Fish has always been one of the most basic human foods and one of the major sources of protein intake. Fishing was a substantial source of food and became a commercial activity in Antiquity. During the period of Ancient Greece, nets were used as main fishing method which was adopted from other cultures in the future. The first record of farming fish in the history of aquaculture is estimated in 500 B.C. In China, Fan Li, a Chinese Politian, was the first to farm Cyprinus carpio (common carp) in ponds with economic advantages (Ling, 1977). About two centuries later, Aristotle seems to have bred species of fish, but with the great difference that he did not aim at their economic exploitation, but at scientific research concerning zoology and especially ichthyology (Oikonomidis, 2005). Marine fish farming was established in Greece in the early 1980 s (FAO, 2006).Recent studies have shown that aquaculture is a major sector of economic activity. Global fish production peaked at about 171 million tons in 2016, with aquaculture representing 47% of the total and 53% if non-food uses (including reduction to fishmeal and fish oil) are excluded. Aquaculture continues to grow faster than other major

Freshwater crayfish are considered as aquatic products of high quality and high nutritional value. The increasing demand has led to populations reduction in several locations throughout their range. Thus, the development of appropriate rearing conditions is considered necessary, among which, optimization of their diet is a basic part. Towards this direction, in the present study, a 98-day feeding trial was carried out to evaluate the impact of dietary fishmeal substitution by Hermetia illucens meal on Pontastacus leptodactylus juveniles kept under laboratory conditions. Insect meals represent an environmentally friendly alternative solution, considered as a high-value feed source, rich in nutrients such as protein and fat. Three dietary regimens were utilized with a fishmeal-based without Hermetia meal (HM) defined as the control diet (HM0), and two diets, the first with 50% (HM50) and the second with 100% (HM100) of fishmeal substitution by HM, respectively. Growth performance, whole-body composition, and fatty acid profiles of individuals were studied in the different treatments. At the end of the feeding trial, statistically significant differences were observed in the mean survival rate (SR), specific growth rate (SGR), feed conversion ratio (FCR) and weight gain (WG) values. More specifically, animals fed with HM-based diets had higher mean SR, while the control group performed better regarding FCR and SGR. The HM inclusion in the diet significantly altered the whole-body chemical composition of the crayfish signifying a different metabolic utilization compared to fishmeal (FM). The fatty acid analysis revealed that 16:0 (palmitic acid) was the predominant saturated fatty acid (SFA), 18:1ω9 (oleic acid) was found to be the main monounsaturated fatty acid (MUFA), while 18:2ω6 (linoleic acid) represented the major polyunsaturated fatty acid (PUFA) followed by C20:3 cis ω3 (cis-11-14-17-eicosatrienoate) and C22:6 cis ω3 (cis-4,7,10,13,16,19-Docosahexaenoic) fatty acids. The inclusion of dietary HM significantly reduced the contents of ∑SFAs, ∑PUFAs and ∑ω6 fatty acids, as well as those of C22:6 cis ω3 and increased the ω6/ω3 and hypocholesterolemic to hypercholesterolemic ratios in the body. In parallel with improvements in balanced diets and in culture conditions that need to be optimised for rearing of freshwater crayfish, our study provides new data that enlighten the suitability of insect meals in the nutrition of P. leptodactylus.

Background: The evolutionary rate of disordered proteins varies greatly due to the lack of structural constraints. So far, few studies have investigated the presence/absence patterns of intrinsically disordered regions (IDRs) across phylogenies in conjunction with human disease. In this study, we report a genome-wide analysis of compositional bias association with disease in human proteins and their taxonomic distribution. Methods: The human genome protein set provided by the Ensembl database was annotated and analysed with respect to both disease associations and the detection of compositional bias. The Uniprot Reference Proteome dataset, containing 11297 proteomes was used as target dataset for the comparative genomics of a well-defined subset of the Human Genome, including 100 characteristic, compositionally biased proteins, some linked to disease. Results: Cross-evaluation of compositional bias and disease-association in the human genome reveals a significant bias towards low complexity regions in disease-associated genes, with charged, hydrophilic amino acids appearing as over-represented. The phylogenetic profiling of 17 disease-associated, low complexity proteins across 11297 proteomes captures characteristic taxonomic distribution patterns. Conclusions: This is the first time that a combined genome-wide analysis of low complexity, disease-association and taxonomic distribution of human proteins is reported, covering structural, functional, and evolutionary properties. The reported framework can form the basis for large-scale, follow-up projects, encompassing the entire human genome and all known gene-disease associations.

Background: The evolutionary rate of disordered protein regions varies greatly due to the lack of structural constraints. So far, few studies have investigated the presence/absence patterns of compositional bias, indicative of disorder, across phylogenies in conjunction with human disease. In this study, we report a genome-wide analysis of compositional bias association with disease in human proteins and their taxonomic distribution. Methods: The human genome protein set provided by the Ensembl database was annotated and analysed with respect to both disease associations and the detection of compositional bias. The Uniprot Reference Proteome dataset, containing 11297 proteomes was used as target dataset for the comparative genomics of a well-defined subset of the Human Genome, including 100 characteristic, compositionally biased proteins, some linked to disease. Results: Cross-evaluation of compositional bias and disease-association in the human genome reveals a significant bias towards biased regions in disease-associated genes, with charged, hydrophilic amino acids appearing as over-represented. The phylogenetic profiling of 17 disease-associated, proteins with compositional bias across 11297 proteomes captures characteristic taxonomic distribution patterns. Conclusions: This is the first time that a combined genome-wide analysis of compositional bias, disease-association and taxonomic distribution of human proteins is reported, covering structural, functional, and evolutionary properties. The reported framework can form the basis for large-scale, follow-up projects, encompassing the entire human genome and all known gene-disease associations.

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