egg

Cytoplasm affects the number of vertebrae in carp-goldfish clones

...n offspring, cloned from nuclei of common carp and egg cytoplasm of goldfish, were virtually identical to...my of Sciences, in Wuhan, China, conclude that the egg cytoplasm, and not the genetic code of the transplanted nucleus, influenced this aspect of the skele...

Researchers reveal the infectious impact of salmon farms on wild salmon

...ys Krkosek. "Some of these fish are so young their egg sacks haven't been fully absorbed ?even fish this small are infected." The anchored farms, open cages of closely packed salmon, are aquatic feedlots providing the ideal conditions for the breeding and spread of sea lice amongst the adult fish. For t...

Needling Chromosomes Reveals Cell Division Secret

...mitosis, as well as the proliferation of sperm and egg cellscalled meiosis."Chromosomes in mitosis and meiosis have to be held together, becauseotherwise they don’t attach to the apparatus called the spindle thatdistributes them to opposite poles," explained Nicklas, who is aResearch Professor of Biology...

Influenza vaccine uses insect cells to speed development

...njected into the fluid surrounding the embryo. The egg is then resealed, the embryo becomes infected, and the resulting virus is then harvested, purified and used to produce the vaccine. In addition to the long development time, another drawback to this method is the possibility that an avian influenza v...

First frozen egg baby born in Canada

...eezing technique, which has dramatically increased egg survival rate. Human eggs are very fragile and hav...ice crystals, damaging the cells and rendering the egg unusable. This problem has now been resolved by a new method of rapid freezing called vitrification ...

Technique may allow cancer patients to freeze eggs, preserving fertility before starting treatment

... worked well because the cells are large. When the egg is thawed, ice crystals cause damage that prevents the egg from being fertilized. U-M researchers looked beyond traditional techniques to a method of freezing...

Of mice and men's (and women's) contraceptives

... protein causes problems in the timing of sperm or egg development. We're working hard on understanding this mechanism." A similar human equivalent of MSY2, Contrin, has been identified by the research group and their studies indicate it is also a germ cell-specific protein. Using MSY2 as a mouse model,...

Retrovirus struck ancestors of chimpanzees and gorillas millions of years ago, but did not affect ancestral humans

... invaded the genome in the germline -- in sperm or egg cells -- allowing the sequence to be passed on to future generations. In those animals in which the virus was taken up next to or inside a gene -- in the part of the genome that codes for the most important biological functions -- the virus had an ev...

Mother birds increase progesterone to hatch females

...ly manipulate the sex of their offspring before an egg is laid," says Stephanie Correa, a doctoral student in neurobiology and behavior at Cornell and the lead author of the study that was posted online recently in The Royal Society's Biology Letters (Vol. 1, 2005). "Most investigators have looked primar...

Human Eggs Can Develop From Ovarian Surface Cells In Vitro

...ong two developmental pathways and becoming either egg or granulosa cells. The authors speculate that this bipotent differentiation may represent a sophisticated mechanism created during the evolution of female reproduction, and not seen in ovaries of female prosimians (ancestral primates) or mice carryi...

Stem cells in bone marrow replenish mouse ovaries

...od of mice can "restock" a depleted ovary with new egg cells within weeks, according to new research publ...in reproductive biology, that female mice generate egg cells only during fetal development and thus are born with a finite stock of eggs that declines thro...

A whole lot of shaking goin' on triggers early hatching in red-eyed tree frogs

...gs are about to make a life-or-death decision. The egg clutch, a gelatinous blob clinging to a leaf overh... to take another morsel, the embryos rupture their egg capsules, drop into the water, and, as tadpoles, swim away to safety -- hatching one to three days e...

Scripps research scientists identify infertility molecule

...able to fertilize the egg. Finally, the fertilized egg must become a viable embryo and implant in the ute...men who are attempting pregnancy because a woman's egg production decreases with age, especially after the age of 35. Often, women will undergo treatments...

First production of human monoclonal antibodies in chicken eggs published in Nature Biotechnology

...d solely in the chicken oviduct and deposited into egg white in concentrations of 1-3 milligrams per egg....regulatory sequences restricting its deposition to egg white. The stem cells were then introduced into chick embryos. At this stage of development, the emb...

