Volume 9 (2004) pp 409-422 |
Title |
PROTECTIVE EFFECTS OF NICOTINE AGAINST GLUTAMATEINDUCED
NEUROTOXICITY IN PC12 CELLS |
Authors |
Xiulan Sun1,2, Yue Liu1,3, Gang Hu2 and Hai Wang1* |
Abstract |
This study aimed to assess whether nicotine prevented glutamate
neurotoxicity in PC12 cells, and to identify the molecular mechanisms of any
effects. The results showed that glutamate neurotoxicity in PC12 cells could be
prevented by treatment with nicotine at concentrations of 10 nmol.l-1-1 mmol.l-1.
This effect was in turn found to be inhibited by the application of the nicotinic
acetylcholine receptor (nAChR) antagonist mecamylamine. Nicotine
significantly decreased the basal level of intracellular free Ca2+ and enhanced the
buffering action on Ca2+ overload induced by high concentrations of glutamate
(5 mmol.l-1). In addition, nicotine treatment up-regulated the mRNA and protein
expression of apoptosis-related factors including bcl-2 mRNA and protein, but
down-regulated the expression of bax mRNA and protein. It is concluded that
the protective effects of nicotine against the neurotoxicity induced by glutamate
are mediated by nAChRs, due to the increased buffering action on Ca2+ and the
modulation of apoptotic processes. |
Address and Contact Information |
1Beijing Institute of Pharmacology and Toxicology, Beijing 100850 ,P.R.China,
2Nanjing Medical University, Nanjing 210029 , P.R.China, 3Thadweik Academy
of Medicine, Beijing 100850, P.R.China * Corresponding author; tel: 86-10-66932651, fax: 86-10-6821-1656,
e-mail: wh@nic.bmi.ac.cn |
|
Volume 9 (2004) pp 423-427 |
Title |
DNA REPLICATION REACTION IN XENOPUS CELL-FREE SYSTEM
IS SUPPRESSED BY HIGH PRESSURE |
Authors |
Hitoshi Takahashi1, Takeo Yamaguchi1, Masaaki Koga2,
Hiroshi Kageura2 and Shigeyuki Terada1 |
Abstract |
Previously, we demonstrated that when mouse erythroleukemia cells
are exposed to a pressure of 80 MPa, the cell-cycle progression of S-phase cells
is retarded. To examine the effects of high pressure on DNA replication, we used
a Xenopus cell-free system. From cell-cycle progression of sperm nuclei, it was
found that sperm nuclei are stable to a pressure of 80 MPa, whereas egg extracts
are susceptible to high pressure. Similarly, biotin-16-dUTP was incorporated
into 80 MPa-treated sperm nuclei in pressure-untreated extracts, but not into
naive sperm nuclei in 80 MPa-treated extracts. These results indicate that DNA
replication in Xenopus cell-free system is suppressed by the susceptibility of the
extracts to a pressure of 80 MPa. |
Address and Contact Information |
1Department of Chemistry and 2Department of Biology, Faculty of Science,
Fukuoka University, Jonan-ku, Fukuoka, 814-80 Japan |
|
Volume 9 (2004) pp 429-437 |
Title |
SITE-SPECIFIC EXCISION OR PROTECTION OF AN ALPHA A
GLOBIN GENE GENOMIC SITE IN APOPTOTIC TRANSFORMED
CHICKEN ERYTHROBLASTS |
Authors |
Nikolajs Sjakste |
Abstract |
There is still no clarity on whether the endonuclease incisions in
apoptotic cells are induced randomly in the genome or induced in some
preferable sites. In order to evaluate the intensity of DNA fragmentation in the
chicken alpha-globin domain, AEV-virus transformed chicken erythroblasts
(HD3) were incubated in a serum free medium, and their DNA was Southern
blotted and hybridised with probes representing different fragments of the
domain. Probes corresponding to the upstream areas of the domain mostly
hybridised with high molecular weight DNA. Unlike these, the probe
corresponding to the 2 Kb BamHI-BamHI fragment, containing the alphaA
globin gene (B18), revealed a 5 Kb band on the hybridisation autoradiographs.
