Can our genes tell the story of our divergence?
...e, that there is a battle between the interests of sperm cells (favoring genetic changes that increase cell number and decrease cell death), and the need for the organism to avoid cancer. Future studies will have to determine whether these explanations - of an evolutionary arms race - prove plausible. W...Scripps research scientists identify infertility molecule
...perm, and a woman has to produce healthy eggs. The sperm has to be able to travel up the fallopian tubes to...lity. A man might not produce enough sperm, or his sperm might be unable to reach the eggs. A woman might have problems producing eggs or her fallopian tubes...Certain fish have a special mating preference
...results from post-mating sexual selection, such as sperm competition or cryptic female choice. That is, most evolutionists have believed that for animals with internal fertilization -- like the livebearing fish Langerhans studies which don't lay eggs-- selection acting within the female's body that biase...Size matters: fish genitalia attractiveness vs. predatory escape value
... been of interest. While competitive advantages of sperm robustness and other post-mating sexual selection ...yzed the gonopodia, or modified fin that transfers sperm to females, in western and Bahamas mosquitofish. Mosquitofish cannot retract their gonopodia and the...Man, chimp difference may have made us prone to cancer
...y researchers suggest that some mutations in human sperm cells might allow them to avoid early death and reproduce, creating an advantage that ensures more sperm cells carry this trait. But this same positive selection could also have made it easier for human ca...PNAS highlights for the week of May 16 - 20
...e centered on postmating sexual selection, such as sperm competition advantages. The roles of premating sex...a--modified anal fins through which males transfer sperm to females--and they often display or swing them during courtship. In laboratory experiments, femal...Mother birds increase progesterone to hatch females
ITHACA, N.Y. -- In mammals, sperm from the male determines the sex of the offspring. In birds, however, it is the female's sex chromosome that determines offspring sex. Now, Cornell University researchers think they understand the mechanism that several bird species use to bias the s...Research marks giant step in potential of using stem cells to treat human disorders
... A somatic cell is any cell in the body other than sperm or egg cells. Among somatic cell donors were individuals who had juvenile diabetes, spinal cord injury and a genetic immune deficiency called congenital hypogammaglobulinemia, which can lead to an increased risk of infections. Using these resources, ...Discovery at UCSB may lead to new drugs to treat cancer, control fertility
... metastasis." Fusion is the process that allows a sperm to fertilize an egg; it also allows a cancer cell to join with a normal cell. The discovery by Rothman and his co-authors reveals that the inappropriate joining of cells by fusion is naturally prevented by a familiar protein, called vacuolar ATPase,...Study is first to show side-stream smoking is as damaging to IVF success as being a smoker
...moke on the female gamete. The damaging effects on sperm are well documented as sperm are more accessible and easier to study. Studying the female gamete, on the other hand, is much more...Technique may allow cancer patients to freeze eggs, preserving fertility before starting treatment
...are low. Instead, researchers have found, a single sperm cell must be injected into a single oocyte, a technique called intracytoplasmic sperm injection, or ICSI. While ICSI is an established technique used in assisted reproduction, it is more...First frozen egg baby born in Canada
...eggs were thawed and fertilized with her partner's sperm through in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), and the resulting embryos implanted in her uterus. "The patient went through an u...Sex discrimination in parasitoid wasps
...ly male offspring develop. In eggs fertilised with sperm from these males, the complete genome from the father is destroyed during the first nuclear division. However, the B chromosome remains intact and is incorporated into the chromosome set of the mother. Such fertilised eggs develop into males with the...Washington State University study points to role of toxins in inherited disease
...ocrine disruptors produced male offspring with low sperm counts and low fertility. Those males were still able to produce offspring, however, and when they were mated with females that had not been exposed to the toxins, their male offspring had the same problems. The effect persisted through all generatio...Study in Royal Society journal on heritability of female orgasm
...Simmons When females mate with more than one male sperm from each male must compete to fertilize eggs. Stu...ow that males increase the quality and quantity of sperm ejaculated under sperm competition. We show that human males respond in a similar manner. When viewi...JCI table of contents, July 1, 2005
EDITOR'S PICK Transplantation of sperm stem cells restores fertility after chemotherapy ...ation of fertility in leukemia patients is to bank sperm before treatment commences. However, as mature germ cells do not develop until the onset of puberty,...Human embryonic stem cells have the potential to develop into eggs and sperm in the laboratory
... Their work opens up the possibility that eggs and sperm could be grown from stem cells and used for assist... the ancestral cells that eventually form eggs and sperm (gametes). "Investigating the mechanisms of human primordial germ cell and gamete development is imp...World first: Scientists succeed in cloning human embryos from eggs matured in the lab
...loned embryos and develop them to provide eggs and sperm for infertile couples, the 21st annual conference ...homologous [matching] chromosomes, instead of from sperm and eggs which carry only one set of chromosomes each." Five oocytes divided to the two-cell stage, ...Eggs from embryonic stem cells could benefit sterile women
...ave children. "Some people just don't have eggs or sperm and there's little we can do for them except use donor material. The ability to develop eggs in vitro could primarily assist sterile women but could also reduce the ongoing strain on donor egg programs." It could also help create a 'bank' of eggs tha......heir reproductive glands. These chemicals kill the sperm of other males that have mated with the same female but they are also toxic to the female -- hence conflict." In a collaborative research effort with insect physiologist and Tufts postdoctoral research fellow Dr. William Woods, Lewis is also examinin...