Scientists have found that Vitamin B12 intake in worms can trigger the development of a predatory mouth structure, which their offspring inherit without any alterations to the underlying DNA. This finding reclassifies a common nutrient as a biological signal linking dietary status to heritability across multiple generations. The study’s outcomes have been featured in the journal Nature Communications.
Within laboratory strains of Pristionchus pacificus, this phenomenon was observed in mouthparts that either remained narrow or transformed into a predatory configuration. By tracking these forms across successive generations, Sheila Perle Kiwobe from the Max Planck Institute for Biology in Tübingen (MPI) documented Vitamin B12 as the catalyst linked to an enduring predisposition for predation.
The observed modifications were not confined only to the worms that consumed the vitamin; they persisted even after subsequent generations reverted to their standard diet. This persistence drew attention to what the mothers were transmitting, thereby connecting nutrition and inheritance via substances stored within the eggs.
Vitamin B12 promoted the rapid emergence of the predatory mouth structure when the worms fed on bacteria or when nutrients were supplied in specially prepared Petri dishes. At sufficiently high concentrations, the structural change persisted even after the organisms returned to their regular sustenance.
Even in minute quantities, the predatory behavioral pattern manifested, though the inherited effect vanished after one to two generations once the diet shifted. “What our research demonstrates is that Vitamin B12 doesn’t just influence the consumer; it has the potential to shape the biology of the generations that follow,” stated Kiwobe.
The bacterium Novosphingobium pushed the worms toward predatory behavior because it supplied them with Vitamin B12 alongside other necessary dietary cues. When researchers utilized bacteria incapable of producing this vitamin, the offspring lost their acquired predatory instinct as soon as their food source changed.
Supplementing with Vitamin B12 reinstated this effect, whereas the deficient bacteria still exerted a partial influence on the initial generation. Other chemical compounds secreted by the bacteria might contribute to mouthpart formation, but Vitamin B12 was responsible for maintaining the signal over an extended duration. Mothers transfer this influence via vitellogenin, an egg yolk protein that nourishes the embryos, rather than through the Vitamin B12 molecule itself.
A vitamin-rich diet boosted vitellogenin gene activity, resulting in more nutrients being deposited into the eggs prior to embryonic development, an effect sustained across several generations.
Worms lacking the natural egg-laying system can adopt a predatory morphology, but their progeny lose this trait in the next generation. These findings enable a correlation between egg contents and DNA sequencing as components of intergenerational hereditary shifts.
The most significant aspect of this discovery is that the worms inherited a behaviorally linked mouth structure without any change to the DNA sequence. Biologists term this type of inheritance epigenetic inheritance, where environmental influences affect descendants without directly modifying genetic traits beyond a single generation.
favicon
valdai.ru
Navigate to site
Prior investigations into human famine effects documented persistent alterations in DNA methylation following prenatal exposure, but the mechanisms underlying these changes remain challenging to isolate.
The worm experiments allow scientists to establish a clearer cause-and-effect relationship between diet and observed outcomes, which can inform human studies without drawing definitive conclusions for people. In trace amounts, supplemental Vitamin B12 retained a “memory” of the predatory state even after the worms left their enriched diet.
With moderate intake, the animals still developed predatory mouths, but the transmission of the conditioned trait ceased before achieving true heritability once the vitamin was removed from the environment.
Even trace levels were sufficient to bring about a change in the mouth structure’s state, whereas extremely minimal quantities left the worms in a condition closely resembling their baseline state under identical conditions.
Dosage proved critical, as the initial response was easily triggered, but establishing the persistent memory required higher vitamin exposure across multiple generations. For the continuing transmission of the vitamin signal, cells required methionine, an amino acid utilized in protein construction.
Methionine supplementation progressively induced the carnivorous mouth structure and maintained this form across subsequent generations following repeated exposure.
Conversely, folate, another B vitamin involved in cellular chemistry, did not elicit a discernible predatory response during these trials. This contrast points toward a specific intracellular pathway rather than a generalized effect of a richer diet or better conditions overall.
Long before this vitamin study, the Max Planck group had monitored 110 lines of genetically similar worms for 101 generations, subjecting them to varied dietary regimens.
Earlier work demonstrated that the predatory mouthparts were only retained after at least five generations consuming a bacterial diet, after which the lines reverted to their ancestral state. In natural habitats, these worms often hitch rides on beetles and encounter food scarcity once the insects decay in the soil upon arrival.
The preserved predatory form can aid the offspring in competition when bacteria, fungi, and other worms must share a carcass during that brief window of opportunity.
Humans also rely on Vitamin B12 for nerve function, blood cells, and DNA maintenance, but these findings from nematode analysis do not constitute medical advice.
During gestation and early development, Vitamin B12 supports growth because dividing cells require it for essential chemical reactions. No studies in humans have confirmed that Vitamin B12 programming transmits specific traits via this pathway to humans.
Nevertheless, this discovery clarifies a more profound takeaway: diet can induce changes in biological processes in certain animals that persist beyond a single lifespan. By linking diet, bacterial chemistry, the nutritional quality of eggs, and inherited behavior into a single continuous chain, this work presents a rare, clear example.
Future research should focus on quantifying the lifespan of this inherited memory in offspring and identifying other nutrients capable of exerting similar effects on controlled descendant lines.
About the Author
