Inheritance of resistance to cotton blue disease

The objective of this work was to determine the inheritance of cotton blue disease resistance by cotton plants. Populations derived from the CD 401 and Delta Opal resistant varieties were evaluated, through a greenhouse test with artificial inoculation by viruliferous aphids. Cotton blue disease resistance is conditioned by one dominant gene, both in CD 401 and Delta Opal varieties.

Patient with Fanconi Syndrome (FS) and retinitis pigmentosa (RP) caused by a deletion and duplication of mitochondrial DNA (mtDNA).

BACKGROUND: We report a patient with a highly unusual presentation of a mitochondrial disorder. HISTORY AND SIGNS: An 8-year old girl presented with muscular cramps as well as height and weight deceleration. Investigations revealed lactic acidosis, electrolytic imbalance and urinary loss of glucose and electrolytes secondary to proximal renal tubulopathy consistent with Fanconi syndrome (FS). Ophthalmic examination revealed asymptomatic retinitis pigmentosa (RP) with no other ocular manifestations. A mitochondriopathy was suspected and genetic analysis performed. THERAPY AND OUTCOME: Southern blotting documented a heteroplasmic mutation of mtDNA with deletion/duplication. Three discrete mitochondrial genomes were detected: normal; deletion of 6.7 kb and a deletion/duplication consisting of 1 normal and 1 deleted genome. The relative proportions varied considerably between tissues. CONCLUSIONS: The association of FS and RP combines features of Kearns-Sayre syndrome and Pearson marrow-pancreas syndrome, without being typical of either. This highly unusual clinical presentation emphasises the need for systemic investigation of patients with FS and further underlines the importance of mtDNA analysis in patients with unexpected associations of affected tissues.

Macular dystrophy associated with the mitochondrial DNA A3243G mutation: pericentral pigment deposits or atrophy? Report of two cases and review of the literature.

BACKGROUND: The A3243G point mutation in mitochondrial DNA (mtDNA) is associated with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) and MIDD syndromes (maternally inherited diabetes and deafness). Both MELAS and MIDD patients can present with visual symptoms due to a retinopathy, sometimes before the genetic diagnosis is made. CASE PRESENTATION: Patient 1: 46 year-old woman with diabetes mellitus and hearing loss was referred for an unspecified maculopathy detected during screening evaluation for diabetic retinopathy. Visual acuity was 20/20 in both eyes. Fundus examination showed bilateral macular and peripapillary hyperpigmented/depigmented areas.Patient 2: 45 year-old woman was referred for recent vision loss in her left eye. History was remarkable for chronic fatigue, migraine and diffuse muscular pain. Visual acuity was 20/20 in her right eye and 20/30 in her left eye. Fundus exhibited several nummular perifoveal islands of retinal pigment epithelium atrophy and adjacent pale deposits in both eyes.Retinal anatomy was investigated with autofluorescence, retinal angiography and optical coherence tomography. Retinal function was assessed with automated static perimetry, full-field and multifocal electroretinography and electro-oculography. Genetic testing of mtDNA identified a point mutation at the locus 3243. CONCLUSION: Observation of RPE abnormalities in the context of suggestive systemic findings should prompt mtDNA testing.

Skeletal muscle mitochondrial energetics are associated with maximal aerobic capacity and walking speed in older adults.

BACKGROUND: Lower ambulatory performance with aging may be related to a reduced oxidative capacity within skeletal muscle. This study examined the associations between skeletal muscle mitochondrial capacity and efficiency with walking performance in a group of older adults. METHODS: Thirty-seven older adults (mean age 78 years; 21 men and 16 women) completed an aerobic capacity (VO peak) test and measurement of preferred walking speed over 400 m. Maximal coupled (State 3; St3) mitochondrial respiration was determined by high-resolution respirometry in saponin-permeabilized myofibers obtained from percutanous biopsies of vastus lateralis (n = 22). Maximal phosphorylation capacity (ATP) of vastus lateralis was determined in vivo by P magnetic resonance spectroscopy (n = 30). Quadriceps contractile volume was determined by magnetic resonance imaging. Mitochondrial efficiency (max ATP production/max O consumption) was characterized using ATP per St3 respiration (ATP/St3). RESULTS: In vitro St3 respiration was significantly correlated with in vivo ATP (r = .47, p = .004). Total oxidative capacity of the quadriceps (St3*quadriceps contractile volume) was a determinant of VO peak (r = .33, p = .006). ATP (r = .158, p = .03) and VO peak (r = .475, p < .0001) were correlated with preferred walking speed. Inclusion of both ATP/St3 and VO peak in a multiple linear regression model improved the prediction of preferred walking speed (r = .647, p < .0001), suggesting that mitochondrial efficiency is an important determinant for preferred walking speed. CONCLUSIONS: Lower mitochondrial capacity and efficiency were both associated with slower walking speed within a group of older participants with a wide range of function. In addition to aerobic capacity, lower mitochondrial capacity and efficiency likely play roles in slowing gait speed with age.