The probe to the neighbouring upstream fragment did not reveal this band, but it
was clearly seen on hybridisations with a downstream 1 Kb BamHI-BamHI
fragment. The intensity of the band increased with overall apoptotic DNA
degradation, hence its appearance should be coupled to apoptosis. Hybridisation
of BamHI-digested DNA with B18 probe revealed a shortening of the 2 Kb band
in preparations of DNA from apoptotic cells. The presumable positions of the
cuts correspond to the formerly described DNase hypersensitive sites in the
domain. Slot-blot and Northern hybridisation of RNA extracted from apoptotic
HD3 cells revealed that the excision of the area of the B18 gene is coupled to a
decrease in the intensity of alphaA globin gene transcription. Transcription of the
non-erythroid NIK gene, transcribed in the upstream part of the domain, did not
depend on the level of apoptotic DNA fragmentation. |
Address and Contact Information |
Faculty of Medicine of the University of Latvia, Sharlotes Street 1a,
Riga LV1001, Latvia |
|
Volume 9 (2004) pp 439-449 |
Title |
SHOOT REGENERATION FROM GUS-TRANSFORMED TOMATO
(Lycopersicon esculentum) HAIRY ROOT |
Authors |
Reda E. A. Moghaieb1,2, Hirofumi Saneoka1
and Kounosuke Fujita1* |
Abstract |
To study the influence of genetic background on the transformation
and regeneration of cultivated tomato plants, hairy root lines of tomato
(Lycopersicon esculentum) were obtained by inoculating the hypocotyl explants
of three tomato cultivars with the Agrobacterium rhizogenes strain DCAR-2,
which harbors the pBI-121 binary vector. The Ri-T-DNA transformation into the
plant DNA was confirmed by both of mikimopine and GUS assay analyses. The
regeneration efficiency from hairy root explants was assessed. The data
indicated that white embryonic calli were formed within two weeks in the
presence of 2 mgl-1 2, 4-D plus 0.25 mgl-1 kinetin. Adventitious shoots emerged
from the embryonic callus in the presence of 1 mgl-1 GA3 along with 0.5 mgl-1
NAA. The regeneration frequency was higher in the cultivar UC-97, followed by
Momotaro and then Edkawi. Molecular confirmation of the integration of the
GUS gene into the hairy root-derived plants genomes was done via PCR using
GUS-specific primers and also using Southern blotting analysis. Our data shows
that regeneration is possible from hairy roots of the cultivated tomato and this
system could be used to produce transgenic tomato plants expressing the genes
present in Agrobacterium rhizogenes binary vectors. |
Address and Contact Information |
1Department of Environmental Dynamics and Management, Graduate School of
Biosphere Sciences, Hiroshima University, Higashi-Hiroshima, 739-8528,
Japan, 2Department of Genetics, Faculty of Agriculture, Cairo University,
Giza, Egypt * Corresponding author: e-mail: fujiko@hiroshima-u.ac.jp |
|
Volume 9 (2004) pp 451-464 |
Title |
THE EFFECT OF ANTISENSE OLIGONUCLEOTIDE TREATMENT
OF PLASMA MEMBRANE Ca2+- ATPase IN PC 12 CELLS |
Authors |
Janusz Szemraj, Iwona Kawecka, Jacek Bartkowiak
and Ludmiła Żyliłska* |
Abstract |
Plasma membrane Ca2+-ATPase (PMCA), encoded by four separate
genes, constitutes a high affinity system extruding Ca2+ outside the cell. The
nerve growth factor-treated PC12 cell line possesses all four main PMCA
