体外受精-胚胎移植周期卵细胞MetaphaseⅠ期停滞的形态学特征

目的:观察体外受精-胚胎移植周期中全部卵细胞M etaphase I期停滞的形态学特征与体外成熟培养促熟率。方法:2例体外受精-胚胎移植周期患者,获得卵细胞均处于M etaphase I期,行体外成熟培养,同期评价其形态学特征。结果:M etaphase I期停滞卵细胞的胞质质地均一,透明带致密透亮,无卵周隙。卵周颗粒细胞与透明带、颗粒细胞之间结构松散,无放射样形态。经体外成熟培养,24、48、72 h形态学特征观察无明显改变,无极体放出,均停滞于M etaphase I期。结论:体外受精-胚胎移植周期出现全部卵细胞M etaphaseⅠ期停滞的卵细胞存在特有形态学特征,现有体外成熟培养方法尚无法促熟。

Spontaneous and Bleomycin-Induced <i>&gamma;</i>H2AX Signals in CHO9 Metaphase Chromosomes

In eukaryotes, a cascade of events named DNA damage response (DDR) has evolved to handle DNA lesions. DDR engages the recruitment of signaling, checkpoint control, repair and chromatin remodeling protein complexes, allowing cell cycle delay, DNA repair or induction of apoptosis. An early DDR event involves the phosphorylation of the histone variant γH2AX on serine 139 (H2AX139 phosphorylation) originating the so-called γH2AX. DDR-related H2AX139 phosphorylation have been extensively studied in interphase nuclei. More recently, γH2AX signals on mitotic chromosomes of asynchronously growing cell cultures were observed. We performed a quantitative analysis of γH2AX signals on γH2AX immunolabeled cytocentrifuged metaphase spreads, analyzing the γH2AX signal distributions of CHO9 chromosomes harboring homologous regions both in control and bleomycin (BLM)-treated cultures. We detected γH2AX signals in CHO9 chromosomes of controls which significantly increase after BLM-exposure. γH2AX signals were uniformly distributed in chromosomes of controls. However, the γH2AX signal distribution in BLM exposed cells was significantly different between chromosomes and among chromosome regions, with few signals near the centromeres and a tendency to increase towards the telomeres. Interestingly, both basal and BLM-induced γH2AX signal distribution were statistically equal between CHO9 homologous chromosome regions. Our results suggest that BLM exerts an effect on H2AX139 phosphorylation, prevailing towards acetylated and gene-rich distal chromosome segments. The comparable H2AX139 phosphorylation of homologous regions puts forward its dependence on chromatin structure or function and its independence of the position in the karyotype.

Effects of vitrification and cryostorage duration on single-cell RNA-Seq profiling of vitrified-thawed human metaphase Ⅱ oocytes

Oocyte cryopreservation is widely used for clinical and social reasons.Previous studies have demonstrated that conventional slow-freezing cryopreservation procedures,but not storage time,can alter the gene expression profiles of frozen oocytes.Whether vitrification procedures and the related frozen storage durations have any effects on the transcriptomes of human metaphase Ⅱ oocytes remain unknown.Four women(30–32 years old)who had undergone IVF treatment were recruited for this study.RNA-Seq profiles of 3 fresh oocytes and 13 surviving vitrified-thawed oocytes(3,3,4,and 3 oocytes were cryostored for 1,2,3,and 12 months)were analyzed at a single-cell resolution.A total of 1987 genes were differentially expressed in the 13 vitrifiedthawed oocytes.However,no differentially expressed genes were found between any two groups among the 1-,2-,3-,and 12-month storage groups.Further analysis revealed that the aberrant genes in the vitrified oocytes were closely related to oogenesis and development.Our findings indicated that the effects of vitrification on the transcriptomes of mature human oocytes are induced by the procedure itself,suggesting that long-term cryostorage of human oocytes is safe.

Neoplastic-Like CELL Changes of Normal Fibroblast Cells Associated with Evolutionary Conserved Maternal and Paternal Genomic Autonomous Behavior (Gonomery)

The present comparative review discusses conservation of early evolutionary, relic genetics in the genome of man, which determine two different mechanistic reductive division systems expressed by normal, human diploid cells. The divisions were orderly and segregated genomes reductively to near-diploid daughter cells, which showed gain of a proliferative advantage (GPA) over cells of origin. This fact of GPA expression is a fundamental requirement for initiation of tumorigenesis. The division systems were responses to a carcinogen-free induction system, consisting of short (1 - 3 days) exposures of young cells to nutritional deprivation of amino acid glutamine (AAD). In recovery growth (2 - 4 days) endo-tetra/ochtoploid cells and normal diploid metaphase cells demonstrated chromosomal reductive divisions to respectively heterozygous and homozygous altered daughter cells. Both division systems showed co-segregating whole complements, which for reduction of the diploid metaphases could only arise from gonomeric-based autonomous behavior of maternal and paternal (mat/pat) genomes. The timely associated appearance with these latter divisions was fast growing small-cells (1/2 volume-size reduced from normal diploidy), which became homozygous from haploid, genomic doubling. Both reductive divisions thus produced genome altered progeny cells with GPA, which was associated with pre-cancer-like cell-phenotypic changes. Since both “undesirable” reductive divisions expressed orderly division sequences, their genetic controls were assumed to be “old genetics”, evolutionarily conserved in the genome of man. Support for this idea was a search for evidential material in the evolutionary record from primeval time, when haploid organisms were established. The theory was that endopolyploid and gonomery-based reductive divisions relieved the early eukaryotic organisms from accidental, non-proliferative diploidy and polyploidy, bringing the organism back to vegetative haploid proliferation. Asexual cycles were common for maintenance of propagating haploid and diploid early unicellular eukaryotes. Reduction of accidental diploidy was referred to as “one-step meiosis” which meant gonomeric-based maternal and paternal genomic independent segregations. This interpretation was supported by exceptional chromosomal behaviors. However, multiple divisions expressing non-disjunction was the choice-explanation from evolutionists, which today is also suggested for the rarer LL-1 near haploid leukemia. These preserved non-mitotic mechanistic divisions systems are today witnessed in apomixes and parthenogenesis in many animal phyla. Thus, the indications are the modern genome of man harbors, relic-genetics from past “good” evolvements assuring “stable” proliferation of ancient, primitive eukaryotes, but with cancer-like effects for normal human cells.

