High-resolution mapping of a gene conferring strong antibiosis to brown planthopper and developing resistant near-isogenic lines in 9311 background

The brown planthopper (BPH), Nilaparvata lugens Stål, is one of the most destructive pests to the rice production in the world. Thus, there is an urgency to identify new resistant genes for breeding. AC-1613 is an indica variety that has been reported to confer broad-spectrum resistance to BPH. In the present study, we found that AC-1613 exhibited strong antibiosis towards BPH insects. The body weight was significantly decreased when the insects fed on AC-1613 plants. By using BPH weight gain as an index of phenotyping, a novel dominant locus for resistance to BPH, designed as Bph30, was identified and its near-isogenic line (NIL) in 9311 background was developed. The F₂ population derived from a cross between AC-1613 and 9311 was used for mapping the gene. Through QTL scan, we located the gene on the short arm of chromosome 4 between RM16278 and RM16425, which explained 42.7% of the phenotypic variance (PEV) of BPH resistance in the F₂ population. The gene was finally located in a region flanking by simple sequence repeat (SSR) markers SSR-28 and SSR-69 through high-resolution mapping, the distance between the two markers in Nipponbare genome is 37.5 kb. In addition, SSR markers RM16294 and RM16299 tightly linked to Bph30 were applied effectively in introgressing Bph30 into elite rice cultivars. The developed NILs showed a strong antibiosis and high resistance to BPH.     

Human nail stem cells are retained but hypofunctional during aging

The nail is a continuous skin appendage. Cells located around the nails, which display coordinated homeostatic dynamics and release a flow of stem cells in response to regeneration, have been identified in mice. However, very few studies regarding human nail stem cells exist in the literature. Using specimens isolated from humans, we detected an unreported population of cells within the basal layer of postnatal human nail proximal folds (NPFs) and the nail matrix around the nail root. These cells were multi-expressing and expressed stem cell markers, such as keratin 15 (K15), keratin 14 (K14), keratin 19 (K19), CD29, CD34, and leucine-rich repeat-containing G protein-coupled receptor 6 (Lgr6). These cells were very similar to mouse nail stem cells in terms of cell marker expression and their location within the nail. We also found that the putative nail stem cells maintained their abundance with advancing age, but cell proliferation and nail growth rate were decreased on comparison of young and aged specimens. To summarize, we found a putative population of stem cells in postnatal human nails located at NPFs and the nail matrix. These cells may have potential for cell differentiation and be capable of responding to injury, and were retained, but may be hypofunctional during aging.     

Identifying normal embryos from reciprocal translocation carriers by whole chromosome haplotyping

正Reciprocal translocation is a chromosomal structural abnormality that arises when two non-homologous chromosomes rearrange and attach with each other, an incidence that occurs in about 1/500to 1/625 newborns (Mackie and Scriven, 2002). This event typically does not lead to any significant loss of genetic material, thus reciprocal translocation carriers do not exhibit any severe abnormal     

Conservation analysis of long non-coding RNAs in plants

Long non-coding RNAs (lncRNAs) are gene regulators that have vital roles in development and adaptation to the environment in eukaryotes. However, the structural and evolutionary analyses of plant lncRNAs are limited. In this study, we performed an analysis of lncRNAs in five monocot and five dicot species. Our results showed that plant lncRNA genes were generally shorter and had fewer exons than protein-coding genes. The numbers of lncRNAs were positively correlated with the numbers of protein-coding genes in different plant species, despite a high range of variation. Sequence conservation analysis showed that the majority of lncRNAs had high sequence conservation at the intra-species and sub-species levels, reminiscent of protein-coding genes. At the inter-species level, a subset of lncRNAs were highly diverged at the nucleotide level, but conserved by position. Interestingly, we found that plant lncRNAs have identical splicing signals, and those which can form precursors or targets of miRNAs have a conservative identity in different species. We also revealed that most of the lowly expressed lncRNAs were tissue-specific, while those highly conserved were constitutively transcribed. Meanwhile, we characterized a subset of rice lncRNAs that were co-expressed with their adjacent protein-coding genes, suggesting they may play cis-regulatory roles. These results will contribute to understanding the biological significance and evolution of lncRNAs in plants.     

