Telomere hypervariability in <i>Magnaporthe oryzae</i>

Farman, Mark L.; Kim, Yun-Sik

doi:10.1111/j.1364-3703.2005.00285.x

Cited by 29 publications

(31 citation statements)

References 37 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…LpKY97TEL-2 is an example of a stable telomere, with the rearrangement in single spore isolate #4 ( Figure 1B) being one of only two such alterations detected in .150 single spores analyzed to date. Recalcitrance to change does not appear to persist over the long term, however, because no telomere restriction fragments appeared to be even remotely conserved among field isolates (Farman and Kim 2005). Indeed, as reported above, the LpKY97-1A and FH clones that contain this telomere (LpKY97TEL-2 and cosmid FH10L7) were polymorphic.…”

Section: Discussionmentioning

confidence: 68%

“…DNA fingerprinting studies have shown that M. oryzae isolates from prg exhibit extreme variation in their telomere profiles, even when there is little or no polymorphism at internal DNA loci (Farman and Kim 2005). In contrast, rice-infecting isolates that have similar "internal DNA" profiles to one another tend also to have highly similar telomere banding patterns (Farman 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Rates of telomere change in M. oryzae isolates from prg and rice M. oryzae isolates collected from rice fields show much less isolate-to-isolate variation in telomeric restriction fragments than do isolates collected from diseased prg turf (Farman and Kim 2005;Farman 2007). This observation suggested that the telomeres of the prg pathogens are less stable.…”

Section: Resultsmentioning

confidence: 99%

“…In striking contrast, M. oryzae strains from perennial ryegrass (prg) often exhibit "absolute" telomere polymorphism-i.e., they share no telomeric fragments in common, even when they have little or no polymorphism at internal loci. Furthermore, analysis of clonal isolates derived from single spores revealed that telomeric fragments underwent frequent rearrangement during mitotic growth both in culture and in planta (Farman and Kim 2005).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Telomere-Targeted Retrotransposons in the Rice Blast Fungus Magnaporthe oryzae: Agents of Telomere Instability

Starnes¹,

Thornbury

Новикова

et al. 2012

Genetics

View full text Add to dashboard Cite

The fungus Magnaporthe oryzae is a serious pathogen of rice and other grasses. Telomeric restriction fragments in Magnaporthe isolates that infect perennial ryegrass (prg) are hotspots for genomic rearrangement and undergo frequent, spontaneous alterations during fungal culture. The telomeres of rice-infecting isolates are very stable by comparison. Sequencing of chromosome ends from a number of prg-infecting isolates revealed two related non-LTR retrotransposons (M. oryzae Telomeric Retrotransposons or MoTeRs) inserted in the telomere repeats. This contrasts with rice pathogen telomeres that are uninterrupted by other sequences. Genetic evidence indicates that the MoTeR elements are responsible for the observed instability. MoTeRs represent a new family of telomere-targeted transposons whose members are found exclusively in fungi.T ELOMERES are the sequences that form the ends of linear chromosomes and are essential for maintaining the integrity of terminal DNA. In most organisms, the telomeres are composed of tandem arrays of short sequence motifs that are added on to the 39 ends of chromosomes by telomerase-a specialized reverse transcriptase (Greider and Blackburn 1989;Yu et al. 1990). This prevents the loss of DNA that would normally occur as a result of conservative DNA replication. The telomeres are bound by numerous proteins that shelter the terminal sequences from degradation (Garvik et al. 1995;Vodenicharov and Wellinger 2006) and illegitimate recombination (Dubois et al. 2002). Certain Diptera lack telomerase and, instead, their chromosome termini are maintained by different types of repeats (Saiga and Edstrom 1985;Biessmann et al. 1998;. The most striking example is in Drosophila whose telomeres are composed of arrays of non-LTR retrotransposons George et al. 2006), which are capable of transposing to free DNA ends (Traverse and Pardue 1988;Biessmann et al. 1990). The extension of chromosome ends through the addition of transposon sequences not only solves the end-replication problem but also serves to establish a nucleoprotein complex that is essential for protecting the chromosome ends and maintaining telomere homoeostasis (Fanti et al. 1998;Perrini et al. 2004).In many organisms, the telomeres are attached to a specific sequence that is duplicated (although often not perfectly) at many, and sometimes all, chromosome ends. Such sequences, which usually are TG-rich and often contain short tandem repeats, define a distinct distal subtelomere domain (Pryde et al. 1997). In addition to possessing distally located subtelomere domains, several organisms have proximal domains that contain genes and gene families that are also variously dispersed among different chromosome ends (Pryde et al. 1997). High levels of subtelomere polymorphism are found in many organisms, including vertebrates (Wilkie et al. 1991;Bassham et al. 1998;Baird et al. 2000;Mefford et al. 2001), insects (Biessmann et al. 1998Anderson et al. 2008;Kern and Begun 2008), plants (Yang et al. 2005), and fungi (Naumov et al. 1995Na...