Targeting microglial KATP channels to treat neurodegenerative diseases: a mitochondrial issue

Neurodegeneration is a complex process involving different cell types and neurotransmitters. A common characteristic of neurodegenerative disorders is the occurrence of a neuroinflammatory reaction in which cellular processes involving glial cells, mainly microglia and astrocytes, are activated in response to neuronal death. Microglia do not constitute a unique cell population but rather present a range of phenotypes closely related to the evolution of neurodegeneration. In a dynamic equilibrium with the lesion microenvironment, microglia phenotypes cover from a proinflammatory activation state to a neurotrophic one directly involved in cell repair and extracellular matrix remodeling. At each moment, the microglial phenotype is likely to depend on the diversity of signals from the environment and of its response capacity. As a consequence, microglia present a high energy demand, for which the mitochondria activity determines the microglia participation in the neurodegenerative process. As such, modulation of microglia activity by controlling microglia mitochondrial activity constitutes an innovative approach to interfere in the neurodegenerative process. In this review, we discuss the mitochondrial KATP channel as a new target to control microglia activity, avoid its toxic phenotype, and facilitate a positive disease outcome.

Targeting microglial KATP channels to treat neurodegenerative diseases: a mitochondrial issue

Neurodegeneration is a complex process involving different cell types and neurotransmitters. A common characteristic of neurodegenerative disorders is the occurrence of a neuroinflammatory reaction in which cellular processes involving glial cells, mainly microglia and astrocytes, are activated in response to neuronal death. Microglia do not constitute a unique cell population but rather present a range of phenotypes closely related to the evolution of neurodegeneration. In a dynamic equilibrium with the lesion microenvironment, microglia phenotypes cover from a proinflammatory activation state to a neurotrophic one directly involved in cell repair and extracellular matrix remodeling. At each moment, the microglial phenotype is likely to depend on the diversity of signals from the environment and of its response capacity. As a consequence, microglia present a high energy demand, for which the mitochondria activity determines the microglia participation in the neurodegenerative process. As such, modulation of microglia activity by controlling microglia mitochondrial activity constitutes an innovative approach to interfere in the neurodegenerative process. In this review, we discuss the mitochondrial KATP channel as a new target to control microglia activity, avoid its toxic phenotype, and facilitate a positive disease outcome.

Phylogeography and recolonization of the Swiss Alps by the Valais shrew (Sorex antinorii), inferred with autosomal and sex-specific markers.

Using one male-inherited, one female-inherited and eight biparentally inherited markers, we investigate the population genetic structure of the Valais shrew (Sorex antinorii) in the Swiss Alps. Bayesian analysis on autosomal microsatellites suggests a clear genetic differentiation between two groups of populations. This geographically based structure is consistent with two separate postglacial recolonization routes of the species into Switzerland from Italian refugia after the last Pleistocene glaciations. Sex-specific markers also confirm genetic structuring among western and eastern areas, since very few haplotypes for either Y chromosome or mtDNA genome are shared between the two regions. Overall, these results suggest that two already well-differentiated genetic lineages colonized the Swiss Alps and came into secondary contact in the Rhône Valley. Low level of admixture between the two lineages is likely explained by the mountainous landscape structure of lateral valleys orthogonal to the main Rhône valley.

Tomato plant inheritance of antixenotic resistance to tomato leafminer

The objective of this work was to determine the inheritance of resistance by antixenosis in tomato plants (Lycopersicon esculentum) to tomato leafminer [Tuta absoluta (Lepidoptera: Gelechiidae)]. Evaluations were performed for tomato plants of the generations P1, P2, F1, F2, RC1 and RC2. The measured characteristic in the parents, BGH-1497 (P2 male) and 'Santa Clara' (P1 female), and in the F1, F2, RC1 and RC2 generations was the number of eggs per plant. This number was converted to the oviposition nonpreference index. The inheritance of antixenosis resistance of genotype BGH-1497 is ruled by a gene of greater effect and polygenes in epistatic interactions, with a phenotypic proportion of 13:3 between susceptible and resistant genotypes, respectively.

Evolutionary and dispersal history of Eurasian house mice Mus musculus clarified by more extensive geographic sampling of mitochondrial DNA.

