Discovering Candidate Chromosomal Regions Linked to Kernel Size-Related Traits via QTL Mapping and Bulked Sample Analysis in Maize

Kernel size-related traits, including kernel length, kernel width, and kernel thickness, are critical components in determining yield and kernel quality in maize (Zea mays L.). Dissecting the phenotypic characteristics of these traits, and discovering the candidate chromosomal regions for these traits, are of potential importance for maize yield and quality improvement. In this study, a total of 139 F2:3 family lines derived from EHel and B73, a distinct line with extremely low ear height (EHel), was used for phenotyping and QTL mapping of three kernel size-related traits, including 10-kernel length (KL), 10-kernel width (KWid), and 10-kernel thickness (KT). The results showed that only one QTL for KWid, i.e., qKWid9 on Chr9, with a phenotypic variation explained (PVE) of 13.4% was detected between SNPs of AX-86298371 and AX-86298372, while no QTLs were detected for KL and KT across all 10 chromosomes. Four bulked groups of family lines, i.e., Groups I to IV, were constructed with F2:3 family lines according to the phenotypic comparisons of KWid between EHel and B73. Among these four groups, Group I possessed a significantly lower KWid than EHel (P = 0.0455), Group II was similar to EHel (P = 0.34), while both Group III and Group IV were statistically higher than EHel (P < 0.05). Besides, except Group IV exhibited a similar KWid to B73 (P = 0.11), KWid of Groups I to III were statistically lower than B73 (P < 0.00). By comparing the bulked genotypes of the four groups to EHel and B73, a stable chromosomal region on Chr9 between SNPs of AX-86298372 to AX-86263154, entirely covered by qKWid9, was identified to link KWid with the positive allele of increasing phenotypic effect to KWid from B73, similar to that of qKWid9. A large amount of enzyme activity and macromolecule binding-related genes were annotated within this chromosomal region, suggesting qKWid9 as a potential QTL for KWid in maize.     

Apoplastic hydrogen peroxide and superoxide anion exhibited different regulatory functions in salt-induced oxidative stress in wheat leaves

The present work aimed to investigate the mechanisms of nitric oxide (NO) and reactive oxygen species (ROS) generations and to explore their roles in the regulation of antioxidative responses in the wheat leaves under salinity. Except for an insignificant change of NO content and nitrate reductase (NR) activity due to 50 mM NaCl, NO, hydrogen peroxide, superoxide anion (O₂^?-), hydroxyl radical (?OH), chlorophyll and malondialdehyde content, as well as activities of nitric oxide synthase, NR, peroxidases (POD), catalase (CAT), and ascorbate peroxidase rose in response to different NaCl concentrations. Meanwhile, leaf superoxide dismutase activity lowered only at 50 mM NaCl. NaCl-stimulatory effects on NO content as well as POD and CAT activities could be partly alleviated by the application of 2-phenyl-4,4,5,5-tetrame-thylimidazoline-3-oxide-1-oxyl (PTIO, NO scavenger), exogenous CAT, or diphenylene iodonium (DPI, NADPH oxidase inhibitor). Native polyacrylamide gel electrophoresis also showed that the amount of POD (especially POD4, POD5, and POD7) and CAT (especially CAT1, CAT2, and CAT3) isozymes increased with increasing salinity but decreased by application of PTIO, CAT, or DPI. Furthermore, histochemical staining showed a similar change of O₂^?- generation. In addition, the inhibition of diamineoxidase (DAO), polyamine oxidase (PAO), and cell wall-bound POD (cw-POD) activities in NaCl-stressed seedlings seemed to be insensitive to the application of PTIO or DPI. Taken together, salinity-induced NO, H₂O₂, and O₂^?- generation influenced each other and played different roles in the regulation of antioxidant enzyme activities in the leaves of wheat seedlings under NaCl treatment.     

