Telomeres

The fission yeast complete genome sequence currently stops short of the telomeric repeats although work is in progress to resolve these regions.

There are 2 small contigs c1348 and c212, which may be proximal to any of the chromosome I or II telomeres but are currently unanchored.

The most proximal anchored cosmids to each telomere are:

• Chromosome I left c977
• Cromosome I right c750
• Chromosome II left pB10D8
• Chromosome II right pB2B2
• There are no telomere proximal clones for chromosome III as the unsequenced rDNA blocks occur inbetween the sequenced portion and the telomeres on both chromosome arms.

You can access all the clones in sequence order by chromosome from Contig Status and EMBL submissions on the S. pombe home page or as spreadsheets giving clone length and overlap details

As part of the ongoing effort to obtain the unique sequence as far as the telomeric repeats a set of small insert clones from a telomere plasmid library has been sequenced. The library was made by Neal Sugawara (sugawara@hydra.rose.brandeis.edu) who was at Harvard University, Cambridge, Massachusetts. Toru Nakamura from the Department of Chemistry and Biochemistry, University of Colorado, Boulder supplied the aliquots. All these telomeric clones start with the prefix pNSU. None can be assigned to a chromosome at present.

The sequences can be downloaded here

It is thought that the clones pNSU21 and pNSU65 possibly represent the same telomere (the restriction map is almost identical). pNSU71, pNSU64, pNSU70 and pNSU21 originate from different telomeres as they have different digest patterns. pNSU77 and pNSU70 represent the same telomere. Apart from those clones representing the same telomere none of the clones are known to overlap.

All the plasmids can be transformed into E.coli and selected on LB+ chloramphenicol (100ug/ml) except pNSU28 and pNSU31 which have telomere sequences inserted into pUC19 and should be grown on LB+ampicillin (100ug/ml). The other plasmids were constructed using pMLC28 which has the same lacZ sequence and polylinker as pUC28.

The sequences of these clones have been included on the S. pombe BLAST server.

Further to the above table:
(b) Terminal refers to the position adjacent to the vector sequences of pMLC12 where the blunt end (SmaI end) ligated to the telomeric sequences. Internal means that an S. pombe sequence intervenes between the telomere and vector sequences.