Articles tagged with Sperm Competition
A recent study led by Harvard Medical School researchers found that genetic changes creating identical sperm cells are more widespread than thought and linked to single-gene diseases. The team identified genes underlying these mutations, which can be passed onto offspring, leading to devastating disorders.
A study from Michigan Medicine researchers reveals that X-carrying and Y-carrying sperm compete for binding to Spindlins, influencing gene expression and the sex ratio. The findings suggest that this competition is crucial for maintaining the optimal balance of female and male offspring in mice.
Research reveals plants have developed strategies similar to sperm manipulation in animals to compete for space on pollinators. A study found that flowers use catapult-like mechanisms to dislodge rival pollen, increasing their chances of reproductive success.
A University at Buffalo-led research team has found that the same genes whose mutations gave rise to a low functioning male gorilla reproductive system may also be responsible for human male infertility. Researchers identified 109 reproductive-related gorilla genes that are often mutated when present in infertile men.
In a 50-generation evolutionary experiment, male beetles from lineages with intense sexual selection produced lower quality offspring after DNA-damaging radiation. This suggests that males invest more in competition at the expense of DNA repair, impacting future offspring survival and fertility.
Researchers discovered two dominant strategies among flatworms: reciprocal males receive more resources, while hypodermic mated species invest heavily in female organs. Self-fertilization in these species increases with hypodermic mating, suggesting a common evolutionary principle between plants and worms.
Research reveals that sperm cells with the t-haplotype exhibit increased motility and competitiveness, attributed to optimal RAC1 activity. This genetic factor enables them to disable competitors while producing an antidote to protect themselves.
Researchers at Uppsala University found that males facing competition for females have offspring with more harmful mutations. This is because increased sperm production comes at the expense of cellular surveillance, which prevents genetic damage.
A study by Uppsala University found that sperm quality varies depending on a male's characteristics, such as attractiveness and age. For less dominant males, longer sperm is beneficial for fertilization success, while more attractive males benefit from smaller sperm.
A study published in BMC Evolutionary Biology found that rival sperm competition makes ant sperm better swimmers, increasing their mobility, speed, and straightness by up to 50%. Researchers discovered that seminal fluid from rival males and queen secretions enhance sperm motility, suggesting a self-non-self-recognition mechanism.
A study found that worms that can self-fertilize have lost approximately one-fourth of their genes, including those giving male sperm competitive edge. This shift may be driven by reduced competition among male worms, allowing populations to grow faster.
In a groundbreaking study, FSU Professor Don Levitan found that sperm from multiple males compete for fertilization, allowing eggs to choose their preferred mate. This discovery has significant implications for the evolution of reproductive compatibility and the creation of new species.
A new study in Nature found that fruit fly sperm tails are the most extreme ornament, with lengths of up to 6 cm, due to female preference for longer sperm. This preference is linked to genetic correlations between female reproductive tracts and male sperm length, as well as a trade-off between sperm length and number.
Researchers found that larger males with more sperm are favored by females, driving the evolution of longer sperm. This study provides the first explanation for the development of giant sperm in fruit flies.
Researchers found that winter hibernation reverses the typical sperm competition outcome in fruit flies. In cold temperatures, only the first male fathered most of the offspring, while subsequent males had little to no success. This discovery could impact pest control strategies and understanding of sperm storage.
A new study reveals that females have evolved a highly-effective counter-strategy to stop males from killing their offspring: by having multiple mates in a short time, causing paternity dilution and reducing infanticide risk. This leads to increased testis size in male mouse lemurs as they produce more sperm to outcompete others.
Evolutionary biologist Steven Ramm explores sperm competition as a key driver of reproductive system evolution, highlighting the diversity of sperm cells and their adaptations to compete for fertilization. This research could inform genetic modification to increase fertility in endangered species.
Correlation discovered between molecular evolutionary rates and testes weights, suggesting sperm competition fuels genetic variation. Testis size may be key factor in determining genome evolution rates among primate species.
Researchers at Syracuse University's College of Arts and Sciences have confirmed that diversifying sperm competition is a critical step in the formation of new species. The study, published in Current Biology, reveals how postcopulatory sexual selection drives rapid evolutionary changes in ejaculate and female reproductive tract traits.
A new study by Syracuse University researchers found that female Drosophila melanogaster flies actively influence sperm competition, allowing them to choose between different male sperm for fertilization. This discovery has major implications for the study of sexual selection and coevolution in animals.
