Desaturase genes in a psychrotolerant Nostoc sp. are constitutively expressed at low temperature.
Antarctic psychrotolerant, Nostoc sp. (SO-36), when grown at 25 degrees C and then shifted to 10 degrees C, showed an increase in the tri-unsaturated fatty acid [C(18:3(9,12,15))] at the expense of mono- [C(18:1(9))] and di-unsaturated [C(18:2(9,12))] fatty acids. These results indicate that the activities of the enzymes DesA and DesB are up-regulated, when cultures were grown at 10 degrees C or shifted to 10 degrees C from 25 degrees C. However, RT-PCR studies indicated a constitutive expression of desA, desB, desC, and desC2 genes when cultures grown at 25 degrees C were shifted to 10 degrees C. This constitutive expression of des genes is in contrast to that observed in mesophilic cyanobacteria, in which desA and desB are transcriptionally up-regulated in response to lowering of growth temperature.
Chintalapati
Suresh
S
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Prakash
J S S
JSS
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Singh
Ashish K
AK
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Ohtani
Shuji
S
Department of Biology, Faculty of Education, Shimane University, Nishikawatsu, Matsue 690, Japan.
Suzuki
Iwane
I
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan.
Murata
Norio
N
National Institute for Basic Biology, Myodaiji, Okazaki 444-8585, Japan.
Shivaji
Sisinthy
S
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India. Electronic address: shivas@ccmb.res.in.
D000864:Antarctic Regions; D003001:Cloning, Molecular; D003080:Cold Temperature; D000458:Cyanobacteria / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D044943:Fatty Acid Desaturases / Q000096:biosynthesis* / Q000378:metabolism* / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D046937:Nostoc / Q000378:metabolism*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature; D015854:Up-Regulation
D017931:DNA Primers; D044943:Fatty Acid Desaturases