Biology subjects

Michael, K.

Publications and source records attributed to Michael, K..

4 recordsLinked to original sources

bioRxiv2026

Rapid population decline of Egyptian fruit bats on Cyprus

Preventing extirpations requires timely detection of rapid declines and immediate conservation response. Egyptian fruit bats (Rousettus aegyptiacus) are globally listed as Least Concern, but their genetically isolated population in Cyprus is Critically Endangered. We document a severe ongoing decline of the Cypriot R. aegyptiacus population observed during standardized counts at major roost sites. April 2024 counts at four principal roosts recorded 4633 bats. Surveys in December 2025 documented 554 individuals across the same sites. April 2026 counts revealed a 90.1% decline since April 2024. Additionally, we found numerous dead bats at three roosts, and residents across the island reported dead bats, suggesting an acute mortality event beginning in early 2025. The cause remains unknown. Given the magnitude and pace of decline, this population potentially faces imminent extirpation. We recommend immediate action to protect roosting and foraging habitat, along with coordinated diagnostics, expedited research permits, standardized monitoring, and technical collaboration to identify and mitigate underlying causes of high mortality.

ecology↗

bioRxiv2023

A catalogue of small proteins from the global microbiome

Small open reading frames (smORFs) shorter than 100 codons are widespread and perform essential roles in microorganisms, where they encode proteins active in several cell functions, including signal pathways, stress response, and antibacterial activities. However, the ecology, distribution and role of small proteins in the global microbiome remain unknown. Here, we constructed a global microbial smORFs catalogue (GMSC) derived from 63,410 publicly available metagenomes across 75 distinct habitats and 87,920 high-quality isolate genomes. GMSC contains 965 million non-redundant smORFs with comprehensive annotations. We found that archaea harbor more small proteins proportionally than bacteria. We moreover provide a tool called GMSC-mapper to identify and annotate small proteins from microbial (meta)genomes. Overall, this publicly-available resource demonstrates the immense and underexplored diversity of small proteins.

bioinformatics↗

bioRxiv2023

A temperature-controlled, circular maintenance system for studying growth and development of pelagic tunicates (Salps)

Salps are pelagic tunicates that are able to form large blooms under favorable conditions by alternating between sexual and asexual reproduction. While their role in the regional carbon cycle is receiving attention, our knowledge of their physiology is still limited. This knowledge gap is mainly due to their fragile gelatinous nature, which makes it difficult to capture intact specimens and maintain them in the laboratory. We present here a modified kreisel tank system, that was tested onboard using the Southern Ocean salp Salpa thompsoni and station-based using the Mediterranean species Salpa fusiformis. Successful maintenance over days to weeks allowed us to obtain comparable relative growth and developmental rates as in situ, and provided insight into their potential life cycle strategies. By providing a starting point for successful maintenance, we hope to stimulate future experimental research on this understudied taxonomic group.

physiology↗

bioRxiv2020

Failures of nerve regeneration caused by aging or chronic denervation are rescued by restoring Schwann cell c-Jun

After nerve injury, myelin and Remak Schwann cells reprogram to repair cells specialized for regeneration. Normally providing strong regenerative support, these cells fail in aging animals, and during the chronic denervation that results from the slow growth of axons. This impairs axonal regeneration and causes a significant clinical problem. In mice, we find that repair cells express reduced c-Jun protein as the regenerative support provided by these cells declines in aging animals and during chronic denervation. In both cases, genetically restoring Schwann cell c-Jun levels restores regeneration to that in controls. We identify potential gene candidates mediating this effect and implicate Shh in the control of Schwann cell c-Jun levels. This establishes that a common mechanism, reduced c-Jun in Schwann cells, regulates the success and failure of nerve repair both during aging and chronic denervation. This provides a molecular framework for addressing important clinical problems, and suggests molecular pathways that can be targeted to promote repair in the PNS.

neuroscience↗