A Fresh Look At Love And War Between The Sexes
...sogamous---we have sex cells of unequal size. Big eggs and littlesperm. And what works to make eggs successful is very different from what worksfor sperm. This fundamental inequality is the underlying...A Mother's Love? New UD Theory Explains Why Good Insect Moms Risk Death To Save Their Only Children
...ack an ovipositor, a needle-like probe for burying eggs in hidingspots. The rule usually holds true, Talla...ain whymany insects with ovipositors and protected eggs still guard. Still another theory, set forth by various researchers, suggests that insectmoms guard ...Sustainable Harvest Of Caiman Falls Short Of Potential
...e in crocodilian farming, which entails collecting eggs from captiveadults, says Thorbjarnarson in a companion commentary on the history of international tradein crocodilian skins. Another threat to crocodilian sustainable harvest programs is the instability ofthe market for crocodilian skins, which are ...Montana Scientist Returns From Dinosaur Nesting Site In Patagonia
...f time because they don't fossilize. "The eggs with bone had no skin, and the eggs with skin had no bones, sothere's an unusual preservational process going on," Jackson said. The sk...First Great American Bluebird Count
...indications of breeding, suchas nesting materials, eggs and young. "There are thousands of nest boxes out there," says Andr Dhondt, director ofthe Cornell Lab's Bird Population Studies program. "We need to know what'sgoing on inside each one. We can use what we learn about one species ofcavity-nesting ......d host, where they reproduce sexually. Finally,the eggs reach another pond via the birds' feces and the cycle begins again.Because birds prey upon them much more often than normal frogs, deformed frogsmay play an unfortunate but critical role in the parasite's reproductionstrategy. Although parasite infe...Male Moth's Sperm Protects Females
...PAs. Until the Cornell study, only Utetheisa's eggs were known to benefit froma male's nuptial gift. The grisly experiment with spiders was performed toprove that the female profits, as well. "It didn't seem right that the female could not benefit from the male'salkaloidal gift," González says,...New Way To Modify Mammalian Genes: Honolulu Transgenesis
... success in producing transgenic mice by injecting eggs in a methodcalled intracytoplasmic sperm injection. About one in five offspring resultingfrom the new procedure contain the introduced DNA. The production of transgenic animals isn't new; transgenic mice were firstproduced in 1974, and the prevailing...Fossilized Emu Eggshells Give Clues To 65,000 Years Of Vegetation And Climate Changes In Australia
...nce metabolized and are found in the shells of the eggs that the animals lay. This information is used by ...mer were still abundant when emu were laying their eggs in winter. Between 28,000 and 15,000 years ago, during the peak of the last glacial period, C4 gras...Engineered Corn Can Kill Monarch Butterflies
...andFlorida, seeking milkweed on which to lay their eggs and feed. By late May orearly June, the second generation of adults has emerged and heads north to areasincluding the Midwest Corn Belt. Monarch caterpillars are feeding on milkweedduring the period when corn is shedding pollen, Losey says. Thus "...'Cousin' Of Snake Venom Toxin Found In Mice
...t Columbia Universitytested lynx1's effect on frog eggs (or oocytes) that had been injected withacetylcholine receptors. Miwa said the eggs' acetylcholine response was 30percent larger after bathing them with lynx1, suggesting that lynx1 mightenhance the action of acetylcholine. By contrast, its cousin,al...University of Hawaii scientists announce first male clone
...Dolly and cumulus cells, which surround developing eggs within theovaries, used to clone the mice. Even ca...hich all geneticinformation has been removed). The eggs are activated to begin dividing and thedeveloping embryos transplanted into a foster mother. The tec...Horseshoe crab studies providing new insight into valuable ancient creatures
...f horseshoe crabs annually lay and fertilize their eggs on the DelawareBay area beaches. Photo courtesy o...e waters of Delaware Bay to lay andfertilize their eggs in the wet sand. On some beaches they will be met byscientists and volunteers who will carefully cou...New study establishes when pregnancy starts
...hen pregnancy starts in humans. Fertilized eggs attach themselves to the lining of the womb six to...ve mechanism, theuterus tends to reject fertilized eggs that take too long to adhere to thelining because they may be less fit, the researchers say. On day ...Embryos that implant in uterus 'late' prove more likely to die in first weeks of pregnancy
...l Health Sciencessaid today that fertilized human eggs that implant late are less likely tosurvive. ...cine, 319, pp 189-94) that 25 percent offertilized eggs fail to survive six weeks -- so early that most mothers did notknow they had been pregnant. Only da...Salamanders may one day monitor degradation in small streams
...nd terrestrial environments. Also, somespecies lay eggs on land while others lay eggs in the water. These differences,among others, may make some species more sensitive to waterborne pol...Economic model to aid alligator farmers
...questions always facing alligator farmers.How many eggs should be collected from the wild? At what size an...wild mothers are morefertile. Harvesting alligator eggs in Louisiana, also helps the wild population.The survival rate of wild hatchlings is very low due to......ut their sperm are in competition to fertilize the eggs once inside thefemale," says Catherine Price, PhD,...number of stored first male spermused to fertilize eggs dropped considerably after the female was re-mated. This 'sperm incapacitation' effect became much ...U-M scientists identify genes that make blood "thicker" and more likely to clot as we get older
... insert these humanminigenes into fertilized mouse eggs to create transgenic mice that producedhuman Factor IX, in addition to the mouse version. After the mice were born,Kurachi and his colleagues selected three to six founder mice for each humanFactor IX minigene to be tested. U-M researchers then m...