Cattle spread throughout the American continent during the colonization years, originating creole breeds that adapted to a wide range of climate conditions. Population of creole cattle in Peru is decreasing mainly due to the introduction of more productive breeds in recent years. During the last 15 years, there have been a significant progress on cattle genomics. However, little is known about the genetics of the Peruvian creole cattle (PCC) even though its importance to (i) improve productivity in the Andean region, (ii) agricultural labor, and (iii) cultural traditions. In addition, the origin and phylogenetic relationship of the PCC is still unclear. In order to promote the conservation of the PCC, we sequenced for the first time the mitochondrial genome of a creole bull from the highlands of Arequipa, which also possessed exceptional fighting skills and was employed for agricultural tasks. The total mitochondrial genome sequence is 16,339 bp in length with the base composition of 31.43 % for A, 28.64 % for T, 26.81 % for C, and 13.12 % for G. It contains 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a control region. Among the 37 genes, 28 were positioned on the H-strand and nine were positioned on the L-strand. The most frequently used codons were CUA (Leucine), AUA (Isoleucine), AUU (Isoleucine), AUC (Isoleucine), y ACA (Threonine). Maximum likelihood reconstruction using complete mitochondrial genome sequences clearly demonstrated that the PCC is strongly related to native African breeds, giving insights into the ancestry of PCC. The annotated mitochondrial genome of PCC would serve as an important genetic data set for further breeding work and conservation strategies.

B chromosomes are supernumerary chromosomes which are found in addition to the normal standard chromosomes (A chromosomes). B chromosomes are well known to accumulate several types of repeats. Although the evolution of B chromosomes has been subject of numerous studies, the mechanisms of accumulation and evolution of repetitive sequences is not fully understood. Recently, new genomic approaches have shed light on the origin and accumulation of different classes of repetitive sequences in the process of B chromosome formation and evolution. Here we discuss the impact of repetitive sequences accumulation on the evolution of plant B chromosomes.

Charcot-Marie-Tooth (CMT) disease is the most commonly inherited neurological disorder, defined by progressive deterioration of the peripheral nerves. Clinical manifestations of CMT mutations are typically limited to peripheral neurons, the longest cells in the body. Currently, mutations in at least 80 different genes are associated with CMT and new mutations are regularly being discovered. A large portion of the proteins mutated in axonal CMT have documented roles in mitochondrial mobility. This suggests that trafficking defects may be a common underlying mechanism in CMT. This review will focus on the potential role of altered mitochondrial mobility in the pathogenesis of axonal CMT, highlighting the challenges and opportunities to this “impaired mobility” model of the disease.

Radical changes in the idea of the organization of the intracellular space that occurred in the early 2010-s made it possible to consider the formation and functioning of the so-called membrane-less organelles (MLOs) based on a single physical principle: the liquid-liquid phase separation (LLPS) of biopolymers. Weak nonspecific inter- and intramolecular interactions of disordered polymers, primarily of intrinsically disordered proteins and RNA, play a central role in the initiation and regulation of these processes. On the other hand, in some cases, the "maturation" of MLOs can be accompanied by the "liquid-gel” phase transition, where other types of interactions can play a significant role in reorganization of their structure. In this work, we conducted a bioinformatics analysis of the propensity of the proteomes of two membrane-less organelles formed in response to stress in the same compartment, nucleolus, for spontaneous phase separation and looked at their intrinsic disorder predispositions. These nucleolar MLOs, amyloid bodies (A-bodies) formed in the response to acidosis and heat shock and nuclear stress bodies (nSBs), are characterized by the partially overlapping composition, but show different functional activities and morphologies. We show that the proteomes of these nucleolar biocondensates are differently enriched in proteins, many of with high potential for spontaneous LLPS that correlates with different morphology and function of these organelles. The results of these analyses allowed us to evaluate the role of weak interactions in the formation and functioning of these important organelles.