Alien genome mobilization and fixation utilizing an apomixis mediated genome addition (AMGA) strategy in Pennisetum to improve domestication traits of P. squamulatum.

KEY MESSAGE: An approach to release 'frozen' variability in apomictic species using sexuality of another species, eventually its utilization in crop improvement and de-novo domestication of crop wild relatives is presented. Pennisetum squamulatum, a secondary gene pool species of pearl millet (P. glaucum), harbours many desirable traits. However, it was neither utilized to improve pearl millet fodder traits nor improvement of its own domestication traits was attempted, due to the complexities of genomes and apomictic reproduction. To overcome this, we followed an Apomixis Mediated Genome Addition (AMGA) strategy and utilized the contrasting reproductive capacities (sexuality and apomixis) of both the species to access the otherwise un-available variability embedded in P. squamulatum. Segregating population of interspecific hybrids exhibited significant variability and heterosis for desired morphological, agronomical, and nutritional traits. Elite apomictic and perennial hybrids were evaluated in breeding trials, and eventually a novel grass cultivar was released for commercial cultivation in India. The performance of newly developed cultivar was superior to other adapted perennial grasses of arid and semi-arid rangelands. Through AMGA, the sexuality of one species was successfully utilized to 'release' the 'frozen' variability embedded in another species. Subsequently, the hybrids representing desirable trait combinations were again 'fixed' utilizing the apomixis alleles from the male parent in a back-and-forth apomixis-sexual-apomixis selection cycle. This study also demonstrated the potential of AMGA to improve crop relatives through genomes introgression as well as de novo domestication of new crops from wild species.

Complementary gene interaction and xenia effect controls the seed coat colour in interspecific cross between Trifolium alexandrinum and T. apertum.

Trifolium alexandrinum (Egyptian clover) is a widely cultivated winter annual fodder. Present work deals with inheritance of the seed coat colour in segregating progenies of the interspecific cross between T. alexandrinum and T. apertum. Although, both the parent species possessed yellow seed coat, the F1 seeds were black coloured in the reciprocal cross (T. apertum × T. alexandrinum). Seeds borne on individual F2 plants and the advancing generations segregated in yellow and black seed coat colour, which confirmed xenia effect. F2 seeds collected from individual F1 plants exhibited nine black and seven yellow segregation ratio. The segregation of the seed coat colour recorded from F3 to F5 generations revealed that yellow seed coat was true breeding (i.e. non-segregating) in this interspecific cross (including the reciprocal crosses). However, the black seeded progenies were either true breeding or segregated in nine black: seven yellow ratio or three black: one yellow ratio suggesting a complementary gene interaction or duplicate recessive epistasis. It indicated that the seed coat colour is controlled by complementary gene interaction along with xenia effect in interspecific crosses between T. alexandrinum and T. apertum. Occurrence of the complementary genes across the species could suggest T. apertum to be the progenitor of T. alexandrinum. Inheritance of seed coat colour in reference to its importance in Egyptian clover breeding is also discussed.

Transcriptomic data of pre-meiotic stage of floret development in apomictic and sexual types of guinea grass (Panicum maximum Jacq.).

Guinea grass (Panicum maximum Jacq), an important fodder crop of humid and sub-humid tropical regions, reproduces through apomixis, a method of clonal propagation through seeds. Lack of knowledge of the genetic and molecular control of this phenomena has hindered the genetic improvement of this crop. The dataset provided here represents the first RNA-Seq based assembly and analysis of florets at pre-meiotic stage from the apomictic and sexual genotypes of guinea grass. The raw sequence files in FASTQ format were deposited in the NCBI SRA database with accession number SRP115883. A total of 24.8 Gb raw sequence data, corresponding to 17,96,65,827 raw reads was obtained by paired end sequencing. We used Trinity for de-novo assembly and identified 57,647 transcripts in sexual and 49,093 transcripts in apomictic type. This transcriptome data will be useful for identification and comparative analysis of genes regulating the mode of reproduction in grasses.

Nano silver-embedded electrospun nanofiber of poly(4-chloro-3-methylphenyl methacrylate): use as water sanitizer.

Water contaminated with microorganisms causes numerous diseases and is a major concern for public health. In search of a simple material which can provide clean water free from pathogens, nanofibers of poly(4-chloro-3-methylphenyl methacrylate, abbreviated as CMPMA, and nano Ag-doped poly(CMPMA) composite nanofibers were used to decontaminate water from microorganisms such as Escherichia coli and Bacillus subtilis. Nanofibers were prepared by electrospinning. X-ray diffraction (XRD) and transmission electron microscopy (TEM) provide the diameters of the Ag nanoparticles which are in the range 18-21 and 13-18 nm. The diameter of the poly(CMPMA) and nano Ag-doped poly(CMPMA) composite nanofiber is seen to vary between 400 and 700 nm with the change of the processing parameters. Optimum parameters for uniform nanofibers have been obtained. The morphology of the fibers is derived from scanning electron microscopy (SEM). The superiority of the nano Ag-doped poly(CMPMA) composite nanofiber was established.

Late onset of rhegmatogenous retinal detachments after successful posterior segment intraocular foreign body removal.

