applications in the research of preimplantation embryos, and provide new insights and perspectives on cell fate regulation.
Topics: Humans; Animals; Mice; Cell Differentiation; Embryo, Mammalian; Blastocyst; Embryonic Development; Zygote; Cell Lineage; Gene Expression Regulation, Developmental; Mammals
PubMed: 37075831
DOI: 10.1016/j.gpb.2023.03.001 -
Poultry Science Aug 2023Cleanliness of eggs is critical in successful hatching egg operations. The objective of this study was to investigate the effect of trans-cinnamaldehyde nanoemulsion...
Cleanliness of eggs is critical in successful hatching egg operations. The objective of this study was to investigate the effect of trans-cinnamaldehyde nanoemulsion (TCNE) wash treatments, as a sanitation strategy, on embryonic development in fertilized eggs. Trans-cinnamaldehyde is a generally recognized as safe status phytochemical obtained from cinnamon bark. TCNE were prepared with emulsifiers Tween 80 (Tw.80) or gum Arabic and lecithin (GAL) by sonication. Day-old fertilized eggs were subjected to TCNE wash treatments at 34°C for 5 min, followed by 18 d of incubation at 37.7°C. Washing of fertilized eggs with TCNE-Tw.80 or GAL at 0.48% concentration did not significantly alter the egg weight at d 18 of incubation, as compared to baseline and control (P > 0.05). The egg weight loss (calculated as percentage) did not differ significantly between eggs subjected to nanoemulsion wash treatments and control eggs (P > 0.05). In case of embryo fertility and mortality, for baseline and control, ∼ 95% fertility rate was achieved, with combined early and midterm mortality at 16%. Likewise, TCNE-Tw.80 or TCNE-GAL resulted in 95% fertility (P > 0.05), with 11% and 17% combined early and midterm mortality, respectively. Furthermore, TCNE wash treatments did not differ significantly in yolk sac and embryo weight (as compared to control) and did not affect the length of the d 18 embryo (P > 0.05). Moreover, TCNE wash treatments did not alter tibia weight and length (P > 0.05). Results suggest that TCNE could potentially be used as a natural antimicrobial for fertilized egg sanitation. Further studies in industry settings are warranted.
Topics: Chick Embryo; Animals; Chickens; Zygote; Ovum; Embryonic Development; Lecithins; Eggs
PubMed: 37302329
DOI: 10.1016/j.psj.2023.102812 -
Frontiers in Plant Science 2023Transcription factors (TFs) are diverse groups of regulatory proteins. Through their specific binding domains, TFs bind to their target genes and regulate their... (Review)
Review
Transcription factors (TFs) are diverse groups of regulatory proteins. Through their specific binding domains, TFs bind to their target genes and regulate their expression, therefore TFs play important roles in various growth and developmental processes. Plant embryogenesis is a highly regulated and intricate process during which embryos arise from various sources and undergo development; it can be further divided into zygotic embryogenesis (ZE) and somatic embryogenesis (SE). TFs play a crucial role in the process of plant embryogenesis with a number of them acting as master regulators in both ZE and SE. In this review, we focus on the master TFs involved in embryogenesis such as BABY BOOM (BBM) from the APETALA2Ethylene-Responsive Factor (AP2/ERF) family, WUSCHEL and WUSCHEL-related homeobox (WOX) from the homeobox family, LEAFY COTYLEDON 2 (LEC2) from the B3 family, AGAMOUS-Like 15 (AGL15) from the MADS family and LEAFY COTYLEDON 1 (LEC1) from the Nuclear Factor Y (NF-Y) family. We aim to present the recent progress pertaining to the diverse roles these master TFs play in both ZE and SE in Arabidopsis, as well as other plant species including crops. We also discuss future perspectives in this context.
PubMed: 38235196
DOI: 10.3389/fpls.2023.1322728 -
The EMBO Journal Sep 2023Cell fragmentation is commonly observed in human preimplantation embryos and is associated with poor prognosis during assisted reproductive technology (ART) procedures....
Cell fragmentation is commonly observed in human preimplantation embryos and is associated with poor prognosis during assisted reproductive technology (ART) procedures. However, the mechanisms leading to cell fragmentation remain largely unknown. Here, light sheet microscopy imaging of mouse embryos reveals that inefficient chromosome separation due to spindle defects, caused by dysfunctional molecular motors Myo1c or dynein, leads to fragmentation during mitosis. Extended exposure of the cell cortex to chromosomes locally triggers actomyosin contractility and pinches off cell fragments. This process is reminiscent of meiosis, during which small GTPase-mediated signals from chromosomes coordinate polar body extrusion (PBE) by actomyosin contraction. By interfering with the signals driving PBE, we find that this meiotic signaling pathway remains active during cleavage stages and is both required and sufficient to trigger fragmentation. Together, we find that fragmentation happens in mitosis after ectopic activation of actomyosin contractility by signals emanating from DNA, similar to those observed during meiosis. Our study uncovers the mechanisms underlying fragmentation in preimplantation embryos and, more generally, offers insight into the regulation of mitosis during the maternal-zygotic transition.
