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The effect of dosage on the protective efficacy of whole-sporozoite formulations for immunization against malaria

Moita D, Rôla C, Nunes-Cabaço H, Nogueira G, Maia TG, Othman AS, et al.

NPJ Vaccines, 2023 Nov 24;8(1):182.
PMID: 37996533 DOI: 10.1038/s41541-023-00778-9

Immunization with Plasmodium sporozoites, either attenuated or administered under the cover of an antimalarial drug, can induce strong protection against malaria in pre-clinical murine models, as well as in human trials. Previous studies have suggested that whole-sporozoite (WSpz) formulations based on parasites with longer liver stage development induce higher protection, but a comparative analysis of four different WSpz formulations has not been reported. We employed a rodent model of malaria to analyze the effect of immunization dosage on the protective efficacy of WSpz formulations consisting of (i) early liver arresting genetically attenuated parasites (EA-GAP) or (ii) radiation-attenuated sporozoites (RAS), (iii) late arresting GAP (LA-GAP), and (iv) sporozoites administered under chemoprophylaxis, that are eliminated upon release into the bloodstream (CPS). Our results show that, unlike all other WSpz formulations, EA-GAP fails to confer complete protection against an infectious challenge at any immunization dosage employed, suggesting that a minimum threshold of liver development is required to elicit fully effective immune responses. Moreover, while immunization with RAS, LA-GAP and CPS WSpz yields comparable, dosage-dependent protection, protection by EA-GAP WSpz peaks at an intermediate dosage and markedly decreases thereafter. In-depth immunological analyses suggest that effector CD8+ T cells elicited by EA-GAP WSpz immunization have limited developmental plasticity, with a potential negative impact on the functional versatility of memory cells and, thus, on protective immunity. Our findings point towards dismissing EA-GAP from prioritization for WSpz malaria vaccination and enhance our understanding of the complexity of the protection elicited by these WSpz vaccine candidates, guiding their future optimization.
Fulltext Desire to stay shorter time at the shopping mall: insight from protection motivation (PMT), behavioral inhibition system (BIS), reactance, and expectancy theories

Alam SS, Masukujjaman M, Al-Shaikh ME, Ali MH, Makhbul ZKM, Othman AS

Curr Psychol, 2022 Dec 17.
PMID: 36570056 DOI: 10.1007/s12144-022-04117-4

After withdrawing the movement control order (MCO), new variant (Omicron) of COVID-19 returns as an outbreak again. Therefore, consumers are very much informed by various media to be more cautious in visiting shopping malls and spend less time in there. The purpose of this study was to identify the predictors influencing the desire to stay shorter at the shopping mall. This study was conducted in Malaysia, with the application of three psychological theories and one behavioural theory. This is quantitative research based on an online cross-sectional survey design. Data were collected from 296 respondents, by applying the online snowball sampling method through numerous media platforms i.e., Viber, WhatsApp, Messenger, and other apps in three severely affected cities in Malaysia i.e., Selangor state, Putrajaya, and Kuala Lumpur. SmartPLS was used to analyse the data. Using structural equation modelling, this study result shows risk, protection motivation, and fear have a significant effect on the desire to stay a shorter time at the shopping mall. Social norm moderates the association between fear and the desire to spend a shorter time at the shopping mall. These findings, highlight the need for a more empirical study to design more robust strategies, and a safer and risk-free shopping mall environment.
Fulltext Creation and preclinical evaluation of genetically attenuated malaria parasites arresting growth late in the liver

Franke-Fayard B, Marin-Mogollon C, Geurten FJA, Chevalley-Maurel S, Ramesar J, Kroeze H, et al.

