ColK is a multicopy naturally occurring plasmid, that is very stably maintained in bacterial host... more ColK is a multicopy naturally occurring plasmid, that is very stably maintained in bacterial host cells. This work shows that the plasmid encodes a stability determinant designated ckr. that is involved in promoting site-specific recombination in multimeric plasmids, efficiently converting them to monomers. This apparently ensures stability by maximizing the number of segregating units at cell division. ckr has been located to a 0.37 kb fragment in ColK, its DNA sequence is highly homologous with that of cer (stability determinant of ColE1, a related plasmid to ColK). Recombination has been found to occur both between directly repeated cer copies and a direct repeat of one copy of cer and one of ckr and results in the deletion of the internal fragment between them. Inversion has been shown to occur between two cer copies in inverted repeat and in a substrate containing a copy of cer and a copy of ckr in inverted repeat. Both deletion and inversion are highly efficient
To determine the epidemiology of dermatophytosis in Palestinian patients, detect changes in the e... more To determine the epidemiology of dermatophytosis in Palestinian patients, detect changes in the etiological agents during the last three decades, and to correlate between concomitant tinea pedis infections, and other cutaneous lesions. 220 suspected dermatophytosis patients were involved in this study. In an additional 38 cases, where consultation was prompted by tinea pedis, the presence of other lesions of concomitant dermatophytosis was studied, to further investigate the diagnosis. Clinical specimens were collected and identification of dermatophyte species was based on gross and microscopic morphology. Epidemiology of tinea capitis has gone the most radical changes in Palestine in the last three decades, with the zoophilic dermatophyte Microsporum canis replacing Trichophyton violaceum, becoming the predominant causative agent. During this study, 21.6% (38/176) patients with tinea pedis and concomitant lesions caused by the same dermatophytes at sites distant from the primary l...
Some naturally occurring plasmids like ColEl and ColK have been found to harbor site-specific rec... more Some naturally occurring plasmids like ColEl and ColK have been found to harbor site-specific recombination sequences, the core regions of such sequences have shown 82% homology when so aligned. The high degree of homology was the basis for testing the possibility of recombination between them. The sequences were cloned in the vector pUC18 in opposite orientation and introduced into E.coli cells and the analysis of the DNA harvested from the transformed cells showed that the sequences had undergone recombination, such recombination, such recombination was of the site-specific mode. No sequence deletion was detected, as was the case with such sequences when they were in the same orientation, Interestingly the event of recombination in this case resulted in the inversion of the region located between the recombination sites of the two cloned fragments.
Journal of Fruit and Ornamental Plant Research, 2010
The effect of different levels of naphthaleneacetic acid (NAA) and benzyladenine (BA) on shoot mu... more The effect of different levels of naphthaleneacetic acid (NAA) and benzyladenine (BA) on shoot multiplication and regeneration of Petunia hybrida was studied. Regenerated shoots from leaf explants were grown ex vitro for analysis of somaclonal variation. Seeds of Petunia hybrida were germinated in vitro on MS basal medium. The seedlings were used as a source of explants for the multiplication and regeneration experiments. For the shoot multiplication experiment, shoot explants taken from germinated seedlings were cultured on MS basal media supplemented with different concentrations of BA (0.1, 0.4, 0.8 mg l − 1) and NAA at concentration of 0.1 mg l − 1. Highest number of axillary shoot was obtained on medium supplemented with 0.8 mg l-1 BA and 0.1 mg l − 1 NAA. For regeneration experiments, leaf sections taken from germinated seedlings were cultured onto MS media supplemented with three levels of BA (0.5, 1.0 and 2.0 mg l − 1) and 0.5 mg l − 1 NAA. The highest shoot regeneration rate (45%) was observed in MS medium supplemented with 2 mg l − 1 BA. For the evaluation of somaclonal variation, lateral bud explants were taken from pink colored petunia plants that were grown in the greenhouse. The buds were disinfected and cultured on MS basal media supplied with 30 mg l − 1 gentamycin sulfate and 30 mg l − 1 Benlate. After shoots grew, leaf sections were then taken from them shoots and cultured onto shoot regeneration medium (MS medium supplemented with 2 mg l − 1 BA). The regenerated adventitious shoots were cultured on MS medium without growth regulator. These shoots were then rooted, acclimatized and transferred to the greenhouse for evaluation. Two forms of leaf shape (orbicular and elliptic) and three flower colors (violet, purple and light pink) appeared on the plantlets.
The legJ subfamily of genes in garden pea, Pisum sativum L., encodes "minor" legumin seed storage... more The legJ subfamily of genes in garden pea, Pisum sativum L., encodes "minor" legumin seed storage protein polypeptides. Data on the differential expression of the 3 genes (legJ,K,L) within this subfamily is reported. The expression of one gene (legJ) is specifically upregulated during the desiccation phase of cotyledon development, when other storage protein genes are downregulated. The complete sequence of a second gene in the subfamily, legK, shows that the failure to observe any expression ofthis gene is due to the mutation of its initiator ATG (methionine) codon to a GTG (valine) codon. The third gene in the subfamily, legL, shows maximal expression during the cotyledon expansion phase of seed development, Le. like other storage protein genes. Evidence for the use of alternative polyadenylation addition signal sequences in these genes is also presented.
