Development of high‐resolution DNA barcodes for Dioscorea species discrimination and phylogenetic analysis

The genus Dioscorea is widely distributed in tropical and subtropical regions, and is economically important in terms of food supply and pharmaceutical applications. However, DNA barcodes are relatively unsuccessful in discriminating between Dioscorea species, with the highest discrimination rate (23.26%) derived from matK sequences. In this study, we compared genic and intergenic regions of three Dioscorea chloroplast genomes and found that the density of SNPs and indels in intergenic sites was about twice and seven times higher than that of SNPs and indels in the genic regions, respectively. A total of 52 primer pairs covering highly variable regions were designed and seven pairs of primers had 80%–100% PCR success rate. PCR amplicons of 73 Dioscorea individuals and assembled sequences of 47 Dioscorea SRAs were used for estimating intraspecific and interspecific divergence for the seven loci: The rpoB‐trnC locus had the highest interspecific divergence. Automatic barcoding gap discovery (ABGD), Poisson tree processes (PTP), and generalized mixed Yule coalescence (GMYC) analysis were applied for species delimitation based on the seven loci and successfully identified the majority of species, except for species in the Enantiophyllum section. Phylogenetic analysis of 51 Dioscorea individuals (28 species) showed that most individuals belonging to the same species tended to cluster in the same group. Our results suggest that the variable loci derived from comparative analysis of plastid genome sequences could be good DNA barcode candidates for taxonomic analysis and species delimitation.     

Transient expression of a TaGRF4-TaGIF1 complex stimulates wheat regeneration and improves genome editing

Science China Life Sciences - Genome editing is an unprecedented technological breakthrough but low plant regeneration frequencies and genotype dependence hinder its implementation for crop...     

Biocontrol: Endophytic bacteria could be crucial to fight soft rot disease in the rare medicinal herb,Anoectochilus roxburghii

Microbial destabilization induced by pathogen infection has severely affected plant quality and output, such as Anoectochilus roxburghii, an economically important herb. Soft rot is the main disease that occurs during A. roxburghii culturing. However, the key members of pathogens and their interplay with non-detrimental microorganisms in diseased plants remain largely unsolved. Here, by utilizing a molecular ecological network approach, the interactions within bacterial communities in endophytic compartments and the surrounding soils during soft rot infection were investigated. Significant differences in bacterial diversity and community composition between healthy and diseased plants were observed, indicating that the endophytic communities were strongly influenced by pathogen invasion. Endophytic stem communities of the diseased plants were primarily derived from roots and the root endophytes were largely derived from rhizosphere soils, which depicts a possible pathogen migration image from soils to roots and finally the stems. Furthermore, interactions among microbial members indicated that pathogen invasion might be aided by positively correlated native microbial members, such as Enterobacter and Microbacterium, who may assist in colonization and multiplication through a mutualistic relationship in roots during the pathogen infection process. Our findings will help open new avenues for developing more accurate strategies for biological control of A. roxburghii bacterial soft rot disease.     

True phosphorus digestibility and the endogenous phosphorus outputs associated with brown rice for weanling pigs measured by the simple linear regression analysis technique

The objectives of this study were to determine true phosphorus (P) digestibility, degradability of phytate-P complex and the endogenous P outputs associated with brown rice feeding in weanling pigs by using the simple linear regression analysis technique. Six barrows with an average initial body weight of 12.5 kg were fitted with a T-cannula and fed six diets according to a 6 × 6 Latin-square design. Six maize starch-based diets, containing six levels of P at 0.80, 1.36, 1.93, 2.49, 3.04, and 3.61 g/kg per kg dry-matter (DM) intake (DMI), were formulated with brown rice. Each experimental period lasted 10 days. After a 7-day adaptation, all faecal samples were collected on days 8 and 9. Ileal digesta samples were collected for a total of 24 h on day 10. The apparent ileal and faecal P digestibility values of brown rice were affected ( P < 0.01) by the P contents in the assay diets. The apparent ileal and faecal P digestibility values increased from − 48.0 to 36.7% and from − 35.6 to 40.0%, respectively, as P content increased from 0.80 to 3.61 g/kg DMI. Linear relationships ( P < 0.05), expressed as g/kg DMI, between the apparent ileal and faecal digestible P and dietary levels of P, suggested that true P digestibility and the endogenous P outputs associated with brown rice feeding could be determined by using the simple regression analysis technique. There were no differences ( P>0.05) in true P digestibility values (57.7 ± 5.4 v. 58.2 ± 5.9%), phytate P degradability (76.4 ± 6.7 v. 79.0 ± 4.4%) and the endogenous P outputs (0.812 ± 0..096 v. 0.725 ± 0.083 g/kg DMI) between the ileal and the faecal levels. The endogenous faecal P output represented 14 and 25% of the National Research Council (1998) recommended daily total and available P requirements in the weanling pig, respectively. About 58% of the total P in brown rice could be digested and absorbed by the weanling pig. Our results suggest that the large intestine of the weanling pigs does not play a significant role in the digestion of P in brown rice. Diet formulation on the basis of total or apparent P digestibility with brown rice may lead to P overfeeding and excessive P excretion in pigs.     

