Molecular and General Genetics (MOL GENET GENOMICS)

Publications in this journal

• Article: Expression diversity and evolutionary dynamics of rice duplicate genes

  Won Cheol Yim, Byung-Moo Lee, Cheol Seong Jang
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  ABSTRACT: Duplicate genes are believed to be a major source of new gene functions over evolutionary time. In order to evaluate the evolutionary dynamics of rice duplicate genes, formed principally by paleoployploidization prior to the speciation of the Poaceae family, we have employed a public microarray dataset including 155 gene expression omnibus sample plates and bioinformatics tools. At least 57.4% of old ~70 million years ago (MYA) duplicate gene pairs exhibit divergences in expression over the given experimental set, whereas at least 50.9% of young ~7.7-MYA duplicate gene pairs were shown to be divergent. When grouping the rice duplicate genes according to functional categories, we noted a striking and significant enrichment of divergent duplicate metabolism-associated genes, as compared to that observed in non-divergent duplicate genes. While both non-synonymous substitution (Ka) and synonymous substitution (Ks) values between non- and divergent duplicate gene pairs evidenced significant differences, the Ka/Ks values between them exhibited no significant differences. Interestingly, the average numbers of conserved motifs of the duplicate gene pairs revealed a pattern of decline along with an increase in expression diversity, partially supporting the subfunctionalization model with degenerative complementation in regulatory motifs. Duplicate gene pairs with high local similarity (HLS) segments, which might be formed via conversion between rice paleologs, evidenced higher expression correlations than were observed in the gene pairs without the HLS segments; this probably resulted in an increased likelihood of gene conversion in promoters of the gene pairs harboring HLS segments. More than 60% of the rice gene families exhibited similar high expression diversity between members as compared to that of randomly selected gene pairs. These findings are likely reflective of the evolutionary dynamics of rice duplicate genes for gene retention.
  Molecular and General Genetics 04/2012; 281(5):483-493.
• Article: Molecular characterization of the Sasanda LTR copia retrotransposon family uncovers their recent amplification in Triticumaestivum (L.) genome

  Raja Ragupathy, Travis Banks, Sylvie Cloutier
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  ABSTRACT: Retrotransposons constitute a major proportion of the Triticeae genomes. Genome-scale studies have revealed their role in evolution affecting both genome structure and function and their potential for the development of novel markers. In this study, family members of an LTR copia retrotransposon which mediated the duplication of the gene encoding the high molecular weight glutenin subunit Bx7 in cultivar Glenlea were characterized. This novel element was named Sasanda_EU157184-1 (TREP3516). High density filters of the Glenlea hexaploid wheat BAC library were screened with a Sasanda long terminal repeat (LTR)-specific probe and ~1,075 positive clones representing an estimated copy number of 347 elements per haploid genome were identified. The 242 BAC clones with the strongest hybridization signal were selected. To maximize isolation of complete elements, this subset of clones was screened with a reverse transcriptase (RT) domain probe and DNA was isolated from the 133 clones that produced a strong hybridization signal. Left (5′) and right (3′) LTRs as well as the RT domains were PCR amplified and sequencing was carried out on the final subset of 121 clones. Evolutionary relationships were inferred from a data set consisting of 100 RT, 102 5′ LTR and 100 3′ LTR sequences representing 233, 451 and 495 informative sites for comparison, respectively. Neighbour-joining tree indicated that the element is at least 1.8 million years old and has evolved into a minimum of five sub-families. The insertion times of the 89 complete elements were estimated based on the divergence between their LTRs. Corroborating the inference from the RT domain, analysis of the LTR domains also indicated bursts of amplification from 2.6million years ago (MYA) to now, except for one member dated to 4.6±0.7MYA, which corresponds to the interval of divergence of Triticum and Aegilops (3MYA) and divergence of Triticum and Rye (7MYA). In 44 elements, the 5′ and 3′ LTRs were identical indicating recent transposition activity. The element can be used to develop retrotransposon-based markers such as sequence-specific amplified polymorphism, retrotransposon microsatellite amplified polymorphism and inter-retrotransposon amplified polymorphism, all of which are well suited for genotyping studies.
  Molecular and General Genetics 04/2012; 283(3):255-271.
• Article: Sequence and structure of the linear mitochondrial genome of Pneumocystis carinii

