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BackgroundMitochondria provide ATP through the process of oxidative phosphorylation, physically located in the inner mitochondrial membrane (IMM). The mitochondrial contact site and organising system (MICOS) complex is known as the ‘mitoskeleton’ due to its role in maintaining IMM architecture. APOOencodes MIC26, a component of MICOS, whose exact function in its maintenance or assembly has still not been completely elucidated.MethodsWe have studied a family in which the most affected subject presented progressive developmental delay, lactic acidosis, muscle weakness, hypotonia, weight loss, gastrointestinal and body temperature dysautonomia, repetitive infections, cognitive impairment and autistic behaviour. Other family members showed variable phenotype presentation. Whole exome sequencing was used to screen for pathological variants. Patient-derived skin fibroblasts were used to confirm the pathogenicity of the variant found in APOO. Knockout models in Drosophila melanogasterand Saccharomyces cerevisiaewere employed to validate MIC26 involvement in MICOS assembly and mitochondrial function.ResultsA likely pathogenic c.350T>C transition was found in APOOpredicting an I117T substitution in MIC26. The mutation caused impaired processing of the protein during import and faulty insertion into the IMM. This was associated with altered MICOS assembly and cristae junction disruption. The corresponding mutation in MIC26 or complete loss was associated with mitochondrial structural and functional deficiencies in yeast and D. melanogastermodels.ConclusionThis is the first case of pathogenic mutation in APOO, causing altered MICOS assembly and neuromuscular impairment. MIC26 is involved in the assembly or stability of MICOS in humans, yeast and flies.

Biallelic mutations in NDUFAF6have been identified as responsible for cases of autosomal recessive Leigh syndrome associated with mitochondrial complex I deficiency. Here we report two siblings and two unrelated subjects with Leigh syndrome, in which we found the same compound heterozygous missense (c.532G>C:p.A178P) and deep intronic (c.420+784C>T) variants in NDUFAF6. We demonstrated that the identified intronic variant creates an alternative splice site, leading to the production of an aberrant transcript. A detailed analysis of whole-exome sequencing data together with the functional validation based on mRNA analysis may reveal pathogenic variants even in non-exonic regions.

BackgroundHereditary myopathy with lactic acidosis and myopathy with deficiency of succinate dehydrogenase and aconitase are variants of a recessive disorder characterised by childhood-onset early fatigue, dyspnoea and palpitations on trivial exercise. The disease is non-progressive, but life-threatening episodes of widespread weakness, metabolic acidosis and rhabdomyolysis may occur. So far, this disease has been molecularly defined only in Swedish patients, all homozygous for a deep intronic splicing affecting mutation in ISCUencoding a scaffold protein for the assembly of iron–sulfur (Fe-S) clusters. A single Scandinavian family was identified with a different mutation, a missense change in compound heterozygosity with the common intronic mutation. The aim of the study was to identify the genetic defect in our proband.MethodsA next-generation sequencing (NGS) approach was carried out on an Italian male who presented in childhood with ptosis, severe muscle weakness and exercise intolerance. His disease was slowly progressive, with partial recovery between episodes. Patient’s specimens and yeast models were investigated.ResultsHistochemical and biochemical analyses on muscle biopsy showed multiple defects affecting mitochondrial respiratory chain complexes. We identified a single heterozygous mutation p.Gly96Val in ISCU, which was absent in DNA from his parents indicating a possible de novo dominant effect in the patient. Patient fibroblasts showed normal levels of ISCU protein and a few variably affected Fe-S cluster-dependent enzymes. Yeast studies confirmed both pathogenicity and dominance of the identified missense mutation.ConclusionWe describe the first heterozygous dominant mutation in ISCUwhich results in a phenotype reminiscent of the recessive disease previously reported.

This article analyzes how Dolores del Rio's great success in Hollywood was due in large part to her producer, Edwin Carewe, who transformed her into a female version of Rudolph Valentino. Her exotic appearance, dark complexion and eroticism fused perfectly with the myth of Carmen and were exploited to the full in Walsh's 1927 film "The Loves of Carmen." These very attributes would characterize the promotion of Latin movie stars such as Dolores del Rio or Rudolph Valentino.

Plant parasitic nematodes belonging to the genus Pratylenchus,also known as root lesion nematodes, cause serious economic damage to different crop plants. In order to explore genetic structures in different isolates, we investigated several P. thornei,P. neglectusand P. penetranspopulations of different geographic origins. The analysis at the species level was also extended to P. penetrans, P. pinguicaudatus, P. vulnusand P. mediterraneus. Sequence analysis of a specific portion of DNA was carried out. In particular, the sequences of the D3 region of the 26S gene were obtained and compared with similar sequences available in databases. The results support the hypothesis that P. penetransmay represent a species complex, while in P. neglectusthe intra-species heterogeneity observed is due to intra-individual variability. Furthermore, the specific conservation of some nucleotides in different P. thorneipopulations indicates their fixation in the rDNA repeats in this species. The presence of these nucleotides, the molecular signature of P. thornei, may assist in determining the nature of nematode infections.

Mitochondria, semi-autonomous organelles possessing their own genetic system, are commonly accepted to descend from free-living eubacteria, namely hydrogen-producing alpha-proteobacteria. The progressive loss of genes from the primitive eubacterium to the nucleus of the eukaryotic cell is strongly justified by the Muller rachet principle, which postulates that asexual genomes, like mitochondrial ones, accumulate deleterious and sublethal mutations faster than sexual genomes, like the nucleus. According to this principle, the mitochondrial genome would be doomed to death; instead, we observe that the mitochondrial genome has a variable size and structure in the different organisms, though it contains more or less the same set of genes. This is an example of genetic conservation versus structural diversity. From an evolutionary point of view the genetic system of organelles is clearly under strong selective pressure and for its survival it needs to utilize strategies to slow down or halt the ratchet. Anyway, the mitochondrial genome changes with time, and the rate of evolution is different for both diverse regions of the mtDNA and between lineages, as demonstrated in the case of mammalian mt genomes. We report here our data on the evolution of the mitochondrial DNA in mammals which demonstrate the suitability of mtDNA as a molecular tool for evolutionary analyses.

