大鼠内细胞团和胎儿神经干细胞构建嵌合体的潜力

嵌合体大鼠是研究人类疾病的重要动物模犁.用囊胚注射法研究了大鼠内细胞团(ICM)和胎儿神经干细胞(FNS)构建嵌合体的潜力.结果发现来自黑色(DA)大鼠第5天(D5)和第6天(D6)囊胚的ICM细胞注入D5 Sprague-Dawley(SD)大鼠囊胚后得到3只嵌合体大鼠:D5 SD大鼠ICM细胞注射入D5 DA囊胚后得到4只嵌合体大鼠:而体外培养的DA或SD人鼠ICM细胞注射后均未能获得嵌合体大鼠.本研究用大鼠胎儿神经干细胞(rFNS)和LacZ转染的rFNS构建嵌介体,未能获得嵌合体人鼠:但在LacZ转染的SD rFNS注射到DA大鼠囊胚后发育来的41只胎儿中,有2只胎儿其组织切片中发现少量LacZ阳性细胞.结果表明DA和SD大鼠ICM具有参与嵌合体发育的潜力,但ICM细胞经体外培养后构建嵌合体的潜力显著F降(P＜0.05);大鼠胎儿神经干细胞构建嵌合体的潜力较低,可能仅具有参与早期胚胎发育的潜力.     

Treatment of lentil (Lens culinaris. L) seeds with various concentrations of salts to check their efficiency against seed-borne mycoflora during storage

Seed sample of lentil collected from the Swabi district were treated with NaCl and KCl at 0.01, 0.1 and 1.0% (w/w). Seed-borne mycoflora was observed at 0, 20, 40, 60 and 80 day intervals. Seed treatment with both the salts was found to be effective against storage fungi; however, KCl was more efficient against storage mycoflora such as Aspergillus species when compared with NaCl. With the passage of time, the incidence of deep-seated fungi was observed in salt-treated seed samples while untreated seed sample showed heavy infestation by the species of Aspergillus. Seed viability also remained unaffected in storage, except in seeds heavily infested with seed-borne mycoflora. Aspergillus spp. were the main cause of seed rot. Surface sterilisation of seeds with 1% Na(OCl)₂ reduced the fungal infestation of seeds. Among various concentrations of salts, 0.1% (w/w) of both salts were better in controlling seed-borne mycoflora.     

Oral Ingestion of Transgenic RIDL Ae. aegypti Larvae Has No Negative Effect on Two Predator Toxorhynchites Species

Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered ‘sterile’ homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment.     

Genome‐wide association study identifies variation of glucosidase being linked to natural variation of the maximal quantum yield of photosystem II

The maximum quantum yield of photosystem II (as reflected by variable to maximum chlorophyll a fluorescence, F_v/F_m) is regarded as one of the most important photosynthetic parameters. The genetic basis underlying natural variation in F_v/F_m, which shows low level of variations in plants under non‐stress conditions, is not easy to be exploited using the conventional gene cloning approaches. Thus, in order to answer this question, we have followed another strategy: we used genome‐wide association study (GWAS) and transgenic analysis in a rice mini‐core collection. We report here that four single‐nucleotide polymorphisms, located in the promoter region of β‐glucosidase 5 (BGlu‐5), are associated with observed variation in F_v/F_m. Indeed, our transgenic analysis showed a good correlation between BGlu‐5 and F_v/F_m. Thus, our work demonstrates the feasibility of using GWAS to study natural variation in F_v/F_m, suggesting that cis‐element polymorphism, affecting the BGlu‐5 expression level, may, indirectly, contribute to F_v/F_m variation in rice through the gibberellin signaling pathway. Further research is needed to understand the mechanism of our novel observation.     

Changes in the photosynthesis properties and photoprotection capacity in rice (Oryza sativa) grown under red,blue, or white light

Photosynthesis Research - Non-photochemical quenching (NPQ) of the excited state of chlorophyll a is a major photoprotective mechanism plants utilize to survive under high light. Here, we report...     

