Cell Division In Embryos Research Articles

Twin Embryos in Arabidopsis thaliana KATANIN 1 Mutants.

Regulation of microtubule dynamics is crucial during key developmental transitions such as gametogenesis, fertilization, embryogenesis, and seed formation, where cells undergo rapid changes in shape and function. In plants, katanin plays an essential role in microtubule dynamics. This study investigates two seed developmental mutants in Arabidopsis thaliana, named elk5-1D (erecta-like 5, ELK5) and loo1 (lollipop 1), which are characterized by round seeds, dwarfism, and fertility defects. Notably, elk5-1D exhibits a dominant inheritance pattern, whereas loo1 is recessive. Through positional cloning, we identified both mutants as new alleles of the KATANIN 1 (KTN1) gene, which encodes a microtubule-severing enzyme critical for cell division and morphology. Mutations in KTN1 disrupt embryo cell division and lead to the emergence of a twin embryo phenotype. Our findings underscore the essential role of KTN1 in fertility and early embryonic development, potentially influencing the fate of reproductive cells.

Efficient high-resolution fluorescence projection imaging over an extended depth of field through optical hardware and deep learning optimizations.

Optical microscopy has witnessed notable advancements but has also become more costly and complex. Conventional wide field microscopy (WFM) has low resolution and shallow depth-of-field (DOF), which limits its applications in practical biological experiments. Recently, confocal and light sheet microscopy become major workhorses for biology that incorporate high-precision scanning to perform imaging within an extended DOF but at the sacrifice of expense, complexity, and imaging speed. Here, we propose deep focus microscopy, an efficient framework optimized both in hardware and algorithm to address the tradeoff between resolution and DOF. Our deep focus microscopy achieves large-DOF and high-resolution projection imaging by integrating a deep focus network (DFnet) into light field microscopy (LFM) setups. Based on our constructed dataset, deep focus microscopy features a significantly enhanced spatial resolution of ∼260 nm, an extended DOF of over 30 µm, and broad generalization across diverse sample structures. It also reduces the computational costs by four orders of magnitude compared to conventional LFM technologies. We demonstrate the excellent performance of deep focus microscopy in vivo, including long-term observations of cell division and migrasome formation in zebrafish embryos and mouse livers at high resolution without background contamination.

MCPIP1 functions as a safeguard of early embryonic development

Monocyte chemoattractant protein-induced protein 1 (MCPIP1), also called Regnase-1, is an RNase that has been described as a key negative modulator of inflammation. MCPIP1 also controls numerous tumor-related processes, such as proliferation, apoptosis and differentiation. In this study, we utilized a zebrafish model to investigate the role of Mcpip1 during embryogenic development. Our results demonstrated that during embryogenesis, the expression of the zc3h12a gene encoding Mcpip1 undergoes dynamic changes. Its transcript levels gradually increase from the 2-cell stage to the spherical stage and then decrease rapidly. We further found that ectopic overexpression of wild-type Mcpip1 but not the catalytically inactive mutant form resulted in an embryonic lethal phenotype in zebrafish embryos (24 hpf). At the molecular level, transcriptomic profiling revealed extensive changes in the expression of genes encoding proteins important in the endoplasmic reticulum stress response and in protein folding as well as involved in the formation of primary germ layer, mesendoderm and endoderm development, heart morphogenesis and cell migration. Altogether, our results demonstrate that the expression of zc3h12a must be tightly controlled during the first cell divisions of zebrafish embryos and that a rapid decrease in its mRNA expression is an important factor promoting proper embryo development.

Centrosome fragmentation and malposition is common in the first cell division of equine ICSI embryos