BACKGROUND/AIM: A lack of data exists concerning the development of late postoperative, non-proliferative vitreoretinopathy (PVR), rhegmatogenous retinal detachments (RRDs) after successful posterior segment intraocular foreign body (PSIOFB) removal. The authors present a series of PSIOFB cases over several years with posterior hyaloid separation resulting in RRD in two patients, 4 and 8 months after initial injury and vitrectomy. This report aims to increase awareness concerning the possibility of late RRDs complicating PSIOFB injuries and to emphasise careful long term observation. METHODS: Medical records of consecutive cases referred for presumed PSIOFB injury during a 4 year period were retrospectively reviewed. All eyes referred for presumed PSIOFB injuries were included. RESULTS: 11 patients were included in the series. Two patients had eyes so badly injured by large PSIOFBs that primary globe closure was followed within days by enucleation. Nine patients underwent pars plana vitrectomy for PSIOFB removal. Two patients experienced late RRDs that were managed with excellent long term visual outcomes. CONCLUSIONS: Late RRD may occur following successful removal of PSIOFBs, even several months after initial management. These RRDs may be successfully managed with a variety of methods, depending upon the extent and location of the detachment and causative break as well as surgeon comfort and preference.

Interspecific hybridization of Trifolium alexandrinum with T. constantinopolitanum using embryo rescue.

The embryo rescue technique was successfully used to raise hybrids between Trifolium alexandrinum and T. constantinopolitanum. As a result of its narrow genetic base, genetic improvement in Egyptian clover (syn. Berseem; T. alexandrinum), an important fodder crop in tropical and subtropical countries, is hampered, thereby making it imperative to introduce alien genes from related species. In a conventional interspecific hybridization program, hybrids could not be raised due to post-fertilization barriers. Of the several combinations tried, pollination 2 days after emasculation was found to be the best. Globular embryos were observed 5-7 days after pollination (DAP), followed by heart-shaped embryos 10-12 DAP. Embryos excised at the heart-shaped stage responded well to EC3 culture medium. Of 612 crosses, 33 healthy embryos could be excised and cultured on EC3 medium. The plumule emerged 8-12 days following inoculation. The embryo-rescued plants were hardened, inoculated with Rhizobium and transferred to the field. The hybrids showed intermediate morphological features with reduced pollen fertility (55-65%) and a chromosomal complement of 2n = 16. Biochemical characterization using isozymes confirmed hybridity.

Modulation of enzymes involved in folate dependent one-carbon metabolism by gamma-radiation stress in mice.

The role of various enzymes in folate dependent one-carbon metabolism, which are involved in mobilizing the folate pool for DNA synthesis and the DNA methylation reaction, was investigated. Male Swiss mice (6 weeks old) were subjected to 2, 5 and 7 Gy total body gamma-irradiation. The animals were killed at intervals of 24, 48, 72, 96, 120 and 192 h and the livers were removed. Using a 12000 x g supernatant of 10% tissue homogenate, the activities of dihydrofolate reductase, thymidylate synthase and methylenetetrahydrofolate reductase were determined. The profiles of these folate enzymes were correlated to DNA damage by monitoring p53 protein profile and by comet tail moment analysis. A significant increase in activity of dihydrofolate reductase and thymidylate synthase was observed up to 96 h post-irradiation and the activity subsided thereafter, reaching control value after 192 h. A sharp decline in methylenetetrahydrofolate reductase activity was observed until 192 h after irradiation. Total folates declined by 54% after 96 h following irradiation, and p53 protein concentration in nuclei increased after irradiation, proportionate to radiation dose, and subsided slowly. Thus results indicate a significant drop in total folate levels and rise in p53 protein concentration in the liver after total body gamma-irradiation. It may appear that, under radiation stress conditions, levels of enzymes involved in one-carbon metabolism for DNA repair, are modulated up to a certain time interval, in a dose specific manner. It may also appear that the requirements of folate for nucleotide base synthesis seem to be met at the expense of other one-carbon transfer reactions.

Peptide mapping and disulfide bond analysis of myeloid progenitor inhibitory chemokine and keratinocyte growth factor by matrix-assisted laser desorption ionization mass spectrometry.

Peptide mapping and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) were conducted to characterize the human genome-based recombinant proteins. Accurate mass values for the deleted forms of the myeloid progenitor inhibitory factor chemokine (MPIF-1d23), and the keratinocyte growth factor (KGF-2d33) were measured as 8848.55 +/- 0.25 and 16,175.87 +/- 0.89 Da, respectively. The mass accuracy of delayed ion extraction MALDI-MS measurements was within 20 ppm of the cDNA predicted value. Reduction and alkylation of the chemokine showed the presence of six cysteine residues and three disulfide bonds. Additional confirmation of disulfide bonding among the cysteine residues of the chemokine was demonstrated by identifying the RP-HPLC separated tryptic and endoprotease Glu-C peptides. Three methionine residues of the chemokine were identified by MALDI-MS of its cyanogen bromide (CNBr) cleavage products. The KGF-2d33 growth factor, however, lacked the disulfide bonding between the two-cysteine residues and contained two free sulfhydryl groups. Direct analysis of the growth factor CNBr digest showed 7542.99, 4993.4, and 3107.7 Da peptides, which identified the methionine residues. Peptide mapping mass spectrometry indicated that host-specific posttranslational modifications had not influenced the gene expression work.

