Numerical simulation research on thermal insulation performance of composite heat-insulation zone structure in hydrothermal high-temperature mine.

In hydrothermal high-temperature abnormal mines, the composite heat-insulation zone structure, formed through a combination of guniting and grouting, serves to mitigate heat dissipation from the surrounding rock into the airflow. To comprehensively understand the thermal insulation performance of the composite heat-insulation zone structure, this study employs numerical simulation to analyze the following aspects: the variation in the temperature field within the surrounding rock of the roadway without insulation, the influence of structural parameters of the composite heat-insulation zone on temperature distribution in the surrounding rock of the roadway, and the thermal insulation effectiveness of the composite heat-insulation zone with varying structures. The findings indicate that the temperature distribution within the surrounding rock of the roadway lacking a heat-insulation zone is relatively uniform. However, as ventilation time extends, the heat regulation zone within the surrounding rock gradually extends deeper, ultimately forming an elliptical cooling area. The composite heat-insulation zone structure effectively mitigates heat transfer from deeper surrounding rock to the roadway wall, consequently altering the scope of the roadway's heat regulation zone. Enhancing the thermal insulation performance of the composite heat-insulation zone structure can be achieved by increasing the thickness of the thermal insulation layer, adjusting grouting rate and depth, and reducing the thermal conductivity of insulation materials. The thermal insulation effectiveness of the thermal insulation layer surpasses that of the grouting layer, with its performance primarily influenced by the thermal conductivity of the materials used. Simulation results demonstrate that the composite heat-insulation zone structure reduces the maximum heat flux on the roadway wall from 47.4 to 37.7 W/m2, resulting in a 20% reduction in heat transfer from deeper surrounding rock. These findings offer valuable insights for implementing thermal insulation techniques in hydrothermal high-temperature anomaly mines.

A modified laser ablation-isotope ratio mass spectrometry method for in situ analysis of sulfur isotope composition of sulfides.

RATIONALE: A novel laser ablation-isotope ratio mass spectrometry (LA-IRMS) method for in situ analysis of sulfur isotopes in sulfides has been developed. Instead of the in situ reaction applied by the traditional laser microprobe, the analyte gas preparation in this method is separated temporally and spatially from the LA, resulting in improved precision and accuracy. METHODS: Our LA-IRMS system combines an ultraviolet LA system, an elemental analyzer (EA), a custom-built cryogenic concentration system, a continuous-flow interface, and an IRMS. The sulfide aerosol particles generated from LA were transferred by a helium carrier gas from the ablation cell into the reaction tube and were then converted into SO2 . Subsequently, SO2 was enriched in two cold traps and was finally introduced into the ion source of the IRMS through the continuous-flow interface. RESULTS: We measured three synthetic and four natural sulfide reference materials to test the performance of this method. Precisions of ±0.25‰-±0.48‰ and ±0.32‰-±0.64‰ (1SD, n = 5) for δ34 S values of synthetic and natural sulfide standards can be obtained for spot sizes ranging from 64 to 80 µm. Measured values and their recommended values showed a good linear relationship (R2 within 0.998 and 0.9995) with the slope of approaching unity (within 1.0509 and 1.1313). CONCLUSIONS: Data from the measurement of reference materials showed that the precision and accuracy of our method were satisfactory. This method is a powerful tool for in situ sulfur isotope measurement of sulfides and can be further applied to in situ carbon and oxygen isotope analyses.

Integration of transcriptome and whole-genome re-sequencing analyses reveal growth-related candidate genes in Procambarus clarkii.