We examined the sequence variation of mitochondrial DNA control region and cytochrome b gene of the house mouse (Mus musculus sensu lato) drawn from ca. 200 localities, with 286 new samples drawn primarily from previously unsampled portions of their Eurasian distribution and with the objective of further clarifying evolutionary episodes of this species before and after the onset of human-mediated long-distance dispersals. Phylogenetic analysis of the expanded data detected five equally distinct clades, with geographic ranges of northern Eurasia (musculus, MUS), India and Southeast Asia (castaneus, CAS), Nepal (unspecified, NEP), western Europe (domesticus, DOM) and Yemen (gentilulus). Our results confirm previous suggestions of Southwestern Asia as the likely place of origin of M. musculus and the region of Iran, Afghanistan, Pakistan, and northern India, specifically as the ancestral homeland of CAS. The divergence of the subspecies lineages and of internal sublineage differentiation within CAS were estimated to be 0.37-0.47 and 0.14-0.23 million years ago (mya), respectively, assuming a split of M. musculus and Mus spretus at 1.7 mya. Of the four CAS sublineages detected, only one extends to eastern parts of India, Southeast Asia, Indonesia, Philippines, South China, Northeast China, Primorye, Sakhalin and Japan, implying a dramatic range expansion of CAS out of its homeland during an evolutionary short time, perhaps associated with the spread of agricultural practices. Multiple and non-coincident eastward dispersal events of MUS sublineages to distant geographic areas, such as northern China, Russia and Korea, are inferred, with the possibility of several different routes.

No longitudinal mitochondrial DNA sequence changes in HIV-infected individuals with and without lipoatrophy.

The potential for mitochondrial (mt) DNA mutation accumulation during antiretroviral therapy (ART), and preferential accumulation in patients with lipoatrophy compared with control participants, remains controversial. We sequenced the entire mitochondrial genome, both before ART and after ART exposure, in 29 human immunodeficiency virus (HIV)-infected Swiss HIV Cohort Study participants initiating a first-line thymidine analogue-containing ART regimen. No accumulation of mtDNA mutations or deletions was detected in 13 participants who developed lipoatrophy or in 16 control participants after significant and comparable ART exposure (median duration, 3.3 and 3.7 years, respectively). In HIV-infected persons, the development of lipoatrophy is unlikely to be associated with accumulation of mtDNA mutations detectable in peripheral blood.

Rift-related inheritance in orogens: a case study from the Austroalpine nappes in Central Alps (SE-Switzerland and N-Italy)

The Austroalpine nappe systems in SE-Switzerland and N-Italy preserve remnants of the Adriatic rifted margin. Based on new maps and cross-sections, we suggest that the complex structure of the Campo, Grosina/Languard, and Bernina nappes is inherited largely from Jurassic rifting. We propose a classification of the Austroalpine domain into Upper, Middle and Lower Austroalpine nappes that is new because it is based primarily on the rift-related Jurassic structure and paleogeography of these nappes. Based on the Alpine structures and pre-Alpine, rift-related geometry of the Lower (Bernina) and Middle (Campo, Grosina/Languard) Austroalpine nappes, we restore these nappes to their original positions along the former margin, as a means of understanding the formation and emplacement of the nappes during initial reactivation of the Alpine Tethyan margin. The Campo and Grosina/Languard nappes can be interpreted as remnants of a former necking zone that comprised pre-rift upper and middle crust. These nappes were juxtaposed with the Mesozoic cover of the Bernina nappe during Jurassic rifting. We find evidence for low-angle detachment faults and extensional allochthons in the Bernina nappe similar to those previously described in the Err nappe and explain their role during subsequent reactivation. Our observations reveal a strong control of rift-related structures during the subsequent Alpine reactivation on all scales of the former distal margin. Two zones of intense deformation, referred to as the Albula-Zebru and Lunghin-Mortirolo movement zones, have been reactivated during Alpine deformation and cannot be described as simple monophase faults or shear zones. We propose a tectonic model for the Austroalpine nappe systems that link inherited, rift-related structures with present-day Alpine structures. In conclusion, we believe that apart from the direct regional implications, the results of this paper are of general interest in understanding the control of rift structures during reactivation of distal-rifted margins.

Mitochondrial control region and microsatellite data show low genetic variability in reared senegalese sole, Solea senegalensis. Preliminary data

Peer reviewed

Inheritance of seed coat color in sesame

The objective of this work was to determine the inheritance mode of seed coat color in sesame. Two crosses and their reciprocals were performed: UCLA37 x UCV3 and UCLA90 x UCV3, of which UCLA37 and UCLA90 are white seed, and UCV3 is brown seed. Results of reciprocal crosses within each cross were identical: F1 seeds had the same phenotype as the maternal parent, and F2 resulted in the phenotype brown color. These results are consistent only with the model in which the maternal effect is the responsible for this trait. This model was validated by recording the seed coat color of 100 F2 plants (F3 seeds) from each cross with its reciprocal, in which the 3:1 expected ratio for plants producing brown and white seeds was tested with the chi-square test. Sesame seed color is determined by the maternal genotype. Proposed names for the alleles participating in sesame seed coat color are: Sc1, for brown color; and Sc2, for white color; Sc1 is dominant over Sc2.