isoforms. To evaluate the potential role of PMCA isoforms in the differentiation
process, we transiently suppressed the expression of PMCA2 and 3 using the
antisense oligonucleotides. In the transfected PC12 cells, we observed
morphological changes, slowed neurite extension and diminished survival of the
cells. The apparent transport activity and affinity of the calcium pump to Ca2+
were lower in the cells with suppressed PMCA2 and 3 isoforms than in the
control cells. Moreover, in the transfected PC12 plasma membranes, the calcium
pump was insensitive to stimulation by calmodulin. These findings suggest that
PMCA2 and 3 isoforms may be involved in developmental and differentiation
processes. |
Address and Contact Information |
Neurochemical Laboratory, Department of Biochemistry, Medical University,
ul. Mazowiecka 6/8, 92-215 Łódź, Poland * Corresponding author: e-mail: luska@csk.am.lodz.pl |
|
Volume 9 (2004) pp 465-473 |
Title |
ISOLATION AND CHARACTERIZATION OF A SERINE/THREONINE
PROTEIN KINASE SOS2 GENE FROM Brassica napus |
Authors |
Jin Wang1,2,3, Weisheng Wu1, Kaijing Zuo2, Jiong Fei2, Xiaofen
Sun1, Juan Lin1, Xufeng Li4 and Kexuan Tang1,2,* |
Abstract |
A full-length cDNA of a new serine/threonine (Ser/Thr) protein
kinase gene, designated as BnSOS2 (GenBank Acc. No.AY310413), was cloned
from Brassica napus by rapid amplification of cDNA ends (RACE). The fulllength
cDNA of BnSOS2 was 1779 bp and contained a 1539-bp open reading
frame encoding a protein of 512 amino acids. Homology analysis shows that
BnSOS2 strongly resembles other Ser/Thr protein kinase genes, and that its
putative protein belongs to a typical Ser/Thr kinase family. Northern blot
analysis reveals that BnSOS2 is salt-inducible. Our results indicate that BnSOS2
is a new member of the plant SOS2 gene family, which may play an important
role in salt tolerance of plants. |
Address and Contact Information |
1State Key Laboratory of Genetic Engineering, School of Life Sciences,
Morgan-Tan International Center for Life Sciences, Fudan-SJTU-Nottingham
Plant Biotechnology R&D Center, Fudan University, Shanghai 200433, China,
2Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant
Biotechnology R&D Center, School of Agriculture and Biology, Shanghai
Jiaotong University, Shanghai 200030, China, 3Mianyang Teacher’s College,
Mianyang 621000, China, 4College of Life Science, Sichuan University,
Chengdu 610064, China *Corresponding author; tel: 021-65642772; fax: 021-65643552; e-mail:
kxtang1@yahoo.com or kxtang1@sohu.com. |
|
Volume 9 (2004) pp 475-481 |
Title |
BIGLYCAN IS INTERNALIZED VIA A CHLORPROMAZINESENSITIVE
ROUTE |
Authors |
Martin Götte1,2,*, David Denis Sofeu Feugaing1
and Hans Kresse1† |
Abstract |
The small leucine-rich proteoglycan biglycan (BGN) is abundantly
expressed in mesenchymal tissues. Its expression level is related to the
phenotypic differentiation of cells. A dysregulation in BGN expression occurs
under several pathological conditions, including glomerulonephritis,
mesothelioma, pancreatic cancer and a mouse model of osteoporosis. Since the
extracellular concentration of BGN is regulated both by secretion and
endocytosis, we performed mechanistic studies on BGN endocytosis in human
skin fibroblasts in vitro, using inhibitors of different endocytic routes.