Growth is a crucial economic trait of all aquaculture species. It is important to explore the molecular regulation on growth, which could help improve the growth rate of species. Mining the growth-related genes is the foundation for revealing its molecular regulation on growth. Presently, the molecular regulation of growth in Procambarus clarkii is not clear, and the study on exploring growth-related genes is limited. In this study, RNA-Seq was used to compare gene expression profiles of the individuals with different growth rates involved in four groups including Big Male (BM), Big Female (BF), Small male (SM), and Small Female (SF) from one P. clarkii family, and the analyses were performed in combination with sex. Meanwhile, whole-genome resequencing data was used to get growth-specific SNP (Single Nucleotide Polymorphism)/InDel (Insertion/Deletion) sites information. Totally, we identified 16,127 genes, of which 9065 were successfully annotated in the GO database. Among these, 1328 DEGs were identified in BM vs. SM, with 357 up-regulated and 971 down-regulated. Additionally, 3507 DEGs were identified in BF vs. SF, with 241 up-regulated and 3266 down-regulated. 96 DEGs were up-regulated and 820 DEGs were down-regulated in Growth-related Group. The expression levels of nine DEGs were validated by RT-qPCR to verify the analysis results of sequencing. 684,040 growth-related SNPs and 182,050 growth-related InDels were obtained after screened. These findings provide candidate growth-related genes and growth-specific SNP/InDel sites for regulation of growth traits in P. clarkii, and new insight into the molecular regulation of P. clarkii growth.

Analysis of mRNA and MicroRNA Expression Profiles of Nervous Tissues and Reproductive Tissues in Male Procambarus clarkii After Silencing IAG.

The insulin-like androgenic gland hormone gene (IAG), primarily expressed in the androgenic gland (AG), plays a crucial role in controlling male sex differentiation and maintaining male secondary sexual characteristics in decapods. In this study, we investigated the mRNA and microRNA expression profiles of male Procambarus clarkii to understand the transcriptomic regulatory mechanism of IAG after the injection of an efficient siRNA (GsiRNA) designed based on IAG. The results revealed that several differentially expressed genes were enriched in reproduction-related pathways, such as the wnt signaling pathway, MAPK signaling pathway, and GnRH signaling pathway. In the testis (Te), the injection of GsiRNA led to the up-regulation of many ovary-related genes and down-regulation of testis-related genes. Moreover, the brain (Br) and abdominal nerve cord (AN) appeared to be involved in the regulation of IAG, with numerous differentially expressed genes found in Br and AN. Notably, the expression of five neuropeptide genes, Crustacean hyperglycemic hormone, pigment-dispersing hormone, red pigment concentrating hormone precursor, corazonin, and gonadotropin-releasing hormone II receptor isoform X1 in Br/AN, was significantly changed. Additionally, three ovary-related miRNAs (miR-263a, miR-263b, miR-133) highly expressed in Te/AG showed significant up-regulation after GsiRNA injection. Furthermore, the long-term interference of GsiRNA was found to inhibit the development of male external sexual characteristics during the juvenile stage and delay it during the adult stage. This research provides valuable insights into the molecular regulatory mechanism and function of IAG in P. clarkii.

Dietary oregano aqueous extract improves growth performance and intestinal health of broilers through modulating gut microbial compositions.

