Human cleaving embryos enable robust homozygotic nucleotide substitutions by base editors.

Base editing installs a precise nucleotide change in specific gene loci without causing a double-strand break. Its efficiency in human embryos is generally low, limiting its utility in functional genetic studies. Here, we report that injecting base editors into human cleaving two-cell and four-cell embryos results in much higher (up to 13-fold) homozygotic nucleotide substitution efficiency as opposed to MII oocytes or zygotes.

Using time-lapse technology to explore vacuolization in embryos on Day 3 and Day 4.

Purpose: To investigate the occurrence and development state of embryo vacuoles between the 8-cell and morula stages, and to explore how vacuoles affected the development of embryos.

Methods: A retrospective study of a cohort of 422 patients undergoing conventional in vitro fertilization or intracytoplasmic sperm injection. With the help of time-lapse imaging, the development processes and outcomes of good quality embryos with or without vacuoles were analyzed.

Tild-CRISPR Allows for Efficient and Precise Gene Knockin in Mouse and Human Cells.

The targeting efficiency of knockin sequences via homologous recombination (HR) is generally low. Here we describe a method we call Tild-CRISPR (targeted integration with linearized dsDNA-CRISPR), a targeting strategy in which a PCR-amplified or precisely enzyme-cut transgene donor with 800-bp homology arms is injected with Cas9 mRNA and single guide RNA into mouse zygotes. Compared with existing targeting strategies, this method achieved much higher knockin efficiency in mouse embryos, as well as brain tissue.

miR-15a-5p levels correlate with poor ovarian response in human follicular fluid.

Poor ovarian response is a significant problem encountered during fertilization and embryo transfer procedures. Many infertile women may suffer from poor ovarian response and its incidence tends to be increasing in young patients nowadays. It is a major cause of maternal infertility because it is associated with low pregnancy and live birth rates.

Synthesis, biological evaluation and modeling studies of terphenyl topoisomerase IIα inhibitors as anticancer agents.

We report the synthesis and evaluation of a series of novel terphenyls. Compound 17 had the most potent anticancer activity, indicating that the phenolic hydroxyl was a key group. A DNA relaxation test showed that compound 17 had a strong inhibitory effect on TOP2α, but not on TOP1, which was consistent with the docking analysis results.

Polycystic ovary syndrome susceptibility single nucleotide polymorphisms in women with a single PCOS clinical feature.

Study Question: What is the direct genetic contribution of the polycystic ovary syndrome (PCOS) susceptibility single nucleotide polymorphisms (SNPs), identified by previous genome-wide association studies (GWAS) to the definitive clinical features of the syndrome?

Summary Answer: Each single PCOS clinical feature had a specific genetic association, and rs4385527 in the chromosome 9 open reading frame 3 (C9orf3) conferred a particular risk to the three defined PCOS clinical features in this study, which suggested its fundamental role in the etiology of PCOS.

What Is Known Already: PCOS is a heterogeneous disorder characterized by anovulation (OA), hyperandrogenism (HA) and polycystic ovary morphology (PCOM). Two previous GWAS in China have identified 15 independent susceptibility SNPs related to PCOS (PCOS-SNPs).

Pregnancy with oocytes characterized by narrow perivitelline space and heterogeneous zona pellucida: is intracytoplasmic sperm injection necessary?

Purpose: This retrospective study analyzed fertilization protocols and pregnancy outcomes for oocytes with with narrow perivitelline space and heterogeneous zona pellucid (NPVS/HZP).

Methods: In 63 in-vitro fertilization cycles filled with NPVS/HZP oocytes (abnormal oocytes group) and 521 cycles with normal oocytes (normal oocytes group), major clinical and laboratory parameters were recorded and compared in different fertilization cycles (conventional IVF cycles, rescue ICSI cycles, and traditional ICSI cycles).

Results: NPVS/HZP oocytes meant lower MIIoocytes rates in both IVF and ICSI cycles compared with normal oocytes (p < 0.

Elective single blastocyst transfer is more suitable for normal responders than for high responders.

Background: Embryo quality and receptivity of the endometrium are two factors that determine the results of in vitro fertilization/intra-cytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET). There is no consensus of the optimal transfer strategy for normal responders or high responders. The current study aimed to find the optimal transfer strategy for different subgroups of patients.

Evaluation of the developmental potential of metaphase I oocytes from stimulated intracytoplasmic sperm injection cycles.

The objective of the present study was to evaluate the developmental potential and clinical application value of metaphase I (MI) oocytes obtained from stimulated intracytoplasmic sperm injection (ICSI) cycles. ICSI was performed on MI oocytes immediately after denudation (Group A), or on in vitro-matured (IVM) oocytes following culture; oocytes in culture were further divided into two groups, being cultured for either 3-5 h (Group B) or 24-28 h (Group C). Metaphase II oocytes from the same cycle(s) isolated for ICSI served as the control group (Group D).

[Comparison of vitrification and slow-freezing of human day 3 cleavage stage embryos: post-vitrification development and pregnancy outcomes].

Objective: To compare the effects of vitrification with slow-freezing on the developmental ability of day 3 cleavage stage embryos.

Methods: Patients who had no less than 4 high quality embryos were included in this study. These embryos were cryopreserved using the methods of vitrification or slow-freezing.