Chlorpromazine, an inhibitor of the clathrin-coated pit-pathway reduced
endocytosis of BGN in human skin fibroblasts by 40%, and decreased
degradation of BGN by 66%. Filipin, an inhibitor of the caveolae pathway, and
Tyrphostin AG 1478, a specific inhibitor of EGF-receptor phosphorylation that
partially inhibits endocytosis of the structurally related proteoglycan decorin,
had no influence on BGN internalization and degradation. Our data indicates
that the classical clathrin-mediated endocytic pathway is a major route for the
internalization of BGN. Based on the differential susceptibility to
pharmacological inhibition, it appears that BGN endocytosis seems to be at least
in part mechanistically different from decorin uptake. |
Address and Contact Information |
1Department of Physiological Chemistry and 2Department of Obstetrics and
Gynecology, Münster University Hospital, Domagkstr. 11, D-48149 Münster,
Germany *Corresponding author; tel: (+49) 251 8356113, fax: (+49) 251 8356114, e-mail:
mgotte@uni-muenster.de †Deceased |
|
Volume 9 (2004) pp 483-495 |
Title |
PROTECTIVE EFFECT OF VACCINATION WITH DNA OF THE
H. pylori GENOMIC LIBRARY IN EXPERIMENTALLY INFECTED
MICE |
Authors |
Artur Dzwonek1, Michał Mikula1, Marek Woszczyłski2,
Ewa Hennig1 and Jerzy Ostrowski1* |
Abstract |
Immunologically mediated protection against H. pylori infection is an
attractive alternative to antibiotic treatment. We compared the efficacy of
conventional protein vaccination with that of genetic vaccination against
experimental infection with H. pylori in mice. For oral immunization, we used
the recombinant peptide of an antigenic fragment of UreB (rUreB) or H. pyloriwhole
cell lysate antigens, and for genetic immunization, we used recombinant
pcDNA and pSec plasmids inserted with the fragment of ureB or DNA of the
H. pylori genomic library. Mice were challenged with the mouse stomachadapted
H. pylori Sidney Strain. The detection of gastric bacterial colonization
was performed by real-time PCR of a 26-kDa Helicobacter-specific gene, and
the presence of serum H. pylori-specific antibodies was determined using direct
ELISA assay. The most effective treatment appeared to be oral vaccination with
rUreB and either intramuscular or intradermal vaccination with DNA of the
H. pylori genomic library. Intradermal genetic vaccination with genomic library
DNA significantly increased the IgG antibody response. Our study revealed
acceptable efficacies of genetic vaccination with DNA of the H. pylori genomic
library. |
Address and Contact Information |
1Department of Gastroenterology, Medical Center for Postgraduate Education,
Maria Skłodowska-Curie Memorial Cancer Center, ul. Roentgena 5, 02-781
Warsaw, Poland, 2Department of Animal Genetics, Cancer Center and Institute
of Oncology, Warsaw, Poland *Corresponding author; tel: (48 22) 6440102, fax: (48 22) 6447601, e-mail:
jostrow@warman.com.pl |
|
Volume 9 (2004) pp 497-509 |
Title |
THE DISTRIBUTION OF PERIPHERAL BLOOD DENDRITIC CELLS
ASSAYED BY A NEW PANEL OF ANTI-BDCA MONOCLONAL
ANTIBODIES IN HEALTHY REPRESENTATIVES OF THE POLISH
POPULATION |
Authors |
Joanna Narbutt1*, Aleksandra Lesiak1, Małgorzata Żakprelich1,
Anna Woźniacka1, Anna Sysa-Jędrzejowska1,
Marzena Tybura2, Tadeusz Robak2 and Piotr Smolewski2** |
Abstract |
A growing number of studies are being performed on the role of
dendritic cells (DCs) in the etiopathogenesis of various conditions. Therefore, it
is extremely important to establish the best comparable methods for the
determination of the absolute count of blood dendritic cells (BDCs) or their
subsets, and the reference normal values for comparisons.
The aim of our study was to assess a normal profile of BDCs in the non-cultured
human blood of healthy Polish volunteers. BDCs were detected among
peripheral blood mononuclear cells (PBMC) from 99 healthy people, aged 18-
56. Based on the panel of novel anti-BDCA1, BDCA2 and BDCA3 monoclonal
antibodies (MoAbs), three main subpopulations of BDCs were distinguished:
two myeloid types of BDCs, MDC1(BDCA-1+/ CD11c+ /HLA-DR+) or MDC2
(BDCA-3+/CD32-/CD64-/HLA-DR+), and a plasmacytoid subtype, PDC
(BDCA-2+/CD123+/HLA-DR+). The number and percentage of BDCs were
correlated with the age, gender, photosensitivity (phototype, minimal erythemal
dose - MED) and morphological parameters of the healthy volunteers. BDCs represented 0.83% of the PBMC and the median total BDC number was 44.0
cell/ml. The total BDC number correlated with the WBC count (r=0.40;
p<0.001) as well as with the lymphocyte and monocyte counts (r=0.20; p=0.045
and r=0.26; p=0.009, respectively). The median percentage of the MDC1 count
(0.20%) was twice as high as the MDC2 count (0.10%). The median PDC count
was 28.2 cell/ml, and these cells represented 0.50% of the PBMC. There was
a positive correlation between PDC and skin photosensitivity (r=0.28; p=0.005).