Human embryonic stem cells have the potential to develop into eggs and sperm in the laboratory

...lls the environment of the developing follicle for egg development or the tissue of the testis for sperm....e to cells that produce the hormones for sperm and egg development and isolate these as well. What is extraordinary is that the embryoid bodies seem to pro...

Multi-species genome comparison sheds new light on evolutionary processes, cancer mutations

...t in terms of evolution. When chromosomes break in egg or sperm cells, opportunities arise for the rearrangement of DNA in the resulting offspring. Such inheritable rearrangements may be lethal or cause disease. However, in some cases, the breaks may lead to the production of new or altered proteins with...

Orientation and the egg

...ture experiments on the premise that the mammalian egg neither has nor requires predetermination for successful development," explains Dr. Hiiragi. ...

New Discovery May Help Doctors Treat Infertility

... beta estrogen receptor plays a role in moving the egg outside the ovary so it can be fertilized,?said Kenneth Korach, Ph.D., Laboratory Chief at the National Institute of Environmental Health Sciences (NIEHS) where the research was conducted. “We never knew before what function this receptor played in r...

What comes first…the chicken, the egg, or the bad attitude?

...ductive hens that "partition" nutrients needed for egg production into their own bodies. "They like to be...their nutrients from the growth of their bodies to egg production, but some of them don't do it very willingly. It is not a conscious thing the bird does, ...

Discovery suggests why stem cells run through stop signs

...from the fruit flies' ovaries and studied how many egg chambers the mutant stem cells produced as compared to normal stem cells. The production rate in the mutant cells fell over the course of 12 days, and the researchers concluded it was because the mutant stem cells were no longer dividing. Without th...

Hanging baskets of sex and death help fruit growers

...he larvae are killed after eating the virus on the egg or plant surface. This brings two key benefits to fruit growers: An end to spraying - Normally Growers wishing to use this form of virus warfare have to spray almost every element of an orchard to ensure the moths come into contact with virus. This ...

Scientists find a maturity gene in fly

... is Disabled Fruit fly development starts when an egg is laid. Embryonic development proceeds within the egg for 24 hours. Then the egg hatches into a first-stage larva. At 48 hours, the larva molts ?sheds the...

MWG Biotech expands siMAX?siRNA portfolio with new scales, lengths and design tools

... is Disabled Fruit fly development starts when an egg is laid. Embryonic development proceeds within the egg for 24 hours. Then the egg hatches into a first-stage larva. At 48 hours, the larva molts ?sheds the...

Micro RNAs play role in egg making

...peculate that this function may allow a developing egg to accumulate large amounts of specific proteins necessary to drive the amazing structural changes seen in embryogenesis. In addition to Carthew and Minden, other authors on the PNAS paper are Kenji Nakahara and Kevin Kim of Northwestern University ...

Most embryos produced during IVF do not result in live births

...d also move the field toward perfecting methods of egg production." ...

Scientists unpick genetics of first 15 minutes of life

...kind of DNA 'dance' when the DNA from the mother's egg cell and the father's sperm cell meet for the firs...one proteins, it contains. When it arrives at the egg cell, however, the sperm DNA needs to be re-packaged with a new set of histone proteins so that the ...

Cornell finds natural selection in humans

... that genes involved in immune function, sperm and egg production, sensory perception and transcription factors (proteins that control which genes are turned on or off) have been particularly affected by positive selection and show rapid evolution in the last 5 million years, when humans shared a common ...

A little telomerase isn't enough

... as they should and die early. Because sperm and egg arise from stem cells, too, their telomeres gradually shorten, and each successive generation starts out with chromosomes whose telomeres are even shorter than their parents, the researchers report. The failure of telomerase to lengthen these telomer...

Researchers offer proof-of-concept for Altered Nuclear Transfer

... taken from a skin cell, is implanted into a donor egg cell from which the nucleus had been removed. This egg cell is then tricked into thinking it has been fertilized. That causes it to grow into a blastocyst...

Removing egg from nest may help save endangered whooping crane

Removing an egg from the endangered whooping crane's nest increase... an Edmonton-based scientist who reasoned that one egg could be taken and used for artificial propagation programs. The idea was so successful, says Boyce,...

