Articles tagged with Sperm
A study of 97 healthy men found that semen quality decreased with age, particularly in sperm motility. The researchers discovered a 0.7% decrease in sperm motility per year, impacting fertility from age 22 to 80.
Researchers at Weizmann Institute find that sperm are attracted to fertilization site by temperature difference. A temperature-driven mechanism, known as thermotaxis, guides the sperm through the fallopian tube and prepares them for penetration of the egg.
Researchers found that MSP binding to VAB-1 receptor triggers oocyte maturation in C. elegans, promoting successful fertilization. The study reveals an unexpected role for VAB-1 in reproduction.
Researchers at Vanderbilt University Medical Center have identified a sperm-sensing receptor in worm eggs, enabling egg maturation and ovulation. The discovery sheds light on reproductive problems in humans, including failed meiosis leading to chromosome instability.
A study by UCSF researchers reveals that the human gene BOULE regulates meiosis in sperm development, a key step in creating sperm and eggs. The finding has significant implications for understanding infertility and developing new treatments, including drugs to assist immature sperm cells or block sperm maturation.
A combination of DEET, permethrin, and pyridostigmine bromide may have inadvertently damaged Gulf War soldiers' testes and sperm production, according to a Duke University Medical Center study. The chemicals caused extensive cell degeneration and cell death in rats, leading to severe testicular damage.
Researchers have successfully transplanted immature mouse and rabbit testicular tissue, resulting in live births and mature sperm production. This breakthrough technique offers new hope for pre-pubertal boys and babies affected by cancer treatment, potentially restoring fertility through autotransplantation.
A recent study reveals that sperm in men older than 35 show more DNA damage, which could be passed on to offspring. The researchers found that older men have lower motility and more damaged DNA, with fewer apoptotic cells, indicating a decline in the ability of sperm to eliminate damaged cells.
Researchers have successfully restored sperm production in infertile mice by transplanting healthy Sertoli cells. The technique, developed by Dr. Ralph L. Brinster, may provide a new way to replace defective Sertoli cells and initiate normal spermatogenesis.
Researchers discover females actively select longer sperm for fertilization, leading to evolutionary changes in sperm size and female reproductive tract shape. This study challenges the long-held belief that males sacrifice quality for quantity in sperm production.
The study found that older men are more likely to have sperm with genetic mutations causing Apert syndrome, which increases the risk of having a child with the disease. The scientists suggest that the number of cell divisions in making sperm plays a role in this link.
A recent study found that nonoxynol-9 spermicide may increase the risk of HIV-1 infection in women due to vaginal lesions caused by frequent use. In contrast, low-frequency use showed no harm or benefit. The findings highlight the need for alternative vaginal microbicides.
Researchers developed a non-invasive method to generate a genetic fingerprint of fertile men's sperm cells, identified around 3000 individual mRNAs, and suggest it could help diagnose idiopathic infertility and reveal paternal influences on fetal development.
Scientists at the University of Pennsylvania successfully transplanted testicular tissue from mice, goats, and pigs into mice, resulting in functional sperm production. This breakthrough has significant implications for preserving endangered species and developing new methods for livestock breeding.
A study found that smoking significantly decreases the success rates of assisted reproduction procedures in both IVF and ICSI. The number of pregnancies among couples receiving IVF treatment was lower when the male partner smoked, with women's egg retrieval capacity also reduced.
Researchers found that environmental oestrogens, such as genistein and nonylphenol, stimulate sperm development and motility, while natural oestrogen has no effect on capacitated sperm. This suggests a different mechanism of action for environmental oestrogens, which could have negative effects over time.
A recent review by the European Society of Human Reproduction and Embryology found that while there is a slightly higher risk of major birth defects after ICSI and IVF, the absolute risk is small. Additionally, new research has shown that ICSI children have normal development by the time they start school.
Researchers at Georgetown University Medical Center have developed a germ cell line derived from spermatogonia, offering a basic tool for studying male infertility and testicular cancer. This cell line exhibits characteristics of normal adult spermatogonial stem cells and differentiates into advanced germ cell types upon stimulation.
Researchers at Duke University Medical Center discovered a gene linked to male infertility in mice, which may also be associated with human infertility. The study found that the miwi gene plays an essential role in sperm production and its deficiency can lead to complete sterility in mice.
Researchers at USC found a significant correlation between decreased sperm count and motility and increased ozone levels in the air, especially in Southern California. The study analyzed over 8,000 sperm samples from men in Los Angeles and Northern California and suggests that air pollution may be affecting male fertility.
