Production and molecular characterization of wide cross derivatives in rice

The reduced genetic variability of modern rice varieties (Oryza sativa L.) is of great concern because it reduces the possibilities of genetic gain in breeding programs. Introgression lines (ILs) containing genetic fragment from wild rice can be used to obtain new improved cultivars. The objective of the present study was to develop ILs from the cross between O. sativa x O. longistminata aiming to be used in rice breeding program. In the present study, 12 ILs were produced. Among them, three ILs were highly resistant to all the isolates of bacterial blight from North West Frontier Province (NWFP) of Pakistan. A 900 bp DNA fragment linked to Xa21 was raised in these introgression lines and in O. longistminata by a pair of primers confirming the presence of Xa21 gene in these lines. Results indicated that Xa21 has broad spectrum of resistance to bacterial blight and wild species are the useful source for resistance

Localizing introgression on the chromosome of rice by genomic in situ hybridization (GISH)

Genomic in situ hybridization was used to detect introgressed segment from Oryza australinesis onto the chromosomes of introgression line derived from the hybrid O. sativa x O. australinesis. Genomic DNA from Oryza australinesis was labeled with biotin and hybridized to the homologous sequences on the O. sativa chromosomes. The probe hybridization fluoresced green and non labeled O. sativa chromosomes appeared red or blue due to counterstaining with propidium iodide (PI) or 4,6-diamidino-2-phenylindole (DAPI). This differential painting of chromosomes unequivocally detected the introgressedsegment. Among the 200 cells analyzed, 6.5% of the cells showed  hybridization signal. Signal appeared on one chromosome in 5%, on two homologous chromosomes in 1% and on sister chromatids in 0.5%of the cells. Hybridization was seen on the short arm of the chromosome 12 of the introgression line

Application of the bacteriophage Mu-driven system for the integration/amplification of target genes in the chromosomes of engineered Gram-negative bacteria—mini review

The advantages of phage Mu transposition-based systems for the chromosomal editing of plasmid-less strains are reviewed. The cis and trans requirements for Mu phage-mediated transposition, which include the L/R ends of the Mu DNA, the transposition factors MuA and MuB, and the cis/trans functioning of the E element as an enhancer, are presented. Mini-Mu(LR)/(LER) units are Mu derivatives that lack most of the Mu genes but contain the L/R ends or a properly arranged E element in cis to the L/R ends. The dual-component system, which consists of an integrative plasmid with a mini-Mu and an easily eliminated helper plasmid encoding inducible transposition factors, is described in detail as a tool for the integration/amplification of recombinant DNAs. This chromosomal editing method is based on replicative transposition through the formation of a cointegrate that can be resolved in a recombination-dependent manner. (E-plus)- or (E-minus)-helpers that differ in the presence of the trans-acting E element are used to achieve the proper mini-Mu transposition intensity. The systems that have been developed for the construction of stably maintained mini-Mu multi-integrant strains of Escherichia coli and Methylophilus methylotrophus are described. A novel integration/amplification/fixation strategy is proposed for consecutive independent replicative transpositions of different mini-Mu(LER) units with “excisable” E elements in methylotrophic cells

Pattern of underreporting of Road Traffic Injuries (RTIs): An investigation of missing burden of RTIs in Pakistan

Background A complete and reliable Road Traffic Injuries (RTIs) data is essential for sustainable transport safety policy and health sector. This paper aims to determine the extent of underreporting of RTIs in Pakistan with police and Punjab Emergency Response Service (PERS), taking Lahore as a case study. Methods Official data of RTIs was collected from five public sector hospitals of the Lahore city and matched with police and PERS data to determine the extent of underreporting. Further a population-based data from 540 respondents of the city was collected to identify different factors affecting underreporting. Results Discordance analysis revealed that the extent of underreporting with police was 99% and with PERS was 39%. Binary logistic regression and Odd-Ratios (OR) informed that car occupants were 4.34 times more likely to report with police. While young people were less likely to report with both police and PERS at rate of 17% and 50% respectively. Different institutional issues in the system were also highlighted based on informal discussions. Conclusions The problem of underreporting is mostly observed for non-fatal crashes and young people. It also recommends to establish a road crash data unit at the city level to assess the actual burden of RTIs