Biology subjects

Marandel, L.

Publications and source records attributed to Marandel, L..

3 recordsLinked to original sources

bioRxiv2025

Characterization of interindividual DNA methylation variability in rainbow trout (Oncorhynchus mykiss)

Interindividual epigenetic variability, particularly in DNA methylation, is now recognized as a significant contributor to phenotypic diversity in humans and mammals. These epivariable regions, which make up a small fraction of the genome, are strongly influenced by genetic factors and environmental factors, especially during early development. In this context, epigenetic variability of DNA methylation has been proposed as an adaptive force involved in various environmental responses. In fish and other vertebrates, environmental factors are known to influence the health, performance and welfare, likely through the alteration of the epigenetic landscape. However, whether interindividual epigenetic variability may contribute to the phenotypic plasticity of fishes is unknown. Here we provide a first description of the rainbow trout methylome variability using a whole-genome bisulfite sequencing approach in an isogenic line to minimize genetic variation. Variable methylation regions were identified in both liver and hypothalamus tissues of 12 replicate fishes and were found enriched at gene regulatory elements, such as promoters and first introns. Gene Ontology analysis revealed functional clusters related to cellular development, neural communication, metabolic balance, and immune response. Interestingly, some variably methylated regions are found at the same genomic loci in both tissues and showed a strong intraindividual correlation in methylation levels, suggesting establishment during early embryogenesis. Overall, our work demonstrates the existence of interindividual epigenetic variability in rainbow trout and provides valuable insights into the regulatory function of DNA methylation variation that is likely involved in developmental and physiological processes.

genomics↗

bioRxiv2024

Dissecting the nutritional regulations of a whole amino acid transporter family from a complex genome species: A holistic approach turning weaknesses into strengths

Amino acid transporters (AATs) are described as pivotal in maintaining circulating and cellular concentrations of AA via regulation of their expression in response to the cellular environment. Rainbow trout (RT), a complex genome species, is poorly described for AATs roles in controlling its predominant AA-based metabolism, despite representing a major challenge in the aquaculture nutrition field. Therefore, we identified the whole repertoire of AAT found in RT genome (>200), its expression in tissues and its nutritional regulations in vitro. Results garnered revealed the existence of different clusters of AATs, notably due to promoters bearing ATF4-related AA response elements. Moreover, the modeling of each AAT-specific cluster activities disclosed mTOR-related signaling functions of Ile and Phe, yet unknown in RT. Thus, this novel approach herein described should help to better grasp AA homeostasis in most organisms and topics such as fish nutrition and evolution.

cell biology↗

bioRxiv2023

Rainbow trout neomales broodstocks are able to eat and use a high carbohydrate diet during a complete reproductive cycle

The main challenge of the aquaculture relies on the shift from fishmeal to more sustainable ingredients. Interest on carbohydrates has growing rapidly as they are considered as promising resources, providing energy and preserving proteins for growth. However, rainbow trout is considered as a poor user of carbohydrates displaying postprandial hyperglycaemia and impaired growth performances when fed with diets containing more than 20% of carbohydrates. Nonetheless, recent evidence points that broodstocks could be better user of high carbohydrate diet compared to juveniles. However, no study investigates how sex-reversed females - neomales - eat, grow and reproduce under a high carbohydrate diet. Our objective was thus to assess growth and reproductive performances of neomales fed with a high carbohydrate diet during an entire reproductive cycle. Our results demonstrate that neomales display specific metabolic and physiological changes when fed with a high carbohydrate diet compared to both females and males broodstocks as well as compared to juveniles. Altogether, our data demonstrate the critical relevance to formulate specific diets in accordance with specificities of each type of broodstocks (i.e. females, males and neomales).

molecular biology↗