No evidence for MHC‐based mate choice in wild giant pandas

Major histocompatibility complex genes (MHC), a gene cluster that controls the immune response to parasites, are regarded as an important determinant of mate choice. However, MHC‐based mate choice studies are especially rare for endangered animals. The giant panda (Ailuropoda melanoleuca), a flagship species, has suffered habitat loss and fragmentation. We investigated the genetic variation of three MHC class II loci, including DRB1, DQA1, and DQA2, for 19 mating‐pairs and 11 parent‐pairs of wild giant pandas based on long‐term field behavior observations and genetic samples. We tested four hypotheses of mate choice based on this MHC variation. We found no supporting evidence for the MHC‐based heterosis, genetic diversity, genetic compatibility and “good gene” hypotheses. These results suggest that giant pandas may not use MHC‐based signals to select mating partners, probably because limited mating opportunities or female‐biased natal dispersal restricts selection for MHC‐based mate choice, acknowledging the caveat of the small sample size often encountered in endangered animal studies. Our study provides insight into the mate choice mechanisms of wild giant pandas and highlights the need to increase the connectivity and facilitate dispersal among fragmented populations and habitats.     

Five New Alkaloids from the Roots of Sophora flavescens

Five new quinolizidine alkaloids, including three sparteine‐type alkaloids ( 1  –  3 ) and two cytisine‐type alkaloids ( 4 and 5 ), along with four known ones, were isolated from the roots of Sophora flavescens. Their structures were determined by extensive spectroscopic techniques including IR, UV, NMR, and HR‐ESI‐MS. All the compounds were evaluated for their antibacterial activities against Staphylococcus aureus and Escherichia coli.     

Noninvasive photoacoustic and fluorescent tracking of optical dye labeled T cellular activities of diseased sites at new depth

The migration of immune cells is crucial to the immune response. Visualization of these processes has previously been limited because of the imaging depth. We developed a deep‐penetrating, sensitive and high‐resolution method to use fast photoacoustic tomography (PAT) to image the dynamic changes of T cells in lymph node and diseases at new depth (up to 9.5 mm). T cells labeled with NIR‐797‐isothiocyanate, an excellent near‐infrared photoacoustic and fluorescent agent, were intravenously injected to the mice. We used fluorescence imaging to determine the location of T cells roughly and photoacoustic imaging is used to observe T‐cell responses in diseased sites deeply and carefully. The dynamic changes of T cells in lymph node, acute disease (bacterial infection) and chronic disease (tumor) were observed noninvasively by photoacoustic and fluorescence imaging at different time points. T cells accumulated gradually and reached a maximum at 4 hours and declined afterwards in lymph node and bacterial infection site. At tumor model, T cells immigrated to the tumor with a maximum at 12 hours. Our study can not only provide a new observing method for immune activities tracking, but also enable continuous monitoring for therapeutic interventions.      

甜菊愈伤组织细胞中的液泡膜内突和液泡内囊泡

对生长在分化培养基上的甜菊愈伤组织分生区细胞的液泡膜内突和液泡内囊泡,进行了超微结构和酸性磷酸酶细胞化学研究。在不同液泡化时期的细胞中,都存在不同大小和形态的液泡膜内突,它们有的缺乏明显的内含物;有的含有许多小泡或复杂膜系;有的含有一个较大的具许多小泡或复杂膜系的膜束缚囊泡。在液泡内还存在一些游离的液泡内囊泡,它们通常具有两层紧贴的界膜或为多层同心膜,推测它们来自液泡膜内突。ＡｃＰａｓｅ定位结果显     

鼢鼠阴道内异物与种群自然调节研究初报

鼢鼠阴道内异物与种群自然调节研究初报曹志东（甘肃省定西地区种草养畜中心,７４３０００）ＡＰｒｅｌｉｍｉｎａｒｙＲｅｐｏｒｔｏｆｔｈｅＦｏｒｅｉｇｎＢｏｄｙｉｎｔｈｅＶａｇｉｎａｏｆＭｙｏｓｐａｌａｘａｎｄｔｈｅＮａｔｕｒａｌＲｅｇｕｌａｔｉｏｎｏｆｔ...     

寄生鳜鱼鳃部河鲈锚首吸虫的摄食特点

本文报道了鳜鱼［Ｓｉｎｉｐｅｒｃａｃｈｕａｔｓｉ（Ｂａｓｉｌｅｗｓｋｙ）］鳃上寄生的河鲈锚首吸虫［Ａｎｃｙｒｏｃｅｐｈａｌｕｓｍｏｇｕｒｎｄａｅ（Ｇｕｓｓｅｖ）］的食物组成及其能量储存的形式。联苯胺—过氧化物酶染色显示河鲈锚首吸虫摄食宿主的血液,过碘酸Ｓｃｈｉｆｆ氏反应显示其也摄食宿主的粘液。尽管在河鲈锚首吸虫的肠腔发现残余的细胞,但这些细胞是否为宿主的鳃组织细胞尚待进一步的研究证实。河鲈锚首吸虫体内储存有大量的脂肪,表明有氧代谢的存在并可能是能量供给的主要形式,尽管在虫体的实质中也有糖原的存在。