Displaying publications 1 - 20 of 32 in total

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  1. Halal pharmaceutical industry: opportunities and challenges
    Nor Norazmi M, Lim LS
    Trends Pharmacol. Sci., 2015 Aug;36(8):496-7.
    PMID: 26187623 DOI: 10.1016/j.tips.2015.06.006
    The expanding global Muslim population has increased the demand for halal pharmaceuticals. However, there are several challenges for this emerging niche industry, foremost of which is the need to establish a proper, well-regulated, and harmonized accreditation and halal management system.
  2. A systematic review on current approaches in bat virus discovered between 2018 and 2022
    Mo Y, Lim LS, Ng SK
    J Virol Methods, 2024 Sep;329:115005.
    PMID: 39128772 DOI: 10.1016/j.jviromet.2024.115005
    Zoonotic viruses are widely seen as the primary threat for future pandemics. Bats are the most diverse group of mammals, with more than 1400 species distributed across most habitats on Earth. So far, 31 known virus families were associated with bats, although the understanding of most viruses were insufficient. Continuous efforts to discover, understand and monitor these bats viruses, is thereby an area of public health interest. This systematic review was designed to catalogue publications reporting novel bat virus discoveries within PubMed, SCOPUS, and Web of Science databases, within a 5-year period from 2018 to 2022. Various experimental parameters, including sampling locations, methodology, bat species diversity, similarity to known viruses, species demarcation of new viruses, and genomic sequencing strategies, were extracted from 41 publications and analyzed. In total, 72 novel viruses from 19 virus families were identified between 2018 and 2022, particularly from Genomoviridae (DNA viruses) and Coronaviridae (RNA viruses). That said, only a limited number of bat families featured extensively despite noticeable shift towards next generation sequencing methods and metagenomics pipeline for virus identification across different sampling methods. This review aims to provide a comprehensive analysis of the global efforts made over the past five years to identify and characterize emerging viruses in bat species, and to provide a detailed overview of the current technologies and methodologies used in these studies.
  3. Fulltext Identification of quantitative trait loci for blast resistance in BC₂F₃ and BC₂F5 advanced backcross families of rice
    Rahim HA, Bhuiyan MA, Lim LS, Sabu KK, Saad A, Azhar M, et al.
    Genet. Mol. Res., 2012;11(3):3277-89.
    PMID: 23079822 DOI: 10.4238/2012.September.12.11
    Advanced backcross families derived from Oryza sativa cv MR219/O. rufipogon IRGC105491 were utilized for identification of quantitative trait loci (QTL) for blast resistance using simple sequence repeat markers. Two hundred and sixty-one BC(2)F(3) families were used to construct a linkage map, using 87 markers, which covered 2375.2 cM of 12 rice chromosomes, with a mean density of 27.3 cM. The families were evaluated in a greenhouse for resistance to blast disease caused by pathotypes P7.2 and P5.0 of Magnaporthe oryzae. Five QTLs (qBL5.1, qBL5.2, qBL6.1, qBL8.1, and qBL10.1) for pathotype P5.0 and four QTLs (qBL5.3, qBL5.4, qBL7.1, and qBL8.2) for pathotype P7.2 were identified using the BC(2)F(3) families. Another linkage map was also constructed based on 31 BC(2)F(5) families, using 63 SSR markers, which covered 474.9 cM of 9 rice chromosomes, with a mean density of 8.01 cM. Five suggestive QTLs (qBL11.2, qBL11.3, qBL12.1, qBL12.2, qBL12.3) and one putative QTL (qBL2.1) were identified for pathotype P7.2. Also, seven suggestive QTLs (qBL1.1, qBL2.2, qBL4.1, qBL4.2, qBL5.3, qBL8.3, and qBL11.1) were detected for pathotype P5.0. We conclude that there is a non-race-specific resistance spectrum of O. rufipogon against M. oryzae pathotypes.
  4. Fulltext Insights into the genome structure and copy-number variation of Eimeria tenella
    Lim LS, Tay YL, Alias H, Wan KL, Dear PH
    BMC Genomics, 2012;13:389.