Roles of noncoding RNAs in drug resistance in multiple myeloma

Despite the administration of new effective drugs in recent years, relapse and drug resistance are still the main obstacles in multiple myeloma (MM) treatment, making MM an incurable disease. To overcome drug resistance in MM, it is critical to understand the underlying mechanisms of malfunctioning gene expression and develop novel targeted therapies. During the past few decades, with the discovery and characterization of noncoding RNAs (ncRNAs), the landscape of dysregulated ncRNAs of cancers as well as their biological and pathobiological functions in tumorigenesis and drug resistance have been recognized. Studies about ncRNAs improved the understanding of variations of drug response among individuals at a level distinguished from genetic polymorphism, and provided with new orientations for targeted therapies. In this review, we will summarize the emerging impact and underlying molecular mechanisms of the most relevant classes of ncRNAs in drug resistance of MM, and discuss the potential as well as strategies of treating ncRNAs as therapeutic targets.     

Acoustic characteristics of eight common Chinese anurans during the breeding season

Anurans often have species-specific vocalizations. To quantify and compare the characteristics of anuran calls in Gutianshan National Nature Reserve, Zhejiang Province, we recorded the advertisement calls of eight species belonging to four families (Ranidae, Microhylidae, Megophryidae and Bufonidae) from June to September 2012 using Sony ICD-FX8 IC recorders. All recordings were analyzed using the "Praat" software. Five acoustics parameters were measured, including temporal traits (call duration, number of notes or pulse number/call) and spectral traits (fundamental frequency, the first three formants and dominant frequency). The characteristic parameters of Microhyla ornate and Fejervarya limnocharis calls were different as were the calls of some populations of the same species recorded in different regions. The advertisement calls of the eight species were specific. Our study has provided a useful reference for identifying the calls of some common Chinese anurans.     

Hepato-specific microRNA-122 facilitates accumulation of newly synthesized miRNA through regulating PRKRA

microRNAs (miRNAs) are a versatile class of non-coding RNAs involved in regulation of various biological processes. miRNA-122 (miR-122) is specifically and abundantly expressed in human liver. In this study, we employed 3'-end biotinylated synthetic miR-122 to identify its targets based on affinity purification. Quantitative RT-PCR analysis of the affinity purified RNAs demonstrated a specific enrichment of several known miR-122 targets such as CAT-1 (also called SLC7A1), ADAM17 and BCL-w. Using microarray analysis of affinity purified RNAs, we also discovered many candidate target genes of miR-122. Among these candidates, we confirmed that protein kinase, interferon-inducible double-stranded RNA-dependent activator (PRKRA), a Dicer-interacting protein, is a direct target gene of miR-122. miRNA quantitative-RT-PCR results indicated that miR-122 and small interfering RNA against PRKRA may facilitate the accumulation of newly synthesized miRNAs but did not detectably affect endogenous miRNAs levels. Our findings will lead to further understanding of multiple functions of this hepato-specific miRNA. We conclude that miR-122 could repress PRKRA expression and facilitate accumulation of newly synthesized miRNAs.     

Comparison of the Accuracy of Two Conventional Phenotypic Methods and Two MALDI-TOF MS Systems with That of DNA Sequencing Analysis for Correctly Identifying Clinically Encountered Yeasts

We assessed the accuracy of species-level identification of two commercially available matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems (Bruker Biotyper and Vitek MS) and two conventional phenotypic methods (Phoenix 100 YBC and Vitek 2 Yeast ID) with that of rDNA gene sequencing analysis among 200 clinical isolates of commonly encountered yeasts. The correct identification rates of the 200 yeast isolates to species or complex (Candida parapsilosis complex, C. guilliermondii complex and C. rugosa complex) levels by the Bruker Biotyper, Vitek MS (using in vitro devices [IVD] database), Phoenix 100 YBC and Vitek 2 Yeast ID (Sabouraud''s dextrose agar) systems were 92.5%, 79.5%, 89%, and 74%, respectively. An additional 72 isolates of C. parapsilosis complex and 18 from the above 200 isolates (30 in each of C. parapsilosis, C. metapsilosis, and C. orthopsilosis) were also evaluated separately. Bruker Biotyper system could accurately identify all C. parapsilosis complex to species level. Using Vitek 2 MS (IVD) system, all C. parapsilosis but none of C. metapsilosis, or C. orthopsilosis could be accurately identified. Among the 89 yeasts misidentified by the Vitek 2 MS (IVD) system, 39 (43.8%), including 27 C. orthopsilosis isolates, could be correctly identified Using the Vitek MS Plus SARAMIS database for research use only. This resulted in an increase in the rate of correct identification of all yeast isolates (87.5%) by Vitek 2 MS. The two species in C. guilliermondii complex (C. guilliermondii and C. fermentati) isolates were correctly identified by cluster analysis of spectra generated by the Bruker Biotyper system. Based on the results obtained in the current study, MALDI-TOF MS systems present a promising alternative for the routine identification of yeast species, including clinically commonly and rarely encountered yeast species and several species belonging to C. parapsilosis complex, C. guilliermondii complex, and C. rugosa complex.     

