Sentences with phrase «oocytes by»

This process, called apoptosis, is triggered in oocytes by the protein p63.

«I had been taught that the sperm gets into the oocyte by its own movement,» he says.

Not exact matches

Many entities that are not embryos (teratomas, parthenotes, complete hydatidiform moles, and even enucleated oocytes) resemble embryos to varying degrees and yet can be reliably distinguished from embryos by careful comparison.

Then, the DNA would be removed from an oocyte (an egg cell) and this enucleated oocyte fused to the altered adult cell» creating a new cell that is neither an oocyte nor an adult cell but a hybrid exhibiting the properties programmed into it by the alterations made to the adult - cell nucleus.

Indeed, the ability to clone animals, such as Dolly the sheep, by fusion of an adult cell to an enucleated oocyte demonstrates that the epigenetic programming responsible for maintaining an adult cell in a stable state can be erased by factors present in the cytoplasm of the oocyte.

In the ovary of a normal mouse (left), a large follicle is shown at a late stage of development (a light pink oocyte surrounded by follicular cells, inset).

Somehow, scientists know, the genes that control development — generally turned off in adult cells — get turned back on again by the oocyte, enabling the cell to take on the youthful potential of a newly fertilized egg.

By turning on a several genes in adult cells, scientists can transform skin or blood cells into stem cells that can become every cell type in the body — without the ethical and practical complications of using embryos or oocytes.

Human oocytes were collected by laparoscopy and fertilized and cultured in vitro.

Alternatively, oocyte quality may be negatively affected by cryopreservation and thawing.»

They noted that a U.S. - led team in Mexico may have prevented Leigh syndrome in a child by replacing the mutation - bearing mitochondria of oocytes with donated mutation - free oocytes.

In the first cell cycle after fertilization the maternal genome inherited from the oocyte (egg) and the paternal genome provided by sperm exist as separate nuclei in the zygote.

An international team headed by Kikuë Tachibana - Konwalski from IMBA in collaboration with researchers from the Massachusetts Institute of Technology (MIT) in Boston and the Lomonosov Moscow State University (MSU) aimed to uncover how chromatin structure is reorganized during the mammalian oocyte - to - zygote transition.

Senior author and IMBA group leader Kikuë Tachibana - Konwalski is fascinated by the secrets of the mammalian oocyte - to - zygote transition and has been studying the miracle of life, and in particular the very first molecular steps, for many years.

Transmission can occur by ingesting oocytes from infected cat feces or by eating undercooked meat containing Toxoplasma cysts.

The other 1 million or so oocytes present at birth die off gradually by programmed cell death, or apoptosis, until a woman reaches menopause at mid-age.

The study, published today in the journal Cell Stem Cell and led by Dr. Shunsuke Ishii from RIKEN, sought to identify the molecule in the mammalian oocyte that induces the complete reprograming of the genome leading to the generation of totipotent embryonic stem cells.

Wilmut and his colleagues fuse the empty oocyte with the donor cell by bringing them together and subjecting them to an electric current.

Today, Roe said three outside labs have determined those two lines were not derived from cloned embryos, but instead came from embryos created by in vitro fertilization at MizMedi Hospital in Seoul, which collected oocytes for Hwang's research.

The paper «Non-canonical function of SAC proteins after APC activation reduces aneuploidy in mouse oocytes» is published in the journal Nature Communications and was funded by the Australian Research Council.

The study Mammalian oocytes locally remodel follicular architecture to provide the foundation for germ line - soma communication was co-authored by Stephany El - Hayek, Qin Yang, Laleh Abbassi, Greg FitzHarris, and Hugh J. Clarke.

The image shows a growing oocyte in the middle, which is very large with a bright green rim, surrounded by many small red follicle cells whose nuclei are stained blue.

The researchers introduced this extra gene, designed to be regulated in a way that is similar to normal huntingtin genes, by injecting rhesus macaque oocytes with a viral vector.

The experiments have been carried out using Xenopus laevis oocytes, an animal model used by the laboratory to study fundamental processes involved in gene regulation.

Outline title: «First live birth using human oocytes reconstituted by spindle nuclear transfer for mitochondrial DNA mutation causing Leigh syndrome» by J. Zhang et al. published in outline form by the American Society of Reproductive Medicine's Fertility and Sterility journal website.

The workshop is designed primarily as a «hands - on» laboratory course program in which participants practice and learn techniques for the cryopreservation of cleavage - stage embryos, spermatozoa, oocyte and ovaries, as developed and currently applied by the EMMA - INFRAFRONTIER partner repositories and by the Jackson Laboratory.

