1022-7954/01/3702- $25.00 © 2001
Russian Journal of Genetics, Vol. 37, No. 2, 2001, pp. 129–134. Translated from Genetika, Vol. 37, No. 2, 2001, pp. 183–189.
Original Russian Text Copyright © 2001 by Katzy, Borisov, Scheludko.
The motility of
determined by ﬂagella of two types: the single polar ﬂa-
gellum (Fla) is synthesized in liquid media, whereas in
solid and semiliquid media, numerous lateral ﬂagella
(Laf) are induced, in addition to Fla . Fla is respon-
sible for swimming (Mot), and Laf is involved in coor-
dinated spreading of bacteria on the surface of
solid/viscous media [2, 3]. In
of ﬂagellas seem to be vital for effective expansion of
bacteria on the surface of media and in semiliquid
media, which is termed swarming in the broad sense
(Swa) [4, 5].
Genetic data on
motility are scarce.
Plasmids with a molecular weight of 4 to 1800 MDa
constitute an appreciable portion of the bacterial
genome . Most
plasmids are little stud-
ied. However, plasmid replicons in two model strains of
Sp7 and Sp245, can induce the synthesis
of ﬂagella and determine some other characters impor-
tant for the formation of rhizocoenosis [7–11]. Inser-
tion of omegon-Km into one locus of a 120-MDa plas-
mid (p120) in the
Sp245 strain was shown
to result in the loss of Fla and to cause strong defects in
swarming, inducible Laf expression being retained at
the wild-type level . Insertion of omegon-Km into
another locus, p120, led to a loss of motility of the
KM018 mutant in liquid and semiliquid media ,
despite the normal production of Fla and Laf (A.V. She-
lud’ko, unpublished data). In two omegon mutants of
SK051 and Mot
ern blot hybridization with pJFF350 DNA revealed a
positive signal provided by plasmid 85-MDa (p85) .
In this work, we found that cointegrates of plasmids
p85 and pJFF350 were formed in
and SK248; the scheme of these cointegrates is pre-
sented. We described a novel mutant of
Sp245 carrying p85::pJFF350 and examined its ﬂagel-
lation and motility.
MATERIALS AND METHODS
Bacterial strains, plasmids, cultivation conditions,
analysis of motility and ﬂagellation.
and plasmids used in this study are listed in the table.
were grown on a malate–salt
medium  with the addition of NH
Cl (1 g/l) (MSM)
cells were grown
in LB  at 37
C. Kanamycin (Km) was added as
required, to a ﬁnal concentration of 50
motility was assessed using phase-contrast microscopy
and measuring diameters of swarming rings formed
after seeding bacteria by an inoculating needle in semi-
liquid MSM (0.2–0.6% agar) and incubating them for
18–96 h. Transmission electron microscopy of bacteria
was conducted as described in  to study ﬂagellation.
Plasmids were visualized by the
Eckhardt method . Isolation and puriﬁcation of
plasmid and total DNA, restriction analysis, electroelu-
tion of DNA fragments from agarose gels, DNA liga-
tion, and bacterial transformation were conducted by
conventional methods . Labelling of DNA frag-
Effect of the Integration
of Vector pJFF350 into Plasmid 85-MDa
on Bacterial Flagellation and Motility
E. I. Katzy, I. V. Borisov, and A. V. Scheludko
Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences,
Saratov, 410015 Russia; fax: (8452)947-30-3; e-mail: firstname.lastname@example.org
Received August 22, 2000
—Results of genetic analysis of three derivatives of
Sp245 (strains BK570,
SK051, and SK248) carrying cointegrates of plasmids 85-MDa and pJFF350 (the vector for omegon mutagen-
esis), which manifest abnormalities in ﬂagellation and motility, are presented. It was shown for the ﬁrst time
that the integration of the suicide vector into one of
resident plasmids is accompanied by the for-
mation of various fusion products and changes in ﬂagellation and motility of these bacteria, such as the loss of
the polar (Fla) and lateral (Laf) ﬂagella in SK051; inactivation of Fla and Laf in SK248; and Fla-dependent
acceleration of expansion in semiliquid media in BK570.