An inverse correlation between the PDC count and the age of the examined
volunteers was also found (r=-0.22; p=0.029). Our study provides the first
referential data on normal rates and counts of BDCs and their subpopulations,
assessed by the new panel of anti-BDCA MoAbs, in healthy Polish subjects. The
method used in the study allowed the determination of BDCs and their subset
numbers in a relatively small blood volume. |
Address and Contact Information |
1Department of Dermatology, Medical University of Łódź, Poland, 2Department
of Haematology, Medical University of Łódź, Poland * tel/fax: (+4842) 6884565; e-mail: joanna.narbutt@onet.pl
** Corresondind author; tel: (+4842) 68951-91; fax: +4842689-51-93; e-mail:
piotr_smolewski@wp.pl |
|
Volume 9 (2004) pp 511-518 |
Title |
THE EFFECT OF BRACHYTHERAPY ON ANTIOXIDANT STATUS
AND LIPID PEROXIDATION IN PATIENTS WITH CANCER OF THE
UTERINE CERVIX |
Authors |
Celestyna Mila-Kierzenkowska1*, Kornelia Kędziorakornatowska2,
Alina Woźniak1, Tomasz Drewa1,3, Bartosz
Woźniak4, Sylwia Drewa5, Ewa Krzyżyłska-Malinowska1
And Roman Makarewicz6 |
Abstract |
The aim of this study was to investigate the effect of brachytherapy
on lipid peroxidation and antioxidant status in patients with uterine cervix
cancer. The study was conducted on 84 uterine cervix cancer patients from the
Brachytherapy Department of the Regional Centre of Oncology in Bydgoszcz.
Patients with uterine cervix cancer were found to have elevated levels of lipid
peroxidation and antioxidant defence system impairment relative to healthy
females. The results of the study indicate that brachytherapy has no direct effect
on the antioxidant system of patients with uterine cervical carcinoma. However,
the normalisation of catalase and glutathione peroxidase activity and erythrocyte
TBARS level observed six months after the end of therapy may be due to the
arrest of the progression of the disease. |
Address and Contact Information |
1Department of Medical Biology, 2Clinic of Geriatrics, 3Clinic of Urology,
4Clinic of Neurosurgery and Neurotraumatology, 5Department of Radiology,
Ludwik Rydygier Medical University, Karłowicza 24, PL-85-092 Bydgoszcz,
Poland, 6Regional Centre of Oncology, Romanowskiej 2, PL-85-796 Bydgoszcz,
Poland * Corresponding author; tel: 48 52 585 3737, fax: 48 52 585 3742, e-mail:
celestyna@go2.pl
|
|
Volume 9 (2004) pp 519-528 |
Title |
GENOTOXICITY OF LEAD IN LUPIN ROOT CELLS AS EVALUATED
BY THE COMET ASSAY |
Authors |
Renata Rucińska, Robert Sobkowiak
and Edward A. Gwóźdź* |
Abstract |
This paper presents the results of a study on the influence of lead
(Pb2+) on DNA integrity on plant cells. The study was performed on the root tips
of lupin (Lupinus luteus cv. Juno) seedlings treated with two selected
concentrations of Pb(NO3)2: 150 and 350 mg l-1, which were found to inhibit
root growth by 50% and 70%, respectively [Ruciłska et al. Plant Physiol.
Biochem. 37 (1999) 37187-37194]. Roots exposed to those external lead
concentrations took up about 50 and 70 mg l-1 Pb2+ g-1 fresh weight (FW) over
48 h of incubation. A dose-dependent increase in the degree of root injury was
observed in the presence of both tested concentrations.
The genotoxicity of lead in lupin root cells was analysed using a mild alkaline
comet assay at pH 12.3, which allows the detection of single strand breaks. The
quantity of the DNA fragments migrating away from the nuclear remnant (tail
area) increased proportionally to the lead content inside the roots, and was
positively correlated with the degree of root injury. At 150 mg l-1 Pb2+, a high
frequency distribution of nuclei having large values of tail lengths and moments
was observed. By contrast, the number of nuclei with minimum values of these
parameters increased at 350 mg l-1 Pb2+. This data suggests that lead at low
concentrations induces the formation of short, rapidly migrating DNA
fragments, whereas at higher concentrations, lead probably causes other changes
to DNA that result in slower DNA migration in the electric field. |
Address and Contact Information |
Laboratory of Plant Ecophysiology, Faculty of Biology, Adam Mickiewicz
University, Al. Niepodległości 14, 61-713 Poznań, Poland *Corresponding author; e-mail: albus@amu.edu.pl; fax: (+4861)8294518. |
|
Volume 9 (2004) pp 529-541 |
Title |
EXTENSION OF THE MESSAPIA - dicoccoides LINKAGE MAP OF
Triticum turgidum (L.) THELL. |
Authors |
Antonio Blanco1*, Rosanna Simeone1, Alberto Cenci1,
Agata Gadaleta1, Oronzo A. Tanzarella2, Enrico
Porceddu2, Silvio Salvi3, Roberto Tuberosa3, Giovanni
Figliuolo4, Pierluigi Spagnoletti4, Marion S. Röder5
and Victor Korzun5,6 |
Abstract |
A set of recombinant inbred lines (RIL) derived from a cross between
the cultivar Messapia of durum wheat (Triticum turgidum var. durum) and the
accession MG4343 of T. turgidum var. dicoccoides was analysed to increase the
number of assigned markers and the resolution of the previously constructed
genetic linkage map. An updated map of the durum wheat genome consisting of
458 loci was constructed. These loci include 261 Restriction Fragment Length
Polymorphisms (RFLPs), 91 microsatellites (Simple Sequence Repeats, SSRs),
87 Amplified Fragment Length Polymorphisms (AFLPs), two ribosomal genes,
and nine biochemical (seven seed storage proteins and two isozymes) and eight
morphological markers. The loci were mapped on all 14 chromosomes of the
A and B genomes, and covered a total distance of 3038.4 cM with an average distance of 6.7 cM between adjacent markers. The molecular markers were
evenly distributed between the A and the B genomes (240 and 218 markers,
respectively). An additional forty loci (8.8%) could not be assigned to a specific
linkage group. A fraction (16.4%) of the markers significantly deviated from the
expected Mendelian ratios; clusters of loci showing distorted segregation were
found on the 1B, 2A, 2B, 3A, 4A, 7A and 7B chromosomes. The genetic lengths
of the chromosomes range from 148.8 cM (chromosome 6B) to 318.0 cM
(chromosome 2B) and approximately concur with their physical lengths.