In vitro production of embryos via Intra-Cytoplasmic-Sperm-Injection (ICSI) has become popular in the horse industry. Although improving, the blastocyst yield in clinical practice remains sub-optimal (∼20%: Stout. JEVS 2020; 89:103011). The high incidence of developmental arrest of ICSI embryos is suggested a result of mitotic errors during the first zygotic cell divisions. A better understanding of the cause of these errors could help develop strategies to prevent mitotic errors in equine in vitro produced (IVP) embryos. In somatic cells, the centrosomes, composed of two centrioles surrounded by pericentriolar material are the major microtubule-organizing centers and play essential roles in spindle assembly and chromosome segregation. Mammalian oocytes lack centrosomes and although two centrioles are re-introduced by the spermatozoon at fertilization, centrosomes make only a minor contribution to zygotic spindle assembly (Schneider et al., J.Cell. Biol. 2021; 220(11):e202010106). Although not essential for spindle assembly, the role of the centrosomes in ensuring fidelity of chromosome segregation during zygotic cell division is unclear. The aim of this study was to evaluate the position and number of centrosomes in horse ICSI zygotes during the first mitotic division. Cumulus-Oocyte-Complexes (COCs) were obtained from Warmblood mares by Ovum-Pick-Up, maintained in H-SOF at room temperature overnight and then matured in vitro, fertilized by ICSI and cultured as described previously (Ducheyne et al. Reprod. Fertil. Dev. 2019; 31(12):1830). After 24h, injected oocytes were fixedand immunostained for alpha-tubulin, acetylated tubulin, (peri-)centrosome material (NEDD1) and chromatin (DAPI). For each zygote, confocal microscopy was performed using a Leica SPE II microscope and a 0.17µm interval z stack generated. Of 326 COCs collected, 177 reached MII and were injected and cultured further. Of the 177, 136 zygotes were fixed and imaged, 13 were at the two pronucleus, 11 at prophase/prometaphase, 14 at metaphase, 11 at anaphase or telophase, 54 at the two cell stage and 33 were either degenerated or poorly stained. During the two pronucleus and prophase/prometaphase stages, centrosomes mainly localized at the interface between the two pronuclei. In 56% (n=14/25) of zygotes in pro-metaphase and metaphase, independent spindles formed around each of the two parental pronuclei. The majority of dual spindles were closely adjacent and synchronous. Moreover, in 64.2% (n=9/14) of the metaphase zygotes, the (peri-)centrosomes were either malpositioned (e.g. not at the poles of the spindle) or fragmented. Fragmented or multiple centrosomes are known to predispose to abnormal chromosome-microtubule attachment and aberrant chromosome segregation. We therefore hypothesize that malposition and fragmentation of the centrosomes contributes to mitotic errors and developmental arrest of equine ICSI embryos. Acknowledgements to CAPES, Brazil, for financial support (Code 88882.433332/2019-01 and 88887.467895/2019-00)

Riboflavin mediates m6A modification targeted by miR408, promoting early somatic embryogenesis in longan.

Plant somatic embryogenesis (SE) is an in vitro biological process wherein bipolar structures are induced to form somatic cells and regenerate into whole plants. MicroRNA (miRNA) is an essential player in plant SE. However, the mechanism of microRNA408 (miR408) in SE remains elusive. Here, we used stable transgenic technology in longan (Dimocarpus longan) embryogenic calli to verify the mechanism by which miR408 promotes cell division and differentiation of longan early SE. dlo-miR408-3p regulated riboflavin biosynthesis by targeting nudix hydrolase 23 (DlNUDT23), a previously unidentified gene mediating N6-methyladenosine (m6A) modification and influencing RNA homeostasis and cell cycle gene expression during longan early SE. We showed that DlMIR408 overexpression (DlMIR408-OE) promoted 21-nt miRNA biosynthesis. In DlMIR408-OE cell lines, dlo-miR408-3p targeted and downregulated DlNUDT23, promoted riboflavin biosynthesis, decreased flavin mononucleotide (FMN) accumulation, promoted m6A level, and influenced miRNA homeostasis. DNA replication, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, the pentose phosphate pathway, and taurine and hypotaurine metabolism were also closely associated with riboflavin metabolism. In a riboflavin feeding assay, dlo-miR408-3p and pre-miR408 were upregulated and DlNUDT23 was downregulated, increasing the m6A level and cell division and differentiation in longan globular embryos. When riboflavin biosynthesis was inhibited, dlo-miR408-3p was downregulated and DlNUDT23 was upregulated, which decreased m6A modification and inhibited cell division but did not inhibit cell differentiation. FMN artificial demethylated m6A modification affected the homeostasis of precursor miRNA and miRNA. Our results revealed a mechanism underlying dlo-miR408-3p-activated riboflavin biosynthesis in which DlNUDT23 is targeted, m6A modification is dynamically mediated, and cell division is affected, promoting early SE in plants.

An approach for live imaging of first cleavage in mouse embryos using fluorescent chemical probes for DNA, microtubules, and microfilaments.

