[Intraflagellar transport is essential for spermiogenesis].

Intra flagellar transport (IFT) is an evolutionarily conserved mechanism thought to be essential for the assembly and maintenance of most eukaryotic cilia and flagella. Development of the sperm tail axoneme resembles the cilia formation, which is organized by intraflagellar transport (IFT). Of all mammalian cells, sperm have the longest motile cilia, but few studies are reported on the role of IFT in the formation of sperm flagella and the mechanisms of IFT in spermiogenesis. This article focuses on the role of IFT in spermatogenesis and the importance of IFT in male fertility.

[The role of SPAG6/SPINK2 protein complex in the formation of sperm acrosome in mice].

OBJECTIVE: To explore the expression and regulatory function of sperm-associated antigen 6 (SPAG6) in the formation of the sperm acrosome in mice. METHODS: The expression of SPAG6 during the first wave of spermatogenesis on postnatal days (PN) 8, 12, 16, 20, 24, 28, 30 and 35 was examined by Western blot and the localization of SPAG6 in the testicular germ cells was determined by immunofluorescence. The expression plasmids of SPAG6 and serine protease inhibitor Kazal-type 2 (SPINK2) were constructed, the interaction between SPAG6 and SPINK2 in the AH109 and CHO cells examined by yeast two-hybrid and co-localization assays, and the expression and localization of SPINK2 in the testicular germ cells of the SPAG6-knockout (SPAG6 KO) mice detected by immunofluorescence. RESULTS: SPAG6 was highly expressed between PN 16 and 28 and localized in the acrosome of the round spermatids. Yeast two-hybrid assay showed the growth of SPAG6 and SPINK2 in the selective culture medium SD/-Leu/-Trp/-His, and the transfection of the CHO cells revealed the co-localization of SPAG6 and SPINK2 around the nuclei. The expression and acrosomal localization of SPINK2 were not found in the testicular germ cells of the SPAG6-KO mice. CONCLUSIONS: SPAG6 interacts with SPINK2 and probably participates in the formation of the sperm acrosome by stabilizing the expression of SPINK2 during spermatogenesis.

Near-real-time global gridded daily CO2 emissions 2021.

We present a near-real-time global gridded daily CO2 emissions dataset (GRACED) throughout 2021. GRACED provides gridded CO2 emissions at a 0.1° × 0.1° spatial resolution and 1-day temporal resolution from cement production and fossil fuel combustion over seven sectors, including industry, power, residential consumption, ground transportation, international aviation, domestic aviation, and international shipping. GRACED is prepared from the near-real-time daily national CO2 emissions estimates (Carbon Monitor), multi-source spatial activity data emissions and satellite NO2 data for time variations of those spatial activity data. GRACED provides the most timely overview of emissions distribution changes, which enables more accurate and timely identification of when and where fossil CO2 emissions have rebounded and decreased. Uncertainty analysis of GRACED gives a grid-level two-sigma uncertainty of value of ±19.9% in 2021, indicating the reliability of GRACED was not sacrificed for the sake of higher spatiotemporal resolution that GRACED provides. Continuing to update GRACED in a timely manner could help policymakers monitor energy and climate policies' effectiveness and make adjustments quickly.

Sulfur transformation and bacterial community dynamics in both desulfurization-denitrification biofilm and suspended activated sludge.

Types of microbial aggregates have essential effects on bacterial communities' characteristics, thus affecting the pollutants removal. An up-flow biofilm reactor was used to study the different performances of S2-/NO2- removal and functional genes in suspended sludge and biofilms. The metabolic pathways of sulfurous and nitrogenous pollutants in the desulfurization-denitrification process were proposed. The results showed that S0 formation dominated the reactor with a high S2- concentration. Autotrophic Sulfurovum responsible for S2-/S0 oxidation was the only dominant bacteria in suspended sludge. Heterotrophic Desulfocapsa responsible for SO42- reduction coexisted with Sulfurovum and dominated in biofilms. S2- oxidation to S0 was catalyzed via fccA/B and sqr genes in suspended sludge. S32-/S0 oxidation to SO42- was catalyzed via dsrA/B gene in biofilms. SO42- and NO2- were removed via the dissimilatory sulfate reduction and denitrification pathway, respectively. This work provides a fundamental and practical basis for optimizing suspended sludge/biofilm systems for S2-/NO2- removal.