A new study by Syracuse University scientists found that slower and/or longer sperm outcompete their faster rivals in fruit fly reproduction. The research, published in Current Biology, used genetically altered fruit flies to observe sperm in real-time inside the female reproductive tract.
Studies of diving beetles reveal that sperm form follows female reproductive organ function, challenging the paradigm of post-mating sexual selection. Researchers found diverse sperm shapes and structures adapted to navigate complex female reproductive tracts, suggesting females can drive evolutionary changes in male traits.
Male fruitflies experience a prolonged mating period with females after encountering rival males, increasing the length of mating by up to 93% in some species. This 'paranoid' behavior is thought to ensure fertilization before females mate with other males.
Researchers found that generation time is a strong indicator of mutation rate, accounting for 40% of variation among species. Male mutation bias, where males have higher DNA mutations than females, was also linked to generation time. In contrast, metabolic rate appeared to be only a moderate predictor of mutation rates.
Research published in BMC Evolutionary Biology shows that polygamous mice produce more fertile offspring due to increased sperm competitiveness. After 12 generations of competitive selection, polygamous males outperformed monogamous males in both paternity and fertility rates.
Researchers found Tuberous Bushcricket produces large testes but less sperm per ejaculate, defying traditional thinking. The study suggests males use larger testes to mate repeatedly without exhausting their sperm reserves.
A new study by the University of East Anglia found that inbred male sperm fertilized fewer eggs when competing with non-inbred males. Inbreeding depression revealed itself in competitive scenarios, potentially affecting conservation and captive breeding projects.
Researchers discovered that leafcutter ant queens can neutralize male-male sperm competition through glandular secretions. This allows them to preserve their own sperm for millions of eggs fertilized over a single day's sexual activity.
Researchers found that mouse sperm from promiscuous species can discriminate between closely related and unrelated sperm, clustering together to swim faster. This cooperative behavior is driven by competition among males and may be widespread among 95% of mammals.
Promiscuous female African cichlids stimulate males to produce larger and speedier sperm, a strategy to outcompete rival suitors for reproduction. Researchers used computer simulations to show that this evolutionary adaptation occurs after species transition to more promiscuous mating behaviors.
A study by Uppsala University researchers found that females' promiscuity leads to males producing faster and larger sperms. The competition among sperms influences various characteristics, including size and speed.
In polyandrous female Australian painted dragon lizards, sperm from different males compete to fertilize eggs. Females prefer mating with mixed-color pairs of males, suggesting a strategy to ensure genetic diversity. This unique behavior may contribute to the persistence of both male types in the population.
Researchers found that quail males who learned to associate a stimulus with access to a female were more likely to fertilize eggs, increasing their reproductive success. The findings suggest that learning plays a significant role in reproductive fitness and evolution.
Researchers investigate natural mitochondrial DNA variation's effect on human male fertility and sperm competitiveness. They found mitochondrial mutations to be a primary cause of low sperm count and poor mobility.
A study by Dr. Martin Edvardsson found that dehydrated female beetles mate more frequently with males to obtain water from their seminal fluid, a strategy that benefits the male by extending the time before fertilization competition resumes. The research sheds new light on the role of 'nuptial gifts' in insect courtship and mating.
A new study suggests that human males have evolved mechanisms to outcompete rivals for fertilization, even after sex. This phenomenon, dubbed 'sperm competition,' can lead to increased sperm count and more aggressive sexual behavior in response to perceived infidelity.
In promiscuous rodents, individual sperm work together in groups to increase competitiveness and successfully reach the female egg. This cooperation enables faster and stronger swimming, making them better competitors in fertilization races.
Researchers discovered that protein translation takes place in sperm prior to fertilization, essential for sperm functions like motility and fertilization. Inhibiting mitochondrial translation machinery leads to decreased sperm motility and fertility rates.
Researchers found that male mounting, even without semen transfer, reduces a hen's tendency to mate with other males and decreases the number of sperm obtained from a new rooster. This behavior helps defend paternity, suggesting copulations without semen transfer have evolutionary significance.
A Royal Society study found that Antarctic fish can compensate for the initial negative impact of elevated temperatures and regain their original performance levels despite being several degrees warmer. The study suggests that rising temperatures do not necessarily have a long-term negative impact on biodiversity.
A new study by researchers Francisco Garcia-Gonzalez and Leigh Simmons shows that the proportion of live sperm in a male's ejaculate determines paternity success. The study used Australian field crickets to test the hypothesis that sperm viability influences insect paternity success.
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.