    PMID: 22889016 DOI: 10.1186/1471-2164-13-389
    Eimeria is a genus of parasites in the same phylum (Apicomplexa) as human parasites such as Toxoplasma, Cryptosporidium and the malaria parasite Plasmodium. As an apicomplexan whose life-cycle involves a single host, Eimeria is a convenient model for understanding this group of organisms. Although the genomes of the Apicomplexa are diverse, that of Eimeria is unique in being composed of large alternating blocks of sequence with very different characteristics - an arrangement seen in no other organism. This arrangement has impeded efforts to fully sequence the genome of Eimeria, which remains the last of the major apicomplexans to be fully analyzed. In order to increase the value of the genome sequence data and aid in the effort to gain a better understanding of the Eimeria tenella genome, we constructed a whole genome map for the parasite.
  5. Diel osmorespiration rhythms of juvenile marble goby (Oxyeleotris marmorata)
    Lim LS, Tan SY, Tuzan AD, Kawamura G, Mustafa S, Rahmah S, et al.
    Fish Physiol Biochem, 2020 Aug;46(4):1621-1629.
    PMID: 32430644 DOI: 10.1007/s10695-020-00817-5
    Oxyeleotris marmorata is an ambush predator. It is known for slow growth rate and high market demand. Farming of O. marmorata still remains a challenge. In order to establish a proper feeding practice to stimulate growth, knowledge of its metabolic processes and cost should be examined. Therefore, this study was designed to investigate the diel osmorespiration rhythms of O. marmorata in response to feeding challenge by using an osmorespirometry assay. The results have shown that oxygen consumption rate of the fed fish was approximately 3 times higher than that of the unfed fish in early evening to support specific dynamic action. Digestion and ingestion processes were likely to be completed within 18-20 h in parallel with the ammonia excretion noticeable in early morning. Under resting metabolism, metabolic oxygen consumption was influenced by diel phase, but no effect was noted in ammonia excretion. As a nocturnal species, O. marmorata exhibited standard aerobic metabolic mode under dark phase followed by light phase, with high oxygen consumption rate found in either fed or unfed fish. It can be confirmed that both the diel phase and feeding have a significant interactive impact on oxygen consumption rate, whereas ammonia metabolism is impacted by feeding state. High metabolic rate of O. marmorata supports the nocturnal foraging activity in this fish. This finding suggested that feeding of O. marmorata should be performed during nighttime and water renewal should be conducted during daytime.
  6. Fulltext Taste Sensitivity and Taste Preference among Malay Children Aged 7 to 12 Years in Kuala Lumpur-A Pilot Study
    Lim LS, Tang XH, Yang WY, Ong SH, Naumovski N, Jani R
    Pediatr Rep, 2021 May 18;13(2):245-256.
    PMID: 34069893 DOI: 10.3390/pediatric13020034
    The taste and food preferences in children can affect their food intake and body weight. Bitter and sweet taste sensitivities were identified as primary taste contributors to children's preference for consuming various foods. This pilot study aimed to determine the taste sensitivity and preference for bitter and sweet tastes in a sample of Malaysian children. A case-control study was conducted among 15 pairs of Malay children aged 7 to 12 years. Seven solutions at different concentrations of 6-n-propylthiouracil and sucrose were prepared for testing bitterness and sweet sensitivity, respectively. The intensity of both bitter and sweet sensitivity was measured using a 100 mm Labelled Magnitude Scale (LMS), while the taste preference was rated using a 5-point Likert scale. The participants were better at identifying bitter than sweet taste (median score 6/7 vs. 4/7). No significant differences were detected for both tastes between normal-weight and overweight groups (bitter: 350 vs. 413, p = 0.273; sweet: 154 vs. 263, p = 0.068), as well as in Likert readings (bitter 9 vs. 8: p = 0.490; sweet 22 vs. 22: p = 0.677). In this sample of Malay children, the participants were more sensitive to bitterness than sweetness, yet presented similar taste sensitivity and preference irrespective of their weight status. Future studies using whole food samples are warranted to better characterize potential taste sensitivity and preference in children.
  7. Fulltext Caffeine and theobromine levels in chocolate couverture and coating products
    Ramli N, Abdul Rahman S, Hassan O, Mohd Yatim A, Said M, Lim LS, et al.
    Malays J Nutr, 2000 Mar;6(1):55-63.