  Thomas M. Sesterhenn, Bradley E. Slaven, Scott P. Keely, A. George Smulian, B. Franz Lang, Melanie T. Cushion
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  ABSTRACT: With the exception of a few genes, most of the mitochondrial (mt) genome of Pneumocystis carinii has not previously been sequenced. Shotgun sequences generated as a result of the Pneumocystis Genome Project (PGP) were assembled with the gap4 assembly program into a 23-kb contig. Annotation of the mt genome identified 4 open reading frames and 20 tRNAs in addition to 17 other genes: ATP synthase, subunits 6, 8, and 9; cytochrome c oxidase, subunits 1, 2, and 3; NADH dehydrogenase, subunits 1, 2, 3, 4, 4L, 5, and 6; apocytochrome b; RNase P RNA gene; and the mitochondrial large and small ribosomal RNA subunits. A 24-bp unit that repeated from one to five times was identified interior to the ends of the mt genome. Migration of the genome on CHEF gels was consistent with that of linear DNA and digestion with BAL31 showed a concomitant reduction in size of the genome, a characteristic of linear DNA. Together with the identification of terminal repeats similar to those found in other linear fungal mt genomes and the inability to join the ends by PCR, these data provide strong evidence that the mt genome of P. carinii is linear.
  Molecular and General Genetics 04/2012; 283(1):63-72.
• Article: Helix 69 in 23S rRNA modulates decoding by wild type and suppressor tRNAs

  Michael O’Connor
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  ABSTRACT: Helix 69 of 23S rRNA forms one of the major inter-subunit bridges of the 70S ribosome and interacts with A- and P-site tRNAs and translation factors. Despite the proximity of h69 to the decoding center and tRNAs, the contribution of h69 to the tRNA selection process is unclear: previous genetic analyses have shown that h69 mutations increase frameshifting and readthrough of stop codons. However, a complete deletion of h69 does not affect the selection of cognate tRNAs in vitro. To address these discrepancies, the in vivo effects of a range of single- and multi-base h69 mutations in Escherichia coli 23S rRNA on various translation errors have been determined. While a majority of the h69 mutations examined here affected readthrough of stop codons and frameshifting, the ΔA1916 single base deletion mutation uniquely influenced missense decoding. Different h69 mutants had either increased or decreased levels of stop codon readthrough. The h69 mutations that decreased UGA readthrough also decreased UGA reading by a mutant, near-cognate tRNATrp carrying a G24A substitution in the D arm, but had far less effect on UGA reading by a suppressor tRNA with a complementary anticodon. These results suggest that h69 interactions with release factors contribute significantly to termination efficiency and that interaction with the D arm of A-site tRNA is important for discrimination between cognate and near-cognate tRNAs.
  Molecular and General Genetics 04/2012; 282(4):371-380.
• Article: Selection for intragenic suppressors of lethal 23S rRNA mutations in Escherichia coli identifies residues important for ribosome assembly and function

  Michael O’Connor
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  ABSTRACT: Mutations in several functionally important regions of the 23S rRNA of E. coli increase the levels of frameshifting and readthrough of stop codons. These mutations include U2555A, U2555G, ΔA1916 and U2493C. The mutant rRNAs are lethal when expressed at high levels from a plasmid, in strains also expressing wild type rRNA from chromosomal rrn operons. The lethal phenotype can be suppressed by a range of second-site mutations in 23S rRNA. However, analysis of the functionality of the double mutant rRNAs in heterogeneous ribosome populations shows that in general, the second site mutations do not restore function. Instead, they prevent the assembly, or entry of the mutant 50S subunits into the functioning 70S ribosome and polysome pools, by affecting the competitiveness of the mutant subunits for association with 30S particles. The second-site mutations lie in regions of the 23S rRNA involved in subunit assembly, intersubunit bridge formation and interactions of the ribosome with tRNAs and factors. These second site suppressor mutations thus define functionally important rRNA nucleotides and this approach may be of general use in the functional mapping of large RNAs.
  Molecular and General Genetics 04/2012; 278(6):677-687.
• Article: Transcription of the singed-weak mutation of Drosophila melanogaster: elimination of P-element sequences by RNA splicing and repression of singed transcription in a P genetic background