The phylogenetic relationships among major lineages of rodents is one of the issues most debated by both paleontologists and molecular biologists. In the present study, we have analyzed all complete mammalian mitochondrial genomes available in the databases, including five rodent species (rat, mouse, dormouse, squirrel and guinea-pig). Phylogenetic analyses were performed on H-strand amino acid sequences by means of maximum-likelihood and on H-strand protein-coding and ribosomal genes by means of distance methods. Also, log-likelihood ratio tests were applied to different tree topologies under the assumption of rodent monophyly, paraphyly or polyphyly. The analyses significantly rejected rodent monophyly and showed the existence of two differentiated clades, one containing non-murids (dormouse, squirrel and guinea-pig) and the other containing murids (rat and mouse). Long-branch attraction between murids and the outgroups could not be responsible for the existence of two different rodent clades, as no significant differences in evolutionary rate have been observed, except in the case of the squirrel, which shows a lower rate. The impact of among-site rate variation models on the phylogeny of rodents has been evaluated using the gamma distribution model. Results have shown that relationships among rodents remained unchanged, and the general topology of the tree was not affected, even though some branches were not properly resolved, most likely due to a lack of fit between estimated and real rate heterogeneity parameters.

The performance of the combination of a floating bead filter and an RBC employing 1-inch diameter N̈orpac® tube media was evaluated in an intensive pilot scale recirculating system stocked with tilapia. The combination maintained favorable water quality, attaining practically complete TAN and NO2-N removal. The average overall removal across the FBF-RBC combination was 60·6 g TAN/day and 59·6 g NO2-N/day, which was 30·7 and 51·7% of the influent loading, respectively. At a feeding level of 2 kg/day with backwashing every 2 days, the bead filter functioned primarily as a solids capture device, while the RBC performed the bulk of the nitrification. Areal removal for the bead filter was 56·2 mg TAN/m2-day at 5% efficiency and 13·1 mg NO2-N/m2-day at 1·1% efficiency, while for the RBC it was 257 mg TAN/m2-day at 52% efficiency, and 282 mg NO2-N/m2-day at 51% efficiency.

Abstract: Ceratitis capitata is one of the most important pest species in the tropical and temperate regions of the world, however, genetic knowledge of this species is still very limited. In the present study, we have attempted for the first time an analysis of the genetic variability in seven natural populations of C. capitata by means of abundant soluble proteins, combining high resolution techniques such as polyacrylamide gel electrophoresis and silver staining methods. A total of 66 polypeptides have been analyzed. The results show the existence of a decreasing trend in the ‘levels’ of polymorphism from the southern areas to the northern that is correlated with the latitude of the sampling areas, most probably due to the colonization process of the Iberian Peninsula. On the other hand, and with relation to the ‘pattern’ of the variability, a geographic differentiation (not strictly latitudinal) is detected when an UPGMA clustering method was applied to the data. Moreover, principal component anaysis has revealed that a part of this differentiation could be explained in relation with environmental factors such as annual rainfall and minimum temperature in winter months. This is suggesting that selection (added to the historical process) could be playing an important role in the process of geographic differentiation, ‘shaping’ the pattern of that variability. No host-related differentiation has been observed in these samples.

Three different molecular techniques—gel electrophoresis of isozymes, restriction fragment-length polymorphism (RFLP) in mitochondrial DNA, and random amplified polymorphic DNA (RAPD-polymerase chain reaction)—have been used to infer the geographical origin of a laboratory population of Ceratitis capitata (Wiedemann). We have analyzed 3 natural populations from different geographical regions of Spain (south, center, and east), and a laboratory population, the origin of which was to be checked by means of these molecular approaches. The results showed that the RAPD-PCR and mitochondrial DNA analysis yielded the correct origin of the laboratory population, whereas the isozyme analysis failed to determine the origin of this population. The results are discussed in relation to the possible bottlenecks and selective effects that could had taken place. These effects may have influenced genetic variability and the suitability of those markers for detecting the geographical origin of populations.

The human cardiovascular system (CVS) and respiratory system (RS) work together in order to supply oxygen (O 2 ) and other substrates needed for metabolism and to remove carbon dioxide (CO 2 ). Global and local control mechanisms act on the CVS in order to adjust blood flow to the different parts of the body. This, in turn, affects the RS since the amount of O 2 and CO 2 transported, respectively to and away from the tissues depends on the cardiac output and blood flow in both the systemic and pulmonary circuits of the CVS. Local metabolic control is influenced by local concentrations of blood gases affecting systemic resistance, resulting to vasoconstriction/vasodilation. Thus, the exchange of blood gases demands a tight coordination between blood flow and ventilation of the lungs. In this work, a model of the cardiovascular-respiratory system (CVRS) is considered to obtain an optimal control for time-dependent ergometric workloads by using the Euler-Lagrange formulation of the optimal control problem. The essential controls in the CVRS model are variations in the heart rate and alveolar ventilation through which the central nervous system restricts the arterial partial pressure of CO 2 ( P a,CO 2 ) close to 40 mmHg. Further, penalization terms in the cost functional are included to match the metabolic need for O 2 and the metabolic production of CO 2 with O 2 - and CO 2 -transport by blood. [ABSTRACT FROM AUTHOR]