Biology subjects

Dias, D.

Publications and source records attributed to Dias, D..

3 recordsLinked to original sources

bioRxiv2023

Reproductive traits of the European catfish (Silurus glanis) during the early stages of invasion in the Lower Tagus River

Freshwater ecosystems face severe challenges from biological invasions, leading to biodiversity loss, disruption of ecosystem services, and economic impacts. Human-mediated activities, such as aquarium trade and sport angling, contribute to species introductions, with potential negative consequences for native ecosystems. The European catfish (Silurus glanis) is one of the worlds largest freshwater fish and has been intentionally introduced into diverse regions, impacting native ecosystems. However, limited research exists on its reproductive traits outside its native range. This study addresses this gap by examining the reproductive characteristics of non-native European catfish populations in the Lower Tagus River in Portugal, focusing on size at maturity, spawning period, and fecundity. The observed balanced sex ratio aligns with studies of native populations. Variations in size at first maturity (TL50) among populations highlight the influence of habitat conditions, temperature, food availability, growth rate, and geographical location on this trait. The extended spawning season (March to June) in the Tagus River is consistent with native populations, but variations may occur based on environmental conditions and water temperature. Absolute fecundity ranged from 8,961 to 335,500 oocytes, showing positive relationships with body size and emphasizing the reproductive potential of European catfish in Portugal. Egg size variations, along with asynchronous egg development, contribute to the species reproductive strategy, favoring its invasive success. Management efforts should include monitoring, regulations on introductions, removal programs, and public awareness to mitigate their impact. Future research should focus on understanding how non-native European catfish populations adapt in various regions and continue to impact ecosystems.

ecology↗

bioRxiv2023

DNA damage-induced interaction between a lineage addiction oncogenic transcription factor and the MRN complex shapes a tissue-specific DNA Damage Response and cancer predisposition

Since genome instability can drive cancer initiation and progression, cells have evolved highly effective and ubiquitous DNA Damage Response (DDR) programs. However, some cells, in skin for example, are normally exposed to high levels of DNA damaging agents. Whether such high-risk cells possess lineage-specific mechanisms that tailor DNA repair to the tissue remains largely unknown. Here we show, using melanoma as a model, that the microphthalmia-associated transcription factor MITF, a lineage addition oncogene that coordinates many aspects of melanocyte and melanoma biology, plays a non-transcriptional role in shaping the DDR. On exposure to DNA damaging agents, MITF is phosphorylated by ATM/DNA-PKcs, and unexpectedly its interactome is dramatically remodelled; most transcription (co)factors dissociate, and instead MITF interacts with the MRE11-RAD50-NBS1 (MRN) complex. Consequently, cells with high MITF levels accumulate stalled replication forks, and display defects in homologous recombination-mediated repair associated with impaired MRN recruitment to DNA damage. In agreement, high MITF levels are associated with increased SNV burden in melanoma. Significantly, the SUMOylation-defective MITF-E318K melanoma predisposition mutation recapitulates the effects of ATM/DNA-PKcs-phosphorylated MITF. Our data suggest that a non-transcriptional function of a lineage-restricted transcription factor contributes to a tissue-specialised modulation of the DDR that can impact cancer initiation.

molecular biology↗

bioRxiv2023

Westwards expansion of the European catfish Silurus glanis in the Douro River (Portugal)

The current study reports the first occurrence and the spread of the European catfish Silurus glanis (Family: Siluridae) in the Portuguese section of the Douro River, suggesting a potential expansion of its distribution in Portugal either via westward dispersal across international rivers and/or human-assisted introductions into new reservoirs and drainages. European catfish has unique features (e.g., opportunistic predator, hunting, and aggregation behaviour) that make it highly suitable for establishing self-sustaining populations in new areas and likely contribute to its invasion success. The species may severely affect native prey communities and modify food web structure and ecosystem functioning. Efficient and sustainable management actions are needed to prevent further introductions in the future.

ecology↗