BACKGROUND: Intestinal health plays a pivotal role in broiler chicken growth. Oregano aqueous extract (OAE) effectively exerts anti-inflammatory and antibacterial effects. However, the protective effects of OAE on intestinal health in broilers and the underlying mechanism remain unclear. This study aimed to investigate the potential effects of OAE on growth performance, the gut microbiota and intestinal health. A total of 840 1-d-old male and female broilers (Arbor Acres) were randomly allocated into 6 groups as follows: basal diet (Con), Con + antibiotics (Anti, colistin sulfate 7 g/kg, roxarsone 35 g/kg), Con + 400, 500, 600 and 700 mg/kg OAE (OAE400, OAE500, OAE600 and OAE700). Subsequently, fermentation in vitro together with oral administration trials were carried out to further assess the function of OAE on intestinal health of broilers. RESULTS: Dietary 700 mg/kg OAE supplementation resulted in an increase (P < 0.05) in body weight and a decrease (P < 0.05) in feed conversion ratio when compared with the control during d 22 to 42 of the trial. OAE addition resulted in lower (P < 0.05) jejunal crypt depth and mRNA expression of IL-4 and IL-10 at d 42. In addition, dietary OAE addition increased the abundance of Firmicutes (P = 0.087) and Lactobacillus (P < 0.05) in the cecum, and increased (P < 0.05) the content of acetic acid and butyric acid. In the in vitro fermentation test, OAE significantly increased (P < 0.05) the abundance of Lactobacillus, decreased (P < 0.05) the abundance of unspecified_Enterobacteriaceae, and increased the content of acetic acid (P < 0.05). In the oral administration trial, higher (P < 0.05) IL-4 expression was found in broilers when oral inoculation with oregano fermentation microorganisms at d 42. And SIgA content in the ileum was significantly increased (P = 0.073) when giving OAE fermentation supernatant. CONCLUSIONS: Dietary OAE addition could maintain intestinal health and improve growth performance through enhancing intestinal mucosal immunity and barrier function mediated by gut microbiota changes.

Inhibition of Wnt activity improves peri-implantation development of somatic cell nuclear transfer embryos.

Somatic cell nuclear transfer (SCNT) can reprogram differentiated somatic cells into totipotency. Although pre-implantation development of SCNT embryos has greatly improved, most SCNT blastocysts are still arrested at the peri-implantation stage, and the underlying mechanism remains elusive. Here, we develop a 3D in vitro culture system for SCNT peri-implantation embryos and discover that persistent Wnt signals block the naïve-to-primed pluripotency transition of epiblasts with aberrant H3K27me3 occupancy, which in turn leads to defects in epiblast transformation events and subsequent implantation failure. Strikingly, manipulating Wnt signals can attenuate the pluripotency transition and H3K27me3 deposition defects in epiblasts and achieve up to a 9-fold increase in cloning efficiency. Finally, single-cell RNA-seq analysis reveals that Wnt inhibition markedly enhances the lineage developmental trajectories of SCNT blastocysts during peri-implantation development. Overall, these findings reveal diminished potentials of SCNT blastocysts for lineage specification and validate a critical peri-implantation barrier for SCNT embryos.

Isolation and characterization of three pairs of verrucosidin epimers from the marine sediment-derived fungus Penicillium cyclopium and configuration revision of penicyrone A and related analogues.

Verrucosidins, a methylated α-pyrone class of polyketides rarely reported upon, have been implicated in one or more neurological diseases. Despite the significance of verrucosidins as neurotoxins, the absolute configurations of most of the derivatives have not been accurately characterized yet. In this study, three pairs of C-9 epimeric verrucosidin derivatives, including the known compounds penicyrones A and B (1a/1b) and 9-O-methylpenicyrones A and B (2a/2b), the new compounds 9-O-ethylpenicyrones A and B (3a/3b), together with the related known derivative verrucosidin (4), were isolated and identified from the culture extract of Penicillium cyclopium SD-413, which was obtained from the marine sediment collected from the East China sea. Their structures were established based on an in-depth analysis of nuclear magnetic resonances (NMR) and mass spectroscopic data. Determination of the absolute configurations of these compounds was accomplished by Mosher's method and time-dependent density functional theory (TDDFT) calculations of electronic circular dichroism (ECD) and optical rotation (OR). The configurational assignment of penicyrone A demonstrated that the previously reported C-6 absolute configuration of verrucosidin derivatives needs to be revised from (6S) to (6R). The 9R/9S epimers of compounds 1-3 were found to exhibit growth inhibition against some pathogenic bacteria, indicating that they have potential as lead compounds for the creation of antimicrobial agents. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-023-00173-2.

Thermal Evolution, Hydrocarbon Generation, and Heat Accumulation of a High Geothermal Coalfield: A Case Study of Pingdingshan Coalfield, China.

