Biology subjects

Karkas, R.

Publications and source records attributed to Karkas, R..

2 recordsLinked to original sources

bioRxiv2026

Intrahepatic reporter assay reveals leaky somatic blockade of L1 retrotransposition in mice

Long interspersed element-1 (LINE-1, L1) retrotransposition has long been proposed to occur in somatic tissues, yet direct experimental evidence distinguishing adult somatic events from early embryonic insertions has remained limited. Here we establish an intrahepatic L1 reporter assay that enables immunohistochemical detection and quantitative analysis of L1 retrotransposition in vivo. Using autonomous and non-autonomous L1 reporter variants, we demonstrate clearly detectable somatic L1 activity in the mouse liver. Comparative analysis of L1 activity in liver tissue and tumor-derived cell culture reveals that tumor cells preferentially restrict L1 at early regulatory stages, consistent with epigenetic control, whereas downstream defence mechanisms are comparatively permissive. In contrast, normal liver tissue shows stronger restriction at later stages of the L1 life cycle. Together, our results provide direct experimental evidence for somatic L1 retrotransposition in vivo in adult liver and reveal distinct regulatory strategies that shape L1 activity in tumor versus normal somatic cells. TeaserGenome destabilizing L1 retrotransposon activity is present in somatic tissues, where it likely contributes to cancer development.

genetics↗

bioRxiv2025

The Cause of Most Common Antler Abnormality is Not a Fracture But an Osteomyelitis Like Disease the Pedunculitis Chronica Deformans

Climate change is increasing the incidence of certain diseases in wildlife, offering a deeper understanding of their underlying causes. Traditionally, the most common antler abnormalities have been attributed to trauma, based on their morphology. However, this explanation does not account for the epidemic-like spread of abnormalities in specific regions, suggesting that they might be a previously undescribed aspect of this anomaly. In fallow deer (Dama dama), using advanced medical diagnostic tools, we identified an osteomyelitis-like condition, Pedunculitis Chronica Deformans (PCD) which is also observed in other Cervidae. The incidence of this disease shows a strong correlation with the production of mycotoxins by molds that are becoming more prevalent with global warming. Mycotoxins can inhibit wound healing through scar formation after the antlers are cast, leading to the development of PCD. In this report we characterize PCD pathomorphology and introduce a scoring system to differentiate it from other deformities. Moreover, we argue that the most common anomalies such as fractures, antler losses, fatal meningoencephalitis and brain abscesses are complications of PCD. Our research underscores the potential of antlers to serve as biomarkers for mycotoxin exposure.

zoology↗