Distribution of Brachionidae (Rotifera,Monogononta) in Inner Mongolian Waters

Two-hundred and fourty-six freshwater and saline-alkaline waters in Inner Mongolia, P.R. China were surveyed for Brachionidae. Twenty-nine brachionid morphospecies (33 taxa) are recorded, four are new to China. Some data on their distribution, and comments on selected taxa are provided. Brachionus asplanchnoides (stat.nov.) is reinstated at the morphospecies level. We suggest that this taxon may be used in aquaculture, considering that, by its large size, it extends the size range of brackish-water Rotifera potentially available as food for fish larvae.     

Rotifera from Peat-Swamps in Phuket Province,Thailand, with the Description of a New Colurella Bory de St. Vincent

The rotifer fauna of three peat-swamps in Phuket province, southern Thailand was investigated. A total of 77 species is identified, 12 of which are new to Thailand. A new species, Colurella sanoamuangae n. sp., is described. The zoogeography of the registered species is discussed.     

Observational constraints reduce model spread but not uncertainty in global wetland methane emission estimates

The recent rise in atmospheric methane (CH₄) concentrations accelerates climate change and offsets mitigation efforts. Although wetlands are the largest natural CH₄ source, estimates of global wetland CH₄ emissions vary widely among approaches taken by bottom-up (BU) process-based biogeochemical models and top-down (TD) atmospheric inversion methods. Here, we integrate in situ measurements, multi-model ensembles, and a machine learning upscaling product into the International Land Model Benchmarking system to examine the relationship between wetland CH₄ emission estimates and model performance. We find that using better-performing models identified by observational constraints reduces the spread of wetland CH₄ emission estimates by 62% and 39% for BU- and TD-based approaches, respectively. However, global BU and TD CH₄ emission estimate discrepancies increased by about 15% (from 31 to 36 TgCH₄ year⁻¹) when the top 20% models were used, although we consider this result moderately uncertain given the unevenly distributed global observations. Our analyses demonstrate that model performance ranking is subject to benchmark selection due to large inter-site variability, highlighting the importance of expanding coverage of benchmark sites to diverse environmental conditions. We encourage future development of wetland CH₄ models to move beyond static benchmarking and focus on evaluating site-specific and ecosystem-specific variabilities inferred from observations.     

Cell Walls of Phaseolus vulgaris Leaves Contain the Azocoll-Digesting Proteinase

The leaves of Phaseolus vulgaris L. cv Greensleeves contain an endopeptidase with a pH optimum of 9.0 and an isoelectric point between 10.0 and 10.5. This endopeptidase is the only abundant Azocoll-digesting proteinase in the leaves. The activity of this enzyme is highest in immature leaves and declines as the leaf matures and senesces. Enzymically isolated protoplasts contain very little of this proteinase. The proteinase can be recovered readily from the extracellular fluid obtained by gentle centrifugation of leaf strips vacuum-infiltrated with a buffered solution. These experiments indicate that the Azocoll digesting proteinase is located in the periplasmic space and/or the cell wall.     

Aquabacter spiritensis,gen. nov., sp. nov. an aerobic,gas-vacuolate aquatic bacterium

A gram-negative, rod-shaped, gas-vacuolate, aerobic, heterotrophic bacterium was isolated from Spirit Lake, Washington. It was further characterized by phase-contrast and electron microscopy and phenotypic tests. The isolate does not utilize carbohydrates. Deoxyribonucleic acid-ribosomal ribonucleic acid (rRNA) hybridizations showed that this bacterium is a member of rRNA superfamily IV where it occupies a separate position on the Azorhizobium caulinodans rRNA sub-branch which, is part of an rRNA cluster containing also the Beijerinckia, the Bradyrhizobium japonicum and the Rhodopseudomonas palustris sub-branches. Its relationship to other gas-vacuolated genera within rRNA superfamily IV is discussed. A new genus Aquabacter with one species Aquabacter spiritensis is proposed. The type strain is strain SPL-1 (=ATCC 43981=LMG 8611).     

Physiological and Cellular Responses Caused by RNAi- Mediated Suppression of Snf7 Orthologue in Western Corn Rootworm (Diabrotica virgifera virgifera) Larvae

Ingestion of double stranded RNA (dsRNA) has been previously demonstrated to be effective in triggering RNA interference (RNAi) in western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte), providing potential novel opportunities for insect pest control. The putative Snf7 homolog of WCR (DvSnf7) has previously been shown to be an effective RNAi target for insect control, as DvSnf7 RNAi leads to lethality of WCR larvae. Snf7 functions as a part of the ESCRT (Endosomal Sorting Complex Required for Transport) pathway which plays a crucial role in cellular housekeeping by internalization, transport, sorting and lysosomal degradation of transmembrane proteins. To understand the effects that lead to death of WCR larvae by DvSnf7 RNAi, we examined some of the distinct cellular processes associated with ESCRT functions such as de-ubiquitination of proteins and autophagy. Our data indicate that ubiquitinated proteins accumulate in DvSnf7 dsRNA-fed larval tissues and that the autophagy process seems to be impaired. These findings suggest that the malfunctioning of these cellular processes in both midgut and fat body tissues triggered by DvSnf7 RNAi were the main effects leading to the death of WCR. This study also illustrates that Snf7 is an essential gene in WCR and its functions are consistent with biological functions described for other eukaryotes.     

Noninvasive Doppler-derived myocardial performance index in rats with myocardial infarction: validation and correlation by conductance catheter

The rodent model of myocardial infarction (MI) is extensively used in heart failure studies. However, long-term follow-up of echocardiographic left ventricular (LV) function parameters such as the myocardial performance index (MPI) and its ratio with the fractional shortening (LVFS/MPI) has not been validated in conjunction with invasive indexes, such as those derived from the conductance catheter (CC). Sprague-Dawley rats with left anterior descending coronary artery ligation (MI group, n = 9) were compared with a sham-operated control group (n = 10) without MI. Transthoracic echocardiography (TTE) was performed every 2 wk over an 8-wk period, after which classic TTE parameters, especially MPI and LVFS/MPI, were compared with invasive indexes obtained by using a CC. Serial TTE data showed significant alterations in the majority of the noninvasive functional and structural parameters (classic and novel) studied in the presence of MI. Both MPI and LVFS/MPI significantly (P < 0.05 for all reported values) correlated with body weight (r = -0.58 and 0.76 for MPI and LVFS/MPI, respectively), preload recruitable stroke work (r = -0.61 and 0.63), LV end-diastolic pressure (LVEDP) (r = 0.82 and -0.80), end-diastolic volume (r = 0.61 and -0.58), and end-systolic volume (r = 0.46 and -0.48). Forward stepwise linear regression analysis revealed that, of all variables tested, LVEDP was the only independent determinant of MPI (r = 0.84) and LVFS/MPI (r = 0.83). We conclude that MPI and LVFS/MPI correlate strongly and better than the classic noninvasive TTE parameters with established, invasively assessed indexes of contractility, preload, and volumetry. These findings support the use of these two new noninvasive indexes for long-term analysis of the post-MI LV remodeling.     

Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid (Simochromis pleurospilus). The expression levels of one of them, the growth hormone receptor (GHR), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis.