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Expression of placental proteins in complete and partial hydatidiform moles

Cheah PL, Looi LM

Pathology, 1994 Apr;26(2):115-8.
PMID: 8090580

Examination of routinely stained haematoxylin and eosin sections may sometimes prove inadequate in differentiating partial hydatidiform moles (PHM) from complete hydatidiform moles (CHM). While cytogenetic analysis can aid in the distinction, such facilities are not always available. The possibility of using immunohistochemistry to aid in the differentiation was studied. Twenty-five histologically proven CHM and 11 PHM were studied for their patterns of expression of human chorionic gonadotrophin (hCG), human placental lactogen (hPL) and placental alkaline phosphatase (PIAP). All CHM stained diffusely with hCG and focally with both hPL and PIAP irrespective of gestational age. Of PHM, 63.6% were diffusely positive for hCG, 27.3% for hPL and 54.5% for PIAP; the rest were focally positive. The hCG pattern changed from diffuse to focal with increasing gestational age of PHM, while those of hPL and PIAP became increasingly diffuse with gestational age. While these protein expressions may be applied in differentiating late PHM from CHM, it is not useful in first trimester cases. The most helpful application is that focal expression of hCG and diffuse expressions of hPL and PIAP is not seen in CHM, thereby excluding such a diagnosis. PHM, in contrast, can show either diffuse or focal expression of all 3 antigens.

Matched MeSH terms: Isoenzymes/analysis*
Diaphroase activity and variants in normal adults and newborns

Eng LI, Loo M, Fah FK

Br J Haematol, 1972 Oct;23(4):419-25.
PMID: 5084807
Matched MeSH terms: Isoenzymes/blood*
Fulltext MicroRNA-6744-5p promotes anoikis in breast cancer and directly targets NAT1 enzyme

Malagobadan S, Ho CS, Nagoor NH

Cancer Biol Med, 2020 Feb 15;17(1):101-111.
PMID: 32296579 DOI: 10.20892/j.issn.2095-3941.2019.0010

Objective: Anoikis is apoptosis that is induced when cells detach from the extracellular matrix and neighboring cells. As anoikis serves as a regulatory barrier, cancer cells often acquire resistance towards anoikis during tumorigenesis to become metastatic. MicroRNAs (miRNAs) are short strand RNA molecules that regulate genes post-transcriptionally by binding to mRNAs and reducing the expression of its target genes. This study aimed to elucidate the role of a novel miRNA, miR-6744-5p, in regulating anoikis in breast cancer and identify its target gene. Methods: An anoikis resistant variant of the luminal A type breast cancer MCF-7 cell line (MCF-7-AR) was generated by selecting and amplifying surviving cells after repeated exposure to growth in suspension. MiRNA microarray analysis identified a list of dysregulated miRNAs from which miR-6744-5p was chosen for overexpression and knockdown studies in MCF-7. Additionally, the miRNA was also overexpressed in a triple-negative breast cancer cell line, MDA-MB-231, to evaluate its ability to impair the metastatic potential of breast cancer cells. Results: This study showed that overexpression and knockdown of miR-6744-5p in MCF-7 increased and decreased anoikis sensitivity, respectively. Similarly, overexpression of miR-6744-5p in MDA-MB-231 increased anoikis and also decreased tumor cell invasion in vitro and in vivo. Furthermore, NAT1 enzyme was identified and validated as the direct target of miR-6744-5p. Conclusions: This study has proven the ability of miR-6744-5p to increase anoikis sensitivity in both luminal A and triple negative breast cancer cell lines, highlighting its therapeutic potential in treating breast cancer.

Matched MeSH terms: Isoenzymes/genetics*
Suppressive effect of maslinic acid on PMA-induced protein kinase C in human B-lymphoblastoid cells