NPJ Vaccines, 2022 Nov 04;7(1):139.
PMID: 36333336 DOI: 10.1038/s41541-022-00558-x

Whole-sporozoite (WSp) malaria vaccines induce protective immune responses in animal malaria models and in humans. A recent clinical trial with a WSp vaccine comprising genetically attenuated parasites (GAP) which arrest growth early in the liver (PfSPZ-GA1), showed that GAPs can be safely administered to humans and immunogenicity is comparable to radiation-attenuated PfSPZ Vaccine. GAPs that arrest late in the liver stage (LA-GAP) have potential for increased potency as shown in rodent malaria models. Here we describe the generation of four putative P. falciparum LA-GAPs, generated by CRISPR/Cas9-mediated gene deletion. One out of four gene-deletion mutants produced sporozoites in sufficient numbers for further preclinical evaluation. This mutant, PfΔmei2, lacking the mei2-like RNA gene, showed late liver growth arrest in human liver-chimeric mice with human erythrocytes, absence of unwanted genetic alterations and sensitivity to antimalarial drugs. These features of PfΔmei2 make it a promising vaccine candidate, supporting further clinical evaluation. PfΔmei2 (GA2) has passed regulatory approval for safety and efficacy testing in humans based on the findings reported in this study.
Fulltext Relationship of an adherence score with blood pressure control status among patients with hypertension and their determinants: Findings from a nationwide blood pressure screening program

Chia YC, Devaraj NK, Ching SM, Ooi PB, Chew MT, Chew BN, et al.

J Clin Hypertens (Greenwich), 2021 03;23(3):638-645.
PMID: 33586334 DOI: 10.1111/jch.14212

This study aimed to examine the relationship of adherence with blood pressure (BP) control and its associated factors in hypertensive patients. This cross-sectional nationwide BP screening study was conducted in Malaysia from May to October 2018. Participants with self-declared hypertension completed the Hill-Bone Compliance to High Blood Pressure Therapy Scale (Hill-Bone CHBPTS) which assesses three important domains of patient behavior to hypertension management namely medication taking, appointment keeping and reduced salt intake. Lower scores indicate better compliance while higher scores indicate otherwise. Participant's body mass index and seated BP were measured based on standard measurement protocol. Determinants of adherence to treatment were analyzed using multiple linear regression. Out of 5167 screened subjects, 1705 were known hypertensives. Of these, 927 (54.4%) answered the Hill-Bone CHBPTS and were entered into analysis. The mean age was 59.0 ± 13.2 years, 55.6% were female and 42.2% were Malays. The mean Hill-Bone CHBPTS score was 20.4 ± 4.4 (range 14-47), and 52.1% had good adherence. The mean systolic BP and diastolic BP were 136.4 ± 17.9 and 80.6 ± 11.6 mmHg, respectively. BP was controlled in 58.3% of those with good adherence compared to 50.2% in those with poor adherence (p = .014). Based on multiple linear regression analysis, female gender (β = -0.72, 95% confidence interval [CI] -1.30, -0.15, p = .014), older age (β = -0.05, 95% CI -0.07, -0.03, p
Fulltext Molecular evidence of the hybrid origin of Cryptocoryne ×purpurea Ridl. nothovar. purpurea (Araceae)

Rosazlina R, Jacobsen N, Ørgaard M, Othman AS

PLoS One, 2021;16(1):e0239499.
PMID: 33476321 DOI: 10.1371/journal.pone.0239499

Natural hybridization has been considered a source of taxonomic complexity in Cryptocoryne. A combined study of DNA sequencing data from the internal transcribed spacer (ITS) of nuclear ribosomal DNA and the trnK-matK region of chloroplast DNA was used to identify the parents of Cryptocoryne putative hybrids from Peninsular Malaysia. Based on the intermediate morphology and sympatric distribution area, the plants were tentatively identified as the hybrid Cryptocoryne ×purpurea nothovar. purpurea. The plants were pollen sterile and had long been considered as hybrids, supposedly between two related and co-existing species, C. cordata var. cordata and C. griffithii. The status of C. ×purpurea nothovar. purpurea was independently confirmed by the presence of an additive ITS sequence pattern from these two parental species in hybrid individuals. An analysis of the chloroplast trnK-matK sequences showed that the hybridization is bidirectional with the putative hybrids sharing identical sequences from C. cordata var. cordata and C. griffithii, indicating that both putative parental species had been the maternal parent in different accessions.
Mitochondrial Markers Identify a Genetic Boundary of the Green Tiger Prawn (Penaeus semisulcatus) in the Indo-Pacific Ocean