Dynamic morphological changes in the chromosome and cytoskeleton occur in mammals and humans during early embryonic development, and abnormalities such as embryonic chromosomal aneuploidy occur when development does not proceed normally. Visualization of the intracellular organelles and cytoskeleton allows elucidation of the development of early mammalian embryos. The behavior of the DNA and cytoskeleton in early mammalian embryos has conventionally been observed by injecting target molecule mRNAs, incorporating a fluorescent substance-expressing gene, into embryos. In this study, we visualized the chronological behavior of male and female chromosome condensation in mouse embryos, beginning in the two-pronuclear zygote, through the first division to the two-cell stage, using fluorescent chemical probes to visualize the behavior of DNA, microtubules, and microfilaments. Mouse two-pronuclear stage embryo were immersed in medium containing fluorescent chemical probes to visualize DNA, microtubules, and microfilaments. Observation was performed with a confocal microscope. This method allowed us to observe how chromosome segregation errors in first somatic cell divisions in mouse embryos and enabled dynamic analysis of a phenomenon called lagging chromosomes. By applying this method, we can observe any stage of embryonic development, which may provide new insights into embryonic development in other mammals.

The effect of early irregular cell division of human embryos on blastocyst euploidy: considerations from the subsequent development of the blastomeres by direct or reverse cleavage

To investigate whether blastocysts that divide irregularly reduce subsequent blastocyst euploidy. Retrospective study. Private clinic. A total of 122 blastocysts for which consent for disposal and research use was obtained. None. Results of next-generation sequencing analysis of the blastocysts and whether blastomeres by normal or irregular divisions subsequently participated in blastocyst formation or not. The embryos were classified according to their dynamics until the second cleavage. The blastocyst euploidy rates were 33.3% (19/57) in the normal cleavage (NC) group, 38.3% (18/47) in the direct cleavage (embryos with one cell dividing into 3 cells) (DC) group, and 72.2% (13/18) in the reverse cleavage (RC) (embryos with fused cells once divided) group. The rate of the RC group was significantly higher than that of the NC group. The blastocyst participation rate of the blastomeres were 95.6% in the NC group and 56.5% in that derived from DC of the first cleavage, and 91.7% in that of blastomeres derived from normal division of the second cleavage and 53.6% in that derived from DC of the second cleavage, both of which were significantly lower in the latter. In the RC group, the rates of fused and nonfused blastomeres were 62.1% and 87.5%, respectively, with no significant difference. The blastomeres generated by DC were often excluded from blastocyst formation, and we speculate that this is one reason why their division does not reduce blastocyst euploidy. The association between RC and euploidy of blastocysts merits further study.

Anti-Mitoticpotential Identification of Nyale (Eunice sp.) in The Tourism Area of Kuta Beach, Lombok Island, West Nusa Tenggara

BACKGROUND: BauNyale festival is a Lombok tradition that originated in the Kuta beach tourism area in Central Lombok. The locals of Lombok Island gathered in this location to harvest marine worms known as Nyale (Eunice sp.). The ability of marine worms to act as anticancer agents has received little attention in Indonesia. AIM: This study aimed to examine the biomolecules compounds of Nyale as antimitotic candidates. METHODS: This was a preliminary study using post-test only with a control group design. The sample of this study was Nyale (Eunice sp.), and sea urchin (Tripneustes ventricosus) collected from Kuta beach, Central Lombok. The Nyale was extracted with 96% ethanol as the solvent. Gas Chromatography-Mass Spectrometry (GCMS) was used to determine the content of bioactive compounds. Sea urchin embryos were divided into four treatment groups (control; 10 mg, 100 mg, and 1000 mg; 1000 mg of Nyale extract). After 2 h of fertilization incubation, the number of cell division phases (2–32 cells) was counted. The data were analyzed using ANOVA. RESULTS: The results of the GCMS test revealed that there were ten different compounds in the Nyale ethanol extract. There was a tendency for cleavage when testing the anti-mitotic potential of Nyale extract in each group. There was a significant difference in the percentage of cell changes in all treatments (control, 10 mg, 100 mg, and 1000 mg) (p < 0.005). CONCLUSION: Bioactive compounds found in marine worms (nyale) influence the percentage of cell division (anti-mitotic) in sea urchin embryos.

Multiple Roles of SMC5/6 Complex during Plant Sexual Reproduction.