  Jamie Paterson, Michael J. Simmons, Kevin O’Hare
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  ABSTRACT: The dysgenesis-induced, hypermutable singed-weak allele has two incomplete P-elements inserted in a head-to-head configuration in the 5′ non-coding exon of the singed bristle locus of Drosophila melanogaster. In the presence of P transposase, each element excises to produce single element derivatives, singed-extreme and singed-(+), that have either an extreme bristle or wild-type phenotype, respectively. In an M background, pseudo-wild-type transcripts are made that initiate at the singed promoter, read through the insertions, and are spliced to remove the P-element sequences and part of the 5′ exon. The abundance of the pseudo-wild-type RNAs in pupae correlates with the bristle phenotype, being highest in singed-(+) and lowest in singed-extreme. Other RNAs are made that retain the insertions, or are truncated with respect to the downstream coding singed exons and have their 3′ ends within the insertions. The mutants are female-fertile in an M background but sterile in a P background where little singed RNA can be detected. Transgenes containing either a complete P-element or an incomplete P-element known as KP impair the fertility of females carrying the singed-weak mutation, suggesting that the proteins encoded by these two widely distributed P-elements may be responsible for inhibiting transcription of singed-weak in a P background.
  Molecular and General Genetics 04/2012; 278(1):53-64.
• Article: Autoregulation of fixK2 gene expression in Bradyrhizobium japonicum

  Luzia Reutimann, Socorro Mesa, Hauke Hennecke
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  ABSTRACT: Several essential Bradyrhizobium japonicum genes for a symbiotic, nitrogen-fixing root-nodule symbiosis are positively controlled under micro-oxic conditions by the FixLJ–FixK2 regulatory cascade. Negative control is exerted by reactive oxygen species at the level of the FixK2 protein. Furthermore, we noticed that fixK 2 gene expression is increased in a fixK 2 mutant, suggesting that FixK2 in the wild type has a negative effect, directly or indirectly, on its own expression. To possibly understand this effect, the transcription pattern of the fixLJ-bll2758-fixK 2 gene region was examined more closely. While fixK 2 gene transcription is activated by FixJ, the bll2758 gene is transcribed from its own promoter in a FixK2-dependent manner, and there is no read-through transcription from bll2758 into fixK 2. The bll2758-encoded protein is predicted to be a stand-alone receiver domain of a response regulator, making it a prime candidate for exerting an inhibitory role on the expression of fixK 2. Transcriptome profiling of a bll2758 knock-out mutant revealed, however, that neither fixK 2 itself nor any of the known FixJ- and FixK2-dependent target genes is significantly affected in their expression. This precludes a role of the bll2758 product as a so-called FixT-like protein in the inhibition of FixLJ function, as was proposed for Sinorhizobium meliloti and Caulobacter crescentus. Instead, we rationalize that other transcription factors, whose genes are activated by FixK2, might be involved in the negative autoregulation of fixK 2 gene expression. Keywords Bradyrhizobium japonicum -Gene regulation-Microarrays-Promoter-Transcription
  Molecular and General Genetics 04/2012; 284(1):25-32.
• Article: Interaction between the ribosomal subunits: 16S rRNA suppressors of the lethal ΔA1916 mutation in the 23S rRNA of Escherichia coli

  Michael O’Connor
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  ABSTRACT: A1916 in 23S rRNA is located in one of the major intersubunit bridges of the 70S ribosome. Deletion of A1916 disrupts the intersubunit bridge B2a, promotes misreading of the genetic code and is lethal. In a genetic selection for suppressor mutations, two base substitutions in 16S rRNA were recovered that restored viability and also allowed expression of ΔA1916-associated capreomycin resistance. These mutations were G1048A in helix 34 and U1471C in helix 44. Restoration of function is incomplete, however, and the double mutants are slow-growing, defective in subunit association and support high levels of translational errors. In contrast, none of these parameters is affected by the single 16S suppressor mutations. U1471C likely affects another intersubunit contact, bridge B6, suggesting that interactions between different bridges and cross-talk between subunits contributes to ribosomal function.
  Molecular and General Genetics 04/2012; 278(3):307-315.
• Article: The peach (Prunus persica [L.] Batsch) homeobox gene KNOPE3, which encodes a class 2 knotted-like transcription factor, is regulated during leaf development and triggered by sugars