Chromosome 2B has the largest number of markers (47), while the
chromosomes with the fewest markers are 3A and 6B (23). There are two gaps
larger than 40 cM on chromosomes 2A and 3B. The durum wheat map was
compared with the published maps of bread and durum wheats; the order of most
common RFLP and SSR markers on the 14 chromosomes of the A and B
genomes were nearly identical. A core-map can be extracted from the highdensity
Messapia x dicoccoides map and a subset of uniformly distributed
markers can be used to detect and map quantitative trait loci. |
Address and Contact Information |
1Department of Environmental and Agro-Forestry Biology and Chemistry,
University of Bari, via Amendola, 165/A, 70126 Bari, Italy, 2Department of
Agrobiology and Agrochemistry, University of Tuscia, 01100 Viterbo, Italy,
3Department of Agroenvironmental Science and Technology, University of
Bologna, 40126 Bologna, Italy, 4Dipartimento di Biologia, Difesa
e Biotecnologie Agro-Ambientali, University of Basilicata, Potenza, Italy,
5Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstr. 3,
D-06466, Gatersleben, Germany, 6present address: Lochow-Petkus GmbH,
PF 1197, D-29296 Bergen, Germany * Corresponding author; tel: 0039 080 5442992, fax: 0039 080 5442200, e-mail:
blanco@agr.uniba.it |
|
Volume 9 (2004) pp 543-556 |
Title |
DNA METHYLATION POLYMORPHISM IN A SET OF ELITE RICE
CULTIVARS AND ITS POSSIBLE CONTRIBUTION TO INTERCULTIVAR
DIFFERENTIAL GENE EXPRESSION |
Authors |
Yongming Wang1, Xiuyun Lin1, Bo Dong1, Yingdian Wang2
and Bao Liu1* |
Abstract |
RAPD (randomly amplified polymorphic DNA) and ISSR (intersimple
sequence repeat) fingerprinting on HpaII/MspI-digested genomic DNA
of nine elite japonica rice cultivars implies inter-cultivar DNA methylation
polymorphism. Using both DNA fragments isolated from RAPD or ISSR gels
and selected low-copy sequences as probes, methylation-sensitive Southern blot
analysis confirms the existence of extensive DNA methylation polymorphism in
both genes and DNA repeats among the rice cultivars. The cultivar-specific
methylation patterns are stably maintained, and can be used as reliable molecular
markers. Transcriptional analysis of four selected sequences (RdRP, AC9,
HSP90 and MMR) on leaves and roots from normal and 5-azacytidine-treated
seedlings of three representative cultivars shows an association between the
transcriptional activity of one of the genes, the mismatch repair (MMR) gene,
and its CG methylation patterns. |
Address and Contact Information |
1Laboratory of Molecular Epigenetics, Institute of Genetics & Cytology,
Northeast Normal University, Changchun 130024, China, 2Laboratory of Plant
Developmental Biology, School of Life Sciences, Beijing Normal University,
Beijing 100875, China |
|
Volume 9 (2004) pp 557-566 |
Title |
ISOLATION, CLONING AND CHARACTERISATION OF MOTIFS
CONTAINING (GA/TC)n REPEATS ISOLATED FROM VETCH, VICIA
BITHYNICA |
Authors |
Tomasz Sakowicz1*, Richard Bowater2
and Paweł Parniewski3 |
Abstract |
Microsatellites are widely distributed in plant genomes and comprise
unstable regions that undergo mutational changes at rates much greater than that
observed for non-repetitive sequences. They demonstrate intrinsic genetic
instability, manifested as frequent length changes due to insertions or deletions
of repeat units. Detailed analysis of 1600 clones containing genomic sequences
of Vicia bithynica revealed the presence of microsatellite repeats in its genome.
Based on the screening of a partial DNA library of plasmids, 13 clones
harbouring (GA/TC)n tracts of various lengths of repeated motif were identified
for further analysis of their internal sequence organization. Sequence analyses
revealed the precise length, number of repeats, interruptions within tracts, as
well as sequence composition flanking the repeat motifs. Representative
plasmids containing different lengths of (GA/TC)n embedded in their original
flanking sequence were used to investigate the genetic stability of the repeats. In
the study presented herein, we employed a well characterised and tractable
bacterial genetic system. Recultivations of Escherichia coli harbouring plasmids
containing (GA/TC)n inserts demonstrated that the genetic instability of
(GA/TC)n microsatellites depends highly on their length (number of repeats).
These observations are in agreement with similar studies performed on repetitive
sequences from humans and other organisms. |
Address and Contact Information |
1University of Łódź, Department of Cytogenetics and Plant Molecular Biology,
90-237 Łódź, Banacha 12/16, Poland, 2University of East Anglia, School of
Biological Sciences, Norwich NR4 7TJ, United Kingdom, 3Centre for Medical
Biology, Polish Academy of Sciences, 93-232 Łódź, Lodowa 106, Poland * Corresponding author; e-mail: tomeksakowicz@wp.pl |
|