The FADS2 catalyzes the first rate-limiting step in the long chain-polyunsaturated fatty acids
(LC-PUFAs) biosynthesis pathway by converting -linolenic acid and linoleic acid into
stearidonic acid and -linolenic acid via the -3 and -6 pathways respectively. In mammals,
PPAR and SREBP-1c have been implicated in the polyunsaturated fatty acids (PUFAs)
mediated transcriptional activation of FADS2 promoter. However, in zebrafish, not much is
known regarding the regulation of fads2 transcriptional regulation. Here, in this study, five
vectors containing different promoter regions were constructed in order to analyse putative
promoter activities. Through truncation analysis, it was found that the 1.2 kb promoter was able
to drive luciferase activity to an approximate 40-fold in HepG2 cells. Upon mutagenesis
analysis, three sites which are the putative NF-Y, SREBP and PPAR binding sites were found
to be essential in driving the promoter activity. Lastly, the 1.2 kb fads2 promoter was able to
direct EGFP expression specifically to the yolk syncytial layer (YSL) when transiently
expressed in microinjected zebrafish embryos.
Filamentous fungi such as Fusarium equiseti KR706303 and Penicillium citrinum KR706304
are capable of sequestering heavy metals from aqueous solutions. In the present study, the role
play by various functional groups present in the cell wall of F. equiseti KR706303 and P.
citrinum KR706304 during lead and copper ions biosorption was investigated. The fungal
biomass was chemically treated to modify the functional groups present in their cell wall. These
modifications were studied through biosorption experiments. It was found that an esterification
of the carboxyl and phosphate groups, methylation of the amine groups and extraction of lipids
significantly decrease the biosorption of both lead and copper ions studied. Therefore, the
carbonyl, hydroxyl and amide groups were recognized as important in the biosorption of metal
ions by the tested fungi. The study showed that there was no release of any metal ions from the
biomass after biosorption, indicating that ion exchange may not be a key mechanism in the
biosorption of lead and copper ions by these fungi but complexation of metal ions within the
fungal cell wall.