  Giulio Testone, Emiliano Condello, Ignazio Verde, Emilia Caboni, Maria Adelaide Iannelli, Leonardo Bruno, Domenico Mariotti, Maria Beatrice Bitonti, Donato Giannino
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  ABSTRACT: Class 1 KNOTTED1-like transcription factors (KNOX) are known to regulate plant development, whereas information on class 2 KNOX has been limited. The peach KNOPE3 gene was cloned, belonged to a family of few class 2 members and was located at 66cM in the Prunus spp. G1 linkage-group. The mRNA localization was diversified in leaf, stem, flower and drupe, but recurred in all organ sieves, suggesting a role in sap nutrient transport. During leaf development, the mRNA earliest localized to primordia sieves and subsequently to mesophyll cells of growing leaves. Consistently, its abundance augmented with leaf expansion. The transcription was monitored in leaves responding to darkening, supply and transport block of sugars. It peaked at 4h after darkness and dropped under prolonged obscurity, showing a similar kinetic to that of sucrose content variation. Feeding leaflets via the transpiration stream caused KNOPE3 up-regulation at 3h after fructose, glucose and sucrose absorption and at 12h after sorbitol. In girdling experiments, leaf KNOPE3 was triggered from 6h onwards along with sucrose and sorbitol raise. Both the phloem-associated expression and sugar-specific gene modulation suggest that KNOPE3 may play a role in sugar translocation during the development of agro-relevant organs such as drupe.
  Molecular and General Genetics 04/2012; 282(1):47-64.
• Article: Isolation of a Latimeria menadoensisheat shock protein 70 (Lmhsp70) that has all the features of an inducible gene and encodes a functional molecular chaperone

  Keoagile W. Modisakeng, Meesbah Jiwaji, Eva-Rachele Pesce, Jacques Robert, Chris T. Amemiya, Rosemary A. Dorrington, Gregory L. Blatch
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  ABSTRACT: Molecular chaperones facilitate the correct folding of other proteins, and heat shock proteins form one of the major classes of molecular chaperones. Heat shock protein 70 (Hsp70) has been extensively studied, and shown to be critically important for cellular protein homeostasis in almost all prokaryotic and eukaryotic systems studied to date. Since there have been very limited studies conducted on coelacanth chaperones, the main objective of this study was to genetically and biochemically characterize a coelacanth Hsp70. We have successfully isolated an Indonesian coelacanth (L. menadoensis) hsp70 gene, Lmhsp70, and found that it contained an intronless coding region and a potential upstream regulatory region. Lmhsp70 encoded a typical Hsp70 based on conserved structural and functional features, and the predicted upstream regulatory region was found to contain six potential promoter elements, and three potential heat shock elements (HSEs). The intronless nature of the coding region and the presence of HSEs suggested that Lmhsp70 was stress-inducible. Phylogenetic analyses provided further evidence that Lmhsp70 was probably inducible, and that it branched as a clade intermediate between bony fish and tetrapods. Recombinant LmHsp70 was successfully overproduced, purified and found to be functional using ATPase activity assays. Taken together, these data provide evidence for the first time that the coelacanth encodes a functional molecular chaperone system.
  Molecular and General Genetics 04/2012; 282(2):185-196.
• Article: Diversity of LTR-retrotransposons and Enhancer/SuppressorMutator-like transposons in cassava (Manihot esculenta Crantz)

  Michael A. Gbadegesin, Matthew A. Wills, John R. Beeching
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  ABSTRACT: Cassava (Manihot esculenta Crantz), though a major world crop with enormous potential, is very under studied. Little is known about its genome structure and organisation. Transposable elements have a key role in the evolution of genome structure, and can be used as important tools in applied genetics. This paper sets out to survey the diversity of members of three major classes of transposable element within the cassava genome and in relation to similar elements in other plants. Members of two classes of LTR-retrotransposons, Ty1/copia-like and Ty3/gypsy-like, and of Enhancer/Suppressor Mutator (En/Spm)-like transposons were isolated and characterised. Analyses revealed 59 families of Ty1/copia, 26 families of Ty3/gypsy retrotransposons, and 40 families of En/Spm in the cassava genome. In the comparative analyses, the predicted amino acid sequences for these transposon classes were compared with those of related elements from other plant species. These revealed that there were multiple lineages of Ty1/copia-like retrotransposons in the genome of cassava and suggested that vertical and horizontal transmission as the source of cassava Mecops may not be mutually exclusive. For the Ty3/gypsy elements network, two groups of cassava Megyps were evident including the Arabidopsis Athila lineage. However, cassava En/Spm-like elements (Meens) constituted a single group within a network of plant En/Spm-like elements. Hybridisation analysis supported the presence of transposons in the genome of cassava in medium (Ty3/gypsy and En/Spm) to high (Ty1/copia) copy numbers. Thus the cassava genome was shown to contain diverse members of three major classes of transposable element; however, the different classes exhibited contrasting evolutionary histories.
  Molecular and General Genetics 04/2012; 280(4):305-317.
• Article: The Bradyrhizobium japonicum Fur protein is an iron-responsive regulator in vivo