Signaling Crosstalk of FHIT,p53, and p38 in etoposide-induced apoptosis in MCF-7 cells

Fragile histidine trail (FHIT) is a tumor suppressor in response to DNA damage which has been deleted in various tumors. However, the signaling mechanisms and interactions of FHIT with regard to apoptotic proteins including p53 and p38 in the DNA damage-induced apoptosis are not well described. In the present study, we used etoposide-induced DNA damage in MCF-7 as a model to address these crosstalks. The time course study showed that the expression of FHIT, p53, and p38MAPK started after 1 hour following etoposide treatment. FHIT overexpression led to increase p53 expression, p38 activation, and augmented apoptosis following etoposide-induced DNA damage compared to wild-type cells. However, FHIT knockdown blocked p53 expression, delayed p38 activation, and completely inhibited etoposide-induced apoptosis. Inhibition of p38 activity prevented induction of p53, FHIT, and apoptosis in this model. Thus, activation of p38 upon etoposide treatment leads to increase in FHIT and p53 expression. In p53 knockdown MCF-7, the FHIT induction was hampered but p38 activation was induced in lower doses of etoposide. In p53 knockdown cells, inhibition of p38 induced FHIT expression and apoptosis. Our data demonstrated that the exposure of MCF-7 cells to etoposide increases apoptosis through a mechanism involving the activation of the p38-FHIT-p53 pathway. Moreover, our findings suggest signaling interaction for these pathways may represent a promising therapy for breast cancer.     

Possible evidence for shift work schedules in the media workers of the ant species Camponotus compressus

The locomotor activity rhythm of the media workers of the ant species Camponotus compressus was monitored under constant conditions of the laboratory to understand the role of circadian clocks in social organization. The locomotor activity rhythm of most ants entrained to a 24 h light/dark (12:12 h; LD) cycle and free-ran under constant darkness (DD) with circadian periodicities. Under entrained conditions about 75% of media workers displayed nocturnal activity patterns, and the rest showed diurnal activity patterns. In free-running conditions these ants displayed three types of activity patterns (turn-around). The free-running period (τ) of the locomotor activity rhythm of some ants (10 out of 21) showed period lengthening, and those of a few (6 out of 21) showed period shortening, whereas the locomotor activity rhythm of the rest of the ants (5 out of 21) underwent large phase shifts. Interestingly, the pre-turn-around τ of those ants that showed nocturnal activity patterns during earlier LD entrainment was shorter than 24 h, which became greater than 24 h after 6-9 days of free-run in DD. On the other hand, the pre-turn-around τ of those ants, which exhibited diurnal patterns during earlier LD entrainment, was greater than 24 h, which became shorter than 24 h after 6-9 days of free-run in DD. The patterns of activity under LD cycles and the turn-around of activity patterns in DD regime suggest that these ants are shift workers in their respective colonies, and they probably use their circadian clocks for this purpose. Circadian plasticity thus appears to be a general strategy of the media workers of the ant species C. compressus to cope with the challenges arising due to their roles in the colony constantly exposed to a fluctuating environment.     

Synthesis and immunomodulatory properties of selected oxazolone derivatives

Eleven oxazolone derivatives were synthesized and characterized by (1)H NMR, EI, IR and UV spectroscopic and CHN analysis. Three compounds, 4-[(E)-(4-nitrophenyl)methylidene]-2-phenyl-1,3-oxazol-5(4H)-one (11), 4-[(E)-(4-methoxyphenyl)methylidene]-2-methyl-1,3-oxazol-5-one (12) and 4-[(E)-(4-nitrophenyl)methylidene]-2-methyl-1,3-oxazol-5(4H)-one (13) were screened for phagocyte chemiluminescence, neutrophil chemotaxis, T-cell proliferation, cytokine production from mononuclear cells and cytotoxicity. 4-[(E)-(4-Nitrophenyl)methylidene]-2-methyl-1,3-oxazol-5(4H)-one (13) was found to be the most potent immunomodulator in the series.     

Evaluation of the leptin receptor in human spermatozoa

Background  

Leptin, a 167 amino acid peptide hormone, profoundly effects reproduction exerting its biological effects via interaction with the leptin receptor (ObR) which is widely expressed on peripheral tissues. In this study, we have attempted to assess leptin receptor expression in the spermatozoa of fertile males and those diagnosed with male factor infertility; both at the mRNA or protein levels.