1022-7954/00/3612- $25.00 © 2000
Russian Journal of Genetics, Vol. 36, No. 12, 2000, pp. 1395–1400. Translated from Genetika, Vol. 36, No. 12, 2000, pp. 1656–1662.
Original Russian Text Copyright © 2000 by Kozlova, Guryev, Blinov, Omelyanchuk.
Screening for lethal insertions of the P[lArB] ele-
ment, which cause cell-division defects in homozygous
individuals, has previously been conducted. This
screening revealed a consensus pattern of the expres-
sion of such genes in different
tissues, speciﬁcally, in neural ganglions, in
imaginal disks of larvae and testes, and in ovarian ger-
mariums of adults [1–3]. These results are in agreement
with independent data on the expression of the
genes [4–6]. Expression zones in the ger-
marium have been detected only for the
genes. However, the mutant
from our collection is
(Sunkel, unpublished data) and is clearly
expressed in the germarium. Moreover, the known
gene involved in chromosomal disjunction manifested
expression in the germarium . Thus, there is every
reason to believe that the expression in the germarium
zone is typical for cell-division genes. In this work, we
studied an insertion of P[lArB] transposon, whose
reporter gene expression agrees well with the expression
pattern of cell-cycle genes, although this gene also has a
different function in the development of an organism.
MATERIALS AND METHODS
Isolation of the
was described in . The insertion allele
gene was obtained from the Bloomington stock
center. The Nikone-AW line was used as a wild-type
X-gal staining for
of larvae and adult ﬂies were dissected in a drop of the
Henks solution . X-gal staining was conducted as in
 with minor modiﬁcations (ﬁxation, 0.75% glut-
araldehyde in 0.1 M sodium–cacodylate buffer for
Neural ganglions of third-
instar larvae were isolated in the Henks solution ,
treated with 1% sodium citrate for 5 min, ﬁxed in a
mixture of methanol–acetic acid (3 : 1) for 20 min, air-
dried, and Giemsa stained.
was conducted by
of genomic DNA (from individuals heterozygous for
) by standard techniques . In this manner, we
obtained an Ap1 clone containing a 3.8-kb fragment
element and used it as a probe in in situ
hybridization and screening for a genomic library.
Screening for a genomic library and clone isolation.
The genomic library of
(Canton S) in
EMBL4 provided by S. Campusano
(Spain) was screened by blot hybridization with the
Ap1 probe. The DNA from positive clones was iso-
lated. DNA from one of the recombinant phages (
was digested with the restriction endonuclease
and the resulting fragments were separated by electro-
phoresis in a 1% agarose gel. The DNA was blotted to
Hybond membrane by the NaOH transfer method.
Plasmid DNA was labeled with [
P]-NTP using the
Prime-a-Gene Labeling System (Promega). The mem-
brane was hybridized at 65
C in a buffer containing
SSC, 0.1% SDS, and 0.2 mg/ml of yeast ribonu-
cleic acid, and washed in 4
SSC, 0.1% SDS at 65
Two of seven positive
were selected for further subcloning into
plasmid pBlueScript. The resulting subclones were
designated as Ap4 and Ap7, respectively.
Clones were sequenced by the direct
dideoxy-chain-termination procedure of Sanger using
the dsDNA Cycle Sequencing Version (Gibco BRL).
In situ hybridization.
Polytene chromosomes for
in situ hybridization were prepared as described in .
Biotin-labeled DNA samples were made using the
BioNick Labeling System (Gibco BRL). A Carnegie-20
Gene: Proliferation or Hormonal Control?
A. V. Kozlova, V. P. Guryev, A. G. Blinov, and L. V. Omelyanchuk
Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, 630090 Russia;
fax: (3832) 33-12-78; e-mail: email@example.com
Received June 8, 1999; in ﬁnal form, March 15, 2000
—A new insertion allele of the
gene was isolated and described. The nucleotide sequence of the
coding region had no detectable homology with genomic DNA of any other
species, except for
Gene expression was found both in adult testes and ovaries and at embryonic and larval stages.
This expression pattern exhibits a strong similarity to that of cell-cycle genes. In contrast to
(a typical cell-
cycle gene), which leads to expression termination after in vivo culturing of the wing disk,
did not arrest
expression. It is concluded that
is a species-speciﬁc differentiation gene, whose regulatory activity in the
development of an organism differs from that of proliferation genes.