On Dryden's 3 types of translation

This paper aims at analyzing and comprising the similarities and differences between metaphase and literal translation,paraphrase and free translation.

Melatonin improves the first cleavage of parthenogenetic embryos from vitrified-warmed mouse oocytes potentially by promoting cell cycle progression

Background:This study investigated the effect of melatonin(MT)on cell cycle(G1/S/G2/M)of parthenogenetic zygotes developed from vitrified-warmed mouse metaphase II(MII)oocytes and elucidated the potential mechanism of MT action in the first cleavage of embryos.Results:After vitrification and warming,oocytes were parthenogenetically activated(PA)and in vitro cultured(IVC).Then the spindle morphology and chromosome segregation in oocytes,the maternal mRNA levels of genes including Miss,Doc1r,Setd2 and Ythdf2 in activated oocytes,pronuclear formation,the S phase duration in zygotes,mitochondrial function at G1 phase,reactive oxygen species(ROS)level at S phase,DNA damage at G2 phase,early apoptosis in 2-cell embryos,cleavage and blastocyst formation rates were evaluated.The results indicated that the vitrification/warming procedures led to following perturbations 1)spindle abnormalities and chromosome misalignment,alteration of maternal mRNAs and delay in pronucleus formation,2)decreased mitochondrial membrane potential(MMP)and lower adenosine triphosphate(ATP)levels,increased ROS production and DNA damage,G1/S and S/G2 phase transition delay,and delayed first cleavage,and 3)increased early apoptosis and lower levels of cleavage and blastocyst formation.Our results further revealed that such negative impacts of oocyte cryopreservation could be alleviated by supplementation of warming,recovery,PA and IVC media with 10^(−9) mol/L MT before the embryos moved into the 2-cell stage of development.Conclusions:MT might promote cell cycle progression via regulation of MMP,ATP,ROS and maternal mRNA levels,potentially increasing the first cleavage of parthenogenetic zygotes developed from vitrified-warmed mouse oocytes and their subsequent development.

卵母细胞成熟障碍4例与同期卵母细胞大部分不成熟患者比较分析

目的分析4例体外受精-胚胎移植(IVF-ET)患者共8个辅助助孕周期,全部73个卵母细胞均处于GV、Metaphase I期的可能原因。并与同期13例IVF-ET患者比较分析,比较组患者>50%卵母细胞处于GV、Metaphase I期。方法回顾分析本中心12年辅助助孕工作中出现的4例患者共8个周期所获卵母细胞均处于GV、MI的临床及实验室资料,并与同期13例超过50%卵母细胞处于GV、MI患者的临床、实验室资料进行比较。结果 4例患者73个卵母细胞均处于GV或MI期,经体外成熟培养,24,48,72 h仍无极体排出,停滞于GV、MI期。同期13例患者大部分卵母细胞不成熟,但体外培养后部分卵母细胞可进一步成熟,并可受精,获得妊娠。结论细胞和遗传机制引起卵母细胞成熟障碍,现有体外成熟培养方法尚无法促其成熟,目前赠卵是该类患者获得妊娠可供选择的助孕方法。但对于在控制性超促排卵中,出现大部分卵母细胞不成熟的患者可以通过延长促超排时间,增大hCG注射日卵泡直径,体外成熟培养等方法获得成熟的卵母细胞,获得妊娠。

Nucleolar Organizer Regions in Oreochromis nilotica Chromosomes

The nucleolar organizer regions (NORs) in the mitotic chromosomes of tilapia Oreochromis niloticus were analyzed using silver nitrate staining Ag detected NORs(Ag NORs) in the chromosomes of the tilapia exhibited heteromorphism. Individual Ag NORs sizes varied on different chromosomes, and the number of Ag NOR per cell varied from three to six. Among the examined 100 cells, 71% of the gnomes carried four Ag NORs, 12% carried 3,11% carried 5, and 6% carried 6. The variance occurred not only among different cells but also among different cells from the same source. The satellite association between homologous chromosomes in No 7 was also observed in 27% of the metaphase chromosome preparations. The heteromorphic properties of Ag NORs were discussed.