Characterization of wide cross derivatives in rice Oryza sativa L. using genomic in situ hybridization (GISH)

Interspecific crosses provide a bridge by which the gene pool of rice can be increased. Introduction of alien genes requires hybridization followed by meiotic pairing and recombination between the chromosomes of cultivated and wild species. Attempts have been made to visualize the genomic constitution of wide-cross derivatives. Genomic in situ hybridization was used to detect Oryza australiensis chromosomes and introgressed segment from O. australiensis into the Oryza sativa background. Genomic DNA from O. australiensis was labeled with biotin-14-dATP and hybridized to the homologous chromosomes in hybrids, back cross progenies, monosomic alien addition line (MAAL) and introgression line. The probe hybridization fluoresced green and non-labeled O. sativa chromosomes appeared red due to counterstaining with propidium iodide (PI). This differential painting of chromosomes unequivocally detected the O. australiensis chromatin introgressed into the O. sativa genome. The probe produced uniform labeling pattern over the entire length of all the O. australiensis chromosomes. Genomic in situ hybridization (GISH) detected 12 O. australiensis chromosomes in the hybrid, O. sativa x O. australiensis in BC1 progenies, and a single chromosome in MAAL. Small segment of O. australiensis was localized on the chromosome 12 of the introgression line. However, results showed that GISH is a powerful technique to be used as an aid in selecting segregating progenies.Key words: Genomic in situ hybridization, wide hybrid, localizing introgression

Genomic affinity between Oryza sativa and Oryza brachyantha as revealed by in situ hybridization and chromosome pairing

Genomic affinity between Oryza sativa (2n = 24 AA), and Oryza brachyantha (2n = 24 FF) was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen andspikelet sterility. The chromosome pairing was examined in pollen mother cells of O. brachyantha, O.sativa and the hybrid between O. sativa and O. brachyantha. The hybrid was highly sterile with no pollen stain ability. Both parents showed regular meiosis with normal chromosome pairing. The F1hybrid exhibited limited chromosome pairing. On an average, 0-2 bivalents and 20-24 univalents were recorded at metaphase-1 and 0 - 1 univalent at diakinesis. The most frequent configuration was twobivalents and twenty univalent. The meiosis was highly irregular showing unequal distribution of chromosomes at anaphase, formation of multipolar bodies and variation in the cell cycle of both genomes. GISH revealed unequivocal discrimination of O. brachyantha chromosomes as appeared red from O. sativa chromosomes that fluoresced yellow. No cross hybridization was examined between the labeled genomic DNA of O. brachyantha and the chromosomes of O. sativa. Mitotic chromosomes of O. brachyantha and O. sativa, in the hybrid, were discriminated by GISH. High sterility in this hybrid could be due to abnormal meiosis and lack of pairing

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

Historical perspective of in situ hybridization for the analysis of genomic constitution of plants

In situ hybridization involves hybridization of DNA or RNA probes to the cytological preparations. The technique originally used auto-radiographic labeling to map both repetitive and low copy DNA sequences. The problem associated with this technique was its short half life, lack of safety and long exposure time which hindered its widespread use in DNA hybridization. To overcome these problems, non isotopic in situ hybridization was developed for use in animal and plant species. In the last decade, the development of haptens and fluorochromes enabled simultaneous multicolored detection of differentially labeled probes. Characterization of parental genomes in interspecific hybrids, restructured chromosomes, gene mapping, detecting nature of chromosome pairing, establishing phylogenetic relationship among the species and localizing introgressed segment have been successfully achieved by fluorescence in situ hybridization. Keywords: In situ hybridization, phylogenetic relationship, homoeologous pairin

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

Efficacy of Avicennia marina (Forsk.) Vierh. leaves extracts against some atmospheric fungi

Crude ethanolic extract of Avicennia marina leaves was tested against seven allergenic fungi viz., Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Cladosporium herbarum, Penicillium notatum and Saccharomyces cerevisiae using five different solvents: dimethyl sulphoxide (DMSO), distilled water (DW), chloroform, ethanol and acetone at 2000, 4000 and 6000 ppm doses. Dose dependent tendency in the increase or decrease in the growth of fungi was observed. Two synthetic drugs miconazole and amphotericin-B were used as positive control. Miconazole was 100% effective against A. alternata, C. herbatum, P. notatum and S. cerevisiae with the concentrations of 95.00 ± 1.62, 78.00 ± 4.99, 100.00 ± 0.69 and 110.00 ± 2.33 (μg/ml of SDA medium), respectively. Amphotericin-B completely controlled the growth of A. flavus, A. fumigatus and A. niger in the concentration of 24.00 ± 17.00, 30.00 ± 15.66 and 18.00 ± 18.34 (μg/ml of SDA medium), respectively. Distilled water and DMSO were considered to be the most effective solvents preventing 83.00 ± 4.73% growth of A. niger, 80.33 ± 5.60% A. flavus, 78.58 ± 3.18% A. alternata, 72.91 ± 7.96% P. notatum, 65.25 ± 3.55% C. herbarum, 63.25 ± 4.52% A. fumigatus and 48.5 ± 7.89% S. cerevisiae. Statistically, the results were compared with negative control and found to be highly significant (p<0.01).Key words: Allergenic fungi, inhibition, dose dependent, growth control, synthetic drugs

Intrusion detection systems for smart home IoT devices: experimental comparison study

Smart homes are one of the most promising applications of the emerging Internet of Things (IoT) technology. With the growing number of IoT related devices such as smart thermostats, smart fridges, smart speaker, smart light bulbs and smart locks, smart homes promise to make our lives easier and more comfortable. However, the increased deployment of such smart devices brings an increase in potential security risks and home privacy breaches. In order to overcome such risks, Intrusion Detection Systems are presented as pertinent tools that can provide network-level protection for smart devices deployed in home environments. These systems monitor the network activities of the smart home-connected de-vices and focus on alerting suspicious or malicious activity. They also can deal with detected abnormal activities by hindering the impostors in accessing the victim devices. However, the employment of such systems in the context of a smart home can be challenging due to the devices hardware limitations, which may restrict their ability to counter the existing and emerging attack vectors. Therefore, this paper proposes an experimental comparison between the widely used open-source NIDSs namely Snort, Suricata and Bro IDS to find the most appropriate one for smart homes in term of detection accuracy and resources consumption including CP and memory utilization. Experimental Results show that Suricata is the best performing NIDS for smart homesComment: 7 pages, 4 figures, 2 table

Novel insights into the cardio-protective effects of FGF21 in lean and obese rat hearts

Aims: Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia. Methods and Results: FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased. Conclusion: In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia