New Study Reveals Bizarre Trait of Hairworms: Missing Genes Responsible for Cilia
In the realm of strange and fascinating creatures, hairworms certainly stand out. These parasitic worms are known for their ability to manipulate the behavior of their hosts, a phenomenon often referred to as “mind control.” However, a recent study published in the journal Current Biology has shed light on a peculiar trait shared by hairworm species – they are missing a significant number of genes responsible for the development of cilia, the hair-like structures found in the cells of almost all known animal species.
Hairworms, resembling thin strands of spaghetti and measuring just a few inches long, can be found around the world. Their unique body structure indicates their parasitic nature, as they lack excretory, respiratory, or circulatory systems and live primarily within other organisms. Lead author of the study, Tauana Cunha, a postdoctoral researcher at Chicago’s Field Museum, explains, “One of the coolest things, maybe the thing that they are most known for, is that they can affect the behavior of their hosts and make them do things that they wouldn’t do otherwise.”
The life cycle of hairworms starts when their eggs hatch in water, and the larvae are consumed by small aquatic predators. These predators, in turn, become prey for larger terrestrial predators, such as crickets. Once matured within their hosts, hairworms manipulate their behavior, prompting them to leap into water. The worms then wriggle out from their hosts and seek mates, repeating the cycle.
The research conducted by Cunha and her colleagues focused on sequencing the genomes of hairworms to better understand their evolutionary relationships with other animals. Surprisingly, the team discovered that both freshwater and marine hairworm species were missing approximately 30% of the genes that are typically present in most animal species. Even more intriguing is the fact that the missing genes are directly linked to the production of cilia.
Cunha explains, “Cilia are small structures present at the cellular level in organisms ranging from protists and plants to animals. They are found in many cells in the human body, including the tails of sperm cells and cells in the retinas of our eyes.” The absence of these vital structures in hairworms had been observed before, but without the genomes, it was impossible to confirm their absence definitively.
The researchers speculate that the absence of cilia in hairworms could have significant implications for their biology and behavior. Cunha suggests that further research should be conducted to explore how the missing cilia genes may be connected to their parasitic nature or other aspects of their unique biology. Additionally, the study of hairworms and their “mind control” abilities could potentially lead to a better understanding of similar behaviors exhibited by other parasites in different species.
This groundbreaking study provides valuable insights into the evolutionary patterns and genetic makeup of hairworms. By uncovering their genetic differences, scientists hope to unlock the secrets of these bizarre creatures and gain a deeper understanding of the intriguing world of parasitic organisms.
Reference:
“Rampant loss of universal metazoan genes revealed by a chromosome-level genome assembly of the parasitic Nematomorpha” by Tauana J. Cunha, Bruno A.S. de Medeiros, Arianna Lord, Martin V. Sørensen and Gonzalo Giribet, 18 July 2023, Current Biology.
DOI: 10.1016/j.cub.2023.07.003