    PMID: 22692392
    Thirty-two samples of chocolate products were analysed by HPLC for caffeine and theobromine contents. Defatted residues of samples were extracted with 80% aqueous acetone. After extraction into boiling water, the methylxanthines were identified and quantified with the use of μ-Bondapak column and mobile phase of methanol:water:acetic acid (20:79:1). Levels of caffein and theobromine in 32 samples of chocolate products averaged 0.62-1.14 mg/g and 0.026-0.153 mg/g respectively. Mean values for theobromine and caffeine content for chocolate coating were 0.82 and 0.07 mg/g respectively. The chocolate coating made from fat substitute had theobromine and caffeine levels ranging from 0.36-0.70 mg/g and 0.027-0.061 mg/g respectively, with mean values of 0.49 mg theobromine/g and 0.039 mg caffeine/g. In local chocolate, the mean theobromine and caffeine levels respectively were 0.72 mg/g and 0.04 mg/g in milk chocolate, and 0.85 mg/g and 0.06 mg/g in dark chocolate. Meanwhile, for imported chocolate, the mean theobromine and caffeine levels respectively were 1.05 mg/g and 0.12 mg/g in dark chocolate; 0.76 mg/g and 0.04 mg/g in milk chocolate; and 0.74 mg/g and 0.03 mg/g in white chocolate. Compared with the local chocolates, imported chocolates had higher levels of theobromine and caffeine at 1.141 mg/g and 0.1533mg/g. The average theobromine and caffeine concentrations in local chocolate were 0.082mg/g and 0.066mg/g. Theobromine concentration in chocolate samples is within the range of 0.62mg/g-1.141mg/g and the range of caffeine concentration is 0.026mg/g-0.153mg/g respectively. Bittersweet chocolates were found to have higher theobromine and caffeine concentrations than normal sweet chocolates and milk chocolates.
  8. Fulltext Low pH Water Impairs the Tactile Sense of the Postlarvae of the Giant Freshwater Prawn Macrobrachium rosenbergii
    Kawamura G, Bagarinao T, Yong ASK, Noor SN, Lim LS
    Trop Life Sci Res, 2018 Mar;29(1):103-112.
    PMID: 29644018 MyJurnal DOI: 10.21315/tlsr2018.29.1.7
    The effect of low pH on the tactile sense of Macrobrachium rosenbergii postlarvae was determined in the laboratory by means of two behavioural assays: shelter (netting) occupancy and jumping response to touch stimuli (taps) by a glass micropipette. The postlarvae were acclimated to pH 4, pH 5, pH 6 and pH 7.5 (control) in 45 L aquaria 5-7 d before the experiments. Shelter occupancy decreased with pH and was significantly lower at pH 4 and pH 5 than at pH 6 and in the control. The jumping response instantly followed a tap 93-98% of the time in the control, pH 6 and pH 5 treatments. However, the postlarvae showed significantly lower jumping response (65%) at pH 4, indicating an impaired tactile sense. Low pH 4-5 probably degrades the chitin of the sensory setae and inhibits the surface mechanoreceptors of the prawn postlarvae.
  9. Fulltext Roles of Carotenoids in Invertebrate Immunology
    Tan K, Zhang H, Lim LS, Ma H, Li S, Zheng H
    Front Immunol, 2019;10:3041.
    PMID: 32010132 DOI: 10.3389/fimmu.2019.03041
    Carotenoids are biologically active pigments that are well-known to enhance the defense and immunity of the vertebrate system. However, in invertebrates, the role of carotenoids in immunity is not clear. Therefore, this study aims to review the scientific evidence for the role of carotenoids in invertebrate immunization. From the analysis of published literatures and recent studies from our laboratory, it is obvious that carotenoids are involved in invertebrate immunity in two ways. On the one hand, carotenoids can act as antioxidant enzymes to remove singlet oxygen, superoxide anion radicals, and hydroxyl radicals, thereby reducing SOD activity and reducing the cost of immunity. In some organisms, carotenoids have been shown to promote SOD activity by up-regulating the expression of the ZnCuSOD gene. Carotenoids, on the other hand, play a role in the expression and regulation of many genes involved in invertebrate immunity, including thioredoxins (TRX), peptidoglycan recognition receptor proteins (PGRPs), ferritins, prophenoloxidase (ProPO), vitellogenin (Vg), toll-like receptor (TLRs), heat shock proteins (HSPs), and CuZnSOD gene. The information in this review is very useful for updating our understanding of the progress of carotenoid research in invertebrate immunology and to help identify topics for future topics.
  10. Aquaculture wastewater-raised Azolla as partial alternative dietary protein for Pangasius catfish
    Rahmah S, Nasrah U, Lim LS, Ishak SD, Rozaini MZH, Liew HJ
    Environ Res, 2022 Jan 18;208:112718.