Chromatin-based processes are essential for cellular functions. Structural maintenance of chromosomes (SMCs) are evolutionarily conserved molecular machines that organize chromosomes throughout the cell cycle, mediate chromosome compaction, promote DNA repair, or control sister chromatid attachment. The SMC5/6 complex is known for its pivotal role during the maintenance of genome stability. However, a dozen recent plant studies expanded the repertoire of SMC5/6 complex functions to the entire plant sexual reproductive phase. The SMC5/6 complex is essential in meiosis, where its activity must be precisely regulated to allow for normal meiocyte development. Initially, it is attenuated by the recombinase RAD51 to allow for efficient strand invasion by the meiosis-specific recombinase DMC1. At later stages, it is essential for the normal ratio of interfering and non-interfering crossovers, detoxifying aberrant joint molecules, preventing chromosome fragmentation, and ensuring normal chromosome/sister chromatid segregation. The latter meiotic defects lead to the production of diploid male gametes in Arabidopsis SMC5/6 complex mutants, increased seed abortion, and production of triploid offspring. The SMC5/6 complex is directly involved in controlling normal embryo and endosperm cell divisions, and pioneer studies show that the SMC5/6 complex is also important for seed development and normal plant growth in cereals.

Cytokinesis During the First Division of a Mouse Embryo.

Cell division consists of nuclear division (mitosis for somatic cells and meiosis for germ cells) and cytoplasmic division (cytokinesis). Embryonic developments are highly programmed, and thus, each cellular event during early embryo development is stable. For mouse embryos, the first time of mitosis is completed about 22 h after fertilization. However, it remains unclear when the embryo completes its first cytokinesis. Here, we microinjected only one cell in the 2-cell stage mouse embryos with mRNA, which encodes green fluorescence protein (GFP). By monitoring the GFP protein transport dynamics between the two cells, we demonstrated that the first time of cytokinesis in mouse embryos is completed about 15 h after mitosis, namely 37 h after fertilization. In addition, our results indicate that the cytoplasmic protein transport between daughter cells is very effective, which relies on microtubules instead of microfilaments in 2-cell mouse embryos. These results should enrich people’s understanding of the first cell division and cytoskeleton in mouse embryos and then learn more about the mechanisms of early embryo development in mammals.

Early and late paternal contribution to cell division of embryos in a time-lapse imaging incubation system.

The objective of this study was to investigate the impact of male age, semen quality and days of ejaculatory abstinence on embryo morphokinetics. A total of 1,220 zygotes obtained from 139 couples in a private in vitro fertilisation centre were analysed. The timing of specific events from the point of insemination, such as timings to pronuclei appearance and fading, to two, three, four, five, six, seven and eight cells and to blastulation were recorded. Multivariate linear regression analysis was used to evaluate the influence of paternal factors on embryo morphokinetic events. Paternal age was positively correlated with delayed cell cleavage and blastulation, and negatively associated with implantation rate, and clinical pregnancy and live-birth chances. The ejaculatory abstinence was inversely correlated with the implantation rate. Inverse relationships were observed between semen parameters (sperm count, progressive sperm motility, total motile sperm count and morphology) and the timing of specific events during embryo development. Sperm morphology was also positively associated with implantation rate and pregnancy and live-birth chances. Increased paternal age and ejaculatory abstinence, and poor semen quality correlate with delayed cell cleavage and blastulation and negatively impact intracytoplasmic sperm injection outcomes.

Small RNA expression and miRNA modification dynamics in human oocytes and early embryos.

Small noncoding RNAs (sRNAs) play important roles during the oocyte-to-embryo transition (OET), when the maternal phenotype is reprogrammed and the embryo genome is gradually activated. The transcriptional program driving early human development has been studied with the focus mainly on protein-coding RNAs, and expression dynamics of sRNAs remain largely unexplored. We profiled sRNAs in human oocytes and early embryos using an RNA-sequencing (RNA-seq) method suitable for low inputs of material. We show that OET in humans is temporally coupled with the transition from predominant expression of oocyte short piRNAs (os-piRNAs) in oocytes, to activation of microRNA (miRNA) expression in cleavage stage embryos. Additionally, 3′ mono- and oligoadenylation of miRNAs is markedly increased in zygotes. We hypothesize that this may modulate the function or stability of maternal miRNAs, some of which are retained throughout the first cell divisions in embryos. This study is the first of its kind elucidating the dynamics of sRNA expression and miRNA modification along a continuous trajectory of early human development and provides a valuable data set for in-depth interpretative analyses.

Analysis of Morphokinetic Parameters of Feline Embryos Using a Time-Lapse System.