Researchers have created a virtual cell model to study cell motion, driven by a single protein that changes shape in response to pH levels. This model has potential implications for understanding various diseases, including cancer, heart disease, and wound healing.
Research on spermatocyte apoptosis highlights the role of cell-cell and cell-extracellular matrix interactions. Key findings include specific molecular pathways involved in regulating spermatocyte death, which may inform therapeutic strategies for male infertility and other reproductive disorders.
Researchers at UCSD found that the Anaphase-Promoting Complex protein complex has two roles in embryonic development, helping set up differences between outer and inner layers of the embryo. This discovery provides a new understanding of how embryos divide into different tissue types.
Researchers at Johns Hopkins University are testing BufferGel, a vaginal gel that reinforces natural vaginal acidity to kill sperm and germs. The trial aims to evaluate the effectiveness of BufferGel in reducing pregnancy risk when combined with a diaphragm.
A new study from the Mayo Clinic has identified a crucial protein involved in male fertility, shedding light on a common cause of infertility. The research found that mice lacking this protein are infertile, highlighting the importance of Hrb protein in acrosome development.
A new study proposes revised guidelines for classifying semen samples as normal or abnormal, potentially rewriting laboratory standards used for 50 years. The research suggests that male infertility is not as clear-cut as current guidelines suggest, and that a 'gray zone' of borderline semen samples requires new treatment approaches.
New guidelines for assessing male fertility provide a more reliable means of estimating fertility, helping specialists tailor treatments to individual patient circumstances. The revised standards identify key parameters, including sperm count, motility, and morphology, to better determine a man's likelihood of fathering a child.
Researchers found AAV DNA in 38% of men with abnormal semen analysis, but only 4.6% of those with normal semen. Further studies are needed to assess the link between AAV and infertility.
Researchers at University of Pennsylvania successfully inserted a foreign gene into male mouse spermatogonial stem cells, achieving high efficiency and expression. The breakthrough enables the creation of transgenic individuals in various species, paving the way for studying human diseases.
Researchers have identified a key molecular cue regulating zygotic genome activation in green algae Chlamydomonas. The abnormal expression of the mt+ gamete-specific gene gsp1 induces zygote development without fertilization. This finding opens up new avenues for understanding zygotic genome activation in higher organisms.
A study of over 1200 Canadian manual workers found that moderate occupational solvent exposure was associated with a significant increase in low sperm counts. Painters, decorators, and builders were at the highest risk, while glycol ethers are suspected to be hazardous to male fertility
Chemist Nicole S. Sampson has made significant breakthroughs in understanding the process of fertilization, discovering that protein fertilin-beta binds to egg protein alpha-6 beta-1 integrin. Her research could lead to new applications for sperm mimics and insights into tissue formation.
Researchers have developed a pre-conception sex-sorting technique that significantly increases the number of female embryos available through IVF. The MicroSort technology, which uses flow cytometry, has shown a 9 out of 10 chance of biopsied embryos being female, benefiting couples with X-linked disorders.
Researchers have discovered a potential cause of male infertility, identifying the ZNF214 gene as a candidate gene. The gene is linked to impaired spermatogenesis and may be inherited from mothers. Further research will help understand its role in sperm production and develop targeted treatments.
A recent study by Dr. Gianpiero Palermo and his team found that ICSI children are developing normally, with no significant delays in cognitive abilities, socio-emotional development, or motor skills. The study contradicts previous concerns about the ICSI technique's impact on babies' development.
Researchers have developed a new fertility test kit that measures natural levels of fertility in couples trying to conceive. The kit assesses the concentration of motile sperm in men and follicle-stimulating hormone (FSH) levels in women, providing an early warning system for potential infertility issues.
A multicentre randomised controlled trial found that conventional IVF had higher implantation rates (30%) compared to ICSI (22%), as well as a lower average laboratory time. The pregnancy rate was also higher after conventional IVF (33%). The study supports the current practice of reserving ICSI only for severe male fertility problems.
Researchers have developed a new test, SUTI, that can accurately diagnose male infertility by detecting high levels of ubiquitin antibodies on the surface of sperm cells. This method could lead to more accurate diagnoses and targeted treatment for couples struggling with infertility.
The targeted disruption of the PCI gene in mice leads to profound defects in sperm development and fertility. Human male infertility is also associated with a lack of PCI in seminal fluid, disrupting the balance of proteinases and proteinase inhibitors.
