Mitochondrial Inheritance, Mito-nuclear Coevolution, and Sex-associated Genes in Bivalve Molluscs: Transcriptomics and Molecular Evolution

Bivalvia represents an ancient taxon including around 25,000 living species that have adapted to a wide range of environmental conditions, and show a great diversity in body size, shell shapes, and anatomic structure. Bivalves are characterized by highly variable genome sizes and extremely high levels of heterozygosity, which obstacle complete and accurate genome assemblies and hinder further genomic studies. Moreover, some bivalve species presented a stable evolutionary exception to the strictly maternal inheritance of mitochondria, namely doubly uniparental inheritance (DUI), making these species a precious model to study mitochondrial biology. During my PhD, I focused on a DUI species, the Manila clam Ruditapes philippinarum, and my work was two-folded. First, taking advantage of a newly assembled draft genome and a large RNA-seq dataset from different tissues of both sexes, I investigated 1) the role of gene expression and alternative splicing in tissue differentiation; 2) the relationship across tissue specificity, regulatory network connectivity, and sequence evolution; 3) sexual contrasting genetic markers potentially associated with sexual differentiation. The detailed information for this part is in Chapter 2. Second, using the same RNA-seq data, I investigated how nuclear oxidative phosphorylation (OXPHOS) genes coordinate with two divergent mitochondrial genomes in DUI species (mito-nuclear coordination and coevolution). To address this question, I compared transcription, polymorphism, and synonymous codon usage in the mitochondrial and nuclear OXPHOS genes of R. philippinarum in Chapter 3. To my knowledge, this thesis represents the first study exploring the role of alternative splicing in tissue differentiation, and the first study analyzing both transcriptional regulation and sequence evolution to investigate the coordination of OXPHOS genes in bivalves.

Massive MIMO-based system analysis and comparison with MIMO based-systems

The thesis is focused on introducing basic MIMO-based and Massive MIMO-based systems and their possible benefits. Then going through the implementation options that we have, according to 3GPP standards, for 5G systems and how the transition is done from a non-standalone 5G RAN to a completely standalone 5G RAN. Having introduced the above-mentioned subjects and providing some definition of telecommunications principles, we move forward to a more technical analysis of the Capacity, Throughput, Power consumption, and Costs. Comparing all the mentioned parameters between a Massive-MIMO-based system and a MIMO-based system. In the analysis of power consumption and costs, we also introduce the concept of virtualization and its benefits in terms of both power and costs. Finally, we try to justify a trade-off between having a more reliable system with a high capacity and throughput while keeping the costs as low as possible.