Direct Bio-Utilization of Untreated Rapeseed Meal for Effective Iturin A Production by Bacillus subtilis in Submerged Fermentation

The feasibility of using untreated rapeseed meal as a nitrogen source for iturin A production by Bacillus subtilis 3–10 in submerged fermentation was first evaluated by comparison with two different commercial nitrogen sources of peptone and ammonium nitrate. A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively. It was shown that rapeseed meal had a positive induction effect on protease secretion, contributing to the release of soluble protein from low water solubility solid rapeseed meal for an effective supply of available nitrogen during fermentation. Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione. The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.     

Testosterone regulates smooth muscle contractile pathways in the rat prostate: emphasis on PDE5 signaling

Testosterone (T) plays a permissive role in the development of benign prostatic hyperplasia (BPH), and phosphodiesterase 5 inhibitors (PDE5is) have been found to be effective for BPH and lower urinary tract symptoms (LUTS) in clinical trials. This study investigated the effect of T on smooth muscle (SM) contractile and regulatory signaling pathways, including PDE5 expression and functional activity in prostate in male rats (sham-operated, surgically castrated, and castrated with T supplementation). In vitro organ bath studies, real-time RT-PCR, Western blot analysis, and immunohistochemistry were performed. Castration heavily attenuated contractility, including sensitivity to phenylephrine with SM myosin immunostaining revealing a disrupted SM cell arrangement in the stroma. PDE5 was immunolocalized exclusively in the prostate stroma, and orchiectomy signficantly reduced PDE5 immunopositivity, mRNA, and protein expression, along with nNOS and ROKβ mRNA, whereas it increased eNOS plus α(1a) and α(1b) adrenoreceptor expression in castrated animals. The PDE5i zaprinast significantly increased prostate strip relaxation to the nitric oxide donor sodium nitroprusside (SNP) in control but not castrated rats. But SNP alone was more effective on castrated rats, comparable with sham treated with SNP plus zaprinast. T supplementation prevented or restored all above changes, including SNP and zaprinast in vitro responsiveness. In conclusion, our data show that T positively regulates PDE5 expression and functional activities in prostate, and T ablation not only suppresses prostate size but also reduces prostatic SM contractility, with several potential SM contraction/relaxation pathways implicated. Zaprinast findings strongly suggest a major role for PDE5/cGMP in this signaling cascade. PDE5 inhibition may represent a novel mechanism for treatment of BPH.     

Integument and sensory nerve differentiation ofDrosophila leg and wing imaginal discs in vitro

Summary An ultrastructural analysis is presented of the cuticular and neural structures formed by the prothoracic leg and wing imaginal discs of maleDrosophila melanogaster larvae during culture in vitro with 0.2 g/ml of -ecdysone. A pupal cuticle, and subsequently an imaginal cuticle with a well-defined epicuticle and a laminated endocuticle is formed. The ultrastructure of the epidermis and of cuticular structures such as bristles, trichomes, apodemes, and tracheoles is very similar to that found in situ. Dendrites and nerve cell bodies are formed in vitro, and sensory axons form nerve bundles similar to those of normal appendages in situ, despite their isolation from the central nervous system. It is concluded that at the ultrastructural level, differentiation in vitro closely parallels the normal course of development.