Mooi LY, Yew WT, Hsum YW, Soo KK, Hoon LS, Chieng YC

Asian Pac J Cancer Prev, 2012;13(4):1177-82.
PMID: 22799301

Protein kinase C (PKC) has been implicated in carcinogenesis and displays variable expression profiles during cancer progression. Studies of dietary phytochemicals on cancer signalling pathway regulation have been conducted to search for potent signalling regulatory agents. The present study was designed to evaluate any suppressive effect of maslinic acid on PKC expression in human B-lymphoblastoid cells (Raji cells), and to identify the PKC isoforms expressed. Effects of maslinic acid on PKC activity were determined using a PepTag assay for non-radioactive detection of PKC. The highest expression in Raji cells was obtained at 20 nM PMA induced for 6 hours. Suppressive effects of maslinic acid were compared with those of four PKC inhibitors (H- 7, rottlerin, sphingosine, staurosporine) and two triterpenes (oleanolic acid and ursolic acid). The IC₅₀ values achieved for maslinic acid, staurosporine, H-7, sphingosine, rottlerin, ursolic acid and oleanolic acid were 11.52, 0.011, 0.767, 2.45, 5.46, 27.93 and 39.29 μM, respectively. Four PKC isoforms, PKC βI, βII, δ, and ζ, were identified in Raji cells via western blotting. Maslinic acid suppressed the expression of PKC βI, δ, and ζ in a concentration-dependent manner. These preliminary results suggest promising suppressive effects of maslinic acid on PKC activity in Raji cells. Maslinic acid could be a potent cancer chemopreventive agent that may be involved in regulating many downstream signalling pathways that are activated through PKC receptors.

Matched MeSH terms: Isoenzymes/drug effects; Isoenzymes/isolation & purification
Isozymes of a rattan species and their genetic interpretation

Bon MC

Electrophoresis, 1996 Jul;17(7):1248-52.
PMID: 8855412

A combination of a modified Feret' (Silvae Genet. 1971, 20, 46-50) extraction buffer and two types of electrophoresis with acrylamide and starch gels were used to characterize allozymes in mature vegetative tissue of a commercially high value species of rattans (Calamus subinermis). From the analysis of allelic segregation from single maternal rattans and their offspring, genetic control of the 16 observed banding zones, which were consistently scorable, was assumed. Seventeen gene loci were identified. The percentage of polymorphic loci within Calamus subinermis was much higher (70.5%) than expected levels of genetic diversity for tropical woody and non-woody species. It is thought that the protocol described may be applied to the analysis of the genetic diversity of all the endangered Calamus species.

Matched MeSH terms: Isoenzymes/analysis*; Isoenzymes/genetics*
Expression of beta-catenin, COX-2 and iNOS in colorectal cancer: relevance of COX-2 adn iNOS inhibitors for treatment in Malaysia

Hong SK, Gul YA, Ithnin H, Talib A, Seow HF

Asian J Surg, 2004 Jan;27(1):10-7.
PMID: 14719508

BACKGROUND: Promising new pharmacological agents and gene therapy targeting cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) could modulate treatment of colorectal cancer in the future. The aim of this study was to elucidate the expression fo beta-catenin and teh presence of COX-2 and iNOS in colorectal cancer specimens in Malaysia. This is a useful prelude to future studies investigating interventions directed towards COX-2 adn iNOS.
METHODS: A cross-section study using retrospective data over a 2-year period (1999-2000) involved 101 archival, formalin-fixed, paraffin-embedded tissue samples of colorectal cancers that were surgically resected in a tertiary referral.
RESULTS: COX-2 production was detected in adjacent normal tissue in 34 sample (33.7%) and in tumour tissue in 60 samples (59.4%). More tumours expressed iNOS (82/101, 81.2%) than COX-2. No iNOS expression was detected in adjacent normal tissue. Intense beta-catenin immunoreactivity at the cell-to-cell border. Poorly differentiated tumours had significantly lower total beta-catenin (p = 0.009) and COX-2 scores (p = 0.031). No significant relationships were established between pathological stage and beta-catenin, COX-2 and iNOS scores.
CONCLUSIONS: the accumulation of beta-catenin does not seem to be sufficient to activate pathways that lead to increased COX-2 and iNOS expression. A high proportion of colorectal cancers were found to express COX-2 and a significant number produced iNOS, suggesting that their inhibitors may be potentially useful as chemotherapeutic agents in the management of colorectal cancer.

