BLUP – Best linear unbiased prediction. In statistics, best linear unbiased prediction (BLUP) is used in linear mixed models for the estimation of random effects. BLUP was derived by Charles Roy Henderson in 1950 but the term “best linear unbiased predictor” (or “prediction”) seems not to have been used until 1962. “Best linear unbiased predictions” (BLUPs) of random effects are similar to best linear unbiased estimates (BLUEs) of fixed effects.

DHA – Docosahexaenoic acid. Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). Most of the docosahexaenoic acid in fish and multi-cellular organisms with access to cold-water oceanic foods originates from photosynthetic and heterotrophic microalgae, and becomes increasingly concentrated in organisms the further they are up the food chain.

DNA-methylation. DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.

EBV – Estimated breeding value. Animal breeding is a branch of animal science that addresses the evaluation (using best linear unbiased prediction and other methods) of the genetic value (estimated breeding value, EBV) of livestock. Selecting for breeding animals with superior EBV in growth rate, egg, meat, milk, or wool production, or with other desirable traits has revolutionized livestock production throughout the entire world.

EPA – Eicosapentaenoic acid.  Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. EPA is a polyunsaturated fatty acid (PUFA).

Epigenetics. In biology, epigenetics is the study of heritable phenotype changes that do not involve alterations in the DNA sequence.

Fetal programming. Fetal programming, also known as prenatal programming, is the theory that environmental cues experienced during fetal development play a seminal role in determining health trajectories across the lifespan.

Genetic correlation. In multivariate quantitative genetics, a genetic correlation is the proportion of variance that two traits share due to genetic causes, the correlation between the genetic influences on a trait and the genetic influences on a different trait estimating the degree of pleiotropy or causal overlap. A genetic correlation of 0 implies that the genetic effects on one trait are independent of the other, while a correlation of 1 implies that all of the genetic influences on the two traits are identical.

GWAS – Genome-wide association study. In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of genetic variants in different individuals to see if any variant is associated with a trait. GWA studies typically focus on associations between single-nucleotide polymorphisms (SNPs) and traits like major human diseases, but can equally be applied to any other genetic variants and any other organisms.

Genomic selection. In genomic selection, genetic potential of an individual to transmit traits to its offspring is predicted from thousands of DNA markers (typically SNPs, single-nucleotide polymorphism). Selection of the superior individuals is based on genomically estimated breeding value (GEBV). (Meuwissen et al. 2001; Genetics 157: 1819–1829; doi:10.1093/genetics/157.4.1819)

GxE – Genotype-by-environment interaction. Gene–environment interaction (or genotype–environment interaction or GxE) is when two different genotypes respond to environmental variation in different ways. A norm of reaction is a graph that shows the relationship between genes and environmental factors when phenotypic differences are continuous. They can help illustrate GxE interactions. When the norm of reaction is not parallel, there is a GxE interaction. This indicates that each genotype responds to environmental variation in a different way. Environmental variation can be physical, chemical, biological, behavior patterns or life events.

Genotype imputation. Imputation in genetics refers to the statistical inference of unobserved genotypes. It is achieved by using known haplotypes in a population, for instance from the HapMap or the 1000 Genomes Project in humans, thereby allowing to test for association between a trait of interest (e.g. a disease) and experimentally untyped genetic variants, but whose genotypes have been statistically inferred (“imputed”). Genotype imputation is usually performed on SNPs, the most common kind of genetic variation. Genotype imputation hence helps tremendously in narrowing down the location of probably causal variants in genome-wide association studies, because it increases the SNP density (the genome size remains constant, but the number of genetic variants increases) and thus reduces the distance between two adjacent SNPs.

h2 – Heritability. Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of variation in a phenotypic trait in a population that is due to genetic variation between individuals in that population.

LD – Linkage disequilibrium. In population genetics, linkage disequilibrium (LD) is the non-random association of alleles at different loci in a given population. Loci are said to be in linkage disequilibrium when the frequency of association of their different alleles is higher or lower than what would be expected if the loci were independent and associated randomly.

Macronutrients. There are three principal classes of macronutrients: carbohydrate, protein, and fat. Macronutrients are defined as a class of chemical compounds which humans (or any other organism) consume in relatively large quantities compared to vitamins and minerals, and which provide humans (or any other organism) with energy.

MAS – Marker-assisted selection. Marker assisted selection or marker aided selection (MAS) is an indirect selection process where a trait of interest is selected based on a marker (morphological, biochemical or DNA/RNA variation) linked to a trait of interest (e.g. productivity, disease resistance, abiotic stress tolerance, and quality), rather than on the trait itself. This process has been extensively researched and proposed for plant and animal breeding.

