•C sequestration and mineralization showed negative correlations at 0–10 cm layer.•Macro-aggregates (>2 mm) were the main carriers of SOC sequestration.•No-till improved C stock in macro-aggregates ...due to less mineralization.•Straw returning increased C concentration due to low mineralization quotient.
Understanding the process of soil organic carbon (SOC) sequestration and mineralization in aggregates is pertinent to mitigate climate change and minimize risks of soil degradation. Thus, soil samples were obtained after a 10-year field experiment to identify the influences of tillage on aggregate-associated SOC sequestration and mineralization in the North China Plain (NCP). Four tillage practices investigated were as follows: no-till with straw retention (NTS, conservation tillage), rotary tillage with straw incorporation (RTS), conventional tillage with straw incorporation (CTS), and conventional tillage with straw removal (CT). Significantly negative correlations were observed between SOC concentration and potentially mineralized carbon in aggregates under different treatments for the 0–10 cm soil layer. The large macro-aggregates (>2 mm) with the highest proportion of size distribution represented the major pool of SOC stock (47.3–51.2%) and mineralization amount (38.2–43.6%) in the 0–30 cm layer, followed by that in the small macro-aggregates (0.25–2 mm), regardless of tillage practices. However, the mineralization quotient (mineralization per unit SOC concentration) of macro-aggregates (>0.25 mm) was lower than that for the other size classes. The NTS enhanced the macro-aggregate formation in the 0–20 cm layer and associated SOC concentration in the 0–10 cm layer. Furthermore, NTS decreased total potential mineralization in the 0–30 cm layer compared with the other tillage practices, attributed to decrease in the large macro-aggregates (30.0–51.4%) with low particulate organic carbon (POC) concentration. The NTS with low straw inputs had higher incremental efficiency with straw incorporation than that in the RTS and CTS by 45.0% and 13.5%, respectively (P < 0.05). Overall, the higher proportion of macro-aggregates recorded under NTS decreased carbon mineralization, and consequently, increased incremental efficiency with straw incorporation, and improved SOC sequestration in the surface soil layer in the NCP.
Primordial follicle assembly in the mouse occurs during perinatal ages and largely determines the ovarian reserve that will be available to support the reproductive life span. The development of ...primordial follicles is controlled by a complex network of interactions between oocytes and ovarian somatic cells that remain poorly understood. In the present research, using single-cell RNA sequencing performed over a time series on murine ovaries, coupled with several bioinformatics analyses, the complete dynamic genetic programs of germ and granulosa cells from E16.5 to postnatal day (PD) 3 were reported. Along with confirming the previously reported expression of genes by germ cells and granulosa cells, our analyses identified 5 distinct cell clusters associated with germ cells and 6 with granulosa cells. Consequently, several new genes expressed at significant levels at each investigated stage were assigned. By building single-cell pseudotemporal trajectories, 3 states and 1 branch point of fate transition for the germ cells were revealed, as well as for the granulosa cells. Moreover, Gene Ontology (GO) term enrichment enabled identification of the biological process most represented in germ cells and granulosa cells or common to both cell types at each specific stage, and the interactions of germ cells and granulosa cells basing on known and novel pathway were presented. Finally, by using single-cell regulatory network inference and clustering (SCENIC) algorithm, we were able to establish a network of regulons that can be postulated as likely candidates for sustaining germ cell-specific transcription programs throughout the period of investigation. Above all, this study provides the whole transcriptome landscape of ovarian cells and unearths new insights during primordial follicle assembly in mice.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Severe oligozoospermia (SO) is an important cause of male infertility. Its etiology and pathogenesis are associated with genetic abnormalities; however, the genetic causes of the majority of ...idiopathic human SO remain unclear. Here, we report a homozygous splice‐site mutation in M1AP (meiosis 1 associated protein; NM_138804, c.1435‐1G>A) observed in a patient with SO from a consanguineous Han Chinese family. His parents and fertile brother were heterozygous for the mutation. The splice variant led to a lack of M1AP protein in the patient's spermatozoa. Ultrastructural and immunostaining analyses of patient's spermatozoa showed highly aberrant swollen mitochondrial sheaths with normal axonemal structures. Subsequent mutation screening identified three additional heterozygous M1AP variants in 4/243 subjects with idiopathic SO, but no M1AP variants among 223 fertile subjects. Additionally, a previously study reported that M1ap knock‐out mice exhibited SO due to meiotic arrest. Hence, our findings indicate that M1AP mutation might represent novel genetic alteration responsible for human SO.