We have identified and characterised a stability function encoded by the high copy plasmid ColK. ... more We have identified and characterised a stability function encoded by the high copy plasmid ColK. The function is analogous to ColE1 cer and maximises stability by maintaining plasmids in the monomeric state. In vivo recombination between cer and ckr (which share more than 90% homology at the DNA sequence level) produced a functional hybrid. Sequence analysis of hybrids indicates that recombination involving cer and ckr is site-specific and occurs within a 35 bp region of DNA which contains palindromic symmetry.
Table of Contents No. Content Page Dedication iii Acknowledgment iv Declaration v List of abbrevi... more Table of Contents No. Content Page Dedication iii Acknowledgment iv Declaration v List of abbreviations vi List of contents vii List of tables ix List of figures x Abstract xi Chapter One: General Introduction 1 1.1 General properties of fungi 2 1.2 Dermatophytes 3 1.3 Ecology 4 1.4 Geographical distribution of the dermatophytes 4 1.5 Dermatophytosis transmission 5 viii No. Content Page Chapter Three: Results and Discussion 27 3.1 Epidemiology of dermatophytes infections 28 3.2 Genotypical pattern of dermatophytes strains by using RAPD analysis primers 36 3.2.1 RAPD-PCR amplification 36 3.2.2 RAPD Data analysis 39 References 43
A library of pea (Pisum sativum L) genomic DNA in bacteriophage EMBL3 was screened for seed stora... more A library of pea (Pisum sativum L) genomic DNA in bacteriophage EMBL3 was screened for seed storage protein genes of the legumin and vicilin families. Three genomic clones were isolated. One of the clones was found to contain a gene in the Leg A sub-family which was designated Leg E. The nucleotide and predicted amino acid sequence of Leg E were compared to those of Leg A. The coding sequences of both genes are strongly homologous with only 9 bases difference out of 1560 bases. A second genomic clone contained two genes from the Leg J subfamily. Leg J and Leg K. The clone was shown to overlap with a genomic clone isolated previously, JC5 (Gatehouse et al. 1988). Strong homology was found between the Leg K and Leg J sequences. The Leg K gene is predicted to be pseudogene, due to the conversion of the ATG methionine start codon to a GTG valine codon and the presence of a stop codon in the 5' end of the coding sequence in the reading frame predicted by the first subsequent start co...
ColK is a multicopy naturally occurring plasmid, that is very stably maintained in bacterial host... more ColK is a multicopy naturally occurring plasmid, that is very stably maintained in bacterial host cells. This work shows that the plasmid encodes a stability determinant designated ckr. that is involved in promoting site-specific recombination in multimeric plasmids, efficiently converting them to monomers. This apparently ensures stability by maximizing the number of segregating units at cell division. ckr has been located to a 0.37 kb fragment in ColK, its DNA sequence is highly homologous with that of cer (stability determinant of ColE1, a related plasmid to ColK). Recombination has been found to occur both between directly repeated cer copies and a direct repeat of one copy of cer and one of ckr and results in the deletion of the internal fragment between them. Inversion has been shown to occur between two cer copies in inverted repeat and in a substrate containing a copy of cer and a copy of ckr in inverted repeat. Both deletion and inversion are highly efficient
To determine the epidemiology of dermatophytosis in Palestinian patients, detect changes in the e... more To determine the epidemiology of dermatophytosis in Palestinian patients, detect changes in the etiological agents during the last three decades, and to correlate between concomitant tinea pedis infections, and other cutaneous lesions. 220 suspected dermatophytosis patients were involved in this study. In an additional 38 cases, where consultation was prompted by tinea pedis, the presence of other lesions of concomitant dermatophytosis was studied, to further investigate the diagnosis. Clinical specimens were collected and identification of dermatophyte species was based on gross and microscopic morphology. Epidemiology of tinea capitis has gone the most radical changes in Palestine in the last three decades, with the zoophilic dermatophyte Microsporum canis replacing Trichophyton violaceum, becoming the predominant causative agent. During this study, 21.6% (38/176) patients with tinea pedis and concomitant lesions caused by the same dermatophytes at sites distant from the primary l...
Some naturally occurring plasmids like ColEl and ColK have been found to harbor site-specific rec... more Some naturally occurring plasmids like ColEl and ColK have been found to harbor site-specific recombination sequences, the core regions of such sequences have shown 82% homology when so aligned. The high degree of homology was the basis for testing the possibility of recombination between them. The sequences were cloned in the vector pUC18 in opposite orientation and introduced into E.coli cells and the analysis of the DNA harvested from the transformed cells showed that the sequences had undergone recombination, such recombination, such recombination was of the site-specific mode. No sequence deletion was detected, as was the case with such sequences when they were in the same orientation, Interestingly the event of recombination in this case resulted in the inversion of the region located between the recombination sites of the two cloned fragments.