As an important energy base in central China, the Pingdingshan coalfield has abundant coal and geothermal resources. The cooperative exploration of coal and geothermal resources is significant for the comprehensive utilization of energy resources. This work collected coal-bearing samples from the Pingdingshan coalfield to investigate the tectono-thermal evolution of a high geothermal coalfield, especially the present geothermal field and hydrocarbon generation model. The geochemical results show that the Shanxi and Taiyuan source rocks have average R o values of 0.88 and 0.97%, respectively, with an average Rock-Eval T max value of 442 °C. Hydrocarbon generation of source rocks started at ∼205 Ma, with the highest rates at ∼170 Ma, reaching the maximum transformation ratio of 40-50% in the middle of the Early Cretaceous. The age and length of apatite fission tracks (AFTs) indicate that coal-bearing strata underwent significant post-depositional annealing after the Late Permian and suggest an abnormal thermal event that occurred in the Late Mesozoic. Meso-Cenozoic thermal event was mainly caused by the plutonic metamorphism of the Early Jurassic and magmatic thermal metamorphism of the Early Cretaceous, achieving a maximum paleotemperature of ∼140 °C. The magmatic thermal event resulted from the intensive post-orogenic extension of the Qinling-Dabie Orogenic Belt caused by the tectonic transition of the North and South China Plates. The present-day high geotemperature of Pingdingshan Coalfield is dominated by the horst structure caused by the regional extension of the basin-mountain system. The Cambrian limestone with a high thermal conductivity underlying coal measure collects deep heat, forming a heat accumulation center of this horst structure with a heat flow of 74 mW/m2 and a maximum temperature of ∼50 °C nowadays.

Bilineage embryo-like structure from EPS cells can produce live mice with tetraploid trophectoderm.

Self-organized blastoids from extended pluripotent stem (EPS) cells possess enormous potential for investigating postimplantation embryo development and related diseases. However, the limited ability of postimplantation development of EPS-blastoids hinders its further application. In this study, single-cell transcriptomic analysis indicated that the "trophectoderm (TE)-like structure" of EPS-blastoids was primarily composed of primitive endoderm (PrE)-related cells instead of TE-related cells. We further identified PrE-like cells in EPS cell culture that contribute to the blastoid formation with TE-like structure. Inhibition of PrE cell differentiation by inhibiting MEK signaling or knockout of Gata6 in EPS cells markedly suppressed EPS-blastoid formation. Furthermore, we demonstrated that blastocyst-like structures reconstituted by combining the EPS-derived bilineage embryo-like structure (BLES) with either tetraploid embryos or tetraploid TE cells could implant normally and develop into live fetuses. In summary, our study reveals that TE improvement is critical for constructing a functional embryo using stem cells in vitro.

Bisabolane sesquiterpene and cyclopentene derivatives from the marine algal-derived endophytic fungus Trichoderma asperellum EN-764.

Four undescribed bisabolane sesquiterpenes and one undescribed cyclopentene derivative, together with one undescribed naturally occurring cyclopentenone derivative, were isolated and identified from the culture of the endophytic fungus Trichoderma asperellum EN-764, which was obtained from the marine red alga Palisada papillosa. Their structures were determined by detailed interpretation of NMR and mass spectroscopic data, while the relative and absolute configurations were unambiguously established based on NOESY experiments, modified Mosher's method, X-ray diffraction, and quantum chemical calculations (ECD and DP4+ probability analysis). The antibacterial activities of the isolated compounds were evaluated, and they exhibited inhibitory activity against some aquatic pathogens with MIC values ranging from 4 to 64 µg/mL.

Impact of Gamification on Consumers' Favorability in Cause-Related Marketing Programs: Between-Subjects Experiments.