Halim SAAA, Othman AS, Akib NAM, Jamaludin NA, Esa Y, Nor SAM

Zool Stud, 2021;60:e8.
PMID: 34386093 DOI: 10.6620/ZS.2021.60-08

A population genetics study of the commercially important Green Tiger Prawn (Penaeus semisulcatus) was conducted in the Indo-Pacific Ocean with a focus on the Indo-Malay Archipelago waters of the South China Sea (SCS), Sulu Sea (SLS), Celebes Sea (CLS) and the Strait of Malacca (SOM), the latter being the main waterway that connects the Indian Ocean with the Pacific Ocean. A 548-base-pair region of mitochondrial COI and 571 base pairs of the control region (CR) were analysed in 284 specimens from 15 locations. Genetic divergences (Tamura 3-parameter) for COI ranged from 0.1% to 7.2% and CR 2.3% to 21.7%, with Bagan Pasir (BGP) in central SOM being the most genetically different from other populations (COI: 3.3-4.2%; CR: 7.1-16.5%). All populations were differentiated into two lineages with a genetic break in the vicinity of BGP; Lineage I comprised populations south of this site (SCS, SLS, CLS and part of SOM) and Lineage II comprised populations north of BGP (part of the SOM). Specifically, most individuals of Bagan Pasir (BGP) and another site just south of it, Batu Pahat (BPT), clustered in Lineage I, while all SOM populations to the north of these sites clustered in Lineage II. The BGP population is believed to be a mixed gene pool between the two lineages. The results could be attributed to the fluctuations of Pleistocene sea levels and a possible influence of the One Fathom Bank in SOM. High genetic diversity was recorded, π (Lineage I: COI: 3.4%; CR: 7.4%) (Lineage II: COI: 3.8%; CR: 12.6%) and, h (Lineage I: COI: 0.81; CR: 1.0) (Lineage II: COI: 0.57; CR: 0.99). Demographic statistics revealed that both lineages underwent a sudden expansion and consequent stabilisation in genetic variability. The findings of this study have wide implications for fisheries in the Indo-Pacific. The increased sampling effort within a narrower geographical scale by the current study permitted a precise locality of the genetic break for this species within the Indo-Pacific Ocean to be identified. The substantial genetic diversity within both lineages should be considered in fishery management and aquaculture development programs of this species in this region.
Fulltext Transcriptome dataset from bark and latex tissues of three Hevea brasiliensis clones

Abu Bakar MF, Kamerkar U, Abdul Rahman SN, Muhd Sakaff MKL, Othman AS

Data Brief, 2020 Oct;32:106188.
PMID: 32904357 DOI: 10.1016/j.dib.2020.106188

Hevea brasiliensis is exploited for its latex production, and it is the only viable source of natural rubber worldwide. The demand for natural rubber remains high due its high-quality properties, which synthetic rubber cannot compete with. In this paper, we present transcriptomic data and analysis of three H. brasiliensis clones using tissue from latex and bark tissues collected from 10-year-old plant. The combined, assembled transcripts were mapped onto an H. brasiliensis draft genome. Gene ontology analysis showed that the most abundant transcripts related to molecular functions, followed by biological processes and cellular components. Simple sequence repeats (SSR) and single nucleotide polymorphisms (SNP) were also identified, and these can be useful for selection of parental and new clones in a breeding program. Data generated by RNA sequencing were deposited in the NCBI public repository under accession number PRJNA629890.
May Measurement Month 2018: an analysis of blood pressure screening results from Malaysia

Chia YC, Ching SM, Devaraj NK, Chew BN, Ooi PB, Mohamed M, et al.

Eur Heart J Suppl, 2020 Aug;22(Suppl H):H83-H85.
PMID: 32884479 DOI: 10.1093/eurheartj/suaa035

Hypertension continues to be the top global killer, contributing to over 10 million deaths annually. As prevalence and unawareness of hypertension remain high in Malaysia, this study was aimed to screen more individuals to identify those with undiagnosed hypertension. Respondents aged ≥18 years were recruited through opportunistic sampling at various screening sites including health clinics, hospitals, student health centres, universities, community halls, shopping malls, as well as through other health screening campaigns. Each respondent completed a questionnaire on socio-demographic, environmental, and lifestyle data. Anthropometric measurements as well as three blood pressure (BP) measurements were obtained from all participants. Hypertension was defined as a systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg or taking antihypertensive medication. The total number of participants was 4866. The mean age of the participants was 39.8 (17.6) years with 61.1% female participants. Of the 4866 participants, 1405 (28.9%) had hypertension. The proportion of those aware of their hypertension status was 76.3% (1073/1405). The proportion of those with hypertension on medication was 71% (998/1405). Of those receiving antihypertensive treatment, 62.4% (623/998) had controlled BP. The proportion of hypertension in this study was 28.9%. The awareness rate of 76.3% compares favourably to a previously reported national level of 43.2%. Hence, BP screening programmes may be effective at increasing awareness and should be conducted annually.
Fulltext DNA barcoding of commercially important reef fishes in Weh Island, Aceh, Indonesia

Fadli N, Mohd Nor SA, Othman AS, Sofyan H, Muchlisin ZA

PeerJ, 2020;8:e9641.
PMID: 32844060 DOI: 10.7717/peerj.9641

Knowledge on the precise identification of fish resources is critical for sustainable fisheries management. This study employs the DNA barcoding approach to generate a molecular taxonomic catalogue of commercially important reef fishes in the waters of Weh Island (Aceh Province), the most northerly inhabited island in the biodiverse Indonesian Archipelago. The waters not only support artisanal fisheries but also a feeder for the industry in the greater island of Aceh. In total, 230 specimens from 72 species belonging to 32 genera and 17 families were DNA barcoded, representing a major segment of the captured reef fish taxa and a quarter of fish species diversity that had previously been recorded. The sequence read lengths were 639 bp revealing 359 conserved sites, 280 variable sites, 269 parsimony informative and 11 singletons. Our molecular findings paralleled the morphological identification with no evidence of cryptic species or new species discovery. This study is a significant contribution to the fisheries statistics of this area, which would facilitate assessment of species catch composition and hence for strategizing management plans. It is an important input to the DNA barcode library of Indonesian marine fishes and to the global DNA barcode entries in general.
Single-nucleotide polymorphism markers within MVA and MEP pathways among Hevea brasiliensis clones through transcriptomic analysis

Abdul Rahman SN, Bakar MFA, Singham GV, Othman AS

3 Biotech, 2019 Nov;9(11):388.
PMID: 31656726 DOI: 10.1007/s13205-019-1921-3

In this study, RNA sequencing of several Hevea brasiliensis clones grown in Malaysia with different annual rubber production yields and disease resistance was performed on the Illumina platform. A total of 29,862,548 reads were generated, resulting in 101,269 assembled transcripts that were used as the reference transcripts. A similarity search against the non-redundant (nr) protein databases presented 83,771 (83%) positive BLASTx hits. The transcriptome was annotated using gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Pfam database. A search for putative molecular markers was performed to identify single-nucleotide polymorphisms (SNPs). Overall, 3,210,629 SNPs were detected and a total of 1314 SNPs associated with the genes involved in MVA and MEP pathways were identified. A total of 176 SNP primer pairs were designed from sequences that were related to the MVA and MEP pathways. The transcriptome of RRIM 3001 and RRIM 712 were subjected to pairwise comparison and the results revealed that there were 1262 significantly differentially expressed genes unique to RRIM 3001, 1499 significantly differentially expressed genes unique to RRIM 712 and several genes related to the MVA and MEP pathways such as AACT, HMGS, PMK, MVD, DXS and HDS were included. The results will facilitate the characterization of H. brasiliensis transcriptomes and the development of a new set of molecular markers in the form of SNPs from transcriptome assembly for the genotype identification of various rubber varieties with superior traits in Malaysia.
Fulltext Identification and characterization of jasmonic acid- and linolenic acid-mediated transcriptional regulation of secondary laticifer differentiation in Hevea brasiliensis