FSU biologists describe key role of signal-transcribing gene during cell cycle

...acked the cell-to-cell communication in Drosophila egg chambers that control cell proliferation. "We bel...d them to the control of cell proliferation in the egg chambers, which they observed at different stages. When Cut accurately transcribed the Notch signal...

Sperm stem cells closer to being like embryonic stem cells

...based therapies. Germ-line cells are those such as egg and sperm and their precursors whose genetic material can be passed to offspring. "The ability to manipulate male germ-line stem cells and get them to grow and self-renew is a major step," said Dr. Garbers, a Howard Hughes Medical Institute investig...

Expert dispels bird flu paranoia

...ar production, swollen sinuses and head, decreased egg production, diarrhoea, convulsions, head arched ba... or bore water. "Consumers of poultry meat and egg products should not be concerned as the risk of infection from eating poultry products is extremely ...

The secret love life of plants

...s each one of its two sperm cells to fertilise the egg cell, from which the embryo hatches, and the centr...sperm cell of the cdc2 pollen merges only with the egg cell and not with the central cell. This shows a hierarchy, never before discovered, in the fertilis...

Yale scientists decipher 'wiring pattern' of cell signaling networks

...tanding both human development from the fertilized egg to full grown organism, and for drug discovery targeting human diseases. ...

Clawed frog helps Fanconi anemia research make leaps

... easily done in mammalian cells. Since a Xenopus egg isn't fertilized until after it is laid outside the body of the female frog, it's in a relative state of suspension until it is fertilized. During this time, when the cell cycle is arrested, scientists can use chemicals and a centrifuge machine to ke...

Cloned stem cells prove identical to fertilized stem cells

... nucleus from a donor cell, then places it into an egg from which the nucleus has been removed. The researcher then tricks the egg into thinking it's been fertilized. The egg develops into a blastocyst, an early stage embryo consis...

Extinctions linked to climate change

...phibian embryos to UV-B radiation in sunlight, and egg mortality in the western toad that approached 100 percent in some years, due to an opportunistic disease. In the current Nature article, researchers pointed to more examples. "The climate change in the Arctic and sub-Arctic has modified the life cy...

Scientists discover a genetic switch that links animal growth and cancer

...d in the research develop quickly, growing from an egg to an adult in three days, as compared to mice, for example, which take several months. The similarities between the number and identity of genes in humans and worms allow researchers to extrapolate from worms to humans in their genetic research. ...

Insects that produce males from unfertilized eggs reveal a surprising cellular feat

...me females. But the development of an unfertilized egg into an adult (called parthenogenesis) remains a m... Cruz, describes a remarkable process by which the egg cells of Hymenopteran insects make new centrosomes from scratch. The process involves enigmatic cell...

Researchers now able to look deep into heart to view triggers of a heart's beat

...me females. But the development of an unfertilized egg into an adult (called parthenogenesis) remains a m... Cruz, describes a remarkable process by which the egg cells of Hymenopteran insects make new centrosomes from scratch. The process involves enigmatic cell...

Component in soy products causes reproductive problems in laboratory mice

...istein, 50 mg/kg per day, had a high percentage of egg cells that remain in clusters, unable to separate ...s found at six days of age where 57 percent of the egg cells in the non-treated ovaries were single or unclustered; and only 36 percent in the genistein tr...

Retinol for combating leukemia cells

... also known as retinol, is present in milk, liver, egg yolk, butter and other foodstuffs and as carotene in vegetables that have a yellow-orange colour, such as carrots and pumpkins. This vitamin is accumulated in the liver where it is transformed into retinoid. Given that vitamin A, as such, has no eff...

US woman gives birth to baby from world's first frozen donor egg bank

... to deliver a baby from the first commercial donor egg bank in the world, which has offices in Lexington,...e Avery. She's beautiful." The first frozen donor egg bank was formed based on new egg freezing technology developed by Jeffrey Boldt, PhD, Scientific Dir...

One big biology question solved

... derivatives of Vitamin A trigger the beginning of egg and sperm production, a process known as meiosis. ...e embryos. "Whether a germ cell develops into an egg or a sperm depends on the time at which meiosis begins," Professor Koopman said. "In females, meio...

Better beetle sought for salt cedar control

...nd chemicaltreatments, Carney said. A total of 25 egg masses have been released at three different sites...t Temple, where other studiesare being done. Each egg mass had 10 to 30 eggs. Another 60 adults were releasedbetween the three sites, Carney said. Each eg...

