Biology subjects

Lopez-Catalina, A.

Publications and source records attributed to Lopez-Catalina, A..

3 recordsLinked to original sources

bioRxiv2025

The RUMIGEN EpiChip: a versatile, medium density DNA methylation Beadchip for large scale population studies in cattle

BackgroundDNA methylation contributes to the elaboration of phenotypes and is hypothesized to account for interindividual variations in farm animals. Currently, methodologies available to investigate DNA methylation in cattle rely on high throughput sequencing, which cannot be applied to large cohorts. To enable large scale DNA methylation analysis, we developed the RUMIGEN EpiChip, the first DNA methylation array specifically designed for cattle. ResultsManufactured by Illumina, the EpiChip contains 43,317 CpG markers allowing analysis of phenotypes of agronomical interest as well as the study of regulatory processes. The assay design drew on data from numerous studies achieved by the scientific community, and includes CpGs where methylation varies with health status, physiological stage, fertility, and environmental challenges, as well as CpGs located in functional genomic elements (promoters, CTCF binding sites, expression quantitative trait loci). The technical performances of the EpiChip were tested on several semen and blood DNA samples and in two laboratories, showing excellent repeatability, accuracy and interoperability. Methylation values were also concordant with those obtained by reduced representation bisulfite sequencing. The EpiChip has demonstrated a good ability to explore biological processes such as genomic imprinting and differences between cell types, opening the possibility of inferring blood cell composition. Finally, analysis of longitudinal ear biopsies allowed accurate age prediction, suggesting the potential of the array to refine epigenetic clocks. ConclusionsThe RUMIGEN EpiChip is a cost-effective and versatile resource that opens new opportunities for the study of regulatory mechanisms underlying phenotypic variation and for large-scale association analyses in cattle.

genomics↗

bioRxiv2023

Accuracy of direct genomic values and methylation profile through genotype-by-LowPass sequencing using Nanopore technology

Genotype-by-sequencing has been proposed as an alternative to SNP genotyping arrays in genomic selection to obtain a high density of markers along the genome. It requires a low sequencing depth to be cost effective, which may increase the error at the genotype assigment. Third generation Nanopore sequencing technology offers low cost sequencing and the possibility to detect genome methylation, which provides added value to genotype-by-sequencing. The aim of this study was to evaluate the performance of genotype-by-LowPass Nanopore sequencing for estimating the direct genomic value in dairy cattle, and the possibility to obtain methylation marks simultaneously. Latest Nanopore chemistry (LSK14 and Q20) achieved a modal base calling accuracy of 99.55 %, whereas previous kit (LSK109) achieved slightly lower accuracy (99.1 %). The direct genomic value accuracy from genotype-by-Low Pass sequencing ranged between 0.79 and 0.99, depending on the trait, with a sequencing depth as low as 2x and using the latest chemistry (LSK114). Lower sequencing depth led to biased estimates, yet with high rank correlations. The LSK109 and Q20 achieved lower accuracies (0.57-0.93). More than one million high reliable methylated sites were obtained, even at low sequencing depth, located mainly in distal intergenic (87 %) and promoter (5 %) regions. This study showed that the latest Nanopore technology can be use in a LowPass sequencing framework to estimate direct genomic values with high reliability. It may provided advantages in populations with no available SNP chip, or when a large density of markers with a wide range of allele frequencies is needed. In addition, Low Pass sequencing provided with nucleotide methylation status of >1 million nucleotides at [≥] 10x, which is an added value for epigenetic studies.

genomics↗

bioRxiv2018

Establishment of the mayfly Cloeon dipterum as a new model system to investigate insect evolution

The great capability of insects to adapt to new environments promoted their extraordinary diversification, resulting in the group of Metazoa with the largest number of species distributed worldwide. To understand this enormous diversity, it is essential to investigate lineages that would allow the reconstruction of the early events in the evolution of insects. However, research on insect ecology, physiology, development and evolution has mostly focused on few well-established model species. The key phylogenetic position of mayflies within Paleoptera, as the sister group of the rest of winged insects and life history traits of mayflies make them an essential order to understand insect evolution. Here, we describe the established of a continuous culture system of the mayfly Cloeon dipterum and a series of experimental protocols and -omics resources that allow the study of its development and its great regenerative capability. Thus, the establishment of Cloeon as an experimental platform paves the way to understand genomic and morphogenetic events that occurred at the origin of winged insects.

evolutionary biology↗