Tag: "testes" at biology news

Early-stage sperm cells created from human bone marrow

...ne marrow. The cells were transplanted into mouse testes and were observed to undergo early meiosis - cell division - the next stage to them becoming mature sperm cells, although they did not develop further. Talking about his newly published research paper, Prof Nayernia, of Newcastle University, said ...

Vasectomy may put men at risk for type of dementia

...-testis barrier. Certain organs ?including the testes and the brain ?exist in what is the equivalent of ...gated community in the body. Tiny tubes within the testes (in which sperm are produced) are protected by a physical barrier of Sertoli cells. The tight connec...

Study of planarians offers insight into germ cell development

...ng nanos in mature adults caused their ovaries and testes to disappear. And when the researchers blocked nan...s these germ cells from developing into functional testes and ovaries. "Having a simple organism that also uses inductive signaling is going to help us tea...

Exposure to dioxins influences male reproductive system, study of Vietnam veterans concludes

...chidism (undescended testes, a condition where the testes are not in their normal location in the scrotum) and hypospadias (abnormality of the urethra). The reason for this increase is not known, but it is thought that these disorders might be caused by environmental chemicals that are estrogenic and ha...

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

...n the laboratory or could be transplanted into the testes of mice where they retained the capacity develop into sperm. Intra-cytoplasmic injection of the ES-derived sperm into mouse eggs resulted in successful fertilization and the resulting early stage embryos were successfully transplanted into mice. Six ...

Viral hitchhiker inhibits Wolbachia bacteria's ability to proliferate

... number of WO-B viruses and Wolbachia cells in the testes of a common host: the fruit-fly-sized jewel wasp, Nasonia vitripennis. The researchers found that the virus was indeed associated with reduced bacterial growth. Then they bred the wasps and confirmed fewer incidences of cytoplasmic incompatibility i...

Injection may prevent infertility in men receiving cancer chemotherapy

It may be possible to protect the testes of cancer patients against the loss of fertility c...up. After 30 days they were euthanized and their testes examined and weighed. The researchers found that a single dose of Taxol had induced significant te...

Genetic tug of war determines sexual differentiation

...les of the adult testis," she continued. "Once the testes are formed, they start producing testosterone, which commits the whole animal to male development. The researchers found that not only does Fgf9 stabilize the expression of Sox9 and secure the male fate of the gonad, it suppresses the activity of th...

Sex chromosome genes influence aggression andmaternal behavior, say UVa researchers

...he presence of Sry leads to the development of the testes and high levels of androgens in males, which is pa...ce with or without the Sry gene (either males with testes or ovary-bearing females) to mice with the XX versus XY sex chromosomes. They tested how long it too...

Tool developed to silence genes in specific tissues using RNAi

... by silencing the WT1 tumor suppressor gene in the testes of mice. They found this gene is important in the ...ion factor that dictates both the formation of the testes in the embryo, and the function of the testes after birth." Researchers worldwide have been trying ...

Testes to incubate stem cells

...eap to humans is considerable, the colonised mouse testes are already providing useful insights. "We'd lik... manipulated to express high levels of GDNF in the testes produce huge clusters of spermatogonial stem cells. But the risk of cancer is boosted too, so it is ...

UCLA scientists find male gene in brain area targeted by Parkinson's

...esponsible for making embryos male and forming the testes is also produced by the brain region targeted by Parkinson's disease. Published in the Feb. 21 edition of Current Biology, the new research may explain why more men than women develop the degenerative disorder, which afflicts roughly 1 million Ameri...

Sperm stem cells closer to being like embryonic stem cells

...ntify when mixed with other cell types. "The rat testes contain other cells types in addition to stem cells," Dr. Hamra said. "If these other cells are included in the culture, they produce chemicals that block the ability of the stem cells to remain stem cells. We're still trying to figure out why. But t...

Sudden change in social status triggers genetic response in male fish, study finds

...ostentatious colors and stripes disappear, and the testes shrink and the male becomes infertile. "Previously we did an experiment in which we moved the subordinate male out of the tank and put him in a situation where he could rise and become dominant," Fernald says. "Because he was in a new situation,...

Most common lung cancers may begin in newly discovered cells

...ed reports of stem cells found in the skin, brain, testes and gut. The lab has already teamed up with another research group to develop microscopic fluorescent probes to image the unique molecular surface of BASCs and track the progress of the naturally arising tumor, Jacks said. The similar genetic activi...

How the environment could be damaging men's reproductive health

...nt of male foetuses. Babies born with undescended testes are at higher risk of developing testicular cancer...ter. Sixty-nine (5.7%) of the boys had one or both testes undescended. After one year the testes had descended fully in 51 of the 68 children (75%) who were f...

A gene's first 'kiss' sets off that affair known as puberty

... turn, these rising levels of LH and FSH cause the testes and ovaries to produce the sex hormones testosterone and estradiol, the culprits responsible for the physical changes and emotional baggage of male and female puberty, respectively. "We now have very good evidence that the GPR54 gene and its switch,...

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