Botanical Studies (2006) 47: 1-11.
*
Corresponding author: E-mail: mbmtchan@gate.sinica.edu.tw; Tel: 886-2-26516194; Fax: 886-2-26511164.
Validation of cDNA microarray as a prototype for
throughput detection of GMOs
Tzy-Li CHEN
1
, SANJAYA
2
, Venkatesh PRASAD
2
, Ching-Hua LEE
2,3
, Kuang-Hung LIN
4
,
Lih-Ching CHIUEH
5
, and Ming-Tsair CHAN
2,
*
1
Department of Food Science and Technology, Tung-Fang Institute of Technology, KaoHsiung 829, Taiwan
2
Institute of BioAgricultural Sciences, Academia Sinica, Taipei 115, Taiwan
3
Graduate Institute of Biotechnology, Chinese Culture University, Taipei 111, Taiwan
4
Department of Horticulture, Chinese Culture University, Taipei 111, Taiwan
5
Bureau of Food and Drug Analysis, Department of Health Executive Yuan, Taipei 115, Taiwan
(Received November 16, 2004; Accepted August 9, 2005)
ABSTRACT
. As a step towards developing an efficient genetically modified organism (GMO) detection
system, the present investigation proposes microarray as a prototype for high-throughput detection of pure
GMO samples. Common T-DNA regions of the expression cassette such as 35S promoter, 35S terminator,
nopaline synthase terminator (NOSt), hygromycin, and kanamycin selection marker genes were detected in
the transgenic rice, tomato, and potato developed in our laboratory. For proof-of-concept purposes, market-
introduced GM potato, GM maize, and cornflakes were screened. The non-GM potato and maize control
detected only the presence of endogenous genes while the GM targets detected the presence of transgenic
genes such as CaMV 35S promoter, 35S terminator, NOSt and nptII, pat, cp4 epsps, cry1 Ab genes on chips.
Moreover, it was observed that the sensitivity of this system for serially diluted GM potato tubers was up
to 0.01-0.002% of the mass fraction. Due to its high accuracy and speed, it is believed that the microarray
detection system will play an important role in routine, high-throughput detection of pure GMO samples in
the future.
Keywords: cDNA microarray; Genetically modified organisms (GMO); GM potato; GM maize.
Abbreviations: 35Sp, promoter from the cauliflower mosaic virus; 35St, CaMV35S poly (A) signal; aadA,
streptomycin-resistance; Actin, rice actin gene; BAR, gene coding for a phosphinothricin acetyltransferase
from Streptomyces hygroscopicus; Bt11, specific gene of Bt11 (Novartis); b-tubulin: tomato b-tubulin gene;
CBH351, specific gene for CBH351 (StarLink, AgrEvo); CryIAb, delta-endotoxin from Bacillus thuringi-
ensis subsp. Kurstaki; EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium tume-
faciens strain CP4; GA21, specific gene of GA21 (Monsanto); GFP, green fluorescent protein gene; GUS,
b-glucuronidase gene; HPT, hygromycin phosphotransferase gene; ivr, maize invertase gene; LUC, luciferase
gene; LE, soybean legumin protein gene; NOSt, terminator of nopaline synthase gene from Agrobacterium
tumefaciens; NPT II, neomycin phosphotransferase gene; Ocst, octopine synthase terminator; tmlt, transcrip-
tion terminator of a tumor morphology large gene from Agrobacterium tumefaciens; T25, specific gene of
T25 Libery (AgrEvo); E35S, enhanced CaMV35S promoter; B P, bacterial promoter; bla, beta lactamase; pat,
phosphinothricin-N-acetyltransferase from S. viridochromogenes; bla, beta-lactamase gene; conveys resistance
to beta-lactam antibiotics; from Tn3; Zmhsp70, maize HSP 70 intron; Cpsp, chloroplast transit peptide from A.
thaliana EPSPS gene; P-ract1/ract1, P-ract1/ract1 intron; Actin 1, rice actin I promoter; RuBisco-sp, ribu-
lose-1,5-bisphosphate carboxylase oxygenase derived chloroplast transit peptide sequence; AI, Actin 1 intron
sequence; IVS 2, IVS2 intron from the maize alcohol dehydrogenase gene; IVS6, IVS6 intron from the maize
alcohol dehydrogenase gene.
MOLECULAR BIOLOGY