BACKGROUND: Successful cause-related marketing (CRM) campaigns can help companies stand out from their competitors; however, CRM may not have pleasant outcomes, even if it receives substantial investment. OBJECTIVE: This research aimed to investigate how gamified CRM projects influence consumers' favorability. METHODS: We introduced 3 different CRM projects in 3 different studies. Every project had 2 versions according to the level of gamification, and participants were randomly assigned into these 2 groups. Additionally, we used a 2 (gamification: lower, higher) 2 (rules presentation: without visual cues, with visual cues) between-subjects design to test the moderation role of rules presentation in gamified CRM projects. RESULTS: In Study 1, we identified that the highly gamified CRM program induces more enjoyment (F1,139=21.11, P<.001) and higher favorability (F1,139=14.57, P<.001). Moreover, we found that enjoyment played a mediation role between gamification and favorability (P<.001) in Study 2. In addition, the results of Study 3 indicated rules presentation in a gamified CRM program can moderate the indirect effect of gamification on favorability via enjoyment (index of the moderated mediation: 95% CI -1.12 to -0.10; for rules presentation with visual cues: 95% CI 0.69 to 1.40; for rules presentation without visual cues: 95% CI 0.08 to 0.83). CONCLUSIONS: Overall, this research contributes to the CRM literature and suggests gamification is an effective way of managing CRM campaigns.

Five new verrucosidin derivatives from Penicillium polonicum, a deep-sea cold-seep sediment isolated fungus.

Five new verrucosidin derivatives, poloncosidins G-K (1-5), were isolated from the deep sea cold-seep sediment-derived fungus Penicillium polonicum CS-252. Their planar structures were elucidated by discreet analysis of the NMR spectroscopic and HRESIMS spectrometric data. The absolute configurations of compounds 1-5 were deduced from the combination of the modified Mosher's method and quantum chemical calculations of their ECD and NMR (with DP4+ probability analysis) data. The antimicrobial activities against several human- and aquatic-pathogenic bacteria of all the isolated compounds were evaluated and the structure-bioactivity relationship was briefly discussed.

Cyclopiumolides A and B, unusual 13-membered macrolides from the deep sea-sourced fungus Penicillium cyclopium SD-413 with antiproliferative activities.

Cyclopiumolides A (1) and B (2), first representatives of two novel biosynthetic related 13-membered macrolides featuring an uncommon verrucosidinol unit condensed with a spiculisporic acidic moiety, were identified from the fungus Penicillium cyclopium SD-413, which was obtained from the deep-sea sediments collected in the East China Sea. The structures of cyclopiumolides A (1) and B (2) were identified on the basis of extensive NMR spectroscopic and mass spectrometric data analysis. Their relative and absolute configurations were determined by quantum mechanical calculations of ECD spectra comparing with that of experimental curves and by DP4 + NMR data calculations. Compounds 1 and 2 exhibited significant cytotoxic potencies against the tumor cell lines SF126, FaDu, and TE-1 with IC50 values ranging from 5.86 to 17.05 µM. The inhibition modes and binding sites of 1 and 2 were inspected using molecular docking simulations.

Two Short Repeats in the 5' Untranslated Region of Insulin-like Androgenic Gland Factor in Procambarus clarkii (PcIAG) That Regulate PcIAG Expression.

Insulin-like androgenic gland factor (IAG) plays an important role in sex manipulation in decapods. Understanding the molecular regulation mechanism of IAG in Procambarus clarkii (PcIAG) is important for realizing its sex control. In this study, the promoter and gene structure of PcIAG, mRNA, and miRNA expression profiles after interfering with two siRNAs synthesized according to the two short repeats in the 5' untranslated regions (5'UTR) of PcIAG were analyzed, and miRNAs of exosomes were investigated to explore the role of repeated sequences with tandem two short repeats located in the 5'UTR of PcIAG isolated from the androgenic gland (AG) in the regulation of IAG expression. The results showed that the repeated sequences of 5'UTR only occurred completely in the cDNA from AG, and the function of the two repeats was different in regulating the expression of PcIAG, in which the Wnt signaling pathway may be involved. Furthermore, we found that six miRNAs including miR-133, miR-193, miR-34, miR-1, miR-100, and let-7 might be involved in the regulation of the expression of PcIAG, wherein miR-133 might directly be related with the repeated sequences of 5'UTR.