  Jianhua Yang, Indu Sangwan, Mark R. O’Brian
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  ABSTRACT: The Fur protein is a global regulator of iron metabolism in many bacterial species. However, Fur homologs from some rhizobia appear not to mediate iron-dependent gene expression in vivo. Here, transcriptional profiling analysis showed that more than one-fourth of the genes within the iron stimulon of Bradyrhizobium japonicum were aberrantly controlled by iron in a fur mutant. However, Fur has only a modest role in regulating iron transport genes. Quantitative real time reverse transcriptase PCR measurements confirmed abnormal gene expression in iron-limited cells of the fur strain, thereby demonstrating that Fur must function under those conditions. The findings show that B. japonicum Fur is involved in iron-dependent gene expression, and support the conclusion that rhizobial Fur proteins have novel functions compared with well studied model systems.
  Molecular and General Genetics 04/2012; 276(6):555-564.
• Article: Characterization and phylogenetic analysis of environmental stress-responsive SAP gene family encoding A20/AN1 zinc finger proteins in tomato

  Amolkumar U. Solanke, Manoj K. Sharma, Akhilesh K. Tyagi, Arun Kumar Sharma
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  ABSTRACT: Characterization of genes responsive to stress is important for efforts on improving stress tolerance of plants. To address components involved in stress tolerance of tomato (Solanum lycopersicum), a stress-responsive gene family encoding A20/AN1 zinc finger proteins was characterized. In the present study, 13 members of this gene family were cloned from tomato cultivar Pusa Ruby and named as Stress Associated Protein (SAP) genes. Out of 13 genes, 12 have been mapped on their respective chromosomes. Expression of these genes in response to cold, heat, salt, desiccation, wounding, abscisic acid, oxidative and submergence stresses was analysed. All tomato SAP genes were found to be responsive to one or other type of environmental stress. The phylogenetic analysis of these genes, along with their orthologs from Solanaceae species suggests the presence of a common set of SAP genes in the studied Solanaceae species. The present study characterizes a SAP gene family, which encodes A20/AN1 zinc finger containing proteins from tomato for the first time. Genes showing high expression in response to a particular stress can be exploited for improving stress tolerance of tomato and other Solanaceae members.
  Molecular and General Genetics 04/2012; 282(2):153-164.
• Article: New mutant versions of yeast FACT subunit Spt16 affect cell integrity

  Allyson F. O’Donnell, Jennifer R. Stevens, Rosemarie Kepkay, Christine A. Barnes, Gerald C. Johnston, Richard A. Singer
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  ABSTRACT: Transcription by RNA polymerase II is impeded by the nucleosomal organization of DNA; these negative effects are modulated at several stages of nucleosomal DNA transcription by FACT, a heterodimeric transcription factor. At promoters, FACT facilitates the binding of TATA-binding factor, while during transcription elongation FACT mediates the necessary destabilization of nucleosomes and subsequent restoration of nucleosome structure in the wake of the transcription elongation complex. Altered FACT activity can impair the fidelity of transcription initiation and affect transcription patterns. Using reporter genes we have identified new mutant versions of the Spt16 subunit of yeast FACT with dominant negative effects on the fidelity of transcription initiation. Two of these spt16 mutant alleles also affect cell integrity. Cells relying on these spt16 mutant alleles display sorbitol-remediated temperature sensitivity, altered sensitivity to detergent, and abnormal morphologies, and are further inhibited by the ssd1-d mutation. The overexpression of components of protein kinase C (Pkc1) signaling diminishes this spt16 ssd1-d temperature sensitivity, whereas gene deletions eliminating components of Pkc1 signaling further impair these spt16 mutant cells. Thus, the FACT subunit Spt16 and Pkc1 signaling have an overlapping essential function, with an unexpected role for FACT in the maintenance of cell integrity.
  Molecular and General Genetics 04/2012; 282(5):487-502.
• Article: Characterization and mapping of Rpi1, a gene that confers dominant resistance to stalk rot in maize

