Penna, M. | bioRxiv Science

bioRxiv2025

Analysis of spectral and photosynthetic response variations of Cystoseira spp. exposed to Chromium

1.This study explores the physiological and spectral responses of different species belonging the genus Cystoseira to varying concentrations of chromium (Cr) in controlled experimental conditions. The research highlights the potential of Cystoseira spp. as a bioindicator for monitoring heavy metal pollution in marine ecosystems. Experiments were conducted in tanks with increasing chromium concentrations (0, 0.1, 1, and 10 {micro}mol l-{superscript 1}), analyzing changes in reflectance, photosynthetic efficiency, and pigment composition over 14 days. Results showed dose-and time-dependent effects, with higher chromium levels causing significant photosynthetic inhibition, oxidative stress, and chlorophyll degradation. Spectral analyses identified key wavelengths (550 nm and 710 nm) correlating with chromium-induced stress, supporting their use in remote sensing for environmental monitoring. The study underscores the importance of integrating field validation and remote sensing for large-scale monitoring of marine ecosystems impacted by heavy metal contamination. These findings contribute to conservation strategies and the development of innovative tools for assessing the ecological quality of coastal waters.

ecology↗

bioRxiv2022

The role of Limch1 alternative splicing in skeletal muscle function

Postnatal skeletal muscle development is a highly dynamic period associated with extensive transcriptome remodeling. A significant aspect of postnatal development is widespread alternative splicing changes, required for the adaptation of tissues to adult function. These splicing events have significant implications since the reversion of adult mRNA isoforms to fetal isoforms is observed in forms of muscular dystrophy. LIM and Calponin Homology Domains 1 (LIMCH1) is a stress fiber associated protein that is alternative spliced to generate uLIMCH1, a ubiquitously expressed isoform, and mLIMCH1, a skeletal muscle-specific isoform. mLIMCH1 contains 454 in-frame amino acids which are encoded by six contiguous exons simultaneously included after birth in mouse. The developmental regulation and tissue specificity of this splicing transition is conserved in mice and humans. To determine the physiologically relevant functions of mLIMCH1 and uLIMCH1, CRISPR-Cas9 was used to delete the genomic segment containing the six alternatively spliced exons of LIMCH1 in mice, thereby forcing the constitutive expression of the predominantly fetal isoform, uLIMCH1 in adult skeletal muscle. mLIMCH1 knockout mice had significant grip strength weakness in vivo and maximum force generated was decreased ex vivo. Calcium handling deficits were observed during myofiber stimulation that could explain the mechanism by which mLIMCH1 knockout leads to muscle weakness. Additionally, LIMCH1 is mis-spliced in myotonic dystrophy type 1 with the muscle blind-like (MBNL) family of proteins acting as the likely major regulator of Limch1 alternative splicing in skeletal muscle.

molecular biology↗