Investigating the role of genetic variation in vgll3 and six6 in the domestication of gilthead seabream (Sparus aurata Linnaeus) and European seabass (Dicentrarchus labrax Linnaeus).

Gene function conservation is crucial in molecular ecology, especially for key traits like growth and maturation in teleost fish. The vgll3 and six6 genes are known to influence age-at-maturity in Atlantic salmon, but their impact on other fish species is poorly understood. Here, we investigated the association of vgll3 and six6 in the domestication of gilthead seabream and European seabass, both undergoing selective breeding for growth-related traits in the Mediterranean. We analysed two different sets of samples using two different genotyping approaches. The first dataset comprised farmed and wild populations from Greece, genotyped for SNPs within the two genes ('gene-level genotyping'). The second dataset examined 300-600 k SNPs located in the chromosomes of the two genes, derived from a meta-analysis of a Pool-Seq experiment involving farmed and wild populations distributed widely across the Mediterranean ('chromosome-level genotyping'). The gene-level analysis revealed a statistically significant allele frequency differences between farmed and wild populations on both genes in each species. This finding was partially supported by the chromosome-level analysis, identifying highly differentiated regions may be involved in the domestication process at varying distances from the candidate genes. Noteworthy genomic features were found, such as a CpG island in gilthead seabream and novel candidate genes in European seabass, warranting further investigation. These findings support a putative role of vgll3 and six6 in the maturation and growth of gilthead seabream and European seabass, emphasizing the need for further research on their conserved function.

Genetic Identification and Traceability of Insect Meals.

Insects have been proposed as a rich alternative source of protein for the partial or total replacement of fishmeal in aquaculture. For maximum safety and effectiveness of insect meals, control of the quality composition of these products is considered mandatory. The aim of this study was the genetic analysis of the composition of commercially available insect meals at the species level. Commercially available Hermetia illucens, Tenebrio molitor and Musca domestica individuals, as well as nine insect meals produced from these species, were analyzed. The genetic identification of insects at the species level was based on a COI fragment, and analysis of the insect meals' composition was performed with the processes of cloning and colony PCR. Genetic analysis indicated that the commercially available larvae morphologically identified as Musca domestica belonged to the species Muscina stabulans. In the commercially available insect meals, no other animal species was identified beyond the expected one. However, in the insect meal produced for research purposes, fungal growth was detected. The used methodology, herein, allows for the qualitative genetic identification of insect meals and could be included in the methods of traceability of products containing insects and other animal species.

Prevalence of SOD1 allele associated with degenerative myelopathy in canine population in Greece.

Canine degenerative myelopathy (CDM) is a late-onset fatal disorder associated with a point mutation of the superoxide dismutase 1 (SOD1) gene (c.118G > A). The purpose of this study was to determine the genotype and allele frequencies of this mutation in 108 dogs, mainly in Belgian Malinois and German Shepherd dogs with (CDM-affected group) and without CDM clinical symptoms (control group) in Greece. Genotyping of the c.118G > A mutation was possible by Sanger sequencing and PCR-RFLP. The observed genotype frequencies for the control group were 89.4% for the homozygous (G/G), 9.6% for the heterozygous (A/G), and 0.96% for the homozygous mutant (A/A) allele. The mutant allele was not common in the Belgian Malinois dogs (allele frequency = 0.029), but quite common in the German Shepherd dogs (allele frequency = 0.138). In the CDM affected group, all 4 dogs were homozygous for the mutant allele. These frequencies were close to those expected, indicating no significant departure from Hardy-Weinberg equilibrium. A strong but not statistically significant association between the mutant allele and CDM was observed. A previously identified deletion upstream of the mutation of interest was found at a high frequency (0.361) in the population.