Carnegie Mellon researchers discover new cell properties

...ly fractured. "The mutant HGPS lamina is like an egg shell that cracks when excessive pressure or force is exerted against it," Dahl said. "By contrast, normal lamina resembles the rubbery outer shell of a racquetball, which does not break under stress or force but can assume its original shape even af...

Study finds how organs monitor themselves during early development

... cells are cells that give rise to either sperm or egg and can ultimately give rise to a new organism and...month. Without the somatic cells of the ovary, the egg on its own would not ripen. The eggs need this environment for their development, she says. In ev...

How can identical twins be genetically different?

...11 pairs of monozygotic twins, who shared the same egg and were genetically identical, but only one of them had RA. They found three new genes that were significantly over-expressed in the twin with RA compared to the one without the disease. This is the first report for RA that examines gene expression ...

With few factors, adult cells take on character of embryonic stem cells

...ammed" by transferring their nuclear contents into egg cell precursors called oocytes or by fusion with embryonic stem cells, earlier studies showed. Those findings provided evidence that unfertilized eggs and embryonic stem cells contain factors that can confer pluripotency to differentiated cells, Ya...

Genetic tug of war determines sexual differentiation

Whether or not a fertilized mammalian egg ultimately develops into a male or female is deter...al Institutes of Health. In mammals, a fertilized egg with two X chromosomes will become a female, while an egg with an X and Y chromosome will become a m...

Rice scientists unveil 'nanoegg'

...the other ?in much the same way that a hard-boiled egg white is thick in some places and thin in others. The off-center core in the nanoegg radically changes its electrical properties, said co-author and theoretical physicist Peter Nordlander, professor of physics and astronomy. The reasons for this ha...

Nutrition a major factor in rise in twin pregnancies

...e any manipulation of the zona ?the 'shell' of the egg ?began. Transfer of just one embryo can therefore still lead to twins. If a higher rate of MZ twinning turns out to be a natural adaptation to improved nutrition or culture conditions, it could prove difficult to reverse as embryo quality continu...

UF scientists restore sight to chickens with blinding disease

...le in the eggshell. The shell was resealed and the egg was incubated to hatching to produce a live chick. "The process sounds straightforward but it really isn't," Semple-Rowland said. "It took quite a long time to build the vector, develop the injection procedure and figure out how to hatch the eggs. B...

FSU biologists uncover mechanisms that shape cells for better or worse

...vel component in the polarization of the fruit fly egg and the signals that determine the anterior-posterior positioning of its head and abdomen," said Deng. "Such a discovery in the biological model provided by Drosophila oocytes has broad implications in humans, where, ...

New egg freezing technique offers hope to hundreds of women

...fer. As a consequence of this new law, interest in egg freezing had grown. "Even although oocyte freezing...n could be the damage done to the structure of the egg during freeze-thawing, in particular to a part called the meiotic spindle which is involved in cell ...

With few factors, adult cells take on character of embryonic stem cells

...ammed" by transferring their nuclear contents into egg cell precursors called oocytes or by fusion with embryonic stem cells, earlier studies showed. Those findings provided evidence that unfertilized eggs and embryonic stem cells contain factors that can confer pluripotency to differentiated cells, Ya...

Gatekeeping: Penn researchers find new way to open ion channels in cell membranes

...entally expressed in the membrane of an oocyte, or egg cell) without changing the membrane voltage. The finding introduces a new paradigm for understanding the gating of ion channels and lays the conceptual groundwork for designing new drugs to control ion-channel activity in medical intervention. Vol...

Sperm created in the laboratory from embryonic stem cells produce viable progeny

...lls that then give rise to cells resembling mature egg and sperm cells, known as gametes. However, the functionality of the gametes has not been thoroughly tested and many questions about the viability of these cells remain unanswered. Dr. Karim Nayernia and Dr. Wolfgang Engel from the Institute of Human...

Major initiative proposed to address amphibian crisis

...traced global warming ultimately to a catastrophic egg mortality in the western toad of the Pacific Northwest Cascade Range. Work is continuing at OSU today on contaminants and the effects of UVB solar radiation that may amplify the impacts of the fungus which causes chytridiomycosis. Amphibian dec...