Washed preparation of faecal microbiota changes the transplantation related safety,quantitative method and delivery

The safety, quantitative method and delivery of faecal microbiota transplantation (FMT) vary a lot from different countries in practice. Recently, the improved methodology of FMT based on the automatic filtration, washing process and the related delivery was named as washed microbiota transplantation (WMT). First, this study aimed to describe the methodology development of FMT from manual to washing preparation from 2012 to 2021 in China Microbiota Transplantation System (CMTS), a centralized stool bank for providing a national non-profit service. The secondary aim is to describe donor screenings, the correlation between faecal weight and treatment doses, incidence of adverse events and delivery decision. The retrospective analysis on the prospectively recorded data was performed. Results showed that the success rate of donor screening was 3.1% (32/1036). The incidence rate of fever decreased significantly from 19.4% (6/31) in manual FMT to 2.7% (24/902) in WMT in patients with ulcerative colitis (UC), which made UC a considerable disease model to reflect the quality control of faecal microbiota preparation. We defined one treatment unit as 10 cm³ microbiota precipitation (1.0 × 10¹³ bacteria) based on enriched microbiota instead of rough faecal weight. For delivering microbiota, colonic transendoscopic enteral tube is a promising way especially for multiple WMTs or frequent colonic administration of drugs combined with WMT. This study should help improve the better practice of FMT for helping more patients in the future.     

Protein degradation in mitochondria: implications for oxidative stress, aging and disease: a novel etiological classification of mitochondrial proteolytic disorders

The mitochondrial genome encodes just a small number of subunits of the respiratory chain. All the other mitochondrial proteins are encoded in the nucleus and produced in the cytosol. Various enzymes participate in the activation and intramitochondrial transport of imported proteins. To finally take their place in the various mitochondrial compartments, the targeting signals of imported proteins have to be cleaved by mitochondrial processing peptidases. Mitochondria must also be able to eliminate peptides that are internally synthesized in excess, as well as those that are improperly assembled, and those with abnormal conformation caused by mutation or oxidative damage. Damaged mitochondrial proteins can be removed in two ways: either through lysosomal autophagy, that can account for at most 25-30% of the biochemically estimated rates of average mitochondrial catabolism; or through an intramitochondrial proteinolytic pathway. Mitochondrial proteases have been extensively studied in yeast, but evidence in recent years has demonstrated the existence of similar systems in mammalian cells, and has pointed to the possible importance of mitochondrial proteolytic enzymes in human diseases and ageing. A number of mitochondrial diseases have been identified whose mechanisms involve proteolytic dysfunction. Similar mechanisms probably play a role in diminished resistance to oxidative stress, and in the aging process. In this paper we review current knowledge of mammalian mitochondrial proteolysis, under normal conditions and in several disease states, and we propose an etiological classification of human diseases characterized by a decline or loss of function of mitochondrial proteolytic enzymes.     

Cutting edge: identification of the orphan receptor G-protein-coupled receptor 2 as CCR10, a specific receptor for the chemokine ESkine

A number of orphan G-protein coupled receptors (GPR) have been reported as putative chemokine receptors. One previously reported orphan receptor is an incomplete PCR clone, called GPR2. Here we report the cloning of full-length human (h)GPR2 and mouse (m)GPR2 cDNAs, and the identification of GPR2 as a receptor for a novel CC chemokine called ESkine. hGPR2 is expressed at high levels in testis and small intestine, and at lower levels in other tissues. mGPR2 was expressed at high levels in small intestine, colon, lymph nodes, and Peyer's patches and at lower levels in thymus and spleen. Stimulation of L1.2/hGPR2 transfectants with hESkine induced their migration and resulted in intracellular calcium mobilization. These results provide evidence that GPR2 is a specific receptor for ESkine. We propose that GPR2 be renamed as CCR10. The expression pattern of mGPR2/CCR10 suggests that it may play a role in the homing/trafficking of leukocytes within intestinal and lymphoid environments.     

Genetic consequences of interglacial isolation in a steppe bird

In response to climate changes that have occurred during Pleistocene glacial cycles, taxa associated to steppe vegetation might have followed a pattern of historical evolution in which isolation and fragmentation of populations occurred during the short interglacials and expansion events occurred during the long glacial periods, in contrast to the pattern described for temperate species. Here, we use molecular genetic data to evaluate this idea in a steppe bird with Palaearctic distribution, the little bustard (Tetrax tetrax). Overall, extremely low genetic diversity and differentiation was observed among eight little bustard populations distributed in Spain and France. Mismatch distribution analyses showed that most little bustard populations expanded during cooling periods previous to, and just after, the last interglacial period (127,000-111,000 years before present), when steppe habitats were widespread across Europe. Coalescent-based methods suggested that glacial expansions have resulted in substantial admixture in Western Europe due to the existence of different interglacial refugia. Our results are consistent with a model of evolution and genetic consequences of Pleistocene cycles with low between-population genetic differentiation as a result of short-term isolation periods during interglacials and long-term exchange during glacial periods.     