Near-real-time global gridded daily CO2 emissions.

Precise and high-resolution carbon dioxide (CO2) emission data is of great importance in achieving carbon neutrality around the world. Here we present for the first time the near-real-time Global Gridded Daily CO2 Emissions Dataset (GRACED) from fossil fuel and cement production with a global spatial resolution of 0.1° by 0.1° and a temporal resolution of 1 day. Gridded fossil emissions are computed for different sectors based on the daily national CO2 emissions from near-real-time dataset (Carbon Monitor), the spatial patterns of point source emission dataset Global Energy Infrastructure Emissions Database (GID), Emission Database for Global Atmospheric Research (EDGAR), and spatiotemporal patters of satellite nitrogen dioxide (NO2) retrievals. Our study on the global CO2 emissions responds to the growing and urgent need for high-quality, fine-grained, near-real-time CO2 emissions estimates to support global emissions monitoring across various spatial scales. We show the spatial patterns of emission changes for power, industry, residential consumption, ground transportation, domestic and international aviation, and international shipping sectors from January 1, 2019, to December 31, 2020. This gives thorough insights into the relative contributions from each sector. Furthermore, it provides the most up-to-date and fine-grained overview of where and when fossil CO2 emissions have decreased and rebounded in response to emergencies (e.g., coronavirus disease 2019 [COVID-19]) and other disturbances of human activities of any previously published dataset. As the world recovers from the pandemic and decarbonizes its energy systems, regular updates of this dataset will enable policymakers to more closely monitor the effectiveness of climate and energy policies and quickly adapt.

The adverse effect of TCIPP and TCEP on neurodevelopment of zebrafish embryos/larvae.

Tris (1-chloro-2-propyl) phosphate (TCIPP) and tris (2-chloroethyl)phosphate (TCEP) are two widely used chlorinated organophosphate flame retardants (ClOPFRs), and have been frequently detected in various environmental media. Concern is now growing whether TCIPP and TCEP can cause neurotoxicity since they have similar chemical structure with organophosphorus pesticide. Therefore, in this study, zebrafish embryos (2-120 h post-fertilization [hpf]) were exposed to TCIPP or TCEP (0, 100, 500 or 2500 µg/L) or a model neurotoxicant, chlorpyrifos (CPF, 100 µg/L) to investigate the adverse effects and possible mechanisms of TCIPP and TCEP on neurodevelopment. Our results showed that CPF exposure resulted in developmental toxicity including decreased hatching, survival rates and increased malformation rates (e.g., spinal curvature) as well as behavior changes such as decreased locomotive activity in dark stimulation. In contrast, TCIPP and TCEP showed no significant effects on developmental parameters, but caused similar effects on locomotive activity at high concentration, indicating that although not as potent as CPF, TCIPP and TCEP may still cause adverse effects on neurodevelopment. Furthermore, our results suggest that TCIPP and TCEP showed no effects on acetylcholine content or AChE activity, which were considered as the main targets of CPF. However, TCIPP and TCEP exposure can significantly down-regulate the expression of selected genes and proteins related to neurodevelopment (e.g., mbp, syn2a, and α1-tubulin) similar as CPF did. Besides that, TCIPP and TCEP can also affect the transcription of shha and gap43, which were not affected by CPF, pointing out a complex mechanism underlying TCIPP and TCEP's neurodevelopmental toxicity. Overall, our results demonstrated that TCEP and TCIPP may have adverse effect on the neurodevelopment of zebrafish embryos/larvae, but the underlying mechanism is not via the inhibition of acetyl cholinesterase activity.