Proteomic changes in response to crystal formation in Drosophila Malpighian tubules

Kidney stone disease is a major health burden with a complex and poorly understood pathophysiology. Drosophila Malpighian tubules have been shown to resemble human renal tubules in their physiological function. Herein, we have used Drosophila as a model to study the proteomic response to crystal formation induced by dietary manipulation in Malpighian tubules. Wild-type male flies were reared in parallel groups on standard medium supplemented with lithogenic agents: control, Sodium Oxalate (NaOx) and Ethylene Glycol (EG). Malpighian tubules were dissected after 2 weeks to visualize crystals with polarized light microscopy. The parallel group was dissected for protein extraction. A new method of Gel Assisted Sample Preparation (GASP) was used for protein extraction. Differentially abundant proteins (p<0.05) were identified by label-free quantitative proteomic analysis in flies fed with NaOx and EG diet compared with control. Their molecular functions were further screened for transmembrane ion transporter, calcium or zinc ion binder. Among these, 11 candidate proteins were shortlisted in NaOx diet and 16 proteins in EG diet. We concluded that GASP is a proteomic sample preparation method that can be applied to individual Drosophila Malpighian tubules. Our results may further increase the understanding of the pathophysiology of human kidney stone disease.     

Protective Cellular Mechanism of Estrogen Against Kidney Stone Formation: A Proteomics Approach and Functional Validation

Females have less incidence/prevalence of kidney stone disease than males. Estrogen thus may serve as the protective factor but with unclear mechanism. This study explores cellular mechanism underlying such stone preventive mechanism of estrogen. Madin darby canine kidney (MDCK) renal tubular cells are incubated with or without 20 nm 17β‐estradiol for 7 days. Comparative proteomics reveals 58 differentially expressed proteins in estrogen‐treated versus control cells that are successfully identified by nanoLC–ESI–Q‐TOF‐MS/MS. Interestingly, these altered proteins are involved mainly in “binding and receptor,” “metabolic process,” and “migration and healing” networks. Functional investigations demonstrate reduction of calcium oxalate (CaOx) crystal‐binding capability of the estrogen‐treated cells consistent with the decreased levels of annexin A1 and α‐enolase (the known CaOx crystal‐binding receptors) on the cell surface. High‐calcium and high‐oxalate challenge initially enhances surface expression of annexin A1 and α‐enolase, respectively, both of which return to their basal levels by estrogen. Additionally, estrogen reduces intracellular ATP level and promotes cell migration and tissue healing. Taken together, estrogen causes changes in cellular proteome of renal tubular cells that lead to decreased surface expression of CaOx crystal receptors, reduced intracellular metabolism, and enhanced cell proliferation and tissue healing, all of which may contribute, at least in part, to stone prevention.     

Managing red pine stand structure to mitigate drought impacts

Reducing forest stand density through silvicultural thinning has demonstrated potential to mitigate drought impacts on growth; however, less has been studied on how changes in stand structure created by different thinning methods influence forest growth responses to drought. This research examined the growth responses to drought of natural-origin red pine in a long-term study contrasting thinning methods. Dendrochronological methods were used to examine growth responses during several drought events among stands where different thinning methods have been applied since 1950. Growth responses to drought were expressed as resistance (maintaining growth during drought), and resilience (regaining pre-drought growth). Results indicate that periodic thinning from above, which resulted in smaller diameters, has the potential to moderate drought-induced growth reductions. Larger tree diameters negatively influenced tree-level resistance and resilience across all treatments; however, the proportion of dominant trees in a stand had contrasting effects on stand-level drought responses. Stands thinned from above exhibited more complex vertical structure and increased stand-level resistance and resilience to drought-induced growth declines because competition is more stratified among smaller diameter trees. Opposite trends were observed in stands thinned from below, where the larger diameters and monolayered structure create greater competition among trees of similar size and crown position. The results of this study highlight the utility in managing for greater structural diversity to mitigate the negative effects of drought in red pine forest ecosystems.     

How needle phenology indicates the changes of xylem cell formation during drought stress in Pinus sylvestris L.