Loh SC, Othman AS, Veera Singham G

Sci Rep, 2019 10 04;9(1):14296.
PMID: 31586098 DOI: 10.1038/s41598-019-50800-1

Hevea brasiliensis remains the primary crop commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. Here, we described the transcriptional events related to jasmonic acid (JA)- and linolenic acid (LA)-induced secondary laticifer differentiation (SLD) in H. brasiliensis clone RRIM 600 based on RNA-seq approach. Histochemical approach proved that JA- and LA-treated samples resulted in SLD in H. brasiliensis when compared to ethephon and untreated control. RNA-seq data resulted in 86,614 unigenes, of which 2,664 genes were differentially expressed in JA and LA-induced secondary laticifer harvested from H. brasiliensis bark samples. Among these, 450 genes were unique to JA and LA as they were not differentially expressed in ethephon-treated samples compared with the untreated samples. Most transcription factors from the JA- and LA-specific dataset were classified under MYB, APETALA2/ethylene response factor (AP2/ERF), and basic-helix-loop-helix (bHLH) gene families that were involved in tissue developmental pathways, and we proposed that Bel5-GA2 oxidase 1-KNOTTED-like homeobox complex are likely involved in JA- and LA-induced SLD in H. brasiliensis. We also discovered alternative spliced transcripts, putative novel transcripts, and cis-natural antisense transcript pairs related to SLD event. This study has advanced understanding on the transcriptional regulatory network of SLD in H. brasiliensis.
Fulltext Author Correction: The Plasmodium falciparum male gametocyte protein P230p, a paralog of P230, is vital for ookinete formation and mosquito transmission

Marin-Mogollon C, van de Vegte-Bolmer M, van Gemert GJ, van Pul FJA, Ramesar J, Othman AS, et al.

Sci Rep, 2019 May 03;9(1):7061.
PMID: 31053746 DOI: 10.1038/s41598-019-43505-y

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Fulltext A P. falciparum NF54 Reporter Line Expressing mCherry-Luciferase in Gametocytes, Sporozoites, and Liver-Stages

Marin-Mogollon C, Salman AM, Koolen KMJ, Bolscher JM, van Pul FJA, Miyazaki S, et al.

Front Cell Infect Microbiol, 2019;9:96.
PMID: 31058097 DOI: 10.3389/fcimb.2019.00096

Transgenic malaria parasites expressing fluorescent and bioluminescent proteins are valuable tools to interrogate malaria-parasite biology and to evaluate drugs and vaccines. Using CRISPR/Cas9 methodology a transgenic Plasmodium falciparum (Pf) NF54 line was generated that expresses a fusion of mCherry and luciferase genes under the control of the Pf etramp10.3 gene promoter (line mCherry-luc@etramp10.3). Pf etramp10.3 is related to rodent Plasmodium uis4 and the uis4 promoter has been used to drive high transgene expression in rodent parasite sporozoites and liver-stages. We examined transgene expression throughout the complete life cycle and compared this expression to transgenic lines expressing mCherry-luciferase and GFP-luciferase under control of the constitutive gapdh and eef1a promoters. The mCherry-luc@etramp10.3 parasites express mCherry in gametocytes, sporozoites, and liver-stages. While no mCherry signal was detected in asexual blood-stage parasites above background levels, luciferase expression was detected in asexual blood-stages, as well as in gametocytes, sporozoites and liver-stages, with the highest levels of reporter expression detected in stage III-V gametocytes and in sporozoites. The expression of mCherry and luciferase in gametocytes and sporozoites makes this transgenic parasite line suitable to use in in vitro assays that examine the effect of transmission blocking inhibitors and to analyse gametocyte and sporozoite biology.
Endocan expression in placenta of women with hypertension

Chew BS, Ghazali R, Othman H, Ismail NAM, Othman AS, Laim NMST, et al.

