Preliminary Phenotypic and SNP-Based Molecular Characterization of Maize (<i>Zea mays</i>L.)-Mexicana (<i>Zea mays</i>SSP. <i>Mexicana</i>) Introgression Lines under Inbred Background of 48-2

Wild relatives possess potential genetic diversity for maize (Zea mays L.) improvement. Characterization of maize-mexicana introgression lines (ILs) is of great value to diversify the genetic base and improve the maize germplasm. Four maize-mexicana IL generations, i.e. BC1, BC2, BC3, and RIL, were constructed under the elite inbred background of 48-2, elite inbred line that is widely used in maize breeding in Southwestern China, and were phenotyped in different years and genotyped with 56110 SNPs. The results indicated that 48-2 had higher phenotypic performances than all the characterized ILs on most of the agronomic traits. Compared with other ILs, BC2 individuals exhibited more similar performance to 48-2 on most traits and possessed the highest kernel ratio (66.5%). Population structure and principal component analysis indicated that BC3 individuals gathered closer to 48-2 and exhibited the lowest mexicana-introgression frequency (0.50%), while BC2 (29.06%) and RIL (18.52%) showed higher introgression frequency. The high level of genetic diversity observed in the maize-mexicana ILs demonstrated that Z. mays ssp. mexicana can serve as a potential source for the enrichment of maize germplasm.

QTL analysis across multiple environments reveals promising chromosome regions associated with yield-related traits in maize under drought conditions

Drought is one of the most critical abiotic stresses influencing maize yield. Improving maize cultivars with drought tolerance using marker-assisted selection requires a better understanding of its genetic basis. In this study, a doubled haploid(DH) population consisting of 217 lines was created by crossing the inbred lines Han 21(drought-tolerant) and Ye 478(drought-sensitive). The population was genotyped with a 6 K SNP assay and 756 SNP(single nucleotide polymorphism) markers were used to construct a linkage map with a length of 1344 c M. Grain yield(GY), ear setting percentage(ESP), and anthesis–silking interval(ASI) were recorded in seven environments under well-watered(WW) and water-stressed(WS) regimes. High phenotypic variation was observed for all traits under both water regimes. Using the LSMEAN(least-squares mean) values from all environments for each trait, 18 QTL were detected, with 9 associated with the WW and 9 with the WS regime. Four chromosome regions,Chr. 3: 219.8–223.7 Mb, Chr. 5: 191.5–194.7 Mb, Chr. 7: 132.2–135.6 Mb, and Chr. 10: 88.2–89.4 Mb, harbored at least 2 QTL in each region, and QTL co-located in a region inherited favorable alleles from the same parent. A set of 64 drought-tolerant BC_3F_6 lines showed preferential accumulation of the favorable alleles in these four regions, supporting an association between the four regions and maize drought tolerance. QTL-by-environment interaction analysis revealed 28 ed QTL(environment-dependent QTL) associated with the WS regime and 22 associated with the WW regime for GY, ESP, and ASI. All WS QTL and55.6% of WW QTL were located in the ed QTL regions. The hotspot genomic regions identified in this work will support further fine mapping and marker-assisted breeding of drought-tolerant maize.

恶性腹膜间皮瘤100例临床病理特征及预后分析

目的:探讨恶性腹膜间皮瘤(malignant peritoneal mesothelioma,MPM)临床病理特点及预后,寻找影响预后独立指标。方法:收集首都医科大学附属北京世纪坛医院2013年1月至2021年12月手术的100例MPM病例,研究石棉接触、CA125、腹水、腹膜癌指数(peritoneal cancer index,PCI)评分、完全细胞减灭(completeness of cytoreduction,CC)评分、TNM分期、组织学分型、脉管瘤栓、神经侵犯、Ki-67指数,收集随访资料。采用Kaplan-Meier法计算患者生存率;生存预后模型进行单因素和多因素分析,研究独立影响MPM预后的临床病理学因素。结果:本研究男性48例(48%),女性52例(52%),中位年龄54(24~72)岁,有石棉接触史患者19例(19%),腹水患者90例(90%),CA125≥35 U/mL 58例(59%),PCI评分≥25分56例(56%)、CC评分为0~1分49例(49%)、2~3分51例(51%)。上皮样型79例(79%),非上皮样型21例(21%),Ⅰ期患者10例(10%)、Ⅱ期和Ⅲ期患者均为45例(45%)。单因素分析发现影响患者生存主要指标:石棉接触、PCI评分、CA125、组织学类型、Ki-67指数、TNM分期。多因素分析显示,有石棉接触史患者死亡风险是无接触史患者的2.3倍(95%CI:0.233~0.806,P=0.008),PCI评分≥25分患者的死亡风险是<25分患者的2.9倍(95%CI:0.200~0.612,P<0.001),Ki-67指数>10%患者死亡风险是指数≤10%患者的5.90倍(95%CI:0.072~0.401,P<0.001)。上皮样型与非上皮样型MPM的Ki-67指数呈显著性差异(P=0.001)。结论:石棉接触史、PCI评分和Ki-67指数是MPM的独立预后因子。

The pentatricopeptide repeat protein EMP601 functions in maize seed development by affecting RNA editing of mitochondrial transcript ccmC