Simple SummaryThis study was conducted with the aim of analyzing the morphokinetic parameters that determine the proper development of feline embryos in vitro. Our research was carried out using a time-lapse monitoring system shows that the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision®, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest proportion of embryos (46%) cleaving between 21 and 24 hpi. The timing of the first cleavage significantly affected further embryo development, with the highest development occurring in embryos that cleaved at 21–22 hpi. Embryos that cleaved very early (17–18 hpi) developed poorly to the blastocyst stage (2%) and none of the embryos that cleaved later than 27 hpi were able to reach the blastocyst stage. Morphological defects were observed in 48% of the embryos. There were no statistically significant differences between the timing intervals of the first cleavage division and the frequency of morphological defects in embryos. Multiple (MUL) morphological defects were detected in more than half (56%) of the abnormal embryos. The most frequent single morphological defects were cytoplasmic fragmentation (FR) (8%) and blastomere asymmetry (AS) (6%). Direct cleavage (DC) from 1–3 or 3–5 blastomeres, reverse cleavage (RC) and vacuoles were rarely observed (2–3%). The timing of blastocyst cavity formation is a very good indicator of embryo quality. In our study, blastocyst cavity formation occurred between 127–167 hpi, with the highest frequency of hatching observed in blastocysts that cavitated between 142–150 hpi. Blastocysts in which cavitation began after 161 h did not hatch. In conclusion, the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.

Three neuroparsin genes from oriental river prawn, Macrobrachium nipponense, involved in ovary maturation.

In this study, we identified three neuroparsin (NP) genes in Macrobrachium nipponense: Mn-NP1, Mn-NP2, and Mn-NP3, encoding 99, 100, and 101 amino acid proteins, respectively. Multiple sequence alignments showed that these genes contained 12 cysteine residues, of which 11 were at conserved positions. The total sequence identity between the genes was 47.5%, and they showed a high degree of sequence identity (> 54% similarity) with other crustacean genes. Phylogenetic tree analysis showed that Mn-NPs were clustered at different branches, indicating that Mn-NPs may have different functions. Tissue distribution data revealed that the three genes were present in males and females during the breeding and nonbreeding season, but their expression patterns differed. Mn-NP1 was highly expressed in the breeding season, in the male testis, and highly expressed in the nonbreeding season, in the female ovary. Mn-NP3 exhibited biased female expression in the breeding and nonbreeding season, with dominant expression in the ovary. All Mn-NPs were detected during embryo development, but with different expression patterns. These data indicated that Mn-NP1 may function during embryonic development, and that Mn-NP2 may be expressed during early embryo cell division, and late larval development. Mn-NP3 expression patterns reflected maternal inheritance, and may be associated with ovarian maturation. These expression data suggested that Mn-NP1 and Mn-NP2 are negatively correlated with ovarian development, with inhibition roles during this development. Mn-NP3 may be involved in vitellogenesis.

Wwc2 Is a Novel Cell Division Regulator During Preimplantation Mouse Embryo Lineage Formation and Oogenesis.

Formation of the hatching mouse blastocyst marks the end of preimplantation development, whereby previous cell cleavages culminate in the formation of three distinct cell lineages (trophectoderm, primitive endoderm and epiblast). We report that dysregulated expression of Wwc2, a genetic paralog of Kibra/Wwc1 (a known activator of Hippo-signaling, a key pathway during preimplantation development), is specifically associated with cell autonomous deficits in embryo cell number and cell division abnormalities. Division phenotypes are also observed during mouse oocyte meiotic maturation, as Wwc2 dysregulation blocks progression to the stage of meiosis II metaphase (MII) arrest and is associated with spindle defects and failed Aurora-A kinase (AURKA) activation. Oocyte and embryo cell division defects, each occurring in the absence of centrosomes, are fully reversible by expression of recombinant HA-epitope tagged WWC2, restoring activated oocyte AURKA levels. Additionally, clonal embryonic dysregulation implicates Wwc2 in maintaining the pluripotent epiblast lineage. Thus, Wwc2 is a novel regulator of meiotic and early mitotic cell divisions, and mouse blastocyst cell fate.

Automated cell division classification in early mouse and human embryos using convolutional neural networks

During in vitro fertilization (IVF), the timing of cell divisions in early human embryos is a key predictor of embryo viability. Recent developments in time-lapse microscopy (TLM) have allowed us to observe cell divisions in much greater detail than previously possible. However, it is a time-consuming process that relies on a highly trained staff and subjective observations. We describe an automated method based on a convolutional neural network to detect and classify cell divisions from original (unprocessed) TLM images. Here, we used two embryo TLM image datasets to evaluate our method: a public dataset with mouse embryos up to the 4-cell stage and a private dataset with human embryos up to the 8-cell stage. Compared to embryologists’ annotations, our results were almost 100% accurate for the mouse embryo images and accurate within five frames in 93.9% of cell stage transitions for the human embryos. Our approach can be used to improve the consistency and quality of the existing annotations or as part of a platform for fully automated embryo assessment. The code is available at http://github.com/JonasEMalmsten/CellDivision .