J Obstet Gynaecol Res, 2018 Oct 10.
PMID: 30306675 DOI: 10.1111/jog.13836

AIM: The aim of our study was to determine the endocan-1 expression in placenta of hypertensive women, and its association with maternal and fetal outcomes.
METHODS: This was a cross-sectional study consisted of 21 pregnant women with hypertension and 23 without hypertension. The gestational age ranged from 28 to 39 weeks (hypertensive) and 32 to 40 weeks (normotensive). The paraffin embedded formalin fixed placenta tissue blocks were retrieved from the pathology archives. Endocan immunohistochemistry was performed on tissue sections of full thickness and maternal surface of the placenta. The endocan expression was determined in fetal endothelial cells, maternal endothelial cells, cytotrophoblasts, syncytiotrophoblasts and decidual cells. The differences in endocan expression in placenta between hypertensive and normotensive subjects were evaluated by Pearson chi-square test and t-test were used in the statistical analysis.
RESULTS: The endocan expression was significantly higher in fetal endothelial cells (P
Fulltext The Plasmodium falciparum male gametocyte protein P230p, a paralog of P230, is vital for ookinete formation and mosquito transmission

Marin-Mogollon C, van de Vegte-Bolmer M, van Gemert GJ, van Pul FJA, Ramesar J, Othman AS, et al.

Sci Rep, 2018 10 08;8(1):14902.
PMID: 30297725 DOI: 10.1038/s41598-018-33236-x

Two members of 6-cysteine (6-cys) protein family, P48/45 and P230, are important for gamete fertility in rodent and human malaria parasites and are leading transmission blocking vaccine antigens. Rodent and human parasites encode a paralog of P230, called P230p. While P230 is expressed in male and female parasites, P230p is expressed only in male gametocytes and gametes. In rodent malaria parasites this protein is dispensable throughout the complete life-cycle; however, its function in P. falciparum is unknown. Using CRISPR/Cas9 methodology we disrupted the gene encoding Pfp230p resulting in P. falciparum mutants (PfΔp230p) lacking P230p expression. The PfΔp230p mutants produced normal numbers of male and female gametocytes, which retained expression of P48/45 and P230. Upon activation male PfΔp230p gametocytes undergo exflagellation and form male gametes. However, male gametes are unable to attach to red blood cells resulting in the absence of characteristic exflagellation centres in vitro. In the absence of P230p, zygote formation as well as oocyst and sporozoite development were strongly reduced (>98%) in mosquitoes. These observations demonstrate that P230p, like P230 and P48/45, has a vital role in P. falciparum male fertility and zygote formation and warrants further investigation as a potential transmission blocking vaccine candidate.
Fulltext Expression of full-length Plasmodium falciparum P48/45 in P. berghei blood stages: A method to express and evaluate vaccine antigens

Othman AS, Lin JW, Franke-Fayard BM, Kroeze H, van Pul FJA, Chevalley-Maurel S, et al.

Mol Biochem Parasitol, 2018 Sep;224:44-49.
PMID: 30053393 DOI: 10.1016/j.molbiopara.2018.07.009