Although several pentatricopeptide repeat(PPR) proteins are involved in post-transcriptional processing of mitochondrial RNA, it is unclear which specific protein is involved in the RNA editing of ccmC in maize(Zea mays). Here we report the identification of the maize empty pericarp 601(emp601) mutant and the map-based cloning of the Emp601 gene, which encodes an E2-type PPR protein that is targeted to mitochondria. A single-nucleotide deletion in the emp601 mutant caused a frameshift and introduced a premature stop codon into the predicted EMP601. This mutation was associated with reduced accumulation of mitochondrial complex Ⅲ as well as with inhibition of growth and differentiation of basal endosperm transfer layer cells, leading to final degeneration of the embryo and endosperm. We determine that loss of EMP601 function prevents the C-to-U RNA editing of the mitochondrial transcript ccmC at position 358.EMP601 binds to the ccmC transcript and directly interacts with Multiple organellar RNA editing factor 8and may be a component of the plant mitochondrial editosome. We conclude that EMP601 functions in RNA editing of mitochondrial ccmC transcripts and influences mitochondrial function and seed development.

IL-25 blockade inhibits metastasis in breasl cancer

Metastasis is the leading cause of death in breast cancer patients. However, the mechanisms underlying metasta- sis are not well understood and there is no effective treatment in the clinic. Here, we demonstrate that in MMTV- PyMT, a highly malignant spontaneous breast tumor model, IL-25 （also called IL-17E） was expressed by tumor- infiltrating CD4＋ T cells and macrophages. An IL-25 neu- tralization antibody, while not affecting primary tumor growth, substantially reduced lung metastasis. Inhibition of IL-25 resulted in decreased type 2 T cells and macro- phages in the primary tumor microenvironments, both reported to enhance breast tumor invasion and subse- quent metastasis to the lung. Taken together, our data suggest IL-25 blockade as a novel treatment for metastatic breast tumor.

CD146,from a melanoma cell adhesion molecule to a signaling receptor

CD146 was originally identified as a melanoma cell adhesion molecule(MCAM)and highly expressed in many tumors and endothelial cells.However,the evidence that CD146 acts as an adhesion molecule to mediate a homophilic adhesion through the direct interactions between CD146 and itself is still lacking.Recent evidence revealed that CD146 is not merely an adhesion molecule,but also a cellular surface receptor of miscellaneous ligands,including some growth factors and extracellular matrixes.Through the bidirectional interactions with its ligands,CD146 is actively involved in numerous physiological and pathological processes of cells.Overexpression of CD146 can be observed in most of malignancies and is implicated in nearly every step of the development and progression of cancers,especially vascular and lymphatic metastasis.Thus,immunotherapy against CD146 would provide a promising strategy to inhibit metastasis,which accounts for the majority of cancer-associated deaths.Therefore,to deepen the understanding of CD146,we review the reports describing the newly identified ligands of CD146 and discuss the implications of these findings in establishing novel strategies for cancer therapy.

Enhancing sensing capacity of terahertz metamaterial absorbers with a surface-relief design

Metamaterial absorbers(MAs)serve as important electromagnetic wave-absorbing devices that have captured the attention of researchers for a long term.Functioning as sensitive detectors to determine perturbations in an ambient environment is another significant subsidiary function.Here,we theoretically propose an optimized fabrication method to implement terahertz MAs with fewer steps and also evaluate both absorption and sensing performances of such MAs realized by the new method.Simulation findings demonstrate that such MAs can basically maintain the original absorption features perfectly,including near-complete absorption at resonance as well as strong robustness to wide incident angles.Specifically,the full width at half-maximum and quality factor of the absorption resonances attenuate less than 26%and 8%with this new method,remaining in the ranges of^0.03–0.04 THz and^20–27 for two selected example MAs.More significantly,sensing capacities of this type of MA,in terms of maximum detection range(enhancing at least 9%),observable spectral modulation(increasing at least 6.3%),and refractive index sensitivity,are improved to a large extent because of more intense coupling between resonant field and matter in the case of surface-relief MAs.This stronger coupling results from exposing more spots of the resonantly high field to direct contact with an approaching analyte,which is illustrated by field profiles of the MAs at resonance in this work.Additionally,other desirable absorber features are also explored with such MAs,like functioning as building blocks to configure multiband MAs and strong robustness against fabrication errors.Such new-style terahertz MAs shown in the paper,acting as good examples,not only prove that terahertz MAs can be fabricated by the proposed time-and cost-saving route in contrast to the traditional MA fabrication process,but also can serve as novel platforms to explore other intriguing terahertz photonic effects,such as the field enhancement effect.

^(18)F-FDG PET/MR Imaging for Evaluating of Obstructive Jaundice:Chinese Expert Consensus

The cause of obstructive jaundice is usually complex which renders its differential diagnosis and lesion localization challenging in clinical practice.Integrated Positron Emission tomography/Magnetic Resonance(PET/MR)offers complementary information from PET and MR in the diagnosis of obstructive jaundice and is becoming widely adopted in clinical setting.While preserving its diagnostic accuracy,it is important to standardize and streamline the clinical scan protocol of PET/MR in evaluating obstructive jaundice.Based on literature review and experience of large number of clinical cases from the author group,this article reports an expert consensus on imaging protocol optimization and case interpretation template standardization.