Crop domestication provided the calories that fueled the rise of civilization. For many crop species, domestication was accompanied by the evolution of weedy crop relatives, which aggressively outcompete crops and reduce harvests. Understanding the genetic mechanisms that underlie the evolution of weedy crop relatives is critical for agricultural weed management and food security. Here we use whole-genome sequences to examine the origin and adaptation of the two major strains of weedy rice found in the United States. We find that de-domestication from cultivated ancestors has had a major role in their evolution, with relatively few genetic changes required for the emergence of weediness traits. Weed strains likely evolved both early and late in the history of rice cultivation and represent an under-recognized component of the domestication process. Genomic regions identified here that show evidence of selection can be considered candidates for future genetic and functional analyses for rice improvement.
Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts.
Hepatocellular carcinoma (HCC) is generally resistant to chemotherapy due to intrinsic or acquired drug resistances. Many molecules and signaling pathways are involved in chemo-resistance of HCC cells. However, the contribution of long noncoding RNA (lncRNA) to chemo-resistance of HCC cells is still largely unknown. In this study, we revealed the critical roles of long noncoding RNA lncARSR in chemo-resistance of HCC cells. lncARSR is upregulated in HCC, associated with large tumor size and advanced BCLC stage, and indicts poor prognosis. Functional assays showed that overexpression of lncARSR enhances doxorubicin resistance of HCC cells in vitro and in vivo. And while knockdown of lncARSR increases sensitivity of HCC cells to doxorubicin in vitro and in vivo. Mechanistically, we found that lncARSR physically associates with PTEN mRNA, promotes PTEN mRNA degradation, decreases PTEN expression, and activates PI3K/Akt pathway. PTEN is downregulated in HCC, and the expression of PTEN is negatively correlated with lncARSR in HCC tissues. Furthermore, the effects of lncARSR overexpression on doxorubicin resistance could be reversed by PI3K/Akt pathway inhibitor, and lncARSR knockdown-induced doxorubicin sensitivity could be reversed by PTEN depletion. Taken together, our results showed that upregulated lncARSR promotes doxorubicin resistance in HCC via modulating PTEN-PI3K/Akt pathway, and implied that lncARSR may serve as a promising prognostic biomarker and therapeutic target for HCC chemo-resistance. J. Cell. Biochem. 118: 4498-4507, 2017. © 2017 Wiley Periodicals, Inc.
Diagnosis of lung cancer is performed using a plasmonic gold (pGOLD) chip through multiplexed near‐infrared (NIR) detection of carcino‐embryonic antigen (CEA), Cyfra21‐1, and neuron‐specific enolase (NSE) in the serum samples of patients. With ≈50‐fold enhancement of NIR fluorescence, multiplexed microarray analysis of CEA, Cyfra21‐1, and NSE in 10 μL of human serum or whole blood samples on pGOLD chip leads to markedly improved limit‐of‐quantification, limit‐of‐detection, reproducibility, and higher diagnostic sensitivity and specificity compared to traditional biochips and Luminex technology currently in use in hospitals.
Photobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification-induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core-shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar-driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell-material complexes.
Summary Allopolyploidization has occurred frequently within the Triticum–Aegilops complex which provides a suitable system to investigate how allopolyploidization shapes the expression patterns of duplicated homeologs. We have conducted transcriptome‐profiling of leaves and young inflorescences in wild and domesticated tetraploid wheats, Triticum turgidum ssp. dicoccoides (BBAA) and ssp. durum (BBAA), an extracted tetraploid (BBAA), and a synthetic tetraploid (SlSlAA) wheat together with its diploid parents, Aegilops longissima (SlSl) and Triticum urartu (AA). The two diploid species showed tissue‐specific differences in genome‐wide ortholog expression, which plays an important role in transcriptome shock‐mediated homeolog expression rewiring and hence transcriptome asymmetry in the synthetic tetraploid. Further changes of homeolog expression apparently occurred in natural tetraploid wheats, which led to novel transcriptome asymmetry between the two subgenomes. In particular, our results showed that extremely biased homeolog expression can occur rapidly upon the allotetraploidzation and this trend is further enhanced in the course of domestication and evolution of polyploid wheats. Our results suggest that allopolyploidization is accompanied by distinct phases of homeolog expression changes, with parental legacy playing major roles in the immediate rewiring of homeolog expression upon allopolyploidization, while evolution and domestication under allotetraploidy drive further homeolog‐expression changes toward re‐established subgenome expression asymmetry.
BackgroundPanax L. is a medicinally important genus within family Araliaceae, where almost all species are of cultural significance for traditional Chinese medicine. Previous studies suggested two independent origins of the East Asia and North America disjunct distribution of this genus and multiple rounds of whole genome duplications (WGDs) might have occurred during the evolutionary process.ResultsWe employed multiple chloroplast and nuclear markers to investigate the evolution and diversification of Panax. Our phylogenetic analyses confirmed previous observations of the independent origins of disjunct distribution and both ancient and recent WGDs have occurred within Panax. The estimations of divergence time implied that the ancient WGD might have occurred before the establishment of Panax. Thereafter, at least two independent recent WGD events have occurred within Panax, one of which has led to the formation of three geographically isolated tetraploid species P. ginseng, P. japonicus and P. quinquefolius. Population genetic analyses showed that the diploid species P. notoginseng harbored significantly lower nucleotide diversity than those of the two tetraploid species P. ginseng and P. quinquefolius and the three species showed distinct nucleotide variation patterns at exon regions.ConclusionOur findings based on the phylogenetic and population genetic analyses, coupled with the species distribution patterns of Panax, suggested that the two rounds of WGD along with the geographic and ecological isolations might have together contributed to the evolution and diversification of this genus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0669-0) contains supplementary material, which is available to authorized users.
PurposeEndometrial carcinoma is the most common gynecologic malignancy in both developed and some developing countries. Unlike cervical cancer, for which there is routine screening, only patients symptomatic for endometrial carcinoma typically seek medical help for its diagnosis and treatment. Dilatation and curettage (D&C) has been the standard procedure for evaluating suspicious endometrial lesions. The discomfort and injury caused by the D&C procedure, however, restrict its use as a screening method for early diagnosis of endometrial lesions. High-risk endometrial cancer patients would benefit from an effective and low-cost screening test. In recent years, several endometrial devices have been developed and proposed as screening tools.MethodsWe have reviewed and evaluated the literature relating to the endometrial sampling devices in clinical use or clinical trials, with the goal of comparing devices and identifying the most appropriate ones for screening for endometrial lesions. Eligible literature was identified from systematic PubMed searches, and the relevant data were extracted. Comments, letters, unpublished data, conference proceedings, and case reports were excluded from our search. Seventy-four articles on endometrial sampling devices were obtained for this review.ResultsThe main screening devices for endometrial carcinoma are aspiration devices (such as the Vabra aspirator), Pipelle, Tao Brush, and SAP-1 device. Among these devices, the Tao Brush is the most promising endometrial sampler for screening for endometrial lesions. However, its sampling insufficiency, cost, and unsuccessful insertion rate (20 % in nulliparous and 8 % in parous women) are problematic.ConclusionsA more accurate and low-cost endometrial sampler, with improved specimen sufficiency and higher sensitivity for endometrial lesions, needs tobe developed and clinically verified.
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