Matched MeSH terms: Isoenzymes/antagonists & inhibitors; Isoenzymes/metabolism*
Antimicrobial Resistance Mechanisms and Genetic Diversity of Multidrug-Resistant Acinetobacter baumannii Isolated from a Teaching Hospital in Malaysia

Biglari S, Hanafiah A, Mohd Puzi S, Ramli R, Rahman M, Lopes BS

Microb Drug Resist, 2017 Jul;23(5):545-555.
PMID: 27854165 DOI: 10.1089/mdr.2016.0130

Multidrug-resistant (MDR) Acinetobacter baumannii has increasingly emerged as an important nosocomial pathogen. The aim of this study was to determine the resistance profiles and genetic diversity in A. baumannii clinical isolates in a tertiary medical center in Malaysia. The minimum inhibitory concentrations of carbapenems (imipenem and meropenem), cephalosporins (ceftazidime and cefepime), and ciprofloxacin were determined by E-test. PCR and sequencing were carried out for the detection of antibiotic resistance genes and mutations. Clonal relatedness among A. baumannii isolates was determined by REP-PCR. Sequence-based typing of OXA-51 and multilocus sequence typing were performed. One hundred twenty-five of 162 (77.2%) A. baumannii isolates had MDR phenotype. From the 162 A. baumannii isolates, 20 strain types were identified and majority of A. baumannii isolates (66%, n = 107) were classified as strain type 1 and were positive for ISAba1-blaOXA-23and ISAba1-blaADCand had mutations in both gyrA and parC genes at positions, 83 and 80, resulting in serine-to-leucine conversion. REP-PCR analysis showed 129 REP types that generated 31 clones with a 90% similarity cutoff value. OXA-66 variant of the blaOXA-51-likegenes was predominantly detected among our A. baumannii clinical isolates belonging to ST195 (found in six clones: 1, 8, 9, 19, 27, and 30) and ST208 (found in clone 21). The study helps us in understanding the genetic diversity of A. baumannii isolates in our setting and confirms that international clone II is the most widely distributed clone in Universiti Kebangsaan Malaysia Medical Centre, Malaysia.

Matched MeSH terms: Isoenzymes/genetics; Isoenzymes/metabolism
Glyphosate-resistant goosegrass. Identification of a mutation in the target enzyme 5-enolpyruvylshikimate-3-phosphate synthase

Baerson SR, Rodriguez DJ, Tran M, Feng Y, Biest NA, Dill GM

Plant Physiol, 2002 Jul;129(3):1265-75.
PMID: 12114580

The spontaneous occurrence of resistance to the herbicide glyphosate in weed species has been an extremely infrequent event, despite over 20 years of extensive use. Recently, a glyphosate-resistant biotype of goosegrass (Eleusine indica) was identified in Malaysia exhibiting an LD(50) value approximately 2- to 4-fold greater than the sensitive biotype collected from the same region. A comparison of the inhibition of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity by glyphosate in extracts prepared from the resistant (R) and sensitive (S) biotypes revealed an approximately 5-fold higher IC(50)(glyphosate) for the (R) biotype. Sequence comparisons of the predicted EPSPS mature protein coding regions from both biotypes revealed four single-nucleotide differences, two of which result in amino acid changes. One of these changes, a proline to serine substitution at position 106 in the (R) biotype, corresponds to a substitution previously identified in a glyphosate-insensitive EPSPS enzyme from Salmonella typhimurium. Kinetic data generated for the recombinant enzymes suggests that the second substitution identified in the (R) EPSPS does not contribute significantly to its reduced glyphosate sensitivity. Escherichia coli aroA- (EPSPS deficient) strains expressing the mature EPSPS enzyme from the (R) biotype exhibited an approximately 3-fold increase in glyphosate tolerance relative to strains expressing the mature EPSPS from the (S) biotype. These results provide the first evidence for an altered EPSPS enzyme as an underlying component of evolved glyphosate resistance in any plant species.

Matched MeSH terms: Isoenzymes/genetics; Isoenzymes/metabolism
Indole-3-acetic acid (IAA) induced changes in oil content, fatty acid profiles and expression of four fatty acid biosynthetic genes in Chlorella vulgaris at early stationary growth phase

Jusoh M, Loh SH, Chuah TS, Aziz A, Cha TS

Phytochemistry, 2015 Mar;111:65-71.
PMID: 25583439 DOI: 10.1016/j.phytochem.2014.12.022

