Kristiansen, T. | Search bioRxiv

bioRxiv2026

Towards molecular-based functional classification of fetal bovine serum

Quality and price of fetal bovine serum (FBS) are traditionally determined by geographical origin and parameters listed in the Certificate of Analysis (CoA). Despite its central role in cell culture, selecting suitable FBS batches remains costly and labor-intensive due to substantial batch-to-batch variation. We propose a molecular assessment strategy based on transcriptomic and cytokine profiling of cells cultured in different FBS batches to evaluate performance more reliably. Analysis of differential gene expression in three cell lines - MRC-5, Jurkat, and THP-1 - enables batch grouping and reveals pathway-specific effects, with immune-related pathways showing the most pronounced variability. Although CoA parameters can stratify batches by origin, they do not consistently correlate with cytokine secretion or gene expression across cell lines. These findings demonstrate that geographical origin is an inadequate predictor of functional FBS performance and that molecular profiling provides a more robust and informative assessment.

molecular biology↗

bioRxiv2019

Modeled buoyancy of eggs and larvae of the deep-sea shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus larvae in the northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers (0-75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined in the studied area: 1) the northern part, along a continental margin crossed by large submarine canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the southern part, with currents flowing through a channel. The number of larvae in the most upper layer (0-5 m depth) was higher if the larval transport model accounted for the ascent of eggs and nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the most water upper layer (0-5 m depth) had higher rates of dispersal than the ones transported below the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have implications for the understanding of A. antennatus larval ecology and for management decisions related to the shrimp fisheries in the northwestern Mediterranean Sea.

biophysics↗