Topics: Humans; Animals; Mice; Polar Bodies; Actomyosin; Blastocyst; Chromosomes; Meiosis; Oocytes; Spindle Apparatus; Myosin Type I
PubMed: 37427462
DOI: 10.15252/embj.2023114415 -
Genetics Oct 2023The zygote has a daunting task ahead of itself; it must develop from a single cell (fertilized egg) into a fully functioning adult with a multitude of different cell... (Review)
Review
The zygote has a daunting task ahead of itself; it must develop from a single cell (fertilized egg) into a fully functioning adult with a multitude of different cell types. In the beginning, the zygote has help from its mother, in the form of gene products deposited into the egg, but eventually, it must rely on its own resources to proceed through development. The transfer of developmental control from the mother to the embryo is called the maternal-to-zygotic transition (MZT). All animals undergo this transition, which is defined by two main processes-the degradation of maternal RNAs and the synthesis of new RNAs from the zygote's own genome. Here, we review the regulation of the MZT in Drosophila, but given the broad conservation of this essential process, much of the regulation is shared among metazoans.
Topics: Animals; Zygote; Drosophila; Gene Expression Regulation, Developmental; Genome; RNA, Messenger; RNA; Embryonic Development
PubMed: 37616526
DOI: 10.1093/genetics/iyad142 -
Environmental Health Perspectives Dec 2023Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF)...
Associations between Phthalate Metabolite Concentrations in Follicular Fluid and Reproductive Outcomes among Women Undergoing Fertilization/Intracytoplasmic Sperm Injection Treatment.
BACKGROUND
Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking.
OBJECTIVES
To investigate the associations between phthalate metabolite concentrations in FF and fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic.
METHODS
We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono--butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models.
RESULTS
After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all for trends ). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites () was associated with a reduction of 9.1% [95% confidence interval (CI): , ] and 10.3% (95% CI: , ) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth.
DISCUSSION
Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. https://doi.org/10.1289/EHP11998.
Topics: Pregnancy; Humans; Male; Female; Sperm Injections, Intracytoplasmic; Abortion, Spontaneous; Follicular Fluid; Bayes Theorem; Environmental Pollutants; Semen; Fertilization in Vitro; Phthalic Acids; Environmental Exposure
PubMed: 38150316
DOI: 10.1289/EHP11998 -
Zygote (Cambridge, England) Oct 2023Based on the fact that the follicular phase in the menstrual cycle has length variation, it has been assumed that the duration of oestrogen (E2) administration could... (Randomized Controlled Trial)
Randomized Controlled Trial
Based on the fact that the follicular phase in the menstrual cycle has length variation, it has been assumed that the duration of oestrogen (E2) administration could also be variable; therefore, for the first time, this randomized clinical trial study was conducted to investigate and compare the duration of estradiol administration and the effect on pregnancy outcomes in the cleavage-stage frozen embryo transfer (FET) cycle. We included women aged 20-40 with a normal uterus on hysteroscopy between September and December 2022 and who were divided randomly into three groups: group A [ = 79; 8-11 days of oestrogen before progesterone (P4) supplementation], group B ( = 78; 12-14 days of oestrogen before P4 supplementation), and group C ( = 76; 15-18 days of estrogen before P4 supplementation). Serum levels for E2 on the initial progesterone day and P4 on the transfer day were measured. The effect of the duration of E2 administration on clinical pregnancy and pregnancy loss was investigated. We found no significant differences between the three groups in the clinical pregnancy rate ( = 0.696) and clinical abortion rate ( = 0.925) according to the duration of the E2. There was no significant difference in the E2, P4 levels, and endometrial thickness in pregnant vs. non-pregnant women. The mean of the E2 and P4 levels was 300.03 ± 22.21 and 25.36 ± 5.78, respectively. Our findings suggest that variation in the length of E2 administration (8-18 days) before progesterone initiation in day 3 FET cycles does not affect pregnancy outcome and transfer time can be flexibly arranged.