  D.E. Yang, D.M. Jin, B. Wang, D.S. Zhang, H.-T. Nguyen, C.L. Zhang, S.J. Chen
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  ABSTRACT: The maize inbred lines 1145 (resistant) and Y331 (susceptible), and the F1, F2 and BC1F1 populations derived from them were inoculated with the pathogen Pythium inflatum Matthews, which causes stalk rot in Zea mays. Field data revealed that the ratio of resistant to susceptible plants was 3:1 in the F2 population, and 1:1 in the BC1F1population, indicating that the resistance to P. inflatum Matthews was controlled by a single dominant gene in the 1145×Y331 cross. The gene that confers resistance to P. inflatum Matthews was designated Rpi1 for resistance to P. inflatum) according to the standard nomenclature for plant disease resistance genes. Fifty SSR markers from 10 chromosomes were first screened in the F2 population to find markers linked to the Rpi1 gene. The results indicated that umc1702 and mmc0371 were both linked to Rpi1, placing the resistance gene on chromosome 4. RAPD (randomly amplified polymorphic DNA) markers were then tested in the F2population using bulked segregant analysis (BSA). Four RAPD products were found to show linkage to the Rpi1 gene. Then 27 SSR markers and 8 RFLP markers in the region encompassing Rpi1 were used for fine-scale mapping of the resistance gene. Two SSR markers and four RFLP markers were linked to the Rpi1 gene. Finally, the Rpi1 gene was mapped between the SSR markers bnlg1937 and agrr286 on chromosome 4, 1.6cM away from the former and 4.1cM distant from the latter. This is the first time that a dominant gene for resistance to maize stalk rot caused by P. inflatum Matthews has been mapped with molecular marker techniques.
  Molecular and General Genetics 04/2012; 274(3):229-234.
• Article: Defining the phosphite-regulated transcriptome of the plant pathogen Phytophthora cinnamomi

  Michaela King, Wayne Reeve, Mark B. Van der Hoek, Nari Williams, Jen McComb, Philip A. O’Brien, Giles E. St. J. Hardy
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  ABSTRACT: Phosphite, an analog of phosphate is used to control oomycete diseases on a wide range of horticultural crops and in native ecosystems. In this study, we investigated morphological and transcriptional changes induced in Phytophthora cinnamomi by phosphite. Cytological observations revealed that phosphite caused hyphal distortions and lysis of cell walls and had an adverse effect on hyphal growth. At the molecular level, the expression levels of 43 transcripts were changed. Many of these encoded proteins involved in cell wall synthesis, or cytoskeleton functioning. The results of both the microscopic and molecular investigations are consistent with phosphite inhibiting the function of the cytoskeleton and cell wall synthesis. Keywords Phytophthora cinnamomi -Phosphite-Gene expression-Microarrays
  Molecular and General Genetics 04/2012; 284(6):425-435.
• Article: High-resolution array comparative genomic hybridization analysis reveals unanticipated complexity of genetic deficiencies on chromosome V in Caenorhabditis elegans

  Martin R. Jones, Shu Yi Chua, Nigel J. O’Neil, Robert C. Johnsen, Ann M. Rose, David L. Baillie
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  ABSTRACT: Genomic rearrangements are widely used in Caenorhabditis elegans research but many remain incompletely characterized at the physical level. We have used oligo-array comparative genomic analysis to assess the physical structure of 20 deficiencies and a single duplication of chromosome V. We find that while deletions internal to the chromosome appear simple in structure, terminal deletions are complex, containing duplications in addition to the deletion. Additionally, we confirm that transposon-induced deficiencies contain breakpoints that initiate at Tc1 elements. Finally, 13 of these deficiencies are known to suppress recombination far beyond the extent of the deletion. These deficiencies fall into two classes: strong and weak suppressors of adjacent recombination. Analysis of the deleted regions in these deficiencies reveals no common physical sites to explain the observed differences in recombination suppression. However, we find a strong correlation between the size of the rearranged chromosome and the severity of recombination suppression. Rearranged chromosomes that have a minor effect on recombination fall within 2% of normal chromosome size. Our observations highlight the use of array-based approaches for the analysis of rearranged genomes, revealing previously unidentified deficiency characteristics and addressing biologically relevant questions.
  Molecular and General Genetics 04/2012; 282(1):37-46.