    PMID: 35051427 DOI: 10.1016/j.envres.2022.112718
    Azolla is a freshwater floating aquatic fern found in the tropical, subtropical and temperate regions with a high nitrogen-fixing rate from the result of symbiotic relationship with the blue-green cyanobacterium, Anabaena azollae. Azolla can effectively remediate aquaculture wastewater owing to its high production capacity and the ability to absorb nutrients and toxic compounds. The Azolla biomass generated as a by-product is currently underutilized and could potentially benefit the aquafeed industry in replacing the unfeasible and expensive fishmeal protein at a certain level. This study evaluates the incorporation of red tilapia wastewater-raised Azolla as a dietary protein for the growth performance, feed efficiency, survival, body indices, body composition and nutrient utilization of Pangasius catfish Pangasianodon hypophthalmus during a 90-days feeding experiment. Dried Azolla was incorporated into four isonitrogenous (30 g kg-1) and isolipidic (12 g kg-1) practical diets containing 0 g kg-1 (Control), 10 g kg-1 (A10), 20 g kg-1 (A20) and 30 g kg-1 (A30) fishmeal protein replacement. One hundred and twenty juveniles with an initial mean weight of 45 ± 15 g were distributed into 12 tanks representing four dietary treatments in triplicates. Results showed significant (p  0.05) effects were recorded for feed intake, survival, body indices and nutrient utilization amongst all dietary treatments. In conclusion, Azolla raised from red tilapia aquaculture wastewater can replace fishmeal protein up to 10 g kg-1 in the diet of Pangasius catfish juveniles having better growth, feed efficiency and nutrient utilization without affecting its survival, body indices and body composition.
  11. Fulltext Evaluation of crystalline amino acids as potent stimulatory chemoattractants for the slipper lobster Thenus orientalis
    Teoh CF, Tuzan AD, Yong AS, Liew KS, Lim LS, Liew HJ
    PeerJ, 2023;11:e15607.
    PMID: 37876908 DOI: 10.7717/peerj.15607
    Intensive research on the effectiveness of chemoattractants has been widely explored to improve the feed qualities in expanding crustacean farming. Taste preferences in slipper lobster remained unknown despite their significant contribution to the lobster fisheries. Chemoattractants allow better performance in aquaculture species by increasing food attractiveness and palatability. Amino acids (AA) have been leading in previous research on crustacean feeding behavior. Given that slipper lobster possesses chemoreceptors to detect and orient towards food, this study investigated an approach to identify the AA with the most potent chemoattractant in eliciting a response from slipper lobster. Behavioral assays were performed to evaluate the responses of slipper lobster Thenus orientalis (carapace length, 52.34 ± 1.52 mm) on 15 crystalline AA and three derivatives of AA (DAA) at three concentrations between 10-1 and 10-3 M as test substances (TS). Meretrix sp. extract was used as a positive control and clean filtered seawater as a negative control. The behavioral responses of 14 T. orientalis were evaluated based on their antennular flicking rate, third maxillipeds activity, and substrate probing by the pereiopods. T. orientalis responded to the solutions of single AA down to a concentration of 10-3 M, excluding histidine and serine. The behavioral activity displayed by T. orientalis increased with the TS concentrations. L-glutamic acid monosodium salt monohydrate, betaine, and glycine solutions elicited the most behavioral responses, whereas histidine exhibited the lowest behavioral responses. Conclusively, L-glutamic acid monosodium salt monohydrate, betaine, and glycine can be potential chemoattractants for T. orientalis.
  12. Fulltext Chemosensitivity and role of swimming legs of mud crab, Scylla paramamosain, in feeding activity as determined by electrocardiographic and behavioural observations
    Kawamura G, Loke CK, Lim LS, Yong ASK, Mustafa S
    PeerJ, 2021;9:e11248.
    PMID: 33976976 DOI: 10.7717/peerj.11248
    Swimming crabs have a characteristic fifth pair of legs that are flattened into paddles for swimming purposes. The dactyl of these legs bears a thick seta along its edge. The chemoreceptive and feeding properties of the seta are supported with scientific evidence; however, there is no available data on the sensitivity of the setae in portunid crabs. The underlying mechanisms of the chemo- and mechano-sensitivity of appendages and their involvement in feeding activities of the mud crab (Scylla paramamosain) were investigated using electrocardiography and behavioural assay, which focused on the responses of the mud crab to chemical and touch stimulus. Electrocardiography revealed the sensory properties of the appendages. The dactyls of swimming legs and the antennules were chemosensitive, but not mechanosensitive and vice versa for the antennae. However, the mouthparts, claws, and walking legs were chemo- and mechanosensitive. Only the chemosensitive appendages, including the swimming legs, were directly involved in feeding. The flattened dactyls of the swimming legs were more efficient than the pointed dactyls of the walking legs in detecting the food organism crawling on the substrate. The structural features enhanced the capacity of the crab in coming into contact with scattered food items. This study revealed that the swimming legs are important appendages for feeding in the mud crab.