Microalgae lipids and oils are potential candidates for renewable biodiesel. Many microalgae species accumulate a substantial amount of lipids and oils under environmental stresses. However, low growth rate under these adverse conditions account for the decrease in overall biomass productivity which directly influence the oil yield. This study was undertaken to investigate the effect of exogenously added auxin (indole-3-acetic acid; IAA) on the oil content, fatty acid compositions, and the expression of fatty acid biosynthetic genes in Chlorella vulgaris (UMT-M1). Auxin has been shown to regulate growth and metabolite production of several microalgae. Results showed that oil accumulation was highest on days after treatment (DAT)-2 with enriched levels of palmitic (C16:0) and stearic (C18:0) acids, while the linoleic (C18:2) and α-linolenic (C18:3n3) acids levels were markedly reduced by IAA. The elevated levels of saturated fatty acids (C16:0 and C18:0) were consistent with high expression of the β-ketoacyl ACP synthase I (KAS I) gene, while low expression of omega-6 fatty acid desaturase (ω-6 FAD) gene was consistent with low production of C18:2. However, the increment of stearoyl-ACP desaturase (SAD) gene expression upon IAA induction did not coincide with oleic acid (C18:1) production. The expression of omega-3 fatty acid desaturase (ω-3 FAD) gene showed a positive correlation with the synthesis of PUFA and C18:3n3.

Matched MeSH terms: Isoenzymes/metabolism
Effect of eurycomanone on cytochrome P450 isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 in vitro

Pan Y, Tiong KH, Abd-Rashid BA, Ismail Z, Ismail R, Mak JW, et al.

J Nat Med, 2014 Apr;68(2):402-6.
PMID: 23881640 DOI: 10.1007/s11418-013-0794-8

Eurycomanone, an active constituent isolated from Eurycoma longifolia Jack, was examined for modulatory effects on cytochrome P450 (CYP) isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 using in vitro assays. The IC50 value was determined to assess the potencies of modulation for each CYP isoform. Our results indicated that eurycomanone did not potently inhibit any of the CYP isoforms investigated, with IC50 values greater than 250 μg/ml. Hence there appears to be little likelihood of drug-herb interaction between eurycomanone or herbal products with high content of this compound and CYP drug substrates via CYP inhibition.

Matched MeSH terms: Isoenzymes/metabolism
Fulltext In-vivo functional study on the involvement of CFTR, SLC26A6, NHE-1 and CA isoenzymes II and XII in uterine fluid pH, volume and electrolyte regulation in rats under different sex-steroid influence

Gholami K, Muniandy S, Salleh N

Int J Med Sci, 2013;10(9):1121-34.
PMID: 23869188 DOI: 10.7150/ijms.5918

Precise control of uterine fluid pH, volume and electrolytes is important for the reproductive processes. In this study, we examined the functional involvement of multiple proteins including Cystic Fibrosis Transmembrane Regulator (CFTR), Cl(-)/HCO3 (-) exchanger (SLC26A6), sodium-hydrogen exchanger-1 (NHE-1) and carbonic anhydrase (CA) in the regulation of these uterine fluid parameters.

Matched MeSH terms: Isoenzymes/metabolism*
Involvement of phenobarbital and SKF 525A in the hepatotoxicity of antifungal drugs itraconazole and fluconazole in rats

Somchit N, Wong CW, Zuraini A, Ahmad Bustamam A, Hasiah AH, Khairi HM, et al.

Drug Chem Toxicol, 2006;29(3):237-53.
PMID: 16777703

Itraconazole and fluconazole are potent wide spectrum antifungal drugs. Both of these drugs induce hepatotoxicity clinically. The mechanism underlying the hepatotoxicity is unknown. The purpose of this study was to investigate the role of phenobarbital (PB), an inducer of cytochrome P450 (CYP), and SKF 525A, an inhibitor of CYP, in the mechanism of hepatotoxicity induced by these two drugs in vivo. Rats were pretreated with PB (75 mg/kg for 4 days) prior to itraconazole or fluconazole dosing (20 and 200 mg/kg for 4 days). In the inhibition study, for 4 consecutive days, rats were pretreated with SKF 525A (50 mg/kg) or saline followed by itraconazole or fluconazole (20 and 200 mg/kg) Dose-dependent increases in plasma alanine aminotransferase (ALT), gamma-glutamyl transferase (gamma-GT), and alkaline phosphatase (ALP) activities and in liver weight were detected in rats receiving itraconazole treatment. Interestingly, pretreatment with PB prior to itraconazole reduced the ALT and gamma-GT activities and the liver weight of rats. No changes were observed in rats treated with fluconazole. Pretreatment with SKF 525A induced more severe hepatotoxicity for both itraconazole and fluconazole. CYP 3A activity was inhibited dose-dependently by itraconazole treatment. Itraconazole had no effects on the activity of CYP 1A and 2E. Fluconazole potently inhibited all three isoenzymes of CYP. PB plays a role in hepatoprotection to itraconazole-induced but not fluconazole-induced hepatotoxicity. SKF 525A enhanced the hepatotoxicity of both antifungal drugs in vivo. Therefore, it can be concluded that inhibition of CYP may play a key role in the mechanism of hepatotoxicity induced by itraconazole and fluconazole.

