Biology subjects

Vortman, Y.

Publications and source records attributed to Vortman, Y..

4 recordsLinked to original sources

bioRxiv2026

Phylogenetic relationship between birds and their magneto-microbiome

Animals from a wide taxonomic range can sense earths magnetic field, however the underlying mechanism remains one of sensory-biology greatest mysteries. One hypothesis suggests that Magnetotactic bacteria (MTB) serve as the underlying mechanism. This hypothesis predicts that MTB will be detected in animal microbiomes and might show a phylogenetic relationship with their hosts. We examined the phylogenetic relationship between various MTB species across 4,048 avian species using databases of MTB genetic presence across the tree of life and an avian phylogenetic tree. We documented 12 genera of MTB in association with 185 avian species. Three genera, Magnetospirillum, Magnetovibrio and Solidesulfovibrio, were found at relative high prevalence of positive samples (84%, 33%, 12% respectively). Further, Magnetospirillum showed a significant phylogenetic relationship with avian species in general and specifically within Psittaciformes, and Passeriformes. Our results demonstrate the power of harnessing the newly published MTB-database, with specific host-related queries. This analysis, to the best of our knowledge has never been done, and could be replicated across the animal kingdom. The relationship detected suggests an evolutionary and ecological relationship between MTB and avian hosts. These results are consistent with the symbiotic magnetic sensing hypothesis and highlights the potential role of microbiome in sensory physiology.

ecology↗

bioRxiv2024

Short-term antibiotics, induced magnetic field, and magnetic sensitivity in a migratory songbird

The use of magnetoreception is widespread in the animal kingdom. Although much effort has been invested in unraveling the receptor and the mechanism behind this ability, the results remain inconclusive. The recently proposed symbiotic magnetic sensing hypothesis suggests that magnetotactic bacteria symbiotically act as magnetic sensors for the host. In this study, we examined the changes in magnetic orientation of Eurasian reed warblers (Acrocephalus scirpaceus) placed in Emlen funnels under the influence of antibiotics, in response to a manipulated magnetic field. We found that reed warblers of the control group showed no significant magnetic orientation when placed in a manipulated magnetic field. In contrast, reed warblers placed in an unplugged coil showed significant magnetic southwest orientation. Furthermore, reed warblers exposed to short-term antibiotic treatment (12 h) demonstrated significant magnetic orientation (southwest, regardless of season) and significantly lower directional variance. We hypothesize that individuals from the control group identified the electromagnetic noise induced by the artificial magnetic field. Taken together, this unexpected result may demonstrate the sensitivity of passerines to electromagnetic noise and a possible damping effect of antibiotics on this sensitivity. Assuming our interpretations are correct, we consider this result as indirect experimental support for the symbiotic magnetic sensing hypothesis.

animal behavior and cognition↗

bioRxiv2022

Quantitative genetic study suggests sex-specific genetic architecture for fetal testosterone in a wild mammal

Testosterone plays a critical role in mediating fitness-related traits in many species. Although it is highly responsive to environmental and social conditions, evidence from several species show a heritable component to its individual variation. Despite the known effects that in utero testosterone exposure have on adult fitness, the heritable component of individual testosterone variation in fetuses is mostly unexplored. Furthermore, testosterone has sex-differential effects on fetal development, i.e., a specific level may be beneficial for male fetuses but detrimental for females. The above mentioned may lead to a different genetic structure underlying the heritability of testosterone between the sexes. Here, we used a wild animal model, the feral nutria, quantified testosterone using hair-testing and estimated its heritability between parent and offspring from the same and opposite sex. We found that in utero accumulated hair testosterone levels were heritable between parents and offspring of the same sex. However, there was a low additive genetic covariance between the sexes, and a relatively low cross-sex genetic correlation, suggesting a potential for sex-dependent trait evolution, expressed early on, in utero.

molecular biology↗

bioRxiv2020

Antibiotics affect migratory restlessness orientation

Magnetoreception is a sense that allows the organism to perceive and act according to different parameters of the magnetic field. This magnetic sense plays a part in many fundamental processes in various living organisms. Much effort was expended in finding the magnetic sensor in animals. While some experiments show a role of the ophthalmic nerve in magnetic sensing, others show that effects of light on processes in the retina are involved. According to these inconclusive and puzzling findings, the scientific community has yet to reach an agreement concerning the underlying mechanism behind animal magnetic sensing. Recently, the symbiotic magnetotaxis hypothesis has been forwarded as a mechanistic explanation for the phenomenon of animal magnetoreception. It suggests a symbiotic relationship between magnetotactic bacteria (MTB) and the navigating host. Here we show that in contrast to the control group, antibiotic treatment caused a lack of clear directionality in an Emlen funnel experiment. Accordingly, the antibiotics treatment group showed a significant increase in directional variance. This effect of antibiotics on behaviors associated with animal magnetic sensing is, to the best of our knowledge, the first experimental support of the symbiotic magnetotactic hypothesis.

animal behavior and cognition↗