Evolution Re-Sculpted Animal Limbs By Genetic Switches Once Thought Too Drastic For Survival
...tremely powerful genes that govern the shape of an embryo from the earlieststages of development have been t...ty comes not so much from controlling where in the embryo the homeoticgenes are initially expressed, but how other genes respond to them." Instead, Patel and ...Jefferson Scientists Find Potential Deadly Effects Of Two Missing Cancer-Suppressor Genes
...emale mice stopped developing and died. "The embryo was undergoing global apoptosis, or programmed cell death," he said. "These embryos are self-destructing. As many as 60 to 90 percent of the cells underwent apoptosis." Men have an X and a Y chromosome; women carry two Xs. During nor...Study Shows Hereditary Legacy Of Radiation Exposure
...ells are then combinedwith four cells from another embryo -- one without a history of radiation-- and allowed to multiply several times. Then the scientists count thetotal number of cells (one of the embryos has a special marker so it canbe distinguished from the other). If there are fewer cells from the ce...At Life's Most Sensitive Stage, Embryos Cope With Stress
...t howembryos cope with their environments, yet the embryo is the most fragile stagein the life cycle, and it... than inadults, Epel said. "One reason is that the embryo has not developed the adult'smechanisms for coping. It is adapted to a particular niche and to a par...Amphibian Mortality Due To UV Radiation
...example, he and his colleagues noted anincrease in embryo mortality of 15 to 20 percent in the Western toad and theCascade frog -- two species with low levels of photolyase -- while the Pacifictree frog, which has a high photolyase level, is thriving. All three specieslive in the same habitat in the Cascad...Uterine Environment Boosts Learning Ability In Mouse Offspring
...nsfer group consisted of BXSB mothers with natural embryo implantation.The In-Strain Transfer group had BXSB mothers with transplanted embryos. And theOut-Strain Transfer group consisted of non-automimmune CB6F1 hybrid mothers withtransplanted embryos. The Non-Transfer and Out-Strain pups were deliveredvagi...Tiny Worm Reveals Workings Of Suspected Tumor Protein
... of the humanprotein p300 helps cells in the early embryo decide what kind of tissue tobecome. Shi found tha...kes activesignaling to dissuade a prospective male embryo from its inherent tendency tobecome a girl. Moreover, a separate line of investigation is co...Human Bone Disorder Reproduced In Mice
...s case, the mutation would affect all cells in the embryo and lead toearly embryo death. The investigators felt that the same principle might applyto individual lesions in MAS patie...Two Environmental Articles: Deformed Frogs & Dioxin In Old Soil
...eaks upinto other products that dramatically alter embryo development. By addingminute amounts of these degradation products to developing embryos of theAfrican clawed frog, Xenospus laevis, the Scripps group found that the embryodeveloped into a juvenile with deformations similar to those found in nature....The First Rejection: Eggs Sequester Bits Of Sperm For Later Elimination
...ilization, persist in the developing midgut of the embryo and are excreted soon after the larva hatches, rep...egment persisted throughout the development of the embryo untouched." Karr and Pitnick decided to look more closely at this stubborn section of sperm tail. U...Precursors To Red Blood Cells Form Earlier Than Previously Thought
...ies' annual meeting in New Orleans.Using the mouse embryo as a model, the researchers sought topinpoint the ...ll fates, if blood cell precursors originatein the embryo or in the yolk sac, and at what point they show upin the body of the embryo," said Jim Palis, M.D., ......rt of the thyroid gland of the mutant embryo is composed of C-cells, and no T4-producing cells are present. The mutation of the Pax8 gene thus affects the major part of the organ, which produces the thyroid hormones. Early diagnosis and therapy of hypothy...Who Needs Flowers? Transgenic Plants Sprout Embryos On Leaves
...y pass thosequalities down to their offspring. But embryo farming could produce "artificial seeds" thatwould all be clones of the hybrid parent and perpetuate itsstrengths, said Harada and another author of the study,biologist Bob Goldberg of UCLA. "If the LEC1 gene paves the way to the development of seeds...First Reproducible Cloning Of Mammals From Adult Cells Reported In Nature
...epeatedly to reach the multi-cellstage at which an embryo is called a blastocyst. Cells in blastocysts beginto mass in preparation to form the first tissues of an embryonic mouse. "We discovered that a relatively high proportion of the oocytesdeveloped into blastocysts and then further developed when we in...Defects In Embryonic Development In Lunatic Fringe Knockout Mice
..., the influence of the primary segmentation of the embryo can beobserved in the segmented pattern of the vertebrae and spinal nerves. The Drosophila fringe gene, which encodes a secreted signaling moleculerequired for Notch activation during wing formation in the fruit fly, has threeknown homologues......gof neural tissue growth in the back region of the embryo and other tissue typesin the abdominal region. "In the swirl mutant, all abdominal tissue is absent, but the surprisecame when we started to look at the dorsal neural tissue and found that most ofit expanded and took over the ventral side,"...... discovered. Using specially altered mouse embryo cells deficient in the gene BRCA1,the scientists found the gene directly or indirectly participates in what iscalled transcription-coupled repair. "BRCA1's exact role is currently unknown, but it seems to be involved ina variety of cellular ......astrulation is the developmental stage at which an embryo first forms its germ layers: the endoderm, mesoderm, and ectoderm. (Germ layers give rise to various organs later in development.) cyclops: the gene The authors founds that the zebrafish cyclops gene resembles the nodal geneof mouse and related gen...Researchers Grow Healthy Human Placental Cells For Drug Research
... during the first few weeks of pregnancy, as an embryo travels down the mother’s fallopian tube t...hat the cells proliferate the fastest. When the embryo attaches itself to the uterus and the umbilical cord forms, the embryo is bathed in oxygen, and c...Fossil Evidence Of Worms Over One Billion Years Old Reported In Science
...ploblastic animals (animals that developed from an embryo and that containthree outer membranes, as do worms). The authors note in their paper that the existence of worm-like animalsso much earlier than the Cambrian period would suggest that "animal body planschanged very little before the explosive...