Autophagy facilitates mitochondrial rebuilding after acute heat stress via a DRP-1–dependent process

Acute heat stress (aHS) can induce strong developmental defects in Caenorhabditis elegans larva but not lethality or sterility. This stress results in transitory fragmentation of mitochondria, formation of aggregates in the matrix, and decrease of mitochondrial respiration. Moreover, active autophagic flux associated with mitophagy events enables the rebuilding of the mitochondrial network and developmental recovery, showing that the autophagic response is protective. This adaptation to aHS does not require Pink1/Parkin or the mitophagy receptors DCT-1/NIX and FUNDC1. We also find that mitochondria are a major site for autophagosome biogenesis in the epidermis in both standard and heat stress conditions. In addition, we report that the depletion of the dynamin-related protein 1 (DRP-1) affects autophagic processes and the adaptation to aHS. In drp-1 animals, the abnormal mitochondria tend to modify their shape upon aHS but are unable to achieve fragmentation. Autophagy is induced, but autophagosomes are abnormally elongated and clustered on mitochondria. Our data support a role for DRP-1 in coordinating mitochondrial fission and autophagosome biogenesis in stress conditions.     

Mycorrhizal colonization decreases respiration of common bean nodulated root in hydroaeroponic culture

The bean-rhizobia symbiosis allows atmospheric nitrogen fixation through nodule formation. Nevertheless, nodule establishment in Mediterranean areas is subjected to various biotic and abiotic constraints such as phosphorus soils deficiency. This study compares plant-growth response to moderate (75 μmol KH₂PO₄ plant^?1 week^?1) versus severe phosphorus deficiency (30 μmol KH₂PO₄ plant^?1 week^?1) after inoculation with Rhizobium tropici CIAT 899 and Glomus intraradices of four Phaseolus vulgaris lines contrasting in P use efficiency (PUE) for their symbiotic nitrogen fixation (SNF) in hydroaeroponic culture. After 5 weeks of growth under glasshouse conditions, the oxygen consumption related to nitrogen fixation was measured on intact nodulated roots. The obtained results revealed that mycorrhizal colonization decreased the nodulated-roots O₂ consumption of P. vulgaris under both P deficiencies although it increased the growth of all plant organs and the nodulation with a large genotypic variability. Moreover, mycorrhizal colonization was higher under severe P deficiency than under moderate one. In conclusion, the tripartite inoculation improved growth parameters under severe P-deficiency with a decrease in nodulated root O₂ consumption.     

Characterization of a rare short arm heteromorphism of chromosome 22 in a girl with down-syndrome like facies

Chromosomal heteromorphisms are described as interindividual variation of chromosomes without phenotypic consequence. Chromosomal polymorphisms detected include most regions of heterochromatin of chromosomes 1, 9, 16 and Y and the short arms of all acrocentric chromosomes. Here, we report a girl with Down-syndrome such as facies and tremendously enlarged short arm of a chromosome 22. Fluorescence in situ hybridization (FISH) with a probe specific for all acrocentric short arms revealed that the enlargement p arms of the chromosome 22 in question contained exclusively heterochromatic material derived from an acrocentric short arm. Parental studies identified a maternal origin of this heteromorphism. Cryptic trisomy 21 of the Down-syndrome critical region was excluded by a corresponding FISH-probe. Here, we report, to the best of our knowledge, largest ever seen chromosome 22 short arm, being ~×1.5 larger than the normal long arm.     

Impact of grazing on the species richness of plant communities in Mediterranean temporary pools (western Morocco)

The impact of grazing on the vegetation of Moroccan temporary pools has been studied at 2 scales: regional (inter-pools) and local (intra-pools). Half of the 16 forest pools studied is located in a reserve and ungrazed. The other half, located within public forest, is grazed. Vegetation relevés coupled to water-depths measurements were carried out in each pool. The results showed a significant effect of grazing on both scales of analysis. This effect was found in the species composition of the vegetation, which differed between the 2 types of pools, and in the lower species richness and abundance of plant species in the grazed pools. These differences are interpreted as resulting from the selection by herbivores and the differential tolerance of species to disturbance. These impacts are likely to expose certain species to local extinction by reducing their populations.     

Fungicidal activity of human antimicrobial peptides and their synergistic interaction with common antifungals against multidrug-resistant Candida auris

International Microbiology - Emergence of Candida auris, a multidrug-resistant yeast, demonstrates the urgent need for novel antifungal agents. Human antimicrobial peptides (AMPs) are naturally...     

Radiation induced esophageal adenocarcinoma in a woman previously treated for breast cancer and renal cell carcinoma

ABSTRACT: BACKGROUND: Secondary radiation-induced cancers are rare but well-documented as long-term side effects of radiation in large populations of breast cancer survivors. Multiple neoplasms are rare. We report a case of esophageal adenocarcinoma in a patient treated previously for breast cancer and clear cell carcinoma of the kidney CASE PRESENTATION: A 56 year-old non smoking woman, with no alcohol intake and no familial history of cancer; followed in the National Institute of Oncology of Rabat Morocco since 1999 for breast carcinoma, presented on consultation on January 2011 with dysphagia. Breast cancer was treated with modified radical mastectomy, 6 courses of chemotherapy based on CMF regimen and radiotherapy to breast, inner mammary chain and to pelvis as castration. Less than a year later, a renal right mass was discovered incidentally. Enlarged nephrectomy realized and showed renal cell carcinoma. A local and metastatic breast cancer recurrence occurred in 2007. Patient had 2 lines of chemotherapy and 2 lines of hormonotherapy with Letrozole and Tamoxifen assuring a stable disease. On January 2011, the patient presented dysphagia. Oesogastric endoscopy showed middle esophagus stenosing mass. Biopsy revealed adenocarcinoma. No evidence of metastasis was noticed on computed tomography and breast disease was controlled. Palliative brachytherapy to esophagus was delivered. Patient presented dysphagia due to progressive disease 4 months later. Jejunostomy was proposed but the patient refused any treatment. She died on July 2011 CONCLUSION: we present here a multiple neoplasm in a patient with no known family history of cancers. Esophageal carcinoma is most likely induced by radiation. However the presence of a third malignancy suggests the presence of genetic disorders.     

Forest restoration is more than firing seeds from a drone

We are witnessing a rapid increase in news sending the message that drone seeding is a promising technological solution to implement forest restoration at large spatial scales. However, there are neither reports regarding success nor peer-reviewed studies to support these assertions. Once in the ground, the seeds and the seedlings and saplings that they generate have to face biotic and abiotic hazards that can strongly reduce regeneration potential. Successful forest restoration, therefore, cannot be achieved by simply dropping seeds from the air. We summarize some aspects to take into account before considering drone seeding as an efficient and widely applicable technology for forest restoration. A first step should be to increase the precision of drone seeding—contrary to the current massive firing of seeds—in order to concentrate the efforts in the best microsites for establishment and reduce the number of seeds needed and the cost of the whole operation.