Journal of Fruit and Ornamental Plant Research, 2010
The effect of different levels of naphthaleneacetic acid (NAA) and benzyladenine (BA) on shoot mu... more The effect of different levels of naphthaleneacetic acid (NAA) and benzyladenine (BA) on shoot multiplication and regeneration of Petunia hybrida was studied. Regenerated shoots from leaf explants were grown ex vitro for analysis of somaclonal variation. Seeds of Petunia hybrida were germinated in vitro on MS basal medium. The seedlings were used as a source of explants for the multiplication and regeneration experiments. For the shoot multiplication experiment, shoot explants taken from germinated seedlings were cultured on MS basal media supplemented with different concentrations of BA (0.1, 0.4, 0.8 mg l − 1) and NAA at concentration of 0.1 mg l − 1. Highest number of axillary shoot was obtained on medium supplemented with 0.8 mg l-1 BA and 0.1 mg l − 1 NAA. For regeneration experiments, leaf sections taken from germinated seedlings were cultured onto MS media supplemented with three levels of BA (0.5, 1.0 and 2.0 mg l − 1) and 0.5 mg l − 1 NAA. The highest shoot regeneration rate (45%) was observed in MS medium supplemented with 2 mg l − 1 BA. For the evaluation of somaclonal variation, lateral bud explants were taken from pink colored petunia plants that were grown in the greenhouse. The buds were disinfected and cultured on MS basal media supplied with 30 mg l − 1 gentamycin sulfate and 30 mg l − 1 Benlate. After shoots grew, leaf sections were then taken from them shoots and cultured onto shoot regeneration medium (MS medium supplemented with 2 mg l − 1 BA). The regenerated adventitious shoots were cultured on MS medium without growth regulator. These shoots were then rooted, acclimatized and transferred to the greenhouse for evaluation. Two forms of leaf shape (orbicular and elliptic) and three flower colors (violet, purple and light pink) appeared on the plantlets.
The legJ subfamily of genes in garden pea, Pisum sativum L., encodes "minor" legumin seed storage... more The legJ subfamily of genes in garden pea, Pisum sativum L., encodes "minor" legumin seed storage protein polypeptides. Data on the differential expression of the 3 genes (legJ,K,L) within this subfamily is reported. The expression of one gene (legJ) is specifically upregulated during the desiccation phase of cotyledon development, when other storage protein genes are downregulated. The complete sequence of a second gene in the subfamily, legK, shows that the failure to observe any expression ofthis gene is due to the mutation of its initiator ATG (methionine) codon to a GTG (valine) codon. The third gene in the subfamily, legL, shows maximal expression during the cotyledon expansion phase of seed development, Le. like other storage protein genes. Evidence for the use of alternative polyadenylation addition signal sequences in these genes is also presented.
We have identified and characterised a stability function encoded by the high copy plasmid ColK. ... more We have identified and characterised a stability function encoded by the high copy plasmid ColK. The function is analogous to ColE1 cer and maximises stability by maintaining plasmids in the monomeric state. In vivo recombination between cer and ckr (which share more than 90% homology at the DNA sequence level) produced a functional hybrid. Sequence analysis of hybrids indicates that recombination involving cer and ckr is site-specific and occurs within a 35 bp region of DNA which contains palindromic symmetry.
Table of Contents No. Content Page Dedication iii Acknowledgment iv Declaration v List of abbrevi... more Table of Contents No. Content Page Dedication iii Acknowledgment iv Declaration v List of abbreviations vi List of contents vii List of tables ix List of figures x Abstract xi Chapter One: General Introduction 1 1.1 General properties of fungi 2 1.2 Dermatophytes 3 1.3 Ecology 4 1.4 Geographical distribution of the dermatophytes 4 1.5 Dermatophytosis transmission 5 viii No. Content Page Chapter Three: Results and Discussion 27 3.1 Epidemiology of dermatophytes infections 28 3.2 Genotypical pattern of dermatophytes strains by using RAPD analysis primers 36 3.2.1 RAPD-PCR amplification 36 3.2.2 RAPD Data analysis 39 References 43
A library of pea (Pisum sativum L) genomic DNA in bacteriophage EMBL3 was screened for seed stora... more A library of pea (Pisum sativum L) genomic DNA in bacteriophage EMBL3 was screened for seed storage protein genes of the legumin and vicilin families. Three genomic clones were isolated. One of the clones was found to contain a gene in the Leg A sub-family which was designated Leg E. The nucleotide and predicted amino acid sequence of Leg E were compared to those of Leg A. The coding sequences of both genes are strongly homologous with only 9 bases difference out of 1560 bases. A second genomic clone contained two genes from the Leg J subfamily. Leg J and Leg K. The clone was shown to overlap with a genomic clone isolated previously, JC5 (Gatehouse et al. 1988). Strong homology was found between the Leg K and Leg J sequences. The Leg K gene is predicted to be pseudogene, due to the conversion of the ATG methionine start codon to a GTG valine codon and the presence of a stop codon in the 5' end of the coding sequence in the reading frame predicted by the first subsequent start co...
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