Temperature, water availability and photoperiod are the primary drivers of tree phenological processes. However, there is lack of information how the spring temperature and summer drought affect phenology of both cambium and needles. We evaluated the interplay between xylem and needle development of mature Scots pine trees in three consecutive years differing in the spring temperatures and onset and duration of summer drought. Cambial activity began on the day of a year (DOY) 83–87, while the bud break occurred on DOY 113–119, when also the secondary cell wall of tracheids started its formation. While the timing of bud break correlated with the sum of effective temperatures, the beginning of cambial zone activity did not. The needles were fully unfolded around DOY 170, which corresponded to the transition between earlywood and latewood tracheids. Summer drought did not affect needle development, but it changed the rate of production and morphology of latewood tracheids. Latewood tracheids from the year 2015 when the drought was longest (i.e. until the second half of August in 2015 compared to the duration from June until the middle of July in the two other years) were 32% narrower and they had 34% thinner cell walls than in 2014 and 2016. The improvement of tree water status in July resulted in the formation of intra-annual density fluctuations (IADF). The interplay between needle and cambium phenology provided an insight into how the tree allocates the resources with varying temperature and soil water availability.     

Population structure and the evolution of Homo sapiens in Africa

It has been proposed that a multiregional model could describe how Homo sapiens evolved in Africa beginning 300,000 years ago. Multiregionalism would require enduring morphological or behavioral differences among African regions and morphological or behavioral continuity within each. African fossils, archeology, and genetics do not comply with either requirement and are unlikely to, because climatic change periodically disrupted continuity and reshuffled populations. As an alternative to multiregionalism, I suggest that reshuffling produced novel gene constellations, including one in which the additive or cumulative effect of newly associated genes enhanced cognitive or communicative potential. Eventual fixation of such a constellation in the lineage leading to modern H. sapiens would explain the abrupt appearance of the African Later Stone Age 50–45 thousand years ago, its nearly simultaneous expansion to Eurasia in the form of the Upper Paleolithic, and the ability of fully modern Upper Paleolithic people to swamp or replace non‐modern Eurasians.     

长白山区阔叶红松林经营历史与研究历程

长白山区位于中国东北东部的山地森林区,地带性植被是阔叶红松林,是我国珍贵木材生产和东北森林带的重要载体,孕育着丰富的物种资源.短短120年来,长白山区广袤的原始森林几乎消失殆尽,被次生林、过伐林和人工林等替代.建国以来,东北的阔叶红松林经营理论与技术在红松更新规律、皆伐与择伐的争论中,在人们对阔叶红松林结构和功能认识不断深入的过程中逐渐完善.但目前红松更新问题依然存在,森林经营依然十分粗放.本文梳理了过去70年来阔叶红松林的经营历史及研究历程,分析当前森林资源类型和经营制度的形成过程,以期为该区天然林可持续经营和质量的精准提升等提供借鉴.     

Effects of chemical pollutants on reproductive and developmental processes in Italian amphibians

It is a widely held belief that environmental contaminants contribute to the decline of amphibian populations. By spending most of their early life in water and later stages on the land, amphibians face a constant risk of exposure to pesticides and other chemical pollutants in both aquatic and terrestrial environments. This review presents an overview of the studies carried out in Italian amphibians to highlight hazardous effects of bioaccumulation of chemical pollutants in juveniles and adults in various contaminated environments. Further, the studies in the laboratory setting assessing the effects of chemical pollutants on reproductive and developmental processes are reported. These studies and their relative references have been summarized in a tabular form. Three prominent contaminant groups were identified: herbicides, insecticides, and fungicides; and only a few works reported the effects of other chemical pollutants. Each pollutant group has been delegated to a section. All through the literature survey, it is seen that interest in this topic in Italy is very recent and sparse, where only a few anuran and caudata species and only some chemical pollutants have been studied.     

Fragments and dust after Holmium laser lithotripsy with or without “Moses technology”: How are they different?

Urinary stones can be readily disintegrated by Holmium:YAG laser (Holmium laser lithotripsy), resulting in a mixture of small stone dust particles, which will spontaneously evacuate with urine and larger residual fragments (RF) requiring mechanical retrieval. Differences between fragments and dust have not been well characterized. Also, it remains unknown how the recently introduced “Moses technology” may alter stone disintegration products. Three complementary analytical techniques have been used in this study to offer an in‐depth characterization of disintegration products after in vitro Holmium laser lithotripsy: stereoscopic microscopy, scanning electron microscopy and Fourier‐transform infrared spectroscopy. Dust was separated from fragments based on its floating ability in saline irrigation. Depending on initial crystalline constituents, stone dust either conserved attributes found in larger RFs or showed changes in crystalline organization. These included conversion of calcium oxalate dihydrate towards calcium oxalate monohydrate, changes in carbapatite spectra towards an amorphous phase, changes of magnesium ammonium phosphate towards a differing amorphous and crystalline phase and the appearance of hydroxyapatite on brushite fragments. Comparatively, “Moses technology” produced more pronounced changes. These findings provide new insights suggesting a photothermal effect occurring in Holmium laser lithotripsy. Figure: Appearance of hydroxyapatite hexagons on stone dust collected after Holmium laser lithotripsy of a brushite stone using “Moses technology.”      

Influence of climate change and postdelisting management on long‐term population viability of the conservation‐reliant Kirtland's Warbler

Rapid global climate change is resulting in novel abiotic and biotic conditions and interactions. Identifying management strategies that maximize probability of long‐term persistence requires an understanding of the vulnerability of species to environmental changes. We sought to quantify the vulnerability of Kirtland's Warbler (Setophaga kirtlandii), a rare Neotropical migratory songbird that breeds almost exclusively in the Lower Peninsula of Michigan and winters in the Bahamian Archipelago, to projected environmental changes on the breeding and wintering grounds. We developed a population‐level simulation model that incorporates the influence of annual environmental conditions on the breeding and wintering grounds, and parameterized the model using empirical relationships. We simulated independent and additive effects of reduced breeding grounds habitat quantity and quality, and wintering grounds habitat quality, on population viability. Our results indicated the Kirtland's Warbler population is stable under current environmental and management conditions. Reduced breeding grounds habitat quantity resulted in reductions of the stable population size, but did not cause extinction under the scenarios we examined. In contrast, projected large reductions in wintering grounds precipitation caused the population to decline, with risk of extinction magnified when breeding habitat quantity or quality also decreased. Our study indicates that probability of long‐term persistence for Kirtland's Warbler will depend on climate change impacts to wintering grounds habitat quality and contributes to the growing literature documenting the importance of considering the full annual cycle for understanding population dynamics of migratory species.     

Allelopathic effects of volatile organic compounds released from Pinus halepensis needles and roots

The Mediterranean region is recognized as a global biodiversity hotspot. However, over the last decades, the cessation of traditional farming in the north part of the Mediterranean basin has given way to strong afforestation leading to occurrence of abandoned agricultural lands colonized by pioneer expansionist species like Pinus halepensis. This pine species is known to synthesize a wide range of secondary metabolites, and previous studies have demonstrated strong allelopathic potentialities of its needle and root leachates. Pinus halepensis is also recognized to release significant amounts of volatile organic compounds (VOC) with potential allelopathic effects that have never been investigated. In this context, the objectives of the present study were to improve our knowledge about the VOC released from P. halepensis needles and roots, determine if these VOC affect the seed germination and root growth of two herbaceous target species (Lactuca sativa and Linum strictum), and evaluate if soil microorganisms modulate the potential allelopathic effects of these VOC. Thirty terpenes were detected from both, needle and root emissions with β‐caryophyllene as the major volatile. Numerous terpenes, such as β‐caryophyllene, δ‐terpinene, or α‐pinene, showed higher headspace concentrations according to the gradient green needles < senescent needles < needle litter. Seed germination and root growth of the two target species were mainly reduced in presence of P. halepensis VOC. In strong contrast with the trend reported with needle leachates in literature, we observed an increasing inhibitory effect of P. halepensis VOC with the progress of needle physiological stages (i.e., green needle < senescent needle < needle litter). Surprisingly, several inhibitory effects observed on filter paper were also found or even amplified when natural soil was used as a substrate, highlighting that soil microorganisms do not necessarily limit the negative effects of VOC released by P. halepensis on herbaceous target species.