show abstract

Section: Discussionmentioning

confidence: 68%

Section: Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Telomere-Targeted Retrotransposons in the Rice Blast Fungus Magnaporthe oryzae: Agents of Telomere Instability

Starnes¹,

Thornbury

Новикова

et al. 2012

Genetics

View full text Add to dashboard Cite

show abstract

“…Telomeric regions of the genome exhibit the most variation, and variation accumulates rapidly in these regions (7,9,12). For example, in Saccharomyces cerevisiae the SUC, MAL, and MEL families have expanded to different extents in strains bred to ferment different carbon sources (sucrose, maltose, and melibiose, respectively) (3,7,10,43); the subtelomeric family of FLO genes, which encode the ability to adhere to different cellular and abiotic surfaces, have expanded in some fermentation and clinical isolates (22,43,45).…”

mentioning

confidence: 99%

The Three Clades of the Telomere-Associated TLO Gene Family of Candida albicans Have Different Splicing, Localization, and Expression Features

et al. 2012

View full text Add to dashboard Cite

bCandida albicans grows within a wide range of host niches, and this adaptability enhances its success as a commensal and as a pathogen. The telomere-associated TLO gene family underwent a recent expansion from one or two copies in other CUG clade members to 14 expressed copies in C. albicans. This correlates with increased virulence and clinical prevalence relative to those of other Candida clade species. The 14 expressed TLO gene family members have a conserved Med2 domain at the N terminus, suggesting a role in general transcription. The C-terminal half is more divergent, distinguishing three clades: clade ␣ and clade ␤ have no introns and encode proteins that localize primarily to the nucleus; clade ␥ sometimes undergoes splicing, and the gene products localize within the mitochondria as well as the nuclei. Additionally, TLO␣ genes are generally expressed at much higher levels than are TLO␥ genes. We propose that expansion of the TLO gene family and the predicted role of Tlo proteins in transcription regulation provide C. albicans with the ability to adapt rapidly to the broad range of different environmental niches within the human host.

show abstract

Targeted Cloning of Fungal Telomeres

Farman

2011

Methods in Molecular Biology

View full text Add to dashboard Cite

Telomeres are the sequences that form the ends of eukaryotic chromosomes and are essential structures that confer genome stability and guide chromosome behavior. In addition, the terminal regions of the chromosomes tend to house genes with predicted roles in ecological adaptation. Unfortunately, however, most fungal genome assemblies contain very few telomeres and, therefore, the identities of genes residing near the chromosome ends are often unknown. In an effort to develop a complete understanding of the organization and gene content of chromosome ends in a number of fungi, we developed efficient methods for the identification and targeted cloning of telomeres. This chapter describes the basic steps and shows exemplary results from the targeted cloning of Epichloë festucae telomeres.

show abstract

Telomere hypervariability in Magnaporthe oryzae

Cited by 29 publications

References 37 publications

Telomere-Targeted Retrotransposons in the Rice Blast Fungus Magnaporthe oryzae: Agents of Telomere Instability

Telomere-Targeted Retrotransposons in the Rice Blast Fungus Magnaporthe oryzae: Agents of Telomere Instability

The Three Clades of the Telomere-Associated TLO Gene Family of Candida albicans Have Different Splicing, Localization, and Expression Features

Targeted Cloning of Fungal Telomeres

Contact Info

Product

Resources

About