Chromosome dynamics and spindle microtubule establishment in mouse embryos.

Chromosome segregation errors in mammalian embryos are common and jeopardize embryo health. Here, we perform for the first time 4-Dimensional imaging and tracking of chromosomes and centromeres through each preimplantation mitotic cell division in mouse embryos to define the normal dynamics of chromosome segregation. We show that a microtubule (MT)-dependent inward movement of chromosomes occurs at the time of nuclear envelope breakdown (NEBD), particularly in the earliest cell divisions, to position chromosomes prior to spindle assembly. Establishment of a rudimentary metaphase plate occurs immediately after NEBD, and is followed by a progressive alignment and biorientation of mitotic chromosomes. Stable end-on kinetochore-MT attachments form rapidly and attachment errors are uncommon. Altogether our data describe a rapid and efficient spindle assembly pathway that apparently minimizes the need for canonical MT attachment error correction in normally dividing embryos.

Mitochondrial ribosomal protein S9M is involved in male gametogenesis and seed development in Arabidopsis.

Mitochondrial function is critical for cell vitality in all eukaryotes including plants. Although plant mitochondria contain many proteins, few have been studied in the context of plant development and physiology. We used knock-down mutant RPS9M to study its important role in male gametogenesis and seed development in Arabidopsis thaliana. Knock-down of RPS9M in the rps9m-3 mutant led to abnormal pollen development and impaired pollen tube growth. In addition, both embryo and endosperm development were affected. Phenotype analysis revealed that the rps9m-3 mutant contained a lower amount of endosperm and nuclear proteins, and both embryo cell division and embryo pattern were affected, resulting in an abnormal and defective embryo. Lowering the level of RPS9M in rps9m-3 affects mitochondrial ribosome biogenesis, energy metabolism and production of ROS. Our data revealed that RPS9M plays important roles in normal gametophyte development and seed formation, possibly by sustaining mitochondrial function.

Effects of late planting on fiber quality and within-boll yield components as mediated by sucrose metabolism in cotton bolls

ABSTRACT The objective of this study was to examine the effect of late planting on sucrose metabolism in cotton bolls and the relationship to fiber properties and within-boll yield components. Two cotton lines A201 and A705 were employed in a sowing date experiment where two temperature regimes during boll maturation period were created at mean daily temperature of 26.8°C, 28.3°C for early planting and 25.2°C, 23.1°C for late planting in 2016 and 2017, respectively. Boll size, seed mass per boll, seed index and fiber length were increased, and lint percentage was decreased by late planting. Greater cell wall invertase activity and the resultant hexose concentration in fibers were observed in late planting, and thus led to decreased osmotic potential accounting for the enhanced fiber length. Similarly, late planting increased the maximum of vacuolar invertase activity in ovules occurring at 5 days post anthesis (DPA) and hexose concentrations in embryos from 10 DPA afterwards which may favor embryo cell division, and thus increase final seed size. Our data indicate that acid invertase and hexose are implicated in the formation of within-boll yield components and fiber properties as affected by the lower temperature regime due to late planting.

Endometriosis accelerates synchronization of early embryo cell divisions but does not change morphokinetic dynamics in endometriosis patients.

ObjectiveThe pathology of endometriosis and its impact on embryo development is still a black box in reproductive medicine. In this time-lapse study we investigated the influence of endometriosis on morphokinetic parameters of embryo development, taking variables of dynamic monitoring into account. Furthermore we evaluated reproductive medicine treatment outcome such as fetal heartbeat and live birth rate.Methods1148 embryos (control: n = 596, endometriosis: n = 552) were retrospectively analyzed. Patients were stimulated with GnRH antagonist protocol. After fertilization, embryos were incubated in a time-lapse system (EmbryoScope).ResultsThe mixed-model analysis revealed a significant main effect of time (p<0.001), with post-hoc tests showing that any time needed to reach a specific developmental stage was significantly different from all the others (all p<0.001). Embryos of endometriosis patients showed the same absolute morphokinetic time parameters as the control group, however, synchronization of early embryo cell divisions (s2) was faster in endometriosis patients compared to the control group.ConclusionIn general, endometriosis does not induce changes in early embryo morphokinetics. However, observed acceleration in cell cycle synchronization of embryo cleavage patterns might be a missing explanation for contradicting results in literature regarding the impairments in reproductive medicine treatment outcome of endometriosis patients.