2. Universidad Cardenal Herrera-CEU

Introduction: Learning molecular genetics techniques is part of the program of the genetics course of the veterinary degree. It is essential to maintain motivation and interest in genetics practice by using a common thread that connects with the students’ interests. This work describes the design, implementation, and results of a gamification strategy developed during two practical sessions in which the student becomes a geneticist to identify which dog a faecal sample collected from the street belongs to, as some municipalities currently do to promote hygiene and public health in their streets. The aim was for students to understand basic concepts and techniques in molecular genetics during these two sessions. This included learning how to extract DNA from different types of samples, describing the amplification using Random Amplification Polymorphic DNA (RAPD), and getting a better understanding of molecular markers and the theory behind Polymerase Chain Reaction (PCR). Methodology: In the first practice, students extracted DNA from fresh dog faeces, while also discussing various DNA sources and extraction methods. Then they used the extracted DNA to create a simulated database of fictional dogs associated with students. They quantified the DNA, analysed its quality, and prepared a dilution to 10ng/μL. In the second practice, the students used RAPD to identify individuals by matching DNA from a simulated collected faeces sample to their fictional dogs DNA database. They performed amplification reactions with various primers pairs, followed by gel electrophoresis, to compare DNA band patterns and identify the dog and the fictional student associated with the uncollected dog faeces. The advantages and limitations of the RAPD technique were discussed, along with its potential applications in veterinary science and genetics. Results and discussion: The students were successful in extracting DNA with concentrations over 100 ng/μL in most cases as well as a good purity with respect to proteins. However, it was found that there was usually a low quality of DNA with respect to salts, although this did not influence the results of the second practice. They were able to generate reproducible RAPD profiles with all primer pairs. The unknown individual could be easily recognized within the database. Conclusions: It is concluded that this educational proposal is an effective option for teaching DNA extraction and the RAPD technique, as well as for many molecular genetics terms and concepts and contributes to the comprehensive training of future veterinary professionals. Additionally, the educational and social value of the practices are highlighted, as they promote interest in science, respect for the environment, and civic responsibility.

Ecometabolomics could be implemented as a powerful tool in molecular ecology studies, but it is necessary to know the baseline of certain metabolites and understand how different traits could affect the metabolome of the animals. Therefore, the main objective of this study was to provide values for the nutritional metabolome profile of different diet groups and animal species, as well as to study the differences in the metabolomic profile due to the effect of diet type and species. To achieve this goal, blood samples were taken from healthy animals (n = 43) of different species: lion (Panthera leo), jaguar (Panthera onca), chimpanzee (Pan troglodytes), bison (Bison bison), gazelle (Gazella cuvieri) and fallow deer (Dama dama), and with different types of diet (carnivore, herbivore and omnivore). Each blood sample was analysed to determine nutritional metabolites. The main results this study provides are the nutritional metabolic profile of these animals based on the type of diet and the animal species. A significant effect of the dietary type was found on nutritional metabolite levels, with those metabolites related to protein metabolism (total protein and creatine) being higher in carnivores. There is also an effect of the species on nutritional metabolites, observing a metabolome differentiation between lion and jaguar. In the case of herbivores, bison showed higher levels of uric acid and cholesterol, and lower urea levels than gazelle and fallow deer. More molecular ecology studies are needed to further the knowledge of the metabolism of these animals.

Phages can use a small-molecule communication arbitrium system to coordinate lysis–lysogeny decisions, but the underlying mechanism remains unknown. Here we determined that the arbitrium system in Bacillus subtilis phage phi3T modulates the bacterial toxin–antitoxin system MazE–MazF to regulate the phage life cycle. We show that phi3T expresses AimX and YosL, which bind to and inactivate MazF. AimX also inhibits the function of phi3T_93, a protein that promotes lysogeny by binding to MazE and releasing MazF. Overall, these mutually exclusive interactions promote the lytic cycle of the phage. After several rounds of infection, the phage-encoded AimP peptide accumulates intracellularly and inactivates the phage antiterminator AimR, a process that eliminates aimX expression from the aimP promoter. Therefore, when AimP increases, MazF activity promotes reversion back to lysogeny, since AimX is absent. Altogether, our study reveals the evolutionary strategy used by arbitrium to control lysis–lysogeny by domesticating and fine-tuning a phage-defence mechanism.