Topics: Pregnancy; Female; Humans; Pregnancy Outcome; Estradiol; Progesterone; Embryo Transfer; Pregnancy Rate; Estrogens; Retrospective Studies
PubMed: 37448263
DOI: 10.1017/S096719942300031X -
Zygote (Cambridge, England) Dec 2023Maintaining genomic stability is crucial for normal development. At earlier stages of preimplantation development, as the embryonic genome activation is not fully...
Maintaining genomic stability is crucial for normal development. At earlier stages of preimplantation development, as the embryonic genome activation is not fully completed, the embryos may be more prone to abnormalities. Aneuploidies are one of the most common genetic causes of implantation failure or first-trimester miscarriages. Apoptosis is a crucial mechanism to eliminate damaged or abnormal cells from the organism to enable healthy growth. Therefore, this study aimed to determine the relationship between the expression levels of genes involved in apoptosis in human aneuploid and euploid blastocysts. In total, 32 human embryos obtained from 21 patients were used for this study. Trophectoderm biopsies were performed and next-generation screening was carried out for aneuploidy screening. Total RNA was extracted from each blastocyst separately and cDNA was synthesized. Gene expression levels were evaluated using RT-PCR. The statistical analysis was performed to evaluate the gene expression level variations in the euploid and aneuploid embryos, respectively. The expression level of the gene was significantly different between the aneuploid and euploid samples. BAX expression levels were found to be 1.5-fold lower in aneuploid cells. However, the expression levels of and genes were similar in each group. This study aimed to investigate the possible role of genes involved in apoptosis and aneuploidy mechanisms. The findings of this investigation revealed that the gene was expressed significantly differently between aneuploid and euploid embryos. Therefore, it is possible that the genes involved in the apoptotic pathway have a role in the aneuploidy mechanism.
Topics: Female; Humans; Pregnancy; Aneuploidy; bcl-2-Associated X Protein; Blastocyst; Cell Cycle Proteins; Gene Expression; Mad2 Proteins; Preimplantation Diagnosis
PubMed: 37994469
DOI: 10.1017/S0967199423000539 -
Frontiers in Endocrinology 2023maturation (IVM) of germinal vesicle intact oocytes prior to fertilization (IVF) is practiced widely in animals. In human assisted reproduction it is generally...
BACKGROUND
maturation (IVM) of germinal vesicle intact oocytes prior to fertilization (IVF) is practiced widely in animals. In human assisted reproduction it is generally reserved for fertility preservation or where ovarian stimulation is contraindicated. Standard practice incorporates complex proteins (CP), in the form of serum and/or albumin, into IVM media to mimic the ovarian follicle environment. However, the undefined nature of CP, together with batch variation and ethical concerns regarding their origin, necessitate the development of more defined formulations. A known component of follicular fluid, melatonin, has multifaceted roles including that of a metabolic regulator and antioxidant. In certain circumstances it can enhance oocyte maturation. At this stage in development, the germinal-vesicle intact oocyte is prone to aneuploidy and epigenetic dysregulation.
OBJECTIVES
To determine the developmental, cytogenetic and epigenetic consequences of removing CP and including melatonin during bovine IVM.
MATERIALS AND METHODS
The study comprised a 2 x 2 factorial arrangement comparing (i) the inclusion or exclusion of CP, and (ii) the addition (100 nM) or omission of melatonin, during IVM. Cumulus-oocyte complexes (COCs) were retrieved from stimulated cycles. Following IVM and IVF, putative zygotes were cultured to Day 8 in standard media. RNAseq was performed on isolated cumulus cells, cytogenetic analyses (SNP-based algorithms) on isolated trophectoderm cells, and DNA methylation analysis (reduced representation bisulfite sequencing) on isolated cells of the inner-cell mass.
RESULTS
Removal of CP during IVM led to modest reductions in blastocyst development, whilst added melatonin was beneficial in the presence but detrimental in the absence of CP. The composition of IVM media did not affect the nature or incidence of chromosomal abnormalities but cumulus-cell transcript expression indicated altered metabolism (primarily lipid) in COCs. These effects preceded the establishment of distinct metabolic and epigenetic signatures several days later in expanded and hatching blastocysts.
CONCLUSIONS
These findings highlight the importance of lipid, particularly sterol, metabolism by the COC during IVM. They lay the foundation for future studies that seek to develop chemically defined systems of IVM for the generation of transferrable embryos that are both cytogenetically and epigenetically normal.
Topics: Female; Animals; Cattle; Humans; Melatonin; In Vitro Oocyte Maturation Techniques; Oocytes; Cytogenetic Analysis; Epigenesis, Genetic; Lipids
PubMed: 38027209
DOI: 10.3389/fendo.2023.1280847