(A) Pedigree and Sanger sequencing analysis of the family. (B) The effect of the splice‐split variant in the M1AP gene. (C) Aberrant swollen mitochondrial sheath in sperm flagella of M1AP mutant spermatozoa.
Black locust (Robinia pseudoacacia) is widely planted throughout semiarid and subhumid regions of the Loess Plateau of China. Determining the changes in transpiration of this species in different ...climatic areas is important for revealing the acclimation mechanism of black locust and developing suitable forest management practices, particularly in the context of global climate change. Here, sap flow and canopy conductance of black locust plantation trees in semiarid (Yan’an) and subhumid (Yongshou) sites were quantified using Granier-type thermal dissipation probes and concurrent environmental observations from 2012 to 2017. Several physiological parameters were measured throughout the growing season. The results showed that sap flow was correlated with phenological factors across seasons within a year. However, interannual changes in sap flow were affected mainly by the reference evapotranspiration (ET0) at the Yongshou site, and jointly by precipitation (P), soil water content, and P/ET0 at the Yan’an site. Sap flow response to meteorological factors showed less discrepancy between pre- and post-rainfall periods at the Yan’an site. Moreover, canopy conductance fluctuated less with a wider range of vapor pressure deficit (VPD) and the slope of canopy resistance as a function of VPD was lower, indicating relatively lower sensitivity of stomatal conductance to environmental factors in Yan’an site. Physiological parameters, except for predawn leaf water potential, were significantly different between the two sites. The results suggested that black locust tended to reduce transpiration, modify leaf morphology, and improve water use efficiency to enhance its adaptability to the dryer site. The species changes stomatal regulation characteristics and general growth rate to acclimatize to distinct water habitats.
•Sap flow characteristics of black locust differ between semiarid and subhumid sites.•Dominant environmental factors controlling transpiration varied with habitats.•Adaptability and responses to long-term and short-term drought are different.•Longterm soil water shortage weakened stomatal regulation and growth.•Future intensified drought potentially threatens the plantation stability.
One biosynthetic gene cluster (BGC) usually governs the biosynthesis of a series of compounds exhibiting either the same or similar molecular scaffolds. Reported here is a multiplex activation ...strategy to awaken a cryptic BGC associated with tetracycline polyketides, resulting in the discovery of compounds having different core structures. By constitutively expressing a positive regulator gene in tandem mode, a single BGC directed the biosynthesis of eight aromatic polyketides with two types of frameworks, two pentacyclic isomers and six glycosylated tetracyclines. The proposed biosynthetic pathway, based on systematic gene inactivation and identification of intermediates, employs two sets of tailoring enzymes with a branching point from the same intermediate. These findings not only provide new insights into the role of tailoring enzymes in the diversification of polyketides, but also highlight a reliable strategy for genome mining of natural products.
Breaking the silence: A silent gene cluster was engaged by the expression of a positive regulator gene in tandem mode, directing the biosynthesis of eight aromatic polyketides. These polyketides comprise two different frameworks, two pentacyclic isomers (1 and 2) and six glycosylated tetracyclines (3–8), which are proposed to arise from divergent pathways originating from a common intermediate.
Five new physalins, including a novel 1,10-seco one, physalin V (1), a tricarboxylic acid cycle one, physalin VIII (5), a rare 11,15-cyclo one, physalin IX (6), and two new ones, physalins VI (2) and ...VII (4) were isolated from stems and leaves of Physalis angulata together with eleven known analogues (3 and 7-16). Their structures were established by MS, IR, UV, and NMR spectroscopic analysis, together with the X-ray diffraction analysis of neophysalin, physalin P (12), and the structure of physalin D
(3) has been revised here. These isolated compounds were evaluated for their antiproliferative activities against human cancer cells (C4-2B, 22Rv1, 786-O, A-498, ACHN, and A375-S2) and inhibitory effects on nitric oxide production. Compounds 9 and 10 showed antiproliferative activities against all tested human cancer cells with IC
values of 0.24-3.17 μM. Compounds 1, 3, 4, 9, 10, 13, 14, and 16 exhibited inhibitory activities against NO production. The IC
values of compounds 9, 10, 13, and 16 were between 0.32 and 4.03 μM, while compounds 1, 3, 4, and 14 had IC
values of 12.83-34.19 μM. Herein, plausible biosynthetic pathways for rare structures 1 and 6 and structure-activity relationships on the inhibition of NO production for all isolated compounds are discussed.