Antler regeneration: a dependent process of stem tissue primed via interaction with its enveloping skin

Deer antlers are unique mammalian appendages in that each year they are cast and fully regenerate from permanent bony protuberances, called pedicles. In a previous study, we found that there is a difference in the degree of association between pedicle bone and its enveloping skin: tight at the distal third and loose at the proximal two thirds of a pedicle stump. The distal part has been termed the "potentiated" region, and the proximal part the "dormant" region. In the present study, pedicle stumps were artificially created in yearling sika deer by cutting off the tissue distal to either the potentiated or the dormant region. A piece of impermeable membrane was then inserted into the space between the bone and the skin of each treated pedicle stump, while the control pedicles had the same surgery without membrane insertion. The results showed that the inserted membrane blocked pedicle skin participation in the process of antler regeneration. All three potentiated bony pedicle stumps regenerated skin-less antlers; whereas, one of the three dormant bony pedicle stumps failed to regenerate any antler tissue. The other two dormant stumps eventually regenerated normal antlers; however, this only occurred after loss of the inserted membrane. No antler tissue regenerated from the dormant stumps while the inserted membrane remained in place (up to 55 days). All control pedicle stumps regenerated normal antlers. Therefore, we conclude that it is the pedicle bone, but not pedicle skin, that gives rise to regenerating antlers, and that pedicle bone can acquire the potential to regenerate an antler only when it is primed via interaction with its enveloping skin.     

细胞因子在ARDS发病机制中的作用

细胞因子是由多种细胞产生的多肽或低分子糖蛋白,在人体内含量极微,在pg水平就发挥作用。作为特异性免疫反应和非特异性免疫反应的蛋白质,细胞因子以自分泌、旁分泌、或内分泌方式产生,与相应的细胞表面受体结合,在局部或全身发挥复杂的生物学效应,它们的代谢异常和疾病的发生、发展有着密切的关系。有些细胞因子已应用于临床的生物学治疗,具有深远的临床应用价值,故对细胞因子的研究将是一个越来越重要的课题。急性肺损伤(ALI)/急性呼吸窘迫综合征(ARDS)发病机制错综复杂,大量临床和实验室研究证明多种效应细胞释放的炎症介质是造成ARDS的"中心环节",其中TNF-α、IL-1、IL-8、IL-10、CXC趋化因子等细胞因子在ARDS发病中的作用尤为重要。本文就细胞因子在ARDS发病机制中的作用做一综述。     

Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition

The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is approached. In birds (living dinosaurs) on the other hand, reproductive activity begins well after somatic maturity. Here we used growth line counts and spacing in all of the known brooding non-avian dinosaurs to determine the stages of development when they perished. It was revealed that sexual maturation occurred well before full adult size was reached-the primitive reptilian condition. In this sense, the life history and physiology of non-avian dinosaurs was not like that of modern birds. Palaeobiological ramifications of these findings include the potential to deduce reproductive lifespan, fecundity and reproductive population sizes in non-avian dinosaurs, as well as aid in the identification of secondary sexual characteristics.     

New therapy with XLQ® to suppress chronic prostatitis through its anti-inflammatory and antioxidative activities

Chronic prostatitis is a common urological disease. The etiology of this disease and effective therapy for its treatment are yet to be elucidated. We investigated the functions of XLQ^® in chronic nonbacterial prostatitis using a complete Freund's adjuvant-induced rat model. Prostates and blood samples were collected for further evaluation after oral gavage with XLQ ^® or a vehicle for 4 weeks. The results showed that XLQ ^® significantly decreased the prostate index, ameliorated the histopathologic changes, and reduced CD3+ and CD45+ cell infiltration in the prostate stroma. Further study showed that XLQ ^® suppressed the expression of proinflammatory cytokines, such as interleukin (IL)-1β, IL-2, IL-6, IL-17A, monocyte chemoattractant protein-1, and tumor necrosis factor-α. XLQ ^® showed a strong antioxidant capacity by enhancing the activities of antioxidative enzymes (e.g., total superoxide dismutase, catalase, and glutathione peroxidase) and decreasing the level of lipid peroxidation products (malondialdehyde). Moreover, XLQ ^® can suppress the activation of nuclear factor-κB and P38-mitogen-activated protein kinase signaling pathways. In summary, XLQ ^® has affirmative effects on chronic prostatitis, which could be attributed to its anti-inflammatory and antioxidative capacities. On the basis of these results, XLQ ^® can be developed as an effective and safe therapy for chronic prostatitis.     

Estrogen inhibits osteoclasts formation and bone resorption via microRNA-27a targeting PPARγ and APC

Inhibition of osteoclasts formation and bone resorption by estrogen is very important in the etiology of postmenopausal osteoporosis. The mechanisms of this process are still not fully understood. Recent studies implicated an important role of microRNAs in estrogen-mediated responses in various cellular processes, including cell differentiation and proliferation. Thus, we hypothesized that these regulatory molecules might be implicated in the process of estrogen-decreased osteoclasts formation and bone resorption. Western blot, quantitative real-time polymerase chain reaction, tartrate-resistant acid phosphatase staining, pit formation assay and luciferase assay were used to investigate the role of microRNAs in estrogen-inhibited osteoclast differentiation and bone resorption. We found that estrogen could directly suppress receptor activator of nuclear factor B ligand/macrophage colony-stimulating factor-induced differentiation of bone marrow-derived macrophages into osteoclasts in the absence of stromal cell. MicroRNA-27a was significantly increased during the process of estrogen-decreased osteoclast differentiation. Overexpressing of microRNA-27a remarkably enhanced the inhibitory effect of estrogen on osteoclast differentiation and bone resorption, whereas which were alleviated by microRNA-27a depletion. Mechanistic studies showed that microRNA-27a inhibited peroxisome proliferator-activated receptor gamma (PPARγ) and adenomatous polyposis coli (APC) expression in osteoclasts through a microRNA-27a binding site within the 3′-untranslational region of PPARγ and APC. PPARγ and APC respectively contributed to microRNA-27a-decreased osteoclast differentiation and bone resorption. Taken together, these results showed that microRNA-27a may play a significant role in the process of estrogen-inhibited osteoclast differentiation and function.