Nav: Home

Cell reproduction dogma challenged

May 22, 2020

Meiosis is essential to sexual reproduction. For almost 15 years, it has been commonly held that retinoic acid, a molecule derived from vitamin A, triggers meiosis in mammalian germ cells. Yet, in joint articles published in Science Advances ( 22 May 2020 ), french researchers from the Institut de Biologie Valrose (CNRS / INSERM / Université Côte d'Azur) and the IGBMC (CNRS / INSERM / University of Strasbourg), with their colleagues, demonstrate that meiosis in mice begins and proceeds normally even in the absence of retinoic acid. These findings set the stage for new research in the field of reproductive biology.

Meiosis is an essential process that results in novel assortments of chromosomes for the transmission of unique sets of genes to offspring. Beginning with a diploid[1] germ cell (an oogonium in females or a spermatogonium in males), it yields haploid[2] gametes (oocytes in females or spermatozoa in males). The union of an oocyte and a spermatozoon combines both parental haploid genomes in a single diploid cell destined to give rise to an embryo, marking the start of the next generation.

In mammals, cells found in developing gonads (ovaries in females or testes in males) provide germ cells with structural support, nourishment, and protection. They also emit molecular signals that determine what will become of the germ cells. One of the signalling molecules is retinoic acid, widely thought to trigger germ cell meiosis. Despite the 2011 publication of findings casting doubt on this assumption, the idea that retinoic acid is a switch for meiosis has risen to the status of dogma.

Together with colleagues,[3] scientists from the Institut de Biologie Valrose in Nice and the IGBMC in Strasbourg conducted two complementary studies of the mouse foetal ovary to clarify the role of this molecule, by (i) inhibiting its synthesis and (ii) removing its receptors. Neither approach prevented normal initiation of meiosis in germ cells. Furthermore, viable infant mice were born after fertilization of oocytes lacking retinoic acid receptors, proving that these cells are functionally intact.

These twin studies therefore refute the dogma of a retinoic acid trigger for meiosis in germ cells, ending a debate that has lasted nearly a decade and a half. By dismissing a long-held tenet, these findings invite the scientific community to reconsider its working assumptions and investigate new leads in the search for the real signals controlling initiation of germ cell meiosis.
-end-
Notes
    1. In diploid cells, there are two sets of chromosomes, representing pairs of maternal and paternal alleles.

    2. In haploid cells, there is only one set of chromosomes.

    3. This work also involved male and female scientists from the Department of Reproductive Biology of the Strasbourg Teaching Hospital Network (HUS: Hôpitaux Universitaires de Strasbourg); the Biologie de la Reproduction, Environnement, Épigénétique, et Développement (BREED) research laboratory (INRAE / Université Paris-Saclay / ENVA); the University of Geneva; and the German Cancer Research Center.


CNRS

Related Retinoic Acid Articles:

Hydrochloric acid boosts catalyst activity
A research team from the Technical University of Munich (TUM) led by chemist Johannes Lercher has developed a synthesis process which drastically increases the activity of catalysts for the desulfurization of crude oil.
Healthy offspring from testicular tissue plantation in mice: Retinoic acid key
Germ cell depletion in recipient testis has adverse effects on spermatogenesis in orthotopically transplanted testis pieces via retinoic acid insufficiency.
Oncotarget Roscovitine enhances all-trans retinoic acid (ATRA)-induced nuclear enrichment
Oncotarget Volume 11, Issue 12 reported that using the HL-60 human non-APL AML model where ATRA causes nuclear enrichment of c-Raf that drives differentiation/G0-arrest, the research team now observe that roscovitine enhanced nuclear enrichment of certain traditionally cytoplasmic signaling molecules and enhanced differentiation and cell cycle arrest.
Control of the fatty acid synthase
Max Planck researchers discover first protein that regulates fatty acid synthase
Alzheimer's: Can an amino acid help to restore memories?
Scientists at the Laboratoire des Maladies Neurodégénératives (CNRS/CEA/Université Paris-Saclay) and the Neurocentre Magendie (INSERM/Université de Bordeaux) have just shown that a metabolic pathway plays a determining role in Alzheimer's disease's memory problems.
New study indicates amino acid may be useful in treating ALS
A naturally occurring amino acid is gaining attention as a possible treatment for ALS following a new study published in the Journal of Neuropathology & Experimental Neurology.
Acid reflux affects nearly a third of US adults weekly
Gastroesophageal reflux disease (GERD), a digestive disorder that causes hearburn and other uncomfortable symptoms, may affect nearly a third of US adults each week, and most of those who take certain popular medications for it still have symptoms, according to a new Cedars-Sinai study.
How plants synthesize salicylic acid
The pain-relieving effect of salicylic acid has been known for thousands of years.
Does weight loss surgery help relieve acid reflux?
Individuals who are obese often experience heartburn and other symptoms of acid reflux.
Nitric acid and ammonia electrosynthesis
The commercial synthesis methods for HNO3 and NH3 chemicals is Ostwald and Haber-Bosch process, respectively, but both of them are energy-intensive and high-emission.
More Retinoic Acid News and Retinoic Acid Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: IRL Online
Original broadcast date: March 20, 2020. Our online lives are now entirely interwoven with our real lives. But the laws that govern real life don't apply online. This hour, TED speakers explore rules to navigate this vast virtual space.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Falling
There are so many ways to fall–in love, asleep, even flat on your face. This hour, Radiolab dives into stories of great falls.  We jump into a black hole, take a trip over Niagara Falls, upend some myths about falling cats, and plunge into our favorite songs about falling. Support Radiolab by becoming a member today at Radiolab.org/donate.