PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

A milestone for reproductive medicine: Producing viable eggs from undeveloped oocytes through In vitro technology

Researchers successfully produce viable, embryo-forming egg cells from underdeveloped oocytes extracted from ovarian follicles

A milestone for reproductive medicine: Producing viable eggs from undeveloped oocytes through In vitro technology
2024-11-11
(Press-News.org)

Mature egg cells, or oocytes, are essential for fertilization in assisted reproductive technologies. However, some ‘denuded’ oocytes, or those lacking the protective granulosa cell layer, fail to mature. Now, in a new study by researchers at Shinshu University, the team has developed a method to culture mature oocytes from these denuded oocytes in the lab. This innovative approach holds promise for overcoming significant challenges in reproductive science, marking a major advancement in fertility research.

Assisted reproductive technology (ART) is a fertility treatment where eggs are removed from the ovaries, combined with sperm outside the human body, and the resulting embryos are placed in the uterus. Typically, eggs or oocytes grow within fluid-filled sacs called follicles in the ovary. Granulosa cells (GCs) surround the developing egg and provide essential nutrients and hormones. However, early-stage follicles have only a thin GC layer, and during isolation for fertility treatments, these cells may detach from the egg, leaving behind “denuded” oocytes, which are unable to mature and cannot be used in ART.

Now, in a study published online on 21 August 2024 in Biology of Reproduction, Assistant Professor Kanako Morohaku and her team at Shinshu University have identified a novel method to produce viable, embryo-forming eggs from denuded oocytes taken from “preantral” follicles in mice. Preantral follicles represent an earlier developmental stage, unlike the more mature antral follicles typically used in ART. While previous research focused on antral follicles, there have been limited attempts to obtain viable eggs from preantral follicles.

To address this issue, the researchers isolated denuded oocytes and GCs from mice, which were then grown together in a U-shaped lab dish for eight days. This led to the formation of granulosa cell-oocyte complexes, or GOCs, which allowed the oocytes to interact with supporting cells again. In a previous study, the team found that oocyte quality was affected by the oxygen concentration under which GOCs were cultured. Hence, these oocytes were cultured with GCs under high (20%) and low (5%) concentrations of oxygen to observe the difference in oocyte growth.

They observed that low oxygen levels significantly improved the development of GOCs and stimulated the formation of transzonal projections, thin cellular connections necessary for oocyte growth. After eight days, these reassembled GOCs were cultured on a collagen-coated membrane for four additional days, leading to the maturation of oocytes into fertilizable eggs.

To test their viability, the researchers fertilized the eggs and transferred 126 embryos into female mice, following which they obtained six live pups. “To the best of our knowledge, our new culture protocol is the first to successfully obtain offspring from preantral follicle-derived denuded oocytes grown by reconstructing GOCs in vitro,” explains Mr. Tomohiro Kohama, a PhD student and one of the authors, highlighting the landmark nature of the study.

Needless to say, study’s implications extend beyond human fertility treatment. The researchers suggest that this new method could also benefit large animals like cattle and pigs, where typical egg maturation techniques often fail due to the unique structure of their ovaries. Additionally, the approach could help converse endangered species by supporting ex vivo (outside an organism’s body) production, offering a new way to preserve genetic resources.

The researchers are confident that these results will prove to be invaluable for the field of ART. Elaborating further, Prof. Morohaku says, “Ex vivo egg production is required for livestock and endangered animals for efficient use of genetic resources, breeding, creating animal models to understand how germ cells develop, and for humans as a treatment for infertility.”

This novel method could prove to be invaluable for animals like cattle and pigs, whose ovarian structures make traditional culturing methods less effective. The research team is optimistic that their findings will advance reproductive biology and fertility treatments. By enhancing the viability of denuded oocytes, this innovative approach could offer renewed hope for individuals facing infertility and contribute to the conservation of endangered species.

Even as the team explores the potential applications of their work, they aim to significantly impact both human reproductive health and the preservation of genetic diversity in the animal kingdom.

 

###

 

About Shinshu University

Shinshu University is a national university founded in 1949 and located nestling under the Japanese Alps in Nagano known for its stunning natural landscapes. Our motto, "Powered by Nature - strengthening our network with society and applying nature to create innovative solutions for a better tomorrow" reflects the mission of fostering promising creative professionals and deepening the collaborative relationship with local communities, which leads to our contribution to regional development by innovation in various fields. We’re working on providing solutions for building a sustainable society through interdisciplinary research fields: material science (carbon, fiber and composites), biomedical science (for intractable diseases and preventive medicine) and mountain science, and aiming to boost research and innovation capability through collaborative projects with distinguished researchers from the world. For more information visit https://www.shinshu-u.ac.jp/english/ or follow us on X (Twitter) @ShinshuUni for our latest news.

About Assistant Professor Kanako Morohaku from Shinshu University

Dr. Kanako Morohaku is an Assistant Professor in the Faculty of Agriculture, Department of Agricultural and Life Sciences, Division of Animal Science at Shinshu University. Her research interests lie in animal science, especially animal reproduction. She has published more than 20 papers with over 800 citations on the topics of germ cell physiology and engineering, animal reproduction, oocytes and ovaries, in vitro culture, and germ cell preservation.

END


[Attachments] See images for this press release:
A milestone for reproductive medicine: Producing viable eggs from undeveloped oocytes through In vitro technology

ELSE PRESS RELEASES FROM THIS DATE:

Vast majority of Trump voters believe American values and prosperity are ‘under threat’

2024-11-11
Almost nine out of ten voters who supported Donald Trump for US President believe that America’s values, traditions and future economic prosperity are under threat – double the number of Kamala Harris supporters.  This is according to new data from Cambridge University’s Political Psychology lab, who worked with YouGov to conduct an opinion poll of US voters shortly before the election.* Some 89% of Trump voters agree that “American values and beliefs are being undermined and cherished traditions are under threat” compared ...

Scientists investigate if red grape chemical can keep bowel cancer at bay

2024-11-11
Cancer Research UK-funded scientists are finding out if an ingredient commonly found in grape juice and wine could keep bowel cancer at bay. Resveratrol – a naturally occurring ingredient found in grapes, blueberries, raspberries and peanuts – will be tested as a potential cancer prevention drug as part of the Cancer Research UK-funded COLO-PREVENT trial. The trial is led from the University of Leicester and the National Institute for Health and Social Care Research (NIHR) Leicester Biomedical Research Centre. The trial ...

The refrigerator as a harbinger of a better life

2024-11-09
To get a good sense of a country’s level of development, you need to look at the items people have in their homes, according to economists Rutger Schilpzand and Jeroen Smits from Radboud University. Research on low- and middle-income countries often focuses on income, health or education, but that doesn’t tell you the full story of a country’s situation. ‘That’s why, for the first time, we are mapping out how the material wealth of households is developing,’ Schilpzand explains. The researchers coin this material wealth growth for households the 'domestic transition'. ...

Windfall profits from oil and gas could cover climate payments

2024-11-09
A central issue at the UN Climate Change Conference, set to start on November 11, will be the negotiations on new payments from industrialized nations to poorer countries. However, the question of whether and how these payments will be financed remains highly controversial. The study by an international team of researchers, with participation by the Technical University of Munich (TUM), has now revealed: The windfall profits alone taken in by oil and gas companies due to the 2022 energy crisis would have been sufficient to cover the existing commitments of the industrialized nations for nearly five years. The researchers ...

Heartier Heinz? How scientists are learning to help tomatoes beat the heat

2024-11-08
PROVIDENCE, R.I. [Brown University] — By studying tomato varieties that produce fruit in exceptionally hot growing seasons, biologists at Brown University identified the growth cycle phase when tomatoes are most vulnerable to extreme heat, as well as the molecular mechanisms that make the plants more heat tolerant. The discovery, detailed in a study in Current Biology, could inform a key strategy to protect the food supply in the face of climate instability, the researchers said. Agricultural productivity is particularly vulnerable to climate change, the study noted, and rising temperatures are predicted to reduce crop yields by 2.5% to 16% for every ...

Breaking carbon–hydrogen bonds to make complex molecules

Breaking carbon–hydrogen bonds to make complex molecules
2024-11-08
A team of scientists led by Caltech and Emory University has synthesized a highly complex natural molecule using a novel strategy that functionalizes normally nonreactive bonds, called carbon–hydrogen (C–H) bonds. The work demonstrates a new category of reactions that organic chemists can consider as they work to create natural products that could be used in pharmaceuticals or new materials, or to produce organic chemicals in more sustainable ways.   "This work moves the field forward by showing the power of C–H functionalization," says ...

Sometimes you're the windshield: Utah State University researcher says vehicles cause significant bee deaths

Sometimes youre the windshield: Utah State University researcher says vehicles cause significant bee deaths
2024-11-08
LOGAN, UTAH, USA -- When a large mammal such as a deer or a moose is struck by a motor vehicle, the damage is usually dramatic. To reduce these unfortunate events, transportation officials have teamed with wildlife researchers to place warning signs, and to construct wildlife underpasses and overpasses, to mitigate mishaps along animal migration paths. In contrast, collisions with much smaller bees often go unnoticed or are perceived by motorists as simply an annoying splat on a windshield. The significance, Utah State University ...

