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Tag: "embryo" at biology news

Loss of stem cells correlates with premature aging in animal study

...vania have found that deleting a gene important in embryo development leads to premature aging and loss of stem cell reservoirs in adult mice. This gene, ATR, is essential for the body’s response to damaged DNA, and mutations in proteins in the DNA damage response underlie certain types of cancer and other ...

Studies to find better ways to preserve human eggs, ovarian tissue under way

...mes can’t properly divide. Typically the resulting embryo dies. Plus, fertilization is unlikely since freezing often hardens the egg’s outer shell that sperm must penetrate. “That is why we have tried to develop technology without freezing,” says Dr. Song, who has pioneered use of vitrification in blood ...

Male-killing bacteria makes female butterflies more promiscuous

...other to son and actually kills the son before the embryo hatches into a caterpillar. Only female offspring of female carriers of the bacteria can survive, which can lead to the male population being as low as one male to every hundred females in some areas. Dr Greg Hurst, of the UCL Department of Biolog...

Scientists discover new, readily available source of stem cells

...all three classes of cells found in the developing embryo - termed ectoderm, mesoderm, and endoderm. In their high degree of flexibility and growth potential, the AFS cells resemble human embryonic stem cells, which are believed capable of generating every type of adult cell. "The full range of cells tha...

Scientists discover stage at which an embryonic cell is fated to become a stem cell

...of Nature. After fertilisation, the cells of the embryo at first undergo equal, symmetrical divisions and ...s. Previously, it was believed that the mammalian embryo starts its development with identical cells and only as these inside and outside cells form do diffe...

Procedure predicts embryos most likely to result in pregnancy

...nt is needed over the current methodology used for embryo evaluation. The new procedure will be presente...scopy, will determine the metabolic profile of the embryo and accurately predict its reproductive potential," said Seli, who plans to confirm the findings in ...

Penn researchers replace organ in adult mice using 'single-parent' stem cells

...er. "The fact that we are not destroying a viable embryo in the process also avoids certain ethical issues ...ation." Parthenogenesis, the act of creating an embryo without fertilization, is common in some plants, insects and animals, including the recent and celeb...

Stem cell therapy shows promise in regenerating damaged muscle in heart attack patients

...ne marrow donors and are not derived from a fetus, embryo or animal. Because they are in an early stage of development, it is believed that they do not trigger an immune response when placed in someone else's body. Similar to Blood Type O, these MSCs are being used without tissue type matching to a speci...

Reversing cancer cells to normal cells

...c reproduction, rapid development, and transparent embryo that develops outside the body (making it especial... the human embryonic stem cell model and the chick embryo model - where inhibiting Nodal signaling led to the reversal of the melanoma cells to a more normal ...

Breathing easy: When it comes to oxygen, a bug's life is full of it

...died the development of the tracheal system in the embryo fruit fly, noting how cells form into trachea, and how trachea branch to smaller trachea and eventually connect to form the tracheal network. His laboratory, which has identified more than 50 genes controlling various aspects of airway development, h...

NYU scientists identify how development of different species uses same genes with distinct features

...er RNA (mRNA), is localized at the anterior of the embryo where it is required both to promote anterior development and to repress posterior development. However, bicoid is unique to flies and does not exist in wasps or other species: The study’s findings show that it takes several mRNAs localized in the eg...

Cloned mice created from fully differentiated cells, a milestone in cloning research

...seases and conditions. Yet, even for cloning of an embryo to the blastocyst stage, from which embryonic stem... scientific term for cloning, involves creating an embryo by using a nucleus that's been removed from a somatic cell ?any cell other than a reproductive cell ...

Cracking the egg

...lization requires more genetic activity than early embryo development. There's a far greater diversity of RN...l than in the two-cell embryo, perhaps because the embryo is independent and the pre-ovulatory egg must still coordinate signals with surrounding tissues. A...

Heavy smoking cuts women's chance of pregnancy -- even with donated oocytes

...ing it less receptive and reducing the chances the embryo will implant, according to research published on l...some women to others or triggers a response in the embryo itself, resulting in a reduced general pregnancy rate overall, but an increased chance of multiple p...

Who gives stem cells their marching orders?

...ory activities -- maintaining stem cells after the embryo has implanted in the mother's uterus, and later pr...ion when the time is ripe. The development of an embryo from a few seemingly identical stem cells is a truly awesome feat of nature. As they bathe in a chem...

Sea urchin genome suprisingly similar to man and may hold key to cures

.... Using a "simple" creature like the sea urchin embryo to uncover the molecular basis underlying development offers several experimental advantages compared to the use of mice. Raising sea urchin embryos is easy and inexpensive. One female can provide up to 20 millions eggs. The embryos develop in just t...

Embryonic patterning makes the feathers fly

...er buds, will appear on the skin of the developing embryo wherever fibroblast growth factor (FGF) is activated. The mystery has been how a pattern of activation was laid down by FGF. Speculation pointed to a downstream cellular signaling pathway but which one (and if it was just one pathway) was unknown. ...

Some butterflies travel farther, reproduce faster

...in is the protein precursor to egg yolk, which the embryo uses for food. Total protein is the most important nutrient for egg maturation, he said. Adds to previous study Previous studies had found other physiological differences between these more robust butterflies and their status quo sisters and br...

How blood flow dictates gene expression

... that the expression of Klf2 in a developing mouse embryo mirrors events in previous tissue-culture studies. They found that Klf2 is expressed on the high-flow side of developing mitral and aortic valves in the heart of a 14-day-old embryo. The researchers surmise that the mechanical stimulus of blood fl...

How does a zebrafish grow a new tail?

...s the fate of these as-yet undeveloped cells as an embryo forms. Through a cascade of signals, cells waiting for their calling learn which spot to take to help form the embryo, what kinds of cells to become there, and how many cells like themselves should be reproduced. These streams of signals also tell st...

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