Bacillus subtilis mutants harbouring a single copy of the rRNA operon exhibit severe defects in growth and sporulation.
The number of copies of rRNA genes in bacterial genomes differs greatly among bacterial species. It is difficult to determine the functional significance of the heterogeneity of each rRNA operon fully due to the existence of multiple rRNA operons and because the sequence heterogeneity among the rRNA genes is extremely low. To overcome this problem, we sequentially deleted the ten rrn operons of Bacillus subtilis and constructed seven mutant strains that each harboured a single rrn operon (either rrnA, B, D, E, I, J or O) in their genome. The growth rates and sporulation frequencies of these mutants were reduced drastically compared with those of the wild-type strain, and this was probably due to decreased levels of ribosomes in the mutants. Interestingly, the ability to sporulate varied significantly among the mutant strains. These mutants have proved to be invaluable in our initial attempts to reveal the functional significance of the heterogeneity of each rRNA operon.
Nanamiya
Hideaki
H
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Sato
Makiko
M
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Masuda
Kenta
K
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Sato
Mikiko
M
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Wada
Tetsuya
T
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Suzuki
Shota
S
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Natori
Yousuke
Y
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Katano
Masato
M
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Akanuma
Genki
G
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
Kawamura
Fujio
F
Laboratory of Molecular Genetics and Research Information Center for Extremophile, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.
D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology; D017353:Gene Deletion; D018628:Gene Dosage; D009154:Mutation; D012270:Ribosomes / Q000235:genetics; D013171:Spores, Bacterial / Q000254:growth & development; D012407:rRNA Operon