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Tag: "embryos" at biology news

Salk scientists get to the root of plant cell fate

...r. A defective TOPLESS gene, however, causes plant embryos to develop into a seedling with two oppositely ori... to discover how cells at the "basal" end of plant embryos become roots, while cells at the top or "apical" end become shoots that give rise to leaves, branche...

Researchers report technique for freezing and preserving genetically enhanced pig embryos

... reported success in freezing and preserving swine embryos that were created by in vitro techniques and that ...ng and transfer to a surrogate mother, some of the embryos went on to produce live piglets with new genetic traits. In a paper posted today (May 3, 2006) on t...

Why mice don't get cancer of the retina

...evelopment. The authors show that, in mutant mouse embryos that do not express Rb at all, the levels of p107 are much higher than in wild-type embryos at the same stage in development. The reverse situation is observed in mutant embryos that do not ex...

Mobile DNA part of evolution's toolbox

...use eggs. Eleven days later, he examined the mouse embryos to see whether and where the reporter gene was switched on. Sure enough, the gene was active in the embryos' developing nervous systems, as would be expected if the LF-SINE copy were regulating the activity of ISL1. The discoverer of mobile DNA el...

Tweedle coat fashions stocky flies

... parts of the cuticle--the tough outer coat in fly embryos and larvae. The exact function of the Tweedles is not known, but the researchers think they strengthen the cuticle. Make one part too weak or too strong and the larvae end up resembling their namesake. Tweedles may be good targets for novel ...

Embryo tests give parents the choice

...ties or specific gene mutations. Seemingly healthy embryos are implanted in the womb; others are discarded or...hirds of PGD procedures were performed to identify embryos at risk of birth defects or being miscarried. However, the survey also revealed that applications o...

A transplant in time

...en experimenting with tissue transplanted from pig embryos ?a possible substitute for human donor organs. Fro...liac mice with spleen tissue transplanted from pig embryos at this time experienced completely normal blood clotting within a month or two of implantation. ...

A giant among minnows: Giant danio can keep growing

...iga said. What makes this intriguing is that human embryos exhibit hyperplasia, but then lose that ability after birth, with one exception. When humans injure a muscle, the muscle sends a signal to special cells attached to the muscle fibers, telling these cells to grow and join to adjacent muscle fiber to r...

Oldest animal fossils may have been bacteria

... phosphorite. The fossils identified as eggs and embryos in 1998 came from southern China's Doushantuo Form...ailey knew that the fossils had been identified as embryos in part because they showed evidence of reductive cell division. Then he thought again about the pho...

Embryonic selection of sex avoids conceiving blind children

...blind. This is because, in order to select healthy embryos in a manner that does not involve sex selection, it would be essential to know the exact mutation in the chromosome, something which has not been achieved in this particular case. This embryonic selection enables the prevention of the transmission...

Down syndrome: It's not just the age factor

...e, have a relaxed stringency of quality control of embryos (or relaxed filtering stringency), which increases the probability that these women will bring children with developmental defects to full term. They believe that this relaxed filtering stringency is an adaptive maternal response and it might explai...

Researchers discover that sheep need retroviruses for reproduction

...eate cells, did not develop. The result was that embryos could not implant and the sheep miscarried, Spencer said. Miscarriage is a serious medical problem for all mammals, including humans. "Our research supports the idea that endogenous retroviruses shaped the evolution of the placenta in mammals and...

Bad blood between boys and girls

...to the researchers, the increased survival of male embryos in infected women may be explained by toxoplasmosis' modulating and suppressing effects on the immune system. The authors caution that this observational study suggests that toxoplasmosis may be the cause of this increase in male births, but it ca...

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

...es 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 three days and are transparent. Also, single cells can be easily observed live in th...

Who gives stem cells their marching orders?

...tant regulatory genes. The ISREC group showed that embryos already need Nodal when they attach to the wall of the uterus, to expand their pool of stem cells, and to let individual cells know where they are with respect to their neighbors. However, to carry out these tasks, the Nodal protein must be cleaved b...

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

...ps of recipients were comparable and the number of embryos transferred in each cycle (between one and three) was also comparable between the groups. Lead researcher Dr Sérgio Soares, Director of the IVI Clinic in Lisbon, said: "The non-heavy smokers had a significantly higher pregnancy rate, with over hal...

NYU biologists identify gene that coordinates two cellular processes

...letely sequenced and a model organism to study how embryos develop. The study appearing in Current Biology was performed by NYU's Fabio Piano, an assistant professor, and Anita Fernandez, a post-doctoral researcher, at the Center for Comparative Functional Genomics. Biologists can draw connections between...

Lost in the labyrinth

...l role in shaping tissues and organs in developing embryos of nearly all animal species. It also helps organisms manage stem cells, by keeping them on hold and preventing their differentiation until the right time. Such pathways are usually switched on and off by external stimuli that help cells respond prop...

Harvard scientists identify compounds that stimulate stem cell growth in the brain

... When stem cells isolated from the brains of mouse embryos were exposed to LTB4 they proliferated and differentiated, giving rise to additional stem cells and to differentiated neurons with limited or absent capacity to divide. When exposed to LXA4, these cells experienced decreased growth and apoptosis. ...

Many couples choose to donate surplus embryos for stem cell research

...zation (IVF) chose to donate their surplus, stored embryos for stem cell research, according to a report by t...the couples would be willing to donate their spare embryos for stem cell research," said Pablo Menendez, director of the Spanish Stem Cell Bank in Granada, Spa...

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