A Single-Center Treatment Experience of Gamma Knife Radiosurgery for Optic Pathway Glioma.

Objectives: To determine the independent prognostic factors that will influence the local tumor control/visual acuity (VA) preservation of optic pathway glioma (OPG) after Gamma Knife radiosurgery (GKS) and to optimize the treatment strategy. Methods: A cohort of 52 consecutive OPG patients who underwent GKS in our center between August 1997 and September 2020 was studied retrospectively. Risk factors such as age at GKS, gender, tumor subtype, tumor site, tumor volume, intratumoral cyst formation, and marginal dose were selected for the univariate and multivariate analysis. COX proportional hazard models were built to determine the independent prognostic factors of local tumor control/VA preservation, and the Kaplan-Meier (K-M) curves were plotted to compare the survival rate among subgroups. Results: 52 OPG patients were included in this study, with a median age of 13.8 years (2-53 years); female outnumbered male at a ratio of 30 : 22; 7 patients (13.5%) had a history of surgical resection; 14 patients (26.9%) were categorized as neurofibromatosis type I (NFI) associated OPG and the rest as sporadic OPG; there were 6 patients (11.5%) with tumors located at hypothalamus/optic chiasm and the rest located in the orbit; the mean tumor volume was 4.36 ml (0.25-11.4 ml); 49 patients (94.2%) presented with VA impairment before GKS; 28 patients (53.8%) underwent single fraction GKS, and the rest underwent fractionated GKS (2-4 fractions); the mean marginal dose (represented with biologically effective dose, BED) was 66.6 Gy (13.3-126.0 Gy); the median follow-up time was 39 months (6-147 months); 11 patients were observed with tumor relapse, 33 with stable disease, and 8 with tumor regression; tumor relapse time varied from 30 to 76 months (mean 54 months); the 1-, 3-, and 5-year progression-free survival (PFS) rates were 100%, 92%, and 78%, respectively; 30 patients were included in the visual analysis; 7 patients were observed with VA deterioration, 19 with stable VA, and 4 with VA improvement; the 1-,3-, and 5-year VA preservation rates were 92%, 84%, and 77%, respectively. COX proportional hazard risk models showed that intratumoral cyst formation and marginal dose were the only two independent prognostic factors of local tumor control/VA preservation; fractionated GKS provided a higher VA preservation rate than single fraction GKS. Four patients were observed with conjunctive edema/conjunctive hyperemia in 1-4 weeks after GKS. Conclusions: GKS is a safe and effective treatment for OPG either as initial treatment or as salvage treatment after surgical resection, it provides good local tumor control and VA preservation, and fractionated GKS could be a preference for OPG patients with baseline VA ≥ 0.2.

Consumer Online Knowledge-Sharing: Motivations and Outcome.

As a new form of online reviews, Q&A reviews have been recently used by many e-commerce platforms to compensate for the weaknesses and problems related to trust and helpfulness found in traditional online reviews. This research documents what motivates people to share products or purchasing knowledge with others through Q&A reviews and why e-commerce platforms should place an emphasis on Q&A reviews. Importantly, our results provide evidence that, when receiving feedback (i.e., comments and likes), people are more likely willing to share knowledge with others and will have a higher level of loyalty. We believe that this study contributes to knowledge sharing and the e-commerce literature, and also has practical implications.

Verrucosidin Derivatives from the Deep Sea Cold-Seep-Derived Fungus Penicillium polonicum CS-252.

