The genome of Mycoplasma pulmonis (strain UAB CTIP) has a
size of 963 879 pb and a G+C% of 26.6%. It has been sequenced at a
depth of 9.8X. The 12,352 assembled reads were obtained from four
different libraries. Libraries A (first created for the pilot study)
and C were constructed with Sau3AI fragments (partial digestion
of the genome) : fragments with a size of 1 to 2 kb (library A) and 2
to 3 kb (library C) were cloned into the pUC18 vector. Partial
digestion of genomic DNA with a second enzyme (Tsp509I) yielded
fragments of 5-6 kb which were cloned in the pBAM3 vector to give
library R. The fourth library (library B, mini-BACs) was constructed
with Tsp509I fragments longer than 15 kb which were cloned in
the pBACe3.6 vector.
Sequencing was performed at both ends of inserts on 500 clones from
library A, 2,000 clones from library C, 1,500 clones from library B
and 4,000 clones from library R. For the first three libraries, ABI
377 sequencers were used (mean length of reads : 600 nucleotides)
and 4 genome equivalents were retained for assembly ; for library R,
Li-Cor 4200L sequencers were used (mean length of reads : 930
nucleotides) and 5.8 genome equivalents were retained for
assembly. Finishing work included the sequencing of several PCR
product in order to fill a cloning gap and to resolve regions with
uncertainties. To achieve a quality up to Bermuda standards, 481
primers were synthesised and 1,144 supplementary sequencing reactions
were performed. Assembly was validated by a comparison between the
theoretical restriction profile and the experimental profile obtained
with a) total genomic DNA, and b) a selection of overlapping clones.