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Sains Malaysiana 45(10)(2016): 1443–1451
Profil Pengekspresan
Gen Mengekod delta 6 dan
delta 12-Asid Lemak Desaturase Cunninghamella
bainieri semasa
Biosintesis Asid Gamma-Linolenik (Expression Profiles of delta
6 and delta 12-Fatty Acid Desaturase Encoding Genes Cunninghamella bainieri during Gamma-Linoleneic Acid Biosynthesis) NOOR
ADILA
ABDUL
KARIM,
ZAMRI
ZAINAL,
AIDIL
ABDUL
HAMID,
FARAH
DIBA
ABU
BAKAR
&
ABDUL
MUNIR
ABDUL
MURAD* Pusat Pengajian Biosains dan Bioteknologi, Fakulti Sains dan
Teknologi, Universiti
Kebangsaaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia Received: 29 November
2015/Accepted: 10 March 2016 ABSTRAK Delta 6-asid lemak desaturase dan delta 12-asid
lemak desaturase merupakan
enzim yang diperlukan bagi langkah desaturasi
semasa proses biosintesis
asid gamma-linolenik (GLA)
oleh kulat
oleaginus. Objektif kajian ini ialah
untuk menganalisis
profil pengekspresan gen mengekod enzim delta 6-asid lemak desaturase (des6) dan
delta 12-asid lemak desaturase (des12)
kulat oleaginus Cunninghamella bainieri semasa penghasilan GLA.
Jujukan gen separa
bersaiz 1372 pb
bagi des6 dan
1008 pb bagi
des12 telah dipencil daripada C. bainieri. Analisis pengekspresan gen menggunakan kaedah tindak balas berantai
polimerase kuantitatif
masa sebenar (RT-qPCR) menunjukkan
perubahan kadar
pengekspresan des6 adalah
lebih tinggi
berbanding kadar pengekspresan des12 semasa
penghasilan GLA. Pengekspresan
des6 adalah tertinggi
selepas 24 jam dikultur
dalam medium penghasilan GLA.
Namun, kadar
pengekspresannya menurun
hingga jam ke-96 pertumbuhan tetapi meningkat semula pada jam ke-120. Bagi des12, kadar
pengekspresannya adalah
lebih sekata dengan
pengekspresan tertinggi
dikesan pada jam ke-120. Analisis penghasilan GLA
menunjukkan jumlah GLA
dalam sel berkolerasi
dengan kadar
pengekspresan des6. Hasil
kajian mencadangkan
bahawa aras
pengekspresan des6 adalah
penting dalam
menentukan aras GLA dalam C. bainieri. Kata kunci:
Asid gamma-linolenik;
Cunninghamella bainieri;
delta 6-asid lemak desaturase; delta
12-asid lemak desaturase; kulat oleaginus ABSTRACT Delta 6-fatty acid desaturase
and delta12-fatty acid desaturase are enzymes required for the
desaturation steps during gamma-linolenic acid (GLA)
biosynthesis in oleaginous fungi. The objectives of this study
were to analyse the expression profiles of genes which encode for
the delta 6-fatty acid desaturase (des6) and delta 12-fatty
acid desaturase (des12) from an oleaginous fungus, Cunninghamella bainieri, during
GLA production. Partial gene sequences with the size of
1372 bp for des6 and 1008 bp
for des12, were isolated
from C. Bainieri. Gene expression analyses via real-time quantitative
PCR (RT-qPCR) indicate that the changes in the expression
profile of des6 is higher during GLA production as compared to
the expression profile of des12. The expression of des6
is the highest after 24 h of growth in the GLA-inducing medium. However,
its expression showed a decreasing pattern until 96 h of growth
but increased at 120 h. The expression profile of des12 is
more consistent with the highest expression levels detected at
120 h of growth. GLA production
analysis showed that the amount of GLA in the cell is correlated
with the expression of des6. The results of this study
suggested that
the expression of des6 plays an important role in determining
GLA production in C. bainieri.
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