Metabolic imprinting. Metabolic imprinting refers to the long-term physiological and metabolic effects that an offspring’s prenatal and postnatal environments have on them.

Metagenomics. Metagenomics is the study of genetic material recovered directly from environmental samples. The broad field may also be referred to as environmental genomics, ecogenomics or community genomics. While traditional microbiology and microbial genome sequencing and genomics rely upon cultivated clonal cultures, early environmental gene sequencing cloned specific genes (often the 16S rRNA gene) to produce a profile of diversity in a natural sample. Such work revealed that the vast majority of microbial biodiversity had been missed by cultivation-based methods.

Microbiome. A microbiome (from Ancient Greek μικρός (mikrós) ‘small’, and βίος (bíos) ‘life’) is the community of microorganisms that can usually be found living together in any given habitat.


Micronutrients. Micronutrients are essential dietary elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements differ between organisms; for example, humans and other animals require numerous vitamins and dietary minerals, whereas plants require specific minerals.

Nutritional programming. ‘Nutritional programming is usually referred to as “metabolic programming” in mammalian systems, referencing the outcome of programming, rather than the cause. Other common terms include “fetal programming”, emphasizing the maternal–fetal interaction, or “developmental programming”, associating programming with developmental processes. Regardless, it is usually linked to several human health conditions (e.g., obesity, insulin resistance, reduced glucose tolerance, hypertension and hypertriglyceridaemia) that are collectively known as metabolic syndrome. Despite important differences in maternal nutrient delivery and developmental processes between mammals and fishes, early nutrition of fishes from both endogenous (maternally derived) and exogenous (larval feeding) sources, could induce similar programming effects on development and metabolism.’ (Hou & Fuiman 2020;

Omega-3. Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chemical structure. They are widely distributed in nature, being important constituents of animal lipid metabolism, and they play an important role in the human diet and in human physiology.

Probiotics. Probiotics are live microorganisms promoted with claims that they provide health benefits when consumed, generally by improving or restoring the gut flora.

Protein sparing. Protein sparing (amino acid sparing) is the process by which the body derives energy from sources other than protein. Such sources can include fatty tissues, dietary fats and carbohydrates. Protein sparing conserves muscle tissue. The balance between digestible protein (DP) and digestible energy (DE) in the diet is a key factor.

PUFA – Polyunsaturated fatty acid. Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. Polyunsaturated fatty acids can be found mostly in nuts, seeds, fish, seed oils, and oysters.

QTL – A quantitative trait locus. A quantitative trait locus (QTL) is a locus (section of DNA) that correlates with variation of a quantitative trait in the phenotype of a population of organisms. QTLs are mapped by identifying which molecular markers (such as SNPs or AFLPs) correlate with an observed trait. This is often an early step in identifying and sequencing the actual genes that cause the trait variation.

SCP – Single-cell proteins. Single-cell proteins (SCP) or microbial proteins refer to edible unicellular microorganisms. The biomass or protein extract from pure or mixed cultures of algae, yeasts, fungi or bacteria may be used as an ingredient or a substitute for protein-rich foods, and is suitable for human consumption or as animal feeds.

SFA – Saturated fat. A saturated fat is a type of fat in which the fatty acid chains have all single bonds. Glyceride fats without any carbon chain double bonds are called saturated because they are “saturated with” hydrogen atoms, having no double bonds available to react with more hydrogen. Most animal fats are saturated. Guidelines released by many medical organizations, including the World Health Organization, have advocated for reduction in the intake of saturated fat to promote health and reduce the risk from cardiovascular diseases.

SNP – Single nucleotide polymorphism. In genetics, a single-nucleotide polymorphism (SNP) is a germline substitution of a single nucleotide at a specific position in the genome.

Transcriptome. The transcriptome is the set of all RNA transcripts, including coding and non-coding, in an individual or a population of cells. The term can also sometimes be used to refer to all RNAs, or just mRNA, depending on the particular experiment. The term transcriptome is a portmanteau of the words transcript and genome; it is associated with the process of transcript production during the biological process of transcription.

Transcriptomics. Transcriptomics technologies are the techniques used to study an organism’s transcriptome, the sum of all of its RNA transcripts. The information content of an organism is recorded in the DNA of its genome and expressed through transcription. Here, mRNA serves as a transient intermediary molecule in the information network, whilst non-coding RNAs perform additional diverse functions. A transcriptome captures a snapshot in time of the total transcripts present in a cell. Transcriptomics technologies provide a broad account of which cellular processes are active and which are dormant. A major challenge in molecular biology lies in understanding how the same genome can give rise to different cell types and how gene expression is regulated.