Crayfish invasion facilitates dispersal of plants and invertebrates by gulls

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Where did Mikrotia magna originate? Drawing ecogeographical inferences from body mass reconstructions

Terre Rosse deposits (upper Miocene; Gargano, Italy) have provided fossil remains of an insular fauna among which the genus Mikrotia (Rodentia) stands out. Several paleobiological studies have already been conducted on this genus, but its body mass has not yet been calculated accurately. The aim of the present work is to reconstruct Mikrotia magna's weight, a paramount aspect of organismal biology, especially on islands where mammals modify their size, becoming giants or dwarfs (‘island rule’). Our analysis using postcranial elements (femora and humeri) predicts weights ranging from 1300 g to 1900 g (old and young populations, respectively). The presence of a large number of micromammals on the Gargano paleo-island suggests a high interspecific competition for species of the same ecological guild (Prolagus or cricetids were direct competitors of Mikrotia), which may lead to only moderate gigantism, or even body mass reductions in small mammals, following Palkovacs's model. This contrasts with the huge weight of M. magna inferred in this study. In this regard, stratigraphic and taxonomic studies suggest that M. magna was an immigrant from a neighboring island, indicating that this species originated and achieved its enormous size under other selective pressures. A native island with a lower number of competitors, and therefore with less resource limitation than Terre Rosse, might be the principal explanation for such a degree of gigantism.     

Expression profiling of microRNAs in human bone tissue from postmenopausal women

Bone tissue is composed of several cell types, which express their own microRNAs (miRNAs) that will play a role in cell function. The set of total miRNAs expressed in all cell types configures the specific signature of the bone tissue in one physiological condition. The aim of this study was to explore the miRNA expression profile of bone tissue from postmenopausal women. Tissue was obtained from trabecular bone and was analyzed in fresh conditions (n = 6). Primary osteoblasts were also obtained from trabecular bone (n = 4) and human osteoclasts were obtained from monocyte precursors after in vitro differentiation (n = 5). MicroRNA expression profiling was obtained for each sample by microarray and a global miRNA analysis was performed combining the data acquired in all the microarray experiments. From the 641 miRNAs detected in bone tissue samples, 346 (54%) were present in osteoblasts and/or osteoclasts. The other 46% were not identified in any of the bone cells analyzed. Intersection of osteoblast and osteoclast arrays identified 101 miRNAs shared by both cell types, which accounts for 30–40% of miRNAs detected in these cells. In osteoblasts, 266 miRNAs were detected, of which 243 (91%) were also present in the total bone array, representing 38% of all bone miRNAs. In osteoclasts, 340 miRNAs were detected, of which 196 (58%) were also present in the bone tissue array, representing 31% of all miRNAs detected in total bone. These analyses provide an overview of miRNAs expressed in bone tissue, broadening our knowledge in the microRNA field.     

Antimitotic and hormone effects on green double haploid plant production through anther culture of Mediterranean japonica rice

Rice double haploid (DH) plants are produced mainly through anther culture. In order to improve the anther culture protocol, microspores of two japonica rice genotypes (NRVC980385 and H28) were subjected to three growth regulator combinations and four colchicine treatments on induction medium. In addition, a post anther culture procedure using colchicine or oryzalin was tested to induce double haploid plantlets from haploid plantlets. A cold pre-treatment of microspores for 9 days at 10 °C increased callus induction 50-fold in the NRCV980385 genotype. For both genotypes, 2 mg L^?1 2,4-D and 1 mg L^?1 kinetin on colchicine-free induction medium gave the best culture responses. The culturability of both genotypes changed on colchicine-supplemented induction media. A high genotype dependency was recorded for callus induction, callus regenerating green plantlets and regeneration of green double haploid plantlets. Colchicine at 300 mg L^?1 for 48 h enhanced callus induction 100-fold in H28. Colchicine-supplemented media clearly improved green double haploid plantlet regeneration. We showed that the post-anther culture treatment of haploid plantlets at 500 mg L^?1 of colchicine permitted fertile double haploid plantlets to be generated. Finally, an enhanced medium-throughput flow cytometry protocol for rice was tested to analyse all the plantlets from anther and post anther culture.     

A net ecosystem carbon budget for snow dominated forested headwater catchments: linking water and carbon fluxes to critical zone carbon storage

Climate-driven changes in carbon (C) cycling of forested ecosystems have the potential to alter long-term C sequestration and the global C balance. Prior studies have shown that C uptake and partitioning in response to hydrologic variation are system specific, suggesting that a comprehensive assessment is required for distinct ecosystems. Many sub-humid montane forest ecosystems in the US are projected to experience increased water limitation over the next decades and existing water-limited forests can be used as a model for how changes in the hydrologic cycle will impact such ecosystems more broadly. Toward that goal we monitored precipitation, net ecosystem exchange and lateral soil and stream C fluxes in three semi-arid to sub-humid montane forest catchments for several years (WY 2009–2013) to investigate how the amount and timing of water delivery affect C stores and fluxes. The key control on aqueous and gaseous C fluxes was the distribution of water between winter and summer precipitation, affecting ecosystem C uptake versus heterotrophic respiration. We furthermore assessed C stores in soil and above- and below-ground biomass to assess how spatial patterns in water availability influence C stores. Topographically-driven patterns in catchment wetness correlated with modeled soil C stores, reflecting both long-term trends in local C uptake as well as lateral redistribution of C leached from upslope organic soil horizons to convergent landscape positions. The results suggest that changes in the seasonality of precipitation from winter snow to summer rain will influence both the amount and the spatial distribution of soil C stores.     

Regulation of Androgen Receptor Activity by Transient Interactions of Its Transactivation Domain with General Transcription Regulators

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The Xerobranching Response Represses Lateral Root Formation When Roots Are Not in Contact with Water

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TMEM41B is a novel regulator of autophagy and lipid mobilization

Autophagy maintains cellular homeostasis by targeting damaged organelles, pathogens, or misfolded protein aggregates for lysosomal degradation. The autophagic process is initiated by the formation of autophagosomes, which can selectively enclose cargo via autophagy cargo receptors. A machinery of well‐characterized autophagy‐related proteins orchestrates the biogenesis of autophagosomes; however, the origin of the required membranes is incompletely understood. Here, we have applied sensitized pooled CRISPR screens and identify the uncharacterized transmembrane protein TMEM41B as a novel regulator of autophagy. In the absence of TMEM41B, autophagosome biogenesis is stalled, LC3 accumulates at WIPI2‐ and DFCP1‐positive isolation membranes, and lysosomal flux of autophagy cargo receptors and intracellular bacteria is impaired. In addition to defective autophagy, TMEM41B knockout cells display significantly enlarged lipid droplets and reduced mobilization and β‐oxidation of fatty acids. Immunostaining and interaction proteomics data suggest that TMEM41B localizes to the endoplasmic reticulum (ER). Taken together, we propose that TMEM41B is a novel ER‐localized regulator of autophagosome biogenesis and lipid mobilization.     

Ultrastructure of the Secondary Egg Envelope of Cyprinodontidae of the Genus Epiplatys Gill, 1862 (Pisces,Teleostei)

Abstract The structure of the secondary egg envelope of seven species of Cyprinodontidae belonging to the genus Epiplatys was observed by transmission and scanning electron microscopy. The transverse structure of the secondary envelope examined by transmission electron microscopy is a constant feature in all the species studied and represents a good criterion for identification. In contrast, the surface structure of the secondary envelope when observed by scanning electron microscopy exhibits a great diversity of form. It is possible to distinguish each of the seven different species by the pattern of ornamentation, the width of the polygons and the size of the granules comprising them on the secondary egg envelope.