Six novel verrucosidin derivatives, namely, poloncosidins A-F (1-6), together with one known analogue (7), were isolated and identified from the deep-sea-derived fungus Penicillium polonicum CS-252, which was obtained from cold-seep sediments collected in the South China Sea at a depth of 1183 m. Their structures were mainly established on the basis of a detailed interpretation of NMR spectroscopic and mass spectrometric data. The relative and absolute configurations of compounds 1-6 were determined by ECD calculations and a DP4+ probability analysis. Compounds 1-5 represent the first examples of verrucosidins with a 2,5-dihydrofuran ring which is uncommon among the known analogues. These compounds exhibited inhibitory activities against several human and aquatic pathogens with MIC values ranging from 4 to 32 µg/mL.

Aberrant H3K4me3 modification of epiblast genes of extraembryonic tissue causes placental defects and implantation failure in mouse IVF embryos.

Assisted reproductive technology has been widely applied in the treatment of human infertility. However, accumulating evidence indicates that in vitro fertilization (IVF) is associated with a low pregnancy rate, placental defects, and metabolic diseases in offspring. Here, we find that IVF manipulation notably disrupts extraembryonic tissue-specific gene expression, and 334 epiblast (Epi)-specific genes and 24 Epi-specific transcription factors are abnormally expressed in extraembryonic ectoderm (ExE) of IVF embryos at embryonic day 7.5. Combined histone modification analysis reveals that aberrant H3K4me3 modification at the Epi active promoters results in increased expression of these genes in ExE. Importantly, we demonstrate that knockdown of the H3K4me3-recruited regulator Kmt2e, which is highly expressed in IVF embryos, greatly improves the development of IVF embryos and reduces abnormal gene expression in ExE. Our study therefore identifies that abnormal H3K4me3 modification in extraembryonic tissue is a major cause of implantation failure and abnormal placental development of IVF embryos.

FTO mediates LINE1 m6A demethylation and chromatin regulation in mESCs and mouse development.

N6-methyladenosine (m6A) is the most abundant internal modification on mammalian messenger RNA. It is installed by a writer complex and can be reversed by erasers such as the fat mass and obesity-associated protein FTO. Despite extensive research, the primary physiological substrates of FTO in mammalian tissues and development remain elusive. Here, we show that FTO mediates m6A demethylation of long-interspersed element-1 (LINE1) RNA in mouse embryonic stem cells (mESCs), regulating LINE1 RNA abundance and the local chromatin state, which in turn modulates the transcription of LINE1-containing genes. FTO-mediated LINE1 RNA m6A demethylation also plays regulatory roles in shaping chromatin state and gene expression during mouse oocyte and embryonic development. Our results suggest broad effects of LINE1 RNA m6A demethylation by FTO in mammals.

N6-methyladenosine regulates maternal RNA maintenance in oocytes and timely RNA decay during mouse maternal-to-zygotic transition.

N6-methyladenosine (m6A) and its regulatory components play critical roles in various developmental processes in mammals. However, the landscape and function of m6A in early embryos remain unclear owing to limited materials. Here we developed a method of ultralow-input m6A RNA immunoprecipitation followed by sequencing to reveal the transcriptome-wide m6A landscape in mouse oocytes and early embryos and found unique enrichment and dynamics of m6A RNA modifications on maternal and zygotic RNAs, including the transcripts of transposable elements MTA and MERVL. Notably, we found that the maternal protein KIAA1429, a component of the m6A methyltransferase complex, was essential for m6A deposition on maternal mRNAs that undergo decay after zygotic genome activation and MTA transcripts to maintain their stability in oocytes. Interestingly, m6A methyltransferases, especially METTL3, deposited m6A on mRNAs transcribed during zygotic genome activation and ensured their decay after the two-cell stage, including Zscan4 and MERVL. Together, our findings uncover the essential functions of m6A in specific contexts during the maternal-to-zygotic transition, namely ensuring the stability of mRNAs in oocytes and the decay of two-cell-specific transcripts after fertilization.