A new double-stranded chain manganese complex has been synthesized and structurally characterized, in which 3, 5, 6-tcpa− ligand adopts a new coordination mode of bidentate bridging-μ2. Magnetic ...studies reveal that it exhibits antiferromagnetic coupling behavior.
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•A new double-stranded chain manganese 1 complex containing 3, 5, 6-Htcpa was described.•The 3, 5, 6-tcpa− ligand adopts a new coordination mode of bidentate bridging-μ2 in 1.•The crystal packing of 1 contain π⋯π stacking and Cl⋯Cl halogen bonds interactions.•The magnetic properties for 1 have been discussed.
A new coordination polymer Mn(3, 5, 6-tcpa)2(2, 2′-bipy)n (1) has been synthesized by the hydrothermal reaction of manganese sulfate hydrate with 3, 5, 6-trichloropyridine-2-oxyacetic acid (3, 5, 6-Htcpa) and 2, 2′-bipyridine (2, 2′-bipy) coligands. The X-ray single-crystal diffraction analysis shows that the MnII center is in deformed octahedral geometry bonded by two pyridyl nitrogen atoms of 2, 2′-bipy molecule and four carboxy oxygen atoms of four different 3, 5, 6-tcpa− ligands. The 3, 5, 6-tcpa− anions play as bidentate bridging-μ2 linkers and connect neighbouring MnII ions together to form the 1D double-stranded chain structure of 1, which displays interesting chair form Mn2(COO)2 eight-membered rings. 1 is further assembled into 3D network by the co-effects of π⋯π stacking and Cl⋯Cl halogen bonds interactions. In addition, the magnetic characterizations indicated weak antiferromagnetic coupling between MnII centers for 1.
Knee injury is known as a frequently occurred damage related to sports, which may affect the function of cartilage. This study aims to explore whether Insulin‐like growth factor 1 (IGF‐1) and bone ...morphogenetic protein‐7 (BMP‐7)‐modified bone‐marrow mesenchymal stem cells (BMSCs) affect the repair of cartilage damage found in the knee. Primarily, BMSCs were treated with a series of pEGFP‐C1, IGF‐1, and BMP‐7, followed by determination of IGF‐1 and BMP‐7 expression. A rabbit cartilage defect model was also established. Afterfward, cell morphology, viability, cartilage damage repair effect, and expression of collagen I and collagen II at the 6th and the 12th week were measured. BMSCs treated with pEGFP‐C1/IGF‐1, pEGFP‐C1/BMP‐7, and pEGFP‐C1/BMP‐7‐IGF‐1 exhibited elevated expression of BMP‐7 and IGF‐1. Besides, BMSCs in the P10 generation displayed decreased cell proliferation. Moreover, BMSCs treated with IGF‐1, BMP‐7, and IGF‐1‐BMP‐7 showed reduced histological score and collagen I expression while elevated collagen II expression, as well as better repair effect, especially in those treated with IGF‐1‐BMP‐7. Collectively, these results demonstrated a synergistic effect of IGF‐1 and BMP‐7 on the BMSC chondrogenic differentiation on the articular cartilage damage repair in the rabbit knees, highlighting its therapeutic potential for the treatment of articular cartilage damage.
These results demonstrate that IGF‐1 and BMP‐7 gene modification may contribute to the repair of cartilage damage in the knee by BMSCs.
Naturally occurring naphthoquinones, usually in forms of botanical extracts, have been implicated with human life since ancient time, far earlier than their isolation and identification in modern ...era. The long use history of naphthoquinones has witnessed their functional shift from the original purposes as dyes and ornaments toward medicinal benefits. Hitherto, numerous studies have been carried out to elucidate the pharmacological profile of both natural and artificial naphthoquinones. A number of entities have been identified with promising therapeutic potential. Apart from the traditional effects of wound healing, anti‐inflammatory, hemostatic, antifertility, insecticidal and antimicrobial, etc., the anticancer potential of naphthoquinones either in combination with other treatment approaches or on their own is being more and more realized. The molecular mechanisms of naphthoquinones in cells mainly fall into two categories as inducing oxidant stress by ROS (reactive oxygen species) generation and directly interacting with traditional therapeutic targets in a non‐oxidant mechanism. Based on this knowledge, optimized agents with naphthoquinones scaffold have been acquired and further tested. Hereby, we summarize the explored biological mechanisms of naphthoquinones in cells and review the application perspective of promising naphthoquinones in cancer therapies.
The explored biological mechanisms of naphthoquinones in cellular and the application perspective of promising naphthoquinones in cancer therapies were reviewed.
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