Observations on the embryogenesis of Trichodorus christiei (Nematodea: Diphtherophoroidea)

1968 ◽  
Vol 46 (2) ◽  
pp. 292-293 ◽  
Author(s):  
G. W. Bird ◽  
R. M. Goodman ◽  
W. F. Mai
Keyword(s):  
Single Cell ◽  
Longitudinal Axis ◽  
Metaphase Chromosomes ◽  
Cell Stage

Trichodorus christiei eggs were laid in the single cell stage. The first two cleavages were transverse to the longitudinal axis of the egg, forming four blastomeres of similar size. Metaphase chromosomes were approximately 3 μ in length. First-stage juveniles were recognizable after 96 hours, and emerged from the egg 100–120 hours after it was laid. Stomatal armature was well developed after 96 hours. The esophagus and intestine developed shortly before emergence.

scholarly journals Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Developmental Potential ◽  
Functional Features ◽  
Early Mouse ◽  
Extraembryonic Tissues

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

scholarly journals Functional Genomics of 5- to 8-Cell Stage Human Embryos by Blastomere Single-Cell cDNA Analysis

PLoS ONE ◽  
2010 ◽  
Vol 5 (10) ◽  
pp. e13615 ◽  
Author(s):  
Amparo Galán ◽  
David Montaner ◽  
M. Eugenia Póo ◽  
Diana Valbuena ◽  
Verónica Ruiz ◽  
...  
Keyword(s):  
Functional Genomics ◽  
Single Cell ◽  
Human Embryos ◽  
Cell Stage ◽  
Cdna Analysis

A Complete Culture System for Avian Transgenesis, Supporting Quail Embryos from the Single-Cell Stage to Hatching

1994 ◽  
Vol 161 (1) ◽  
pp. 126-130 ◽  
Author(s):  
Tamao Ono ◽  
Taro Murakami ◽  
Makoto Mochii ◽  
Kiyokazu Agata ◽  
Katsutoshi Kino ◽  
...  
Keyword(s):  
Single Cell ◽  
Culture System ◽  
Cell Stage

scholarly journals Assessing heterogeneity among single embryos and single blastomeres using open microfluidic design

2020 ◽  
Vol 6 (17) ◽  
pp. eaay1751
Author(s):  
Elisabet Rosàs-Canyelles ◽  
Andrew J. Modzelewski ◽  
Alisha Geldert ◽  
Lin He ◽  
Amy E. Herr
Keyword(s):  
Single Cell ◽  
Preimplantation Embryo ◽  
Single Cell Protein ◽  
Cell Protein ◽  
Molecular Heterogeneity ◽  
Cell Stage ◽  
Multimodal Data ◽  
Preimplantation Embryo Development ◽  
Specificity And Sensitivity ◽  
Single Blastomeres

The process by which a zygote develops from a single cell into a multicellular organism is poorly understood. Advances are hindered by detection specificity and sensitivity limitations of single-cell protein tools and by challenges in integrating multimodal data. We introduce an open microfluidic tool expressly designed for same-cell phenotypic, protein, and mRNA profiling. We examine difficult-to-study—yet critically important—murine preimplantation embryo stages. In blastomeres dissociated from less well-studied two-cell embryos, we observe no significant GADD45a protein expression heterogeneity, apparent at the four-cell stage. In oocytes, we detect differences in full-length versus truncated DICER-1 mRNA and protein, which are insignificant by the two-cell stage. Single-embryo analyses reveal intraembryonic heterogeneity, differences between embryos of the same fertilization event and between donors, and reductions in the burden of animal sacrifice. Open microfluidic design integrates with existing workflows and opens new avenues for assessing the cellular-to-molecular heterogeneity inherent to preimplantation embryo development.

scholarly journals O2 Altered morphokinetic parameters of embryos identified as aneuploid by single cell array CGH analysis at the 8-cell stage

2012 ◽  
Vol 24 ◽  
pp. S39-S40
Author(s):  
S. Davies ◽  
D. Christopikou ◽  
E. Tsorva ◽  
T. Karagianni ◽  
M. Mastrominas ◽  
...  
Keyword(s):  
Single Cell ◽  
Array Cgh ◽  
Cell Array ◽  
Cell Stage ◽  
Morphokinetic Parameters

scholarly journals Single-Cell Sequencing of Primate Preimplantation Embryos Reveals Chromosome Elimination Via Cellular Fragmentation and Blastomere Exclusion