The transmission-blocking vaccine candidate Pfs48/45 from the human malaria parasite Plasmodium falciparum is known to be difficult to express in heterologous systems, either as full-length protein or as correctly folded protein fragments that retain conformational epitopes. In this study we express full-length Pfs48/45 in the rodent parasite P. berghei. Pfs48/45 is expressed as a transgene under control of the strong P. berghei schizont-specific msp1 gene promoter (Pfs48/45@PbMSP1). Pfs48/45@PbMSP1 schizont-infected red blood cells produced full-length Pfs48/45 and the structural integrity of Pfs48/45 was confirmed using a panel of conformation-specific monoclonal antibodies that bind to different Pfs48/45 epitopes. Sera from mice immunized with transgenic Pfs48/45@PbMSP1 schizonts showed strong transmission-reducing activity in mosquitoes infected with P. falciparum using standard membrane feeding. These results demonstrate that transgenic rodent malaria parasites expressing human malaria antigens may be used as means to evaluate immunogenicity and functionality of difficult to express malaria vaccine candidate antigens.
Morphometrics and Mitochondrial DNA Genes Analysis Suggest a New Species of Penaeus (Crustacea: Penaeidae) from the Persian Gulf

Tamadoni Jahromi S, Othman AS, Rosazlina R

Biochem Genet, 2018 Aug 12.
PMID: 30099639 DOI: 10.1007/s10528-018-9884-3

There are two morphotypes of Penaeus semisulcatus described hitherto in the Persian Gulf, namely the banded and non-banded antennae morphotypes. In this study, we used morphometric measurements and two mitochondrial genes (16S rRNA and cytochrome oxidase subunit I-COI) to assess relationships between the two morphotypes of P. semisulcatus. Out of 25 morphological characters examined, 10 characters were found significantly different between the two morphotypes when tested against separate sexes or both sexes combined. Results from the 16S rRNA and COI sequence analysis of two morphotypes of P. semisulcatus morphotype showed up to 6% and 17% sequence divergence, respectively. The 16S rDNA and COI sequences of the non-banding morphotype were not only very different to those of the banding morphotype but was also very different to all other Penaeus species (i.e., P. monodon, P. merguiensis, and P. indicus) included in the study. Both parsimony and Neighbor-Joining trees based on 16S rDNA and COI sequences provide similar tree topology that clearly separated the two morphotypes into two distinct groups. Based on these findings, we propose the two morphotypes of P. semisulcatus to be relegated as two sympatric species.
Fulltext Chimeric Plasmodium falciparum parasites expressing Plasmodium vivax circumsporozoite protein fail to produce salivary gland sporozoites

Marin-Mogollon C, van Pul FJA, Miyazaki S, Imai T, Ramesar J, Salman AM, et al.

Malar J, 2018 Aug 09;17(1):288.
PMID: 30092798 DOI: 10.1186/s12936-018-2431-1

BACKGROUND: Rodent malaria parasites where the gene encoding circumsporozoite protein (CSP) has been replaced with csp genes from the human malaria parasites, Plasmodium falciparum or Plasmodium vivax, are used as pre-clinical tools to evaluate CSP vaccines in vivo. These chimeric rodent parasites produce sporozoites in Anopheles stephensi mosquitoes that are capable of infecting rodent and human hepatocytes. The availability of chimeric P. falciparum parasites where the pfcsp gene has been replaced by the pvcsp would open up possibilities to test P. vivax CSP vaccines in small scale clinical trials using controlled human malaria infection studies.
METHODS: Using CRISPR/Cas9 gene editing two chimeric P. falciparum parasites, were generated, where the pfcsp gene has been replaced by either one of the two major pvcsp alleles, VK210 or VK247. In addition, a P. falciparum parasite line that lacks CSP expression was also generated. These parasite lines have been analysed for sporozoite production in An. stephensi mosquitoes.
RESULTS: The two chimeric Pf-PvCSP lines exhibit normal asexual and sexual blood stage development in vitro and produce sporozoite-containing oocysts in An. stephensi mosquitoes. Expression of the corresponding PvCSP was confirmed in oocyst-derived Pf-PvCSP sporozoites. However, most oocysts degenerate before sporozoite formation and sporozoites were not found in either the mosquito haemocoel or salivary glands. Unlike the chimeric Pf-PvCSP parasites, oocysts of P. falciparum parasites lacking CSP expression do not produce sporozoites.
CONCLUSIONS: Chimeric P. falciparum parasites expressing P. vivax circumsporozoite protein fail to produce salivary gland sporozoites. Combined, these studies show that while PvCSP can partially complement the function of PfCSP, species-specific features of CSP govern full sporozoite maturation and development in the two human malaria parasites.
Fulltext Construction of Pará rubber tree genome and multi-transcriptome database accelerates rubber researches

