A repetitive DNA sequence associated with the centromeres of Chironomus<i>pallidivittatus</i>

Rovira, Carlos; Beermann, Wolfgang; Edström, Jan‐Erik

doi:10.1093/nar/21.8.1775

Cited by 48 publications

(45 citation statements)

References 29 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In Chironomus pallidivittatus only the centric end of the telocentric chromosome 4 does not reveal the species-specific telomeric satellite sequence. Instead, a repetitive sequence occurring at all centromeres of this species was found at this chromosome end (Rovira et al 1993). This is another example of substitution on one and the same species of the primary telomeric repeats by two different sequences that might also have other functions.…”

Section: Telomeres In Alliaceaementioning

confidence: 76%

How do Alliaceae stabilize their chromosome ends in the absence of TTTAGGG sequences?

Pich¹,

Fuchs²,

Schubert³

1996

Chromosome Res

141

View full text Add to dashboard Cite

The Arabidopsis-type telomeric repeats (5'-TTTAGGG-3) are highly conserved. In most families of different plant phyla they represent the basic sequence of telomeres that stabilize and protect the chromosome termini. The results presented here show that Alliaceae and some related liliaceous species have no tandemly repeated TTTAGGG sequences. Instead, their chromosomes reveal highly repetitive satellite and/or rDNA sequences at the very ends. These apparently substitute the original plant telomeric sequences in Alliaceae. Both sequence types are very active in homologous recombination and may contribute to the stabilization of chromosome termini via compensation of replication-mediated shortening.

show abstract

Section: Telomeres In Alliaceaementioning

confidence: 76%

How do Alliaceae stabilize their chromosome ends in the absence of TTTAGGG sequences?

Pich¹,

Fuchs²,

Schubert³

1996

Chromosome Res

141

View full text Add to dashboard Cite

show abstract

“…Interestingly, 340-bp repeats are detectable at only seven of the eight chromosome ends, the remaining, telocentric 4L end containing 155-bp tandem repeats, present also in other centromeres (26). Although it is not yet known whether the 155-bp repeat is terminal, it is likely that different kinds of DNA are used as chromosome terminal DNA in one and the same organism like in D. melanogaster, where two different retrotransposons, HeT-A and TART, have been found at the chromosome ends (3,30).…”

Section: Discussionmentioning

confidence: 99%

Terminal Long Tandem Repeats in Chromosomes from Chironomus pallidivittatus

López

Nielsen

Edström

1996

Molecular and Cellular Biology

View full text Add to dashboard Cite

We provide evidence that a chromosome end in the dipteran Chironomus pallidivittatus contains 340-bp tandem repeats reaching the extreme terminus of the chromosome. After adding synthetic oligonucleotide tails to DNA extracted from the microdissected right end of the fourth chromosome, we could demonstrate that the blocks of repeats were tailed at only one end, the chromosome terminus, the interior of the arrays being unavailable for tailing. Using PCR, we furthermore showed that the added tails were connected to 340-bp repeat DNA directly, i.e., without intervening DNA of any other kind. The tailed repeats belong to a subfamily previously known to be the most peripheral one of the different types of 340-bp units. Using plasmid controls, we could also make certain that we did not amplify rare or nonrepresentative DNA termini.Telomeres of most investigated eukaryotic species terminate with short repeats, usually with guanine excess in the 3Ј-terminating strand (4). Such repeats, whether regular, as in most cases (5,17,21,25), or irregular, as in Saccharomyces cerevisiae (29) among others, are likely to result from telomerase activities (6,11,16,31).Short repeats are also found in several insect orders (23), but for the dipteran Drosophila melanogaster a different mode of chromosome termination has been established. Here terminally deleted chromosomes can be capped by non-long-terminal-repeat retrotransposons (2,3,30,33), which can also be recovered at the ends of normal chromosomes (15).No other type of ending is known for nuclear chromosomes, but the linear mitochondrial DNA from Tetrahymena thermophila ends with Ͼ50-bp-long repeat units (19,20). We present evidence that this alternative, here in the form of 340-bp tandem repeats (27), is used by nuclear chromosomes in the dipteran Chironomus pallidivittatus.The 340-bp tandem repeat family is localized at seven of the eight (pairs of) chromosome ends in Ͻ200-kb blocks. Although the blocks are close to the chromosome ends as revealed by Bal 31 digestions (34), it has not been known whether they reach the extreme termini. The repeat family contains four different subfamilies, three of which, D1, D2, and D3, are derived from the fourth one, M1, each by a cluster of mutations in short regions designated ds1, ds2, and ds3, respectively (7). In the case of D3 there is a second difference, i.e., one large region has become substituted for another one. Telomeres differ in subfamily composition (8,34). When D3 is present together with other kinds of repeats, it is always the most peripheral unit (34).Briefly, our strategy was to gently release DNA from single microdissected right ends of the fourth chromosome and provide it with tails. Anchors added to the tails and primers for the 340-bp repeat were used for PCR amplifications. We could demonstrate that no internal breaks were tailed within the repeat blocks and that the tails were added directly to the 340-bp repeat DNA. We also showed that only DNA from a specific subfamily, previously shown to be distal (34), was amp...

show abstract

“…They occur in distinct subfamilies, three of which, Dl, D2, and D3, are derived from a fourth one, Ml, each by a cluster of mutations (12,13). They are present in seven chromosome ends; the eighth one, at the telocentric end of chromosome 4, contains a different repeat (42). Here we ask whether this differentiation is correlated to properties that could explain the functions of telomere-associated DNA.…”

mentioning

confidence: 98%

A family of complex tandem DNA repeats in the telomeres of Chironomus pallidivittatus.

Yj¹,

Kamnert²,

López³

et al. 1994

Mol. Cell. Biol.

View full text Add to dashboard Cite

A family of 340-bp tandem telomere-associated DNA repeats is present in 50-to 200-kb (18,30,48). Thus, there is no absolute topological distinction between the two types of DNA. One telomeric function, for which telomerase is responsible, is to restore DNA that is lost after replications (22,23). Another is the maintenance of chromosomal integrity (see reference 2 and references therein) believed to be related to the propensity of telomeric DNA to form secondary structures (see reference 6 and references therein). Obviously, telomere-associated DNA, when in a terminal position, also has to fulfil these functions. Processes like unequal crossing over (34), gene conversion (39), and transposition (1,3,4,16,26,45,46) can be invoked to explain DNA additions. Little is known, however, about how telomereassociated DNA could maintain chromosomal integrity and about its subtelomeric roles.Chromosome ends in the dipteran insect Chironomus pallidivittatus have a potential value in the study of telomereassociated DNA, because of the schematic structure of their long tandem arrays of complex 340-bp repeat units (TA re-* Corresponding author. Mailing address:

show abstract

A repetitive DNA sequence associated with the centromeres of Chironomuspallidivittatus

Cited by 48 publications

References 29 publications

How do Alliaceae stabilize their chromosome ends in the absence of TTTAGGG sequences?

How do Alliaceae stabilize their chromosome ends in the absence of TTTAGGG sequences?

Terminal Long Tandem Repeats in Chromosomes from Chironomus pallidivittatus

A family of complex tandem DNA repeats in the telomeres of Chironomus pallidivittatus.

Contact Info

Product

Resources

About