AMS Science Preview: Turbulence & thunderstorms, heat stress, future derechos

2024-11-08
The American Meteorological Society continuously publishes research on climate, weather, and water in its 12 journals. Many of these articles are available for early online access–they are peer-reviewed, but not yet in their final published form. Below is a selection of articles published early online recently. Some articles are open-access; to view others, members of the media can contact kpflaumer@ametsoc.org for press login credentials. JOURNAL ARTICLES A New Heat Stress Index For Climate Change Assessment Bulletin of the American Meteorological Society Heat Index may dramatically underestimate heat stress in extreme temperatures. This work compares the ...

Study of mountaineering mice sheds light on evolutionary adaptation

Study of mountaineering mice sheds light on evolutionary adaptation
2024-11-08
Teams of mountaineering mice are helping advance understanding into how evolutionary adaptation to localized conditions can enable a single species to thrive across diverse environments. In a study led by Naim Bautista, a postdoctoral researcher in Jay Storz’s lab at the University of Nebraska–Lincoln, the team took highland deer mice and their lowland cousins on a simulated ascent to 6,000 meters. The “climb” ventured from sea level and the mice reached the simulated summit seven weeks later. Along the way, Bautista tracked how the mice responded to cold stress at progressively lower oxygen levels. “Deer ...

Geologists rewrite textbooks with new insights from the bottom of the Grand Canyon

Geologists rewrite textbooks with new insights from the bottom of the Grand Canyon
2024-11-08
LOGAN, UTAH, USA – Any boomer, gen xer, millennial, gen zer or alpha who’s studied geology has likely gained foundational knowledge from Edwin Dinwiddie McKee’s landmark studies of the Grand Canyon’s sedimentary record – even if they don’t readily recognize McKee’s name. The legendary scientist, who lived from 1906-1984, studied and documented the stratigraphy and sedimentation of Colorado Plateau geology, especially the Grand Canyon’s Cambrian Tonto Group, for more than 50 years. His time-tested ...

LAST 30 PRESS RELEASES:

Solving complex problems faster: Innovations in Ising machine technology

Grief-specific cognitive behavioral therapy vs present-centered therapy

New species discovered with refined DNA technology

C-PATH announces Gender Equitable Medicines for Parkinson's Disease (GEM-PD) initiative

Faster flowing glaciers could help predict nearby volcanic activity

MIT engineers make converting CO2 into useful products more practical

Primary care professionals key to helping people achieve & maintain heart health

Early detection, intensive treatment critical for high-risk patients with Kawasaki Disease

A phase-transformable membrane for efficient gas separation could revolutionize industrial applications

From camera to lab: Dr. Etienne Sibille transforms brain aging and depression research

Depression rates in LGBTQIA+ students are three times higher than their peers, new research suggests

Most parents don’t ask about firearms in the homes their kids visit

Beer-only drinkers’ diets are worse than wine drinkers

Eco-friendly biomass pretreatment method yields efficient biofuels and adsorbents

How graph convolutions amplify popularity bias for recommendation?

New lignin-based hydrogel breakthrough for wound healing and controlled drug release

Enhancing compatibility and biodegradability of PLA/biomass composites via forest residue torrefaction

Time alone heightens ‘threat alert’ in teenagers – even when connecting on social media

Study challenges long-held theories on how migratory birds navigate 

Unlocking the secrets of ketosis

AI analysis of PET/CT images can predict side effects of immunotherapy in lung cancer

Making an impact. Research studies a new side of helmet safety: faceguard failures

Specific long term condition combinations have major role in NHS ‘winter pressures’

Men often struggle with transition to fatherhood amid lack of targeted information and support

More green space linked to fewer preventable deaths in most deprived areas of UK

Immunotherapy drug pembrolizumab improves outcomes for patients with soft tissue sarcoma

A formula for life? New model calculates chances of intelligent beings in our Universe and beyond

Could a genetic flaw be the key to stopping people craving sugary treats?

Experts urge complex systems approach to assess A.I. risks

Fossil fuel CO2 emissions increase again in 2024

[Press-News.org] A milestone for reproductive medicine: Producing viable eggs from undeveloped oocytes through In vitro technology
Researchers successfully produce viable, embryo-forming egg cells from underdeveloped oocytes extracted from ovarian follicles