Developmental-stage specific single-cell human embryo dissociation

Summary: Isolation of individual cells ensures detailed analysis of human embryos and promotes our understanding of molecular mechanisms driving embryo development and cell specification. Here, we present a protocol for the processing of human embryos for single-cell analysis. We describe steps for growing embryos and individualizing cells from the polar and the mural parts of trophectoderm at the blastocyst stage using laser dissection. We then detail embryo dissociation followed by steps to pick, wash, and dispense cells in plates. : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

Comparison of two automated sperm analyzers using 2 different detection methods versus manual semen assessment

International audiencePurpose: The exploration of male infertility is mainly based on semen analysis, but its evaluation might be affected by the operator's competence and subjectivity. This led to the development of automated semen analyzing systems. Despite continuous improvement, the precision and correlation of these automated systems with manual sperm assessment performed strictly according to WHO guidelines remains variable in the literature, and their role in daily practice is debated.Methods: In this double blind prospective study, we compared the results provided by 2 automated systems based on different concepts (CASA and electro-optical signal) with manual sperm assessment. Sperm concentration, motility and morphology were performed simultaneously and independently by different operators, blinded to each other.Results: A total of 102 unselected men attending the andrology department for routine sperm analysis were included in the study. We found no significant difference between each automated method and manual assessment for all sperm parameters, except for sperm morphology assessment where the electro-optical system gave higher results and performed slightly poorer than CASA. Correlation was moderate to high between manual assessment and each automated methods for all sperm parameters, with randomly distributed differences.Conclusions: Overall, these results show that both types of automated systems can be implemented in andrology laboratory for routine sperm analysis

Time-lapse technology improves total cumulative live birth rate and shortens time to live birth as compared to conventional incubation system in couples undergoing ICSI

International audiencePurpose: The improvement of clinical outcome provided by time-lapse technology (TLT) in IVF over conventional incubation (CI) still remains controversial. This study aimed at evaluating whether the exclusive use of time-lapse technology (TLT) during whole IVF care improves total cumulative live birth rate (TCLBR) and shortens time to live birth (TTLB) as compared to the use of CI in couples undergoing ICSI.Methods: This retrospective cohort study was conducted in couples with male infertility undergoing their first ICSI cycle in 2014-2015 and for whom embryo culture system remained the same during their whole IVF care, i.e., TLT or CI. Couples were followed up up to 2020, including all following frozen-embryo transfers and ICSI cycles (if any). Survival analysis was used to compare clinical outcome and time-related endpoints between both groups.Results: A total of 151 and 250 couples underwent their whole IVF care with the exclusive use of TLT and CI, respectively. Survival analysis showed that TCLBR after whole IVF care was significantly higher in TLT than in CI group (66.9 vs 56.4%, p=0.02, log-rank test). Median live birth time was significantly shorter in TLT than CI group (464 vs 596 days, p=0.01).Conclusions: We found that TCLBR and TTLB were significantly improved with TLT over CI in couples undergoing ICSI for male factor. This study fuels the debate on the clinical benefit of using TLT. The use of time-related endpoints adds important information for both patients and practitioners

The limit of cell specification concept: a lesson from scRNA-Seq on early human development

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Comorbidity Burden in Adults With Autism Spectrum Disorders and Intellectual Disabilities—A Report From the EFAAR (Frailty Assessment in Ageing Adults With Autism Spectrum and Intellectual Disabilities) Study

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Partial characterization of an exopolysaccharide secreted by a marine bacterium, Vibrio neocaledonicus sp nov., from New Caledonia

Aims Exopolysaccharides (EPS) are industrially valuable molecules with numerous useful properties. This study describes the techniques used for the identification of a novel Vibrio bacterium and preliminary characterization of its EPS. Methods and Results Bioprospection in marine intertidal areas of New Caledonia followed by screening for EPS producing brought to selection of the isolate NC470. Phylogenetic analysis (biochemical tests, gene sequencing and DNADNA relatedness) permitted to identify NC470 as a new member of the Vibrio genus. The EPS was produced in batch fermentation, purified using the ultrafiltration process and analysed by colorimetry, Fourier Transform Infrared spectroscopy, gas chromatography, Nuclear Magnetic Resonance and HPLC-size exclusion chromatography. This EPS exhibits a high N-acetyl-hexosamines and uronic acid content with a low amount of neutral sugar. The molecular mass was 672x103Da. These data are relevant for possible technological exploitation. Conclusions We propose the name Vibrio neocaledonicus sp. nov for this isolate NC470, producing an EPS with an unusual sugar composition. Comparison with other known polymers permitted to select applications for this polymer. Significance and Impact of the Study This study contributes to evaluate the marine biodiversity of New Caledonia. It also highlights the biotechnological potential of New Caledonia marine bacteria

Identification of cryptic Candida species by MALDI-TOF mass spectrometry, not all MALDI-TOF systems are the same: focus on the C. parapsilosis species complex

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Integrated pseudotime analysis of human pre-implantation embryo single-cell transcriptomes reveals the dynamics of lineage specification

Understanding lineage specification during human pre-implantation development is a gateway to improving assisted reproductive technologies and stem cell research. Here we employ pseudotime analysis of single-cell RNA sequencing (scRNA-seq) data to reconstruct early mouse and human embryo development. Using time-lapse imaging of annotated embryos, we provide an integrated, ordered, and continuous analysis of transcriptomics changes throughout human development. We reveal that human trophectoderm/inner cell mass transcriptomes diverge at the transition from the B2 to the B3 blastocyst stage, just before blastocyst expansion. We explore the dynamics of the fate markers IFI16 and GATA4 and show that they gradually become mutually exclusive upon establishment of epiblast and primitive endoderm fates, respectively. We also provide evidence that NR2F2 marks trophectoderm maturation, initiating from the polar side, and subsequently spreads to all cells after implantation. Our study pinpoints the precise timing of lineage specification events in the human embryo and identifies transcriptomics hallmarks and cell fate markers

Induction of human trophoblast stem cells from somatic cells and pluripotent stem cells

International audienceHuman trophoblast stem cells (hTSCs) derived from blastocysts and first-trimester cytotrophoblasts offer an unprecedented opportunity to study the placenta. However, access to human embryos and first-trimester placentas is limited, thus preventing the establishment of hTSCs from diverse genetic backgrounds associated with placental disorders. Here, we show that hTSCs can be generated from numerous genetic backgrounds using post-natal cells via two alternative methods: (1) somatic cell reprogramming of adult fibroblasts with OCT4, SOX2, KLF4, MYC (OSKM) and (2) cell fate conversion of naive and extended pluripotent stem cells. The resulting induced/converted hTSCs recapitulated hallmarks of hTSCs including long-term self-renewal, expression of specific transcription factors, transcriptomic signature, and the potential to differentiate into syncytiotrophoblast and extravillous trophoblast cells. We also clarified the developmental stage of hTSCs and show that these cells resemble day 8 cytotrophoblasts. Altogether, hTSC lines of diverse genetic origins open the possibility to model both placental development and diseases in a dish