Matched MeSH terms: Isoenzymes/metabolism
Glutathione S transferase-theta (GSTT1) genetic polymorphism among Chinese, Malays and Indians in Singapore

Lee EJ, Wong JY, Yeoh PN, Gong NH

Pharmacogenetics, 1995 Oct;5(5):332-4.
PMID: 8563775

Glutathione S-transferase-theta (GSTT1) is subject to a genetic polymorphism where approximately 50% of a Caucasian population are homozygous for the null allele. Because of the possible association of the polymorphism with increased cancer risk in individuals, we genotyped by polymerase chain reaction 187 normal Chinese, 167 normal Malays and 152 normal Indians from Singapore and Malaysia. The proportion of Chinese, Malays and Indians with the null genotype were 58%, 38% and 16% respectively and mirrored previously reported frequencies of the GSTM1 null genotype in these populations. The frequency of the combined GSTM1 and GSTT1 null genotypes among Chinese, Malays and Indians were 37%, 22% and 5% respectively. The similarity with predicted frequencies indicated no interaction between the two genetic polymorphisms.

Matched MeSH terms: Isoenzymes/genetics*
Design and synthesis of mono and bicyclic tetrapeptides thioester as potent inhibitor of histone deacetylases

Hoque MA, Islam MS, Islam MN, Kato T, Nishino N, Ito A, et al.

Amino Acids, 2014 Oct;46(10):2435-44.
PMID: 25048030 DOI: 10.1007/s00726-014-1800-5

Inhibitors of histone deacetylases (HDACs) are a promising class of anticancer agents that have an effect on gene regulation. The naturally occurring cyclic depsipeptide FK228 containing disulfide and Largazole possessing thioester functionalities act as pro-drugs and share the same HDAC inhibition mechanism in cell. Inspired from these facts, we have reported bicyclic tetrapeptide disulfide HDAC inhibitors resembling FK228 with potent activity and enhanced selectivity. In the present study, we report the design and synthesis of several mono and bicyclic tetrapeptide thioester HDAC inhibitors that share the inhibition mechanism similar to Largazole. Most of the compounds showed HDAC1 and HDAC4 inhibition and p21 promoting activity in nanomolar ranges. Among these the monocyclic peptides 1, 2 and bicyclic peptide, 4 are notable demanding more advanced research to be promising anticancer drug candidates.

Matched MeSH terms: Isoenzymes/antagonists & inhibitors; Isoenzymes/genetics; Isoenzymes/metabolism
Fulltext Separation of sulfated urinary glycosaminoglycans by high-resolution electrophoresis for isotyping of mucopolysaccharidoses in Malaysia

Nor A, Zabedah MY, Norsiah MD, Ngu LH, Suhaila AR

Malays J Pathol, 2010 Jun;32(1):35-42.
PMID: 20614724

Mucopolysaccharidoses (MPS) are a group of inherited disorders caused by the deficiency of specific lysosomal enzymes involved in glycosaminoglycans (GAGs) degradation. Currently, there are 11 enzyme deficiencies resulting in seven distinct MPS clinical syndromes and their subtypes. Different MPS syndromes cannot be clearly distinguished clinically due to overlapping signs and symptoms. Measurement of GAGs content in urine and separation of GAGs using high-resolution electrophoresis (HRE) are very useful initial screening tests for isotyping of MPS before specific enzyme diagnostics. In this study, we measured total urinary GAGs by a method using dimethylmethylene blue (DMB), and followed by isolation and separation of GAGs using high resolution electrophoresis (HRE) technique. Of 760 urine samples analyzed, 40 have abnormal GAGs HRE patterns. Thirty-five of these 40 cases have elevated urinary GAGs levels as well. These abnormal HRE patterns could be classified into 4 patterns: Pattern A (elevated DS and HS; suggestive of MPS I, II or VII; 16 cases), Pattern B (elevated HS and CS; suggestive of MPS III; 17 cases), and Pattern C (elevated KS and CS; suggestive of MPS IV, 5 cases), and Pattern D (elevated DS; suggestive of MPS VI; 2 cases). Based on the GAGs HRE pattern and a few discriminating clinical signs, we performed selective enzymatic investigation in 16 cases. In all except one case with MPS VII, the enzymatic diagnosis correlated well with the provisional MPS type as suggested by the abnormal HRE pattern. Our results showed that GAGs HRE is a useful, inexpensive and practical first-line screening test when MPS is suspected clinically, and it provides an important guide to further enzymatic studies on a selective basis.