Capture myopathy in little bustards after trapping and marking

Four little bustards (Tetrax tetrax) (one adult and three juvenile males), captured with leg nooses and fitted with a backpack radiotag, died after capture. The first bird was found after 16 days with its left foot caught in the harness and died after 1 day. The other birds showed symptoms of capture myopathy after release, such as the difficulty or inability to fly and/or walk. They died after 5, 6, and 8 days, respectively. At necropsy, muscles affected in all cases were those from the legs, and these were diffusely pale and dull, with a soft friable texture. Microscopically these muscles had multiple foci of myofiber fragmentation, loss of striation, and necrosis; a mononuclear cell infiltrate was observed in muscle from two birds. These findings suggest the little bustard is susceptible to capture myopathy and that caution should be exercised during its capture and handling.     

Fallow management for steppe bird conservation: the impact of cultural practices on vegetation structure and food resources

The potential of fallow lands to favor farmland bird conservation is widely recognized. Since fallows provide key resources for birds within the agricultural matrix, such as nesting sites, shelter and forage, complete understanding of the effect of field-management strategies on vegetation structure and food is essential to fulfill bird requirements and improve habitat management. In this study we experimentally compare the most common field practices (ploughing, shredding, herbicide application and cover cropping) on fallow lands by assessing the resources they provide for birds in terms of vegetation structure and food resources (leaf and seed availability), as well as the economic costs of their implementation. Fallow management treatments are ranked for six target species in a lowland area of the north-eastern Iberian Peninsula, according to the available information on their requirements. The different agronomic practices offer various quantities and types of resources, highlighting the importance of fallow management in bird conservation. Shredding and early herbicide application (February) are estimated to be good practices for Little Bustard (Tetrax tetrax) and Calandra Lark (Melanocorypha calandra), providing both favorable habitat and foraging conditions, while being economical. Meanwhile, superficial tillage in spring is found to be optimum for the rest of the species tested, despite being among the poorest food providers. Alternating patches of the best treatments would improve the effectiveness of agri-environmental schemes by maximizing the harboring habitat for the endangered species.     

Intraspecific and interspecific competition induces density‐dependent habitat niche shifts in an endangered steppe bird

Interspecific competition is a dominant force in animal communities that induces niche shifts in ecological and evolutionary time. If competition occurs, niche expansion can be expected when the competitor disappears because resources previously inaccessible due to competitive constraints can then be exploited (i.e., ecological release). Here, we aimed to determine the potential effects of interspecific competition between the little bustard (Tetrax tetrax) and the great bustard (Otis tarda) using a multidimensional niche approach with habitat distribution data. We explored whether the degree of niche overlap between the species was a density‐dependent function of interspecific competition. We then looked for evidences of ecological release by comparing measures of niche breadth and position of the little bustard between allopatric and sympatric situations. Furthermore, we evaluated whether niche shifts could depend not only on the presence of great bustard but also on the density of little and great bustards. The habitat niches of these bustard species partially overlapped when co‐occurring, but we found no relationship between degree of overlap and great bustard density. In the presence of the competitor, little bustard's niche was displaced toward increased use of the species' primary habitat. Little bustard's niche breadth decreased proportionally with great bustard density in sympatric sites, in consistence with theory. Overall, our results suggest that density‐dependent variation in little bustard's niche is the outcome of interspecific competition with the great bustard. The use of computational tools like kernel density estimators to obtain multidimensional niches should bring novel insights on how species' ecological niches behave under the effects of interspecific competition in ecological communities.     

Adjustments of water use efficiency by stomatal regulation during drought and recovery in the drought-adapted Vitis hybrid Richter-110 (V. berlandieri x V. rupestris)

The hybrid Richter-110 (Vitis berlandieri x Vitis rupestris) (R-110) has the reputation of being a genotype strongly adapted to drought. A study was performed with plants of R-110 subjected to water withholding followed by re-watering. The goal was to analyze how stomatal conductance (g(s)) is regulated with respect to different physiological variables under water stress and recovery, as well as how water stress affects adjustments of water use efficiency (WUE) at the leaf level. Water stress induced a substantial stomatal closure and an increase in WUE, which persisted many days after re-watering. The g(s) during water stress was mainly related to the content of ABA in the xylem and partly related to plant hydraulic conductivity but not to leaf water potential. By contrast, low g(s) during re-watering did not correlate with ABA contents and was only related to a sustained decreased hydraulic conductivity. In addition to a complex physiological regulation of stomatal closure, g(s) and rate of transpiration (E) were strongly affected by leaf-to-air vapor pressure deficit (VPD) in a way dependent of the treatment. Interestingly, E increased with increasing VPD in control plants, but decreased with increasing VPD in severely stressed plants. All together, the fine stomatal regulation in R-110 resulted in very high WUE at the leaf level. This genotype is revealed to be very interesting for further studies on the physiological mechanisms leading to regulation of stomatal responsiveness and WUE in response to drought.