Makita Y, Kawashima M, Lau NS, Othman AS, Matsui M

BMC Genomics, 2018 01 19;19(Suppl 1):922.
PMID: 29363422 DOI: 10.1186/s12864-017-4333-y

BACKGROUND: Natural rubber is an economically important material. Currently the Pará rubber tree, Hevea brasiliensis is the main commercial source. Little is known about rubber biosynthesis at the molecular level. Next-generation sequencing (NGS) technologies brought draft genomes of three rubber cultivars and a variety of RNA sequencing (RNA-seq) data. However, no current genome or transcriptome databases (DB) are organized by gene.
RESULTS: A gene-oriented database is a valuable support for rubber research. Based on our original draft genome sequence of H. brasiliensis RRIM600, we constructed a rubber tree genome and transcriptome DB. Our DB provides genome information including gene functional annotations and multi-transcriptome data of RNA-seq, full-length cDNAs including PacBio Isoform sequencing (Iso-Seq), ESTs and genome wide transcription start sites (TSSs) derived from CAGE technology. Using our original and publically available RNA-seq data, we calculated co-expressed genes for identifying functionally related gene sets and/or genes regulated by the same transcription factor (TF). Users can access multi-transcriptome data through both a gene-oriented web page and a genome browser. For the gene searching system, we provide keyword search, sequence homology search and gene expression search; users can also select their expression threshold easily.
CONCLUSION: The rubber genome and transcriptome DB provides rubber tree genome sequence and multi-transcriptomics data. This DB is useful for comprehensive understanding of the rubber transcriptome. This will assist both industrial and academic researchers for rubber and economically important close relatives such as R. communis, M. esculenta and J. curcas. The Rubber Transcriptome DB release 2017.03 is accessible at http://matsui-lab.riken.jp/rubber/ .
Fulltext Assessment of three plastid DNA barcode markers for identification of Clinacanthus nutans (Acanthaceae)

Ismail NZ, Arsad H, Samian MR, Hamdan MR, Othman AS

3 Biotech, 2018 Jan;8(1):62.
PMID: 29354373 DOI: 10.1007/s13205-018-1092-7

This study was conducted to determine the feasibility of using three plastid DNA regions (matK, trnH-psbA, and rbcL) as DNA barcodes to identify the medicinal plant Clinacanthus nutans. In this study, C. nutans was collected at several different locations. Total genomic DNA was extracted, amplified by polymerase chain reaction (PCR), and sequenced using matK, trnH-psbA, and rbcL, primers. DNA sequences generated from PCR were submitted to the National Center for Biotechnology Information's (NCBI) GenBank. Identification of C. nutans was carried out using NCBI's Basic Local Alignment Search Tool (BLAST). The rbcL and trnH-psbA regions successfully identified C. nutans with sequencing rates of 100% through BLAST identification. Molecular Evolutionary Genetics Analysis (MEGA) 6.0 was used to analyze interspecific and intraspecific divergence of plastid DNA sequences. rbcL and matK exhibited the lowest average interspecific distance (0.0487 and 0.0963, respectively), whereas trnH-psbA exhibited the highest average interspecific distance (0.2029). The R package Spider revealed that trnH-psbA correctly identified Barcode of Life Data System (BOLD) 96%, best close match 79%, and near neighbor 100% of the species, compared to matK (BOLD 72%; best close match 64%; near neighbor 78%) and rbcL (BOLD 77%; best close match 62%; near neighbor 88%). These results indicate that trnH-psbA is very effective at identifying C. nutans, as it performed well in discriminating species in Acanthaceae.

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