Matched MeSH terms: Isoenzymes
Purification and properties of a beta-galactosidase from carambola fruit with significant activity towards cell wall polysaccharides

Balasubramaniam S, Lee HC, Lazan H, Othman R, Ali ZM

Phytochemistry, 2005 Jan;66(2):153-63.
PMID: 15652572

beta-Galactosidase (EC. 3.2.1.23) from ripe carambola (Averrhoa carambola L. cv. B10) fruit was fractionated through a combination of ion exchange and gel filtration chromatography into four isoforms, viz. beta-galactosidase I, II, III and IV. This beta-galactosidases had apparent native molecular masses of 84, 77, 58 and 130 kDa, respectively. beta-Galactosidase I, the predominant isoform, was purified to electrophoretic homogeneity; analysis of the protein by SDS-PAGE revealed two subunits with molecular masses of 48 and 36 kDa. N-terminal amino acid sequence of the respective polypeptides shared high similarities albeit at different domains, with the deduced amino acid sequence of certain plant beta-galactosidases, thus, explaining the observed low similarity between the two subunits. beta-Galactosidase I was probably a heterodimer that have glycoprotein properties and a pI value of 7.2, with one of the potential glycosylation sites appeared to reside within the 48-kDa-polypeptide. The purified beta-galactosidase I was substantially active in hydrolyzing (1-->4)beta-linked spruce and a mixture of (1-->3)beta- and (1-->6)beta-linked gum arabic galactans. This isoform also had the capability to solubilize and depolymerize structurally intact pectins as well as to modify alkaline-soluble hemicelluloses, reflecting in part changes that occur during ripening.

Matched MeSH terms: Isoenzymes
Spatial structure and genetic diversity of two tropical tree species with contrasting breeding systems and different ploidy levels

Ng KK, Lee SL, Koh CL

Mol Ecol, 2004 Mar;13(3):657-69.
PMID: 14871369

Analyses of the spatial distribution pattern, spatial genetic structure and of genetic diversity were carried out in two tropical tree species with contrasting breeding systems and different ploidy levels using a 50-ha demographic plot in a lowland dipterocarp forest in Peninsular Malaysia. Shorea leprosula is a diploid and predominantly outcrossed species, whereas S. ovalis ssp. sericea is an autotetraploid species with apomictic mode of reproduction. Genetic diversity parameters estimated for S. leprosula using microsatellite were consistently higher than using allozyme. In comparisons with S. leprosula and other tropical tree species, S. ovalis ssp. sericea also displayed relatively high levels of genetic diversity. This might be explained by the lower pressure of genetic drift due to tetrasomic inheritance, and for autotetraploids each locus can accommodate up to four different alleles and this allows maintenance of more alleles at individual loci. The observed high levels of genetic diversity in S. ovalis ssp. sericea can also be due to a random retention of more heterogeneous individuals in the past, and the apomictic mode of reproduction might be an evolutionary strategy, which allows the species to maintain high levels of genetic diversity. The spatial distribution pattern analyses of both species showed significant levels of aggregation at small and medium but random distribution at the big diameter-class. The decrease in magnitude of spatial aggregation from small- to large-diameter classes might be due to compensatory mortality during recruitment and survival under competitive thinning process. Spatial genetic structure analyses for both species revealed significant spatial genetic structure for short distances in all the three diameter-classes. The magnitude of spatial genetic structure in both species was observed to be decreasing from smaller- to larger-diameter classes. The high spatial genetic structuring observed in S. ovalis ssp. sericea at the small-diameter class is due primarily to limited seed dispersal and apomictic mode of reproduction. The similar observation in S. leprosula, however, can be explained by limited seed and pollen dispersal, which supports further the fact that the species is pollinated by weak fliers, mainly of Thrips and Megalurothrips in the lowland dipterocarp forest.