Studies on the effect of fenbendazole and mebendazole on some enzymes of swine kidney worm Stephanurus dentatus.

The effect of fenbendazole and mebendazole on the activity of some enzymes of the homogenates of swine kidney worm Stephanurus dentatus was investigated. Fenbendazole at 10(-5) M inhibited malate oxidation by 49% and 51% and oxaloacetate reduction by 33% and 40% whereas, mebendazole at 10(-5) M diminished malate oxidation by 25% and 35% and oxaloacetate reduction by 12% and 14% in male and female S. dentatus, respectively. Lactate dehydrogenase activity was inhibited by 45% and 50% in male and female worm respectively by 10(-5) M fenbendazole. Aldolase activity in both male and female S. dentatus was inhibited by 10(-5) M fenbendazole and mebendazole. Fenbendazole at 10(-5) M caused moderate inhibition of acid and alkaline phosphomonoesterases but mebendazole did not show a significant effect on these enzymes. Cholinesterase activity was not affected significantly with either compound. The possible mode of action of the two compounds is compared.

Planting stress, water status and non-structural carbohydrate concentrations in Corsican pine seedlings.

Two-year-old Corsican pine (Pinus nigra ssp. laricio var. Corsicana) seedlings were either well watered or subjected to a moderate drought for one month before being lifted from the nursery bed on October 9 and transplanted. Well-watered, non-transplanted seedlings served as controls. Needle predawn water potential (Psi(wp)), non-structural carbohydrate concentrations and plant development (survival, bud break, shoot elongation) were assessed before and during the first growing season after transplanting. On April 16, just before bud break, Psi(wp) was lower for the well-watered + transplanted and drought-conditioned + transplanted seedlings (Psi(wp) = -1.45 and -1.83 MPa, respectively) than for the controls (Psi(wp) = -0.56). There was a close relationship between the Psi(wp) measured on April 16 and bud break, shoot elongation and plant survival during the following growing period. Above a Psi(wp) of -1.1 MPa, all plants developed normally. Between -1.1 MPa and -1.6 MPa, bud break, and thus shoot elongation, did not occur in all plants. Between -1.6 MPa and -2.1 MPa, the plants were characterized by the absence of shoot growth, but mortality was zero. Below -2.1 MPa, there was a large increase in plant mortality. On April 16, starch concentrations were markedly lower in the roots of transplanted seedlings than in the controls. There was a positive correlation between Psi(wp) and root starch concentration. The Psi(wp) (-2.3 MPa) at which complete starch depletion was observed in the roots corresponded to the Psi(wp) below which plants did not survive. These results suggest that mechanisms specifically linked to altered water status and metabolic processes associated with altered carbohydrate status are involved in transplanting stress; however, it was not possible to disentangle the two effects. Drought conditioning did not lead to a marked increase in soluble carbohydrate concentrations, as reported for other species, and did not increase plant tolerance to transplanting stress.

Prevention of venous thromboembolism after total knee replacement by high-dose aspirin or intermittent calf and thigh compression.

A prospective study of patients undergoing total knee replacement was carried out by using a combination of 125I-fibrinogen scanning and phlebography, and showed a high incidence of venous thromboembolic disease (TE). Ventilation-perfusion lung scanning was performed to detect pulmonary emboli in most patients. High doses of aspirin and an intermittent low-pressure pneumatic compression device (IPCD) were effective, even in women, in preventing TE. Low doses of aspirin and placebo were equally ineffective in preventing TE. Lung-scan abnormalities compatible with pulmonary emboli were found in six out of 10 patients with isolated calf-vein thrombi. Conventional tests of platelet function did not predict the development of TE. No significant differences were found between the patients receiving low and high doses of aspirin with respect to the mean template bleeding time or platelet aggregation in response to adenosine diphosphate, collagen, and epinephrine, although these variables were significantly abnormal in the two groups receiving aspirin compared with those treated with placebo and the IPCD. Thus high doses of aspirin and a new low-pressure IPCD were effective in preventing venous TE in patients (predominantly women) undergoing total knee replacement.

Fatal anaphylaxis-like reaction induced by yeast mannans in nonsensitized mice.

Some yeast mannans increased vascular permeability and caused anaphylaxis-like reactions, fatal in some cases, in nonsensitized CFW mice. In SWR mice deficient in the complement system component C5, anaphylactic shock did not develop after the injection of mannans but was readily induced by goat serum after the mice had been sensitized with Bordetella pertussis and goat serum. The observed biological activity of the yeast mannans appears to depend upon the alpha(1 --> 2) and alpha(1 --> 6) linkages in their main chain. Their relative inactivity in C5-deficient mice and the consumption of whole hemolytic complement after their addition to normal mouse serum suggest that yeast mannans may activate late-acting complement components to produce anaphylatoxin from complement components C5 and C3.