2018 ◽  
Author(s):  
Brittany L. Daughtry ◽  
Jimi L. Rosenkrantz ◽  
Nathan H. Lazar ◽  
Suzanne S. Fei ◽  
Nash Redmayne ◽  
...  
Keyword(s):  
Dna Damage ◽  
Single Cell ◽  
Chromosome Instability ◽  
Complex Mixture ◽  
Chromosome Elimination ◽  
Early Embryo ◽  
Preimplantation Embryos ◽  
Cleavage Stage ◽  
Primate Model ◽  
Cell Stage

ABSTRACTAneuploidy that arises during meiosis and/or mitosis is a major contributor to early embryo loss. We previously demonstrated that human preimplantation embryos encapsulate mis-segregated chromosomes into micronuclei while undergoing cellular fragmentation and that fragments can contain chromosomal material, but the source of this DNA was unknown. Here, we leveraged the use of a non-human primate model and single-cell DNA-sequencing (scDNA-seq) to examine the chromosomal content of 471 individual samples comprising 254 blastomeres, 42 polar bodies, and 175 cellular fragments from a large number (N=50) of disassembled rhesus cleavage-stage embryos. Our analysis revealed that the frequency of aneuploidy and micronucleation is conserved between humans and macaques and that cellular fragments encapsulate whole and/or partial chromosomes lost from blastomeres. Single-cell/fragment genotyping demonstrated that these chromosome-containing cellular fragments (CCFs) can be either maternal or paternal in origin and display DNA damage via double-stranded breaks. Chromosome breakage and abnormal cytokinesis resulted in reciprocal losses/gains at the terminal ends of chromosome arms, uniparental genome segregation, and mixoploidy between blastomeres. Combining time-lapse imaging with scDNA-seq, we also determined that multipolar divisions at the zygote or 2-cell stage generated chaotic aneuploidy encompassing a complex mixture of maternal and paternal chromosomes. Despite frequent chromosomal mis-segregation at the cleavage-stage, we show that CCFs and non-dividing aneuploid blastomeres exhibiting extensive DNA damage are prevented from incorporation at the blastocyst stage. These findings suggest that embryos respond to chromosomal errors by encapsulation into micronuclei, elimination by cellular fragmentation, and selection against highly aneuploid blastomeres to overcome chromosome instability during preimplantation development.

205 Towards the correction of meconium ileus with cystic fibrosis transmembrane conductance regulator (CFTR) intestinal expression in CFTR knockout sheep

2019 ◽  
Vol 31 (1) ◽  
pp. 228
Author(s):  
I. Viotti Perisse ◽  
Z. Fan ◽  
Y. Liu ◽  
M. Regouski ◽  
A. Van Wettere ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Sequence Analysis ◽  
Single Cell ◽  
Meconium Ileus ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Cell Stage ◽  
Fatty Acid Binding ◽  
Fetal Fibroblasts ◽  
Cystic Fibrosis Transmembrane