Matched MeSH terms: Isoenzymes
Erythrocyte and leukocyte phosphoglucomutase in Chinese

Lie-Injo Luan Eng, Lopez CG, Poey-Oey Hoey Giok

Am J Hum Genet, 1968 Mar;20(2):101-6.
PMID: 5643177
Matched MeSH terms: Isoenzymes
Genetic diversity of oil palm (Elaeis guineensis Jacq.) germplasm collections from Africa: implications for improvement and conservation of genetic resources

Hayati A, Wickneswari R, Maizura I, Rajanaidu N

Theor Appl Genet, 2004 May;108(7):1274-84.
PMID: 14676949

A total of 723 accessions of oil palm ( Elaeis guineensis Jacq.) from 26 populations representing ten countries in Africa and one Deli dura family were screened for allelic variation at seven enzyme loci from six enzyme systems using starch gel electrophoresis. On average, 54.5% of the loci were polymorphic (0.99 criterion). The average and effective number of alleles per locus was 1.80 and 1.35, respectively. Mean expected heterozygosity was 0.184, with values ranging from 0.109 (population 8, Senegal) to 0.261 (population 29, Cameroon). The genetic differentiation among populations was high (F(ST)=0.301), indicating high genetic divergence. The calculation of F(ST) by geographic zones revealed that the high F(ST) was largely due to F(ST) among populations in West Africa, suggesting diversifying selection in this region. The mean genetic distance across populations was 0.113. The lowest genetic distance (D) was observed between population 5 from Tanzania and population 7 from the Democratic Republic of the Congo (0.000) and the highest was found between population 4 from Madagascar and population 13 from Sierra Leone (0.568). The total gene flow across oil palm populations was low, with an Nm of 0.576, enhancing genetic structuring, as evident from the high F(ST) values. UPGMA cluster analysis revealed three main clusters; the western outlying populations from Senegal and Sierra Leone were in one cluster but separated into two distinct sub-clusters; the eastern outlying populations from Madagascar were in one cluster; the populations from Angola, Cameroon, The Democratic Republic of the Congo, Ghana, Tanzania, Nigeria and Guinea were in one cluster. The Deli dura family seems to be closely related to population 6 from Guinea. Oil palm populations with high genetic diversity-i.e. all of the populations from Nigeria, Cameroon and Sierra Leone, population 6 of Guinea, population 1 of Madagascar and population 2 of Senegal should be used in improvement programmes, whereas for conservation purposes, oil palm populations with high allelic diversity (A(e)), which include populations 22 and 29 from Cameroon, populations 39 and 45 from Nigeria, population 6 from Guinea, populations 5 and 13 from Sierra Leone and population 1 from Madagascar should be selected for capturing as much genetic variation as possible.

Matched MeSH terms: Isoenzymes
Exogenous Abscisic Acid Supplementation at Early Stationary Growth Phase Triggers Changes in the Regulation of Fatty Acid Biosynthesis in Chlorella vulgaris UMT-M1

Norlina R, Norashikin MN, Loh SH, Aziz A, Cha TS

Appl Biochem Biotechnol, 2020 Aug;191(4):1653-1669.
PMID: 32198601 DOI: 10.1007/s12010-020-03312-y

Abscisic acid (ABA) has been known to exist in a microalgal system and serves as one of the chemical stimuli in various biological pathways. Nonetheless, the involvement of ABA in fatty acid biosynthesis, particularly at the transcription level in microalgae is poorly understood. The objective of this study was to determine the effects of exogenous ABA on growth, total oil content, fatty acid composition, and the expression level of beta ketoacyl-ACP synthase I (KAS I) and omega-3 fatty acid desaturase (ω-3 FAD) genes in Chlorella vulgaris UMT-M1. ABA was applied to early stationary C. vulgaris cultures at concentrations of 0, 10, 20, and 80 μM for 48 h. The results showed that ABA significantly increased biomass production and total oil content. The increment of palmitic (C16:0) and stearic (C18:0) acids was coupled by decrement in linoleic (C18:2) and α-linolenic (C18:3n3) acids. Both KAS I and ω-3 FAD gene expression were downregulated, which was negatively correlated to saturated fatty acid (SFAs), but positively correlated to polyunsaturated fatty acid (PUFA) accumulations. Further analysis of both KAS I and ω-3 FAD promoters revealed the presence of multiple ABA-responsive elements (ABREs) in addition to other phytohormone-responsive elements. However, the role of these phytohormone-responsive elements in regulating KAS I and ω-3 FAD gene expression still remains elusive. This revelation might suggest that phytohormone-responsive gene regulation in C. vulgaris and microalgae as a whole might diverge from higher plants which deserve further scientific research to elucidate its functional roles.

Matched MeSH terms: Isoenzymes

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