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Tag: "sperm" at biology news

Malaria vaccine prompts victims' immune system to eliminate parasite from mosquitoes

...exual forms of the parasite that are equivalent to sperm and eggs. Fertilization takes place in the mosquito gut, after which the parasite imbeds itself in the gut lining. There, it passes through discrete stages, before migrating to the insect's salivary glands, where it is passed on to the next host th...

Humpback whales have brain cells also found in humans

...ee bottlenose dolphins, an Amazon river dolphin, a sperm whale, two beluga whales, a killer whale and sever...cies, it is important to note in this context that sperm whales, killer whales, and certainly humpback whales, exhibit complex social patterns that included ...

St. Jude finds clues to hearing loss from chemotherapy

...ed ENU, a chemical that causes random mutations in sperm of mice that were subsequently mated with females. Offspring of this mating carried mutations in one or more specific spots in their DNA, Zuo explained. The random mutations caused a variety of disruptions of normal functions. However, only some of t...

Looking to a new era in bee research

...o the remarkable longevity of queen honey bees and sperm stored in the spermatheca. The HBGSP has united a broad range of scientists, from leaders in human genomics and bioinformatics to members of diverse disciplinary and organism-based communities, including those studying mammals and humans. A total...

'Cellular antennae' on algae give clues to how human cells receive signals

...many functions on human cells; they propel egg and sperm cells to make fertilization possible, line the nose to pick up odors, and purify the blood, among other tasks. With such a range of abilities, cilia serve as both motors and "cellular antennae," said Dr. William Snell, a professor of cell biology a...

Eminent inventor of DNA fingerprinting gains new recognition

...cal father of a child? Whose blood, sweat, hair or sperm has been left behind at the scene of a crime? Who is this tsunami victim? Are these bones truly the remains of the last Czar of Russia? Jeffreys' technique was even able to tell us whether Dolly was in fact the clone of another sheep. "The new disci...

What controls stickiness of 'smart' chromosomal glue

...erstanding of the process cells use to ensure that sperm and eggs begin life with exactly one copy of each ...he specialized cell division process that produces sperm and eggs ?enabling them to separate properly. The researchers, led by Howard Hughes Medical Instit...

Origen publishes in Nature a robust and versatile method for creating transgenic chickens

...n to primordial germ cells, the precursor cells to sperm and eggs," said Marie-Cecile van de Lavoir, senior...cells known as primordial germ cells (PGCs) become sperm or eggs in the adult animal. Previous attempts to culture PGCs from mice and humans produced embryon...

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

... (ES) cells cultured in the laboratory can produce sperm with the capacity to produce viable offspring. The... including investigation of mechanisms involved in sperm production and development of new treatment strategies for infertility. Previous studies have shown...

Even when faint, ovary scent draws sperm cells

...ton report biochemical machinery that allows mouse sperm cells to follow the weakest of scents. Even when ovary extracts were diluted 100,000 times, some sperm cells still found their mark. A video demonstrating sperm chemotaxis (oriented motion in response t...

Viral hitchhiker inhibits Wolbachia bacteria's ability to proliferate

...proliferate. One way it does this is by hijacking sperm of its insect hosts and genetically tricking them to bear more infected females, the only sex that transmits the bacteria. Now, a new study from the MBL (Marine Biological Laboratory), published in the May 18 issue of PLoS Pathogens, demonstrates th...

Study links high levels of nitric oxide to infertility and sperm DNA damage

...lays an essential role in many bodily functions to sperm DNA damage and male infertility, the 22nd annual c...ctive system, and we know that it can affect human sperm functions, such as motility, viability and metabolism. At low concentrations it can have a positive ...

New egg freezing technique offers hope to hundreds of women

... men have been able to use their previously frozen sperm for IVF treatment but women have not been able to ...ashige Kuwayama told a news briefing that although sperm could be frozen, thawed and used for in vitro fertilisation with high levels of success, the freeze-...

Slow-frozen people? Latest research supports possibility of cyropreservation

...Only certain kinds of cells and tissues, including sperm and embryos, currently can be frozen and successfully rewarmed. A major problem hindering wider use of cyropreservation is formation of ice crystals, which damage cell structures. Cyropreservation may be most familiar, however, as the controversial ...

Ecologists home in on how sperm whales find their prey

Ecologists have at last got a view of sperm whales' behaviour during their long, deep dives, t...sh Ecological Society's Journal of Animal Ecology, sperm whales ?like bats ?use echolocation consistently to track down their prey at depth. Working in th...

Chromosomal abnormalities in sperm higher after vasectomy reversal

...greater rate of chromosomal abnormalities in their sperm than do normal fertile men, a scientist told the 2...en with obstructive azoospermia, a condition where sperm are created but cannot be mixed with the ejaculatory fluid due to a physical obstruction (such as a ...

Study finds how organs monitor themselves during early development

...ses. Germ cells are cells that give rise to either sperm or egg and can ultimately give rise to a new organ...ment, she says. In every organism, both egg and sperm cells cannot develop unless they are embedded in a matrix of somatic cells, says Dr. Lehmann. Inter...

One big biology question solved

...gy's most fundamental questions ?why males produce sperm and females produce eggs. The finding is a break...ives of Vitamin A trigger the beginning of egg and sperm production, a process known as meiosis. The cells that eventually turn into either eggs or sperm ?...

'Scent of a woman' tells male redback spiders to find a mate

...ir life -- into it. In the process, they deposit a sperm plug -- a small part of their copulatory organ that stays inside the female -- that prevents any future males from successfully fertilizing her eggs, meaning that males have to mate with a virgin to maximize their reproductive success. "On the one h...

Underwater listening devices yield discoveries about endangered large whales

..., fin, humpback, North Pacific right, bowhead, and sperm whales, an article in the January 2006 issue of BioScience reports. Because whale calls can be detected and recognized over tens of miles, such devices (which emit no sound) have added to scientific knowledge of the movements and calling behavior ...

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