Cystic fibrosis (CF) is a human autosomal genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which is responsible for Cl − anion transport in epithelial cells. We previously generated CFTR +/− and CFTR −/− lambs using CRISPR/Cas9 and somatic cell nuclear transfer (SCNT) techniques. The CFTR −/− lambs display many features similar to humans with CF, including meconium ileus (MI), pancreatic fibrosis, portal fibrosis and biliary hyperplasia, small gallbladder, and absence of the vas deferens. Although MI affects only 15 to 20% of human babies with CF, it was observed in 100% of newborn CFTR −/− lambs and was the primary cause of death. We here hypothesized that the transgenic expression of ovine CFTR cDNA under regulation of the rat intestinal fatty acid binding protein (iFABP) promoter would promote the correction of MI in CFTR −/− sheep. In this study, we constructed the pcDNA3.1>iFABP>CFTR expression vector in order to generate iFABP>CFTR transgenic CFTR −/− sheep. PCR and sequence analysis of all junction regions confirmed the presence of the inserts in the vector. We transfected male and female CFTR −/− sheep fetal fibroblasts with the construct. Three days after transfection, limiting dilution and G418 selection were used for the isolation of resistant single cell derived colonies. A total of 15 male colonies containing the pcDNA3.1>iFABP>CFTR vector was confirmed by PCR and sequence analysis. Three male cell colonies were used as nuclear donors for SCNT. In total, 129 one-cell-stage cloned embryos were generated and transferred into 11 estrus-synchronized recipients. Four recipients (4/11; 36.3%) were confirmed pregnant at Day 40 to 45 of gestation. One pregnancy went to term and resulted in the birth of a single lamb. The necropsy indicated the same abnormalities, including MI, seen in CFTR −/− lambs. A PCR assay confirmed the presence of the iFABP>CFTR transgene in the genome of the cloned offspring. The lack of MI correction is likely due to the low expression of CFTR in this particular colony. Western blot analysis is in progress. Additional embryo transfers will be performed using different single-cell-derived colonies.

scholarly journals Spatio-temporal mRNA tracking in the early zebrafish embryo

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Karoline Holler ◽  
Anika Neuschulz ◽  
Philipp Drewe-Boß ◽  
Janita Mintcheva ◽  
Bastiaan Spanjaard ◽  
...  
Keyword(s):  
Single Cell ◽  
Primordial Germ Cells ◽  
Temporal Analysis ◽  
Sequence Motifs ◽  
Cell Stage ◽  
Systematic Analysis ◽  
Spatially Resolved ◽  
Rna Labeling ◽  
Stage Embryo ◽  
Spatio Temporal

AbstractEarly stages of embryogenesis depend on subcellular localization and transport of maternal mRNA. However, systematic analysis of these processes is hindered by a lack of spatio-temporal information in single-cell RNA sequencing. Here, we combine spatially-resolved transcriptomics and single-cell RNA labeling to perform a spatio-temporal analysis of the transcriptome during early zebrafish development. We measure spatial localization of mRNA molecules within the one-cell stage embryo, which allows us to identify a class of mRNAs that are specifically localized at an extraembryonic position, the vegetal pole. Furthermore, we establish a method for high-throughput single-cell RNA labeling in early zebrafish embryos, which enables us to follow the fate of individual maternal transcripts until gastrulation. This approach reveals that many localized transcripts are specifically transported to the primordial germ cells. Finally, we acquire spatial transcriptomes of two xenopus species and compare evolutionary conservation of localized genes as well as enriched sequence motifs.

scholarly journals α spectrin is essential for morphogenesis and body wall muscle formation in Caenorhabditis elegans

2002 ◽  
Vol 157 (4) ◽  
pp. 665-677 ◽  
Author(s):  
Kenneth R. Norman ◽  
Donald G. Moerman
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Membrane ◽  
Body Wall ◽  
Longitudinal Axis ◽  
The Body ◽  
Body Wall Muscle ◽  
Cell Stage ◽  
Muscle Formation ◽  
Spectrin Cytoskeleton ◽  
Caenorhabditis Elegans Genome

Acommon feature of multicellular animals is the ubiquitous presence of the spectrin cytoskeleton. Although discovered over 30 yr ago, the function of spectrin in nonerythrocytes has remained elusive. We have found that the spc-1 gene encodes the only α spectrin gene in the Caenorhabditis elegans genome. During embryogenesis, α spectrin localizes to the cell membrane in most if not all cells, starting at the first cell stage. Interestingly, this localization is dependent on β spectrin but not βHeavy spectrin. Furthermore, analysis of spc-1 mutants indicates that β spectrin requires α spectrin to be stably recruited to the cell membrane. Animals lacking functional α spectrin fail to complete embryonic elongation and die just after hatching. These mutant animals have defects in the organization of the hypodermal apical actin cytoskeleton that is required for elongation. In addition, we find that the process of elongation is required for the proper differentiation of the body wall muscle. Specifically, when compared with myofilaments in wild-type animals the myofilaments of the body wall muscle in mutant animals are abnormally oriented relative to the longitudinal axis of the embryo, and the body wall muscle cells do not undergo normal cell shape changes.

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