# Maternal Genes Determine Shell Coiling Direction in Japanese Snails

Researchers identify the genetic mechanism behind left and right-handed shell development in Euhadra snails.

- **Source:** [Science News | Latest Updates on Scientific Discoveries | The Hindu](https://www.thehindu.com/sci-tech/science/)
- **Published:** 2026-11-03
- **Topic:** [Business](https://brifing.si/c/business)
- **Original article:** <https://www.thehindu.com/sci-tech/science/a-mothers-hidden-genes-decide-which-way-her-snail-baby-spirals/article71660357.ece>
- **On Brifing:** https://brifing.si/s/e803ea11-e4d7-4ab3-8d6d-cff5c72333d1

## Biological Mirror Images

Snails exhibit distinct chirality, where their shells coil either clockwise or counter-clockwise. This physical orientation mirrors the structural differences seen in characters like 'e' and '9'. Scientists have long investigated the biological triggers behind this asymmetry, comparing it to the fundamental handedness observed in various complex organisms throughout the natural world.

## Research Collaboration Findings

A joint team of researchers from the United Kingdom and Japan recently concluded a study on Japanese Euhadra snails. The investigation aimed to pinpoint the specific biological factors that dictate shell coiling direction. By analyzing these specific mollusks, the team successfully identified the underlying mechanism responsible for this unique developmental trait.

## Maternal Genetic Influence

The study reveals that a mother's hidden genes are the primary drivers of her offspring's shell orientation. This maternal effect dictates whether the snail develops a left-handed or right-handed coil during the early stages of growth. The genetic information passed from the parent determines the structural outcome before the shell even forms.

## The Euhadra Snail Model

Euhadra snails serve as a critical model organism for studying biological asymmetry in nature. Because these snails display clear, observable differences in their shell coiling, they provide a reliable framework for geneticists. The recent findings clarify how maternal inheritance patterns influence physical morphology in these specific gastropod populations within the Japanese region.

## Developmental Asymmetry Mechanisms

The process of shell coiling is not random but strictly regulated by inherited genetic instructions. By isolating the maternal genes involved, researchers have mapped the pathway from genetic expression to physical shell structure. This discovery provides a clearer picture of how developmental pathways are established during the very earliest phases of snail embryogenesis.

## Comparative Biological Perspectives

While human handedness is a complex trait, snail chirality offers a simplified system for studying symmetry breaking. The research highlights how maternal factors can override other environmental variables in determining physical traits. Understanding these mechanisms helps scientists compare developmental biology across different species, revealing common patterns in how organisms establish their body plans.

## Scientific Implications of Chirality

Identifying the specific genes involved in shell coiling represents a significant step in evolutionary biology. This knowledge allows researchers to better understand how species adapt their physical structures over time. The study confirms that maternal influence is a powerful determinant in the morphological development of these snails, shaping their survival and interaction patterns.

## Future Research Directions

The findings published on November 4, 2026, open new avenues for exploring genetic inheritance in mollusks. Future studies may investigate whether similar maternal mechanisms exist in other snail species globally. By focusing on these genetic triggers, scientists hope to further decode the complex relationship between inherited DNA and the physical manifestation of shell chirality.

## Sources covering this story

- https://www.thehindu.com/sci-tech/science/a-mothers-hidden-genes-decide-which-way-her-snail-baby-spirals/article71660357.ece — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._
