ISSN 10227954, Russian Journal of Genetics, 2015, Vol. 51, No. 3, pp. 313–317. © Pleiades Publishing, Inc., 2015.
Original Russian Text © T.V. Butina, S.A. Potapov, O.I. Belykh, S.I. Belikov, 2015, published in Genetika, 2015, Vol. 51, No. 3, pp. 384–388.
Viruses are known to affect the genetic diversity
and abundance of bacteria. They also regulate the cir
culation of substance and energy in water ecosystems
[1, 2]. However, despite intense research in the field of
water virology, viruses from symbiotic associations and
particularly those coming from freshwater systems
have yet to be studied.
Sponges, which are the most ancient multicellular
invertebrates (type Porifera), are unique and ecologi
cally important representatives of complex symbioses
inhabiting the world ocean and freshwater reservoirs.
A sponge community includes a variety of microor
ganisms: fungi, algae, archaea, bacteria, and viruses.
Sponge communities have a complex structuralfunc
tional organization, allowing them to adapt and
respond to any changes in their environment [3–5].
The abundance and diversity of viruses in the commu
nity may be significant because of the great number of
potential hosts for viruses in sponges. Nevertheless,
the biodiversity and significance of viruses inhabiting
sponges are still to be studied .
In the known coral communities, the majority of
viruses constitute those of associated microorganisms,
including cyanophages—viruses, that infect cyano
bacteria . Cyanophages, aside from their patho
genic nature, are thought to participate in photosyn
thetic processes under unfavorable environmental
conditions  because of the additional synthesis of
the D1 and D2 proteins of photosystem II encoded by
genes, respectively . Metage
nomic study revealed a high number of the
in viruses associated with coral communities . The
known cyanophage genomes contain other cyanobac
terial genes, which are expressed in the course of
infection and participate in the host metabolism.
tocyanin), and others [9–11]. Thus, cyanophages rep
resent a gene reservoir and participate in gene transfer
and the microevolutionary processes of cyanobacteria.
As shown previously, cyanobacteria were found in
communities of sea and freshwater sponges, including
ones from Lake Baikal [3, 4, 12]. Since cyanobacteria
are the primary producers, they supply the sponge with
organic substances and participate in lifesustaining
activity of the complex symbiotic community [4, 13].
For this reason, in sponges, interaction of cyanoph
ages with their hosts can significantly affect the total
functional state of communities.
The goal of this study is identification and estima
tion of the genetic diversity of cyanophages belonging
to the family Myoviridae as part of the associated com
munity of the endemic Baikal sponge
. For this purpose, the
was used as a genetic marker [14, 15]. The marker is
widely used in the analysis of cyanophages associated
with a variety of water ecosystems [14–20].
sponges were collected in 2–3 cm
volume together with 50 mL control water sample
taken from the sample site. Sampling was performed
by deep divers in April 2010 in the southern basin of
the Lake Baikal. The control water sample were fil
tered through 0.2
m filter. The sample of sponge was
washed twice in sterile water and squeezed. The liquid
was centrifuged at13000 rpm for 20 min and superna
tant was subsequently filtered through three filters
with pore diameters of 1.2, 0.8, and 0.2
resultant samples were used as PCR templates with the
CPS1 and CPS4 primers [14, 15]. The amplified frag
ments were cloned and analyzed as described previ
Genetic Diversity of Cyanophages of the Myoviridae Family
as a Constituent of the Associated Community
of the Baikal Sponge
T. V. Butina, S. A. Potapov, O. I. Belykh, and S. I. Belikov
Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, 664033 Russia
Received July 21, 2014
—Moleculargenetic analysis of cyanophages of the family Myoviridae from the associated commu
nity of the endemic Baikal sponge
was carried out based on the
gene fragment. A
high cyanophage diversity according to the
marker gene was found in the sponge. The Baikal sponge
cyanophages were shown to be similar to those inhabiting plankton. Moreover, specific cyanophage groups
that are significantly different from all of the known groups inhabiting the Lake Baikal were revealed.