Researchers found a cellular signaling system that responds to THC and anandamide regulates sperm functions required for fertilization in humans. Heavy marijuana users may jeopardize fertility by overloading this natural signaling system.
Researchers at Stanford University discovered that nitric oxide gas plays a crucial role in triggering fertilization, which could lead to new treatments for infertility. The study focused on sea urchins, but the findings also have implications for human reproduction and genetic engineering.
Researchers at USC found no significant change in average sperm count over three decades, contradicting previous studies. Sperm abnormalities were common, but did not impact overall fertility.
Researchers have identified a family of proteins that bind to human sperm, which may help explain why sperm that haven't passed through the epididymis fertilize eggs poorly. The discovery could lead to identifying potential targets for male contraception, including a contraceptive vaccine.
The study found that a gene called Tcr, which is transmitted at up to 95% from male carriers to their progeny, encodes a protein kinase likely to control sperm motility. This allows for the manipulation of transmission ratios and potentially exclusive fathering of female offspring in farm animals.
Researchers discovered that male fruit flies displace and incapacitate a previous male's sperm to fertilize eggs. The study found that the last fruit fly to mate with the female sires most offspring, and that seminal fluid alone cannot cause displacement of stored sperm.
A study found that some boys will be infertile due to inherited Y chromosome deletions from their fathers, who underwent intracytoplasmic sperm injection (ICSI). The deletion region AZFc accounts for 10% of male infertility cases. Genetic counseling is recommended for couples concerned about passing on the condition to their sons.
Researchers have discovered that sons conceived through ICSI can inherit the same genetic defects in their fathers, including AZFc deletions. This finding raises ethical questions about assisted reproduction techniques and potential remedies for affected males.
Gene therapy's concern about viral DNA insertion into gametes is unfounded, as naturally occurring insertions in sperm cells are 100 times more common than the FDA limit. Researchers estimate that 1 individual in every 8 carries a new retrotransposon insertion.
University of Hawaii scientists have developed a new method for producing transgenic mammals by injecting DNA into eggs using mouse sperm. The technique, called Honolulu transgenesis, has shown success in producing green mice with a jellyfish 'green gene'.
A male rattlebox moth donates a plant-derived chemical to his female, protecting her against spiders and her eggs. The female can also benefit from this nuptial gift, with the Cornell study proving that she profits from the male's alkaloidal gift.
A study on non-Western folk beliefs found that partible paternity is a common concept among indigenous groups in South America and New Guinea. This ancient tradition suggests that every man who contributes sperm during pregnancy biologically contributes to the child, challenging the long-held assumption of a single biological father.
Researchers found that pig eggs with multiple sperm can develop into healthy embryos with a normal number of chromosomes. The extra set of chromosomes is segregated into a separate cell, which shrivels and dies.
Researchers identify receptor on egg surface that binds to sperm surface protein, offering new avenue for contraception. The target, alpha-6/beta-1 integrin, could be used to deceive an egg into changing its outer coat to keep sperm out.
A new study reveals that fruit-fly mating conflicts lead to continual changes in genes, a game of leapfrog that could have significant evolutionary consequences. Females frequently alter their genetic profiles to adjust the males' competitive odds.
Human sperm contain receptors for cannabinoids, which can inhibit the acrosome reaction, regulate swimming patterns, and prevent sperm binding to the egg. The study found that marijuana-like compounds can significantly alter these processes, with implications for diagnosis of infertility and understanding human biology.
Researchers at UT Southwestern Medical Center have identified a mutation that prevents sperm maturation in mice, which could lead to treatments for male sterility and development of new male contraceptives. The morc gene is expressed only in males during the earliest stages of sperm production.
Researchers have discovered that certain bacteria can prevent sperm from swimming well enough to reach an egg, affecting fertility. Infertile men with asymptomatic infections may benefit from broad-spectrum antibiotics to eliminate the bacteria before attempting IVF.
Researchers at NIEHS and U.C. Davis have identified a key protein involved in sperm-egg fusion, paving the way for new approaches to family planning and infertility diagnosis. A vaccine targeting this protein may provide women with a non-hormonal means of birth control.
A protein on sperm surfaces is essential for binding to eggs and traveling into the oviduct. Mice without this protein have reduced fertility rates, opening possibilities for new male contraceptives and treatments for infertility.
A team led by Cappy Rothman has successfully used sperm from a dead man to establish a pregnancy. The woman is now one month pregnant after being injected with eggs harvested from the deceased man's wife. Bioethicist Arthur Caplan fears that regulations are lagging behind technical advances in posthumous reproduction.