Ishiyama, G. | Search bioRxiv

bioRxiv2026

Dermatomycosis associated with Nannizziopsis arthrosporioides in a breeding colony of gecko (Correlophus ciliatus and Rhacodactylus auriculatus).

This report describes lethal Nannizziopsis-associated dermatomycosis in a breeding colony of the family Diplodactylidae (Correlophus ciliatus and Rhacodactylus auriculatus). After introducing one gecko from overseas, three with indirect contact history died due to severe skin lesions. Extensive lesions were observed on the toe pads and ventral surface, along with necrotic dermatitis and cellulitis associated with fungi forming hyphae. Subsequently, four geckos developed diarrhea, melena, emaciation, and fungal dermatitis of the toe pads and died. Histopathologically, the fungal morphologies observed in the skin lesions of the seven geckos were consistent, and Nannizziopsis arthrosporioides was isolated and identified in two of them. To our knowledge, this is the first report of a fatal outbreak of N. arthrosporioides in geckos.

pathology↗

bioRxiv2025

DNA Specimen Preservation using DESS and DNA Extraction in Museum Collections: A Case Study Report

Recent advances in DNA research have increased the necessity for museums to preserve not only morphological specimens but also their DNA, leading us to maintain tissue samples linked to specimens at -80{degrees}C. DNA analysis has become an essential tool for taxonomic research and biodiversity assessment; however, freezer storage for all samples is impractical due to space limitations and operational costs. This creates a pressing need to develop more widely applicable DNA preservation methods. We investigated the comparative effects of traditional preservation methods versus DESS (DMSO/EDTA/saturated NaCl solution) preservation on both morphology and DNA integrity using museum specimens from various taxonomic groups. Our results demonstrated that DESS preservation maintained high-quality DNA fragments exceeding >15 kb at room temperature across all examined species, with nematode samples maintaining DNA integrity even after 10 years of storage. When preserving whole organisms, the optimal preservation solution conditions for maintaining both morphological features and DNA integrity varied among species. Notably, DNA integrity was maintained even after complete evaporation of the DESS solution. These findings suggest that DESS utilization for specimen DNA preservation is effective across many species, not only for long-term storage in environments without freezer facilities but also for temporary preservation until freezing. Simple SummaryRecent advances in DNA research have increased the necessity for museums to preserve not only morphological specimens but also their DNA, leading us to maintain tissue samples linked to specimens at -80{degrees}C. However, as freezer storage for all samples is impractical, there is a pressing need to develop more widely applicable DNA preservation methods. In this study, we investigated the effectiveness of traditional preservation methods versus DESS (DMSO/EDTA/saturated NaCl solution) preservation with regards to both morphology and DNA integrity using our museum specimens. Our results demonstrated that DESS preservation maintained high molecular weight DNA at room temperature across all examined species. When preserving whole organisms, the optimal preservation solution conditions for maintaining both morphological features and DNA integrity varied among species. Notably, DNA integrity was maintained even after complete evaporation of the DESS solution. These findings suggest that DESS utilization for specimen DNA preservation is effective across many species, not only for long-term storage in environments without freezer facilities but also for temporary preservation until freezing is possible.

zoology↗