Oocyte maturation and embryo development data were entered into a two - by - two contingency table, and Fisher's exact test was used to generate P - values in Prism version 5.02 for windows (GraphPad Software, Inc.).

FGF2 and its receptors have been shown to be expressed at the protein level by both oocytes and granulosa cells up to secondary follicles [28], but the expression patterns in antral follicles have not been studied to date.

The cumulus cells that surround oocytes within follicles modulate nuclear and cytoplasmic maturation by both physical cell - cell contact and the combined actions of paracrine factors [8].

Gene expression data (CNRQ) of oocytes and cumulus cells were analyzed by one - way ANOVA with Bonferroni post test in Prism version 5.02.

Parthenogenesis, which can be induced in vitro by various electric, mechanical or chemical stimulations, is a valuable functional assay of oocyte developmental competence [15].

However, whether human oocytes express the receptors for FSH and LH is controversial [9],, and it is known that EGF affects oocyte maturation through the EGF receptor (EGFR), which is expressed by cumulus cells rather than the oocyte [11].

Both animal and human studies have demonstrated the important roles of neurotrophins (BDNF, NTF3 and NTF4) in oocyte maturation mediated by their receptors (NTRK1 — 3 and NGFRAP1)[20], [25].

In order to improve culture conditions for maturation of cumulus - free oocytes in vitro, we began by assaying the expression of 15 growth factors (BDNF, IGF - I, estradiol, GDNF, leptin, FGF1, FGF2, GM - CSF, EGF, TGF - α, TGF - β1; 2; 3, and ET - 1; 2) and 27 of their cognate receptors that have been shown to regulate oocyte maturation.

Then we tested functionality of oocytes matured in vitro by assessing the ability to develop to the blastocyst stage, and by comparing the gene expression profiles of parthenogenic embryos and those obtained from IVF / ICSI.

Following in vitro maturation, oocytes at metaphase II with the presence of a first polar body were activated using 10 µM calcium ionophore A23187 (Sigma - Aldrich) for 5 min followed by 2 mM DMAP (Sigma - Aldrich) for 4 h at 37 °C in 6 % CO2, 5 % O2 and 89 % N2.

By identifying these factors, it should be possible to induce pluripotency in somatic cells without using embryos or oocytes.

Oocytes, cumulus cells and frozen embryos were collected from Stanford Fertility and Reproductive Medicine Center after approval by the Stanford Institutional Review Board (IRB); all samples were obtained with written informed consent from all participants involved in the study.

Cumulus - oocyte complexes (COCs) were aspirated from 2 to 5 mm follicles with PBS (containing 5 % FCS) by using a 5 ml syringe fitted with a 20 - gauge needle.

Somatic cells can be reprogrammed either by nuclear transfer into oocytes or by fusion with embryonic stem (ES) cells.

These oocytes are arrested in prophase I (prophase of the first meiotic division) with fully cohesed homologs and sisters, and resume meiosis one by one each menstrual cycle.

In early - stage oocytes oskar - TRICK mRNA is labeled by both NLS - PCP - GFP (green) and NLS - MCP - RFP (red), fluorescent RNA - binding proteins, indicating translational repression.

Left: superimposed traces of junctional currents evoked by 10 mV voltage steps from -100 to +100 mV in one of a pair of Xenopus oocytes injected with cRNAs for the UNC proteins indicated below.

The presence of Stem Cells in the ovaries and their transformation into mature oocytes (egg cells) has been demonstrated in mice by Harvard researchers.

Women with a higher intake of dietary saturated fats have fewer mature oocytes available for collection in IVF, according to results of a study from the Harvard School of Public Health funded by the US National Institutes of Health.

Myo - inositol and melatonin have shown to enhance, synergistically, oocyte and embryo quality and may even help improve IVF outcomes in women with PCOS by offering protection against cell damage from oxidative stress.

Our results are in line with those of Choi et al's (43) finding that, despite lower E2 concentrations in women with moderate to high caffeine intake, the number of oocytes retrieved did not differ by caffeine category.

By the end of the follicular phase, the luteinizing hormone surge results in ejection of the oocyte and transforms the remaining follicle into the corpus luteum; small and large luteal cells are formed from theca and granulosa cells, respectively.

Mukherjee A, Malik H, Saha AP, Dubey A, Singhal DK, Boateng S, Saugandhika S, Kumar S, De S, Guha SK, Malakar D. Resveratrol treatment during goat oocytes maturation enhances developmental competence of parthenogenetic and hand - made cloned blastocysts by modulating intracellular glutathione level and embryonic gene expression.