  13. Fulltext Mini review: surveillance of Lyme borreliosis in Southeast Asia and method of diagnosis
    Teh KJ, Tang HY, Lim LS, Pung HS, Gan SY, Lai NS
    Eur Rev Med Pharmacol Sci, 2023 May;27(10):4378-4385.
    PMID: 37259718 DOI: 10.26355/eurrev_202305_32443
    Lyme borreliosis is caused by the Gram-negative spirochetes Borrelia spp., particularly Borrelia burgdorferi sensu lato complex. The disease is transmitted through the bite of the infected black-legged Ixodes tick. Lyme borreliosis extensively occurs in the Northern Hemisphere, mainly in the United States. Lyme borreliosis cases are also detected in Asian countries including Korea, Nepal, China, Taiwan, and Japan. However, there is an inadequate understanding of Lyme borreliosis in the Southeast Asian region. Hence, this review aims to provide a brief update on the prevalence of Lyme borreliosis infection in Southeast Asia based on the latest literature on this issue. Lyme borreliosis has been discovered in human serum in Indonesia, Malaysia, and Singapore. The human serum samples were mainly examined with ELISA test using Borrelia spp. IgG and IgM antigens. Borrelia spp. also has been detected in ticks found on host animals such as Sundamys muelleri and Python in Malaysia, Thailand, and Laos. Polymerase chain reaction (PCR) is used to detect the presence of Borrelia DNAs in the samples. The published studies have demonstrated that Borrelia spp. exists in Southeast Asia and although the incidence is relatively low, it is believed that Lyme disease cases are under-reported.
  14. Development of the muscular and nervous systems during the larval ontogeny of the stalked barnacle, Octolasmis angulata Aurivillius 1894 (Cirripedia: Thoracicalcerea: Poecilasmatidae)
    Yap FC, Wong WL, Chong VC, Bong CW, Lim LS
    Arthropod Struct Dev, 2023 Sep;76:101298.
    PMID: 37672818 DOI: 10.1016/j.asd.2023.101298
    The advancements in microscopic techniques have stimulated great interest in the muscular and neural architectures of invertebrates, specifically using muscle and neural structures to infer phylogenetic relationships. Here, we provide the data on the development of the muscular and nervous systems during the larval development of stalked barnacle, Octolasmis angulata using the phalloidin F-actin and immunohistochemical labelling (e.g. acetylated α-tubulin and serotonin) and confocal laser scanning microscopy analysis. All naupliar stages shared the same muscle and neural architectures with only the discrepancy in size. The nauplii have a complex muscle arrangement in their feeding apparatus and naupliar appendages. Most naupliar muscles undergo histolyse during the cyprid metamorphosis. The cyprid muscles form beneath the head shield at the end of nauplius VI. The naupliar and cyprid central nervous systems exhibit the typical tripartite brain comprising the protocerebrum, deutocerebrum and tritocerebrum. The serotonin-like immunoreactivity is mainly found in the naupliar brain, mandibular ganglia, cyprid brain and posterior ganglia. Our study revealed that numerous muscle and neural architectures in the naupliar and cyprids have phylogenetic significance, but future studies on the myoanatomy and neuroanatomy of other barnacle species are necessary to determine the homology of these structures.
  15. siRNA Silencing of FpVtg Induces Ovarian Cell Apoptosis in Redtail Prawn, Fenneropenaeus penicillatus
    Tan K, Dong Y, Tan K, Lim LS, Waiho K, Chen J, et al.
    Mar Biotechnol (NY), 2023 Dec;25(6):1176-1190.
    PMID: 38010485 DOI: 10.1007/s10126-023-10269-6
    Inadequate gonadal maturation and poor spawning performance increasingly threaten the sustainability of shrimp aquaculture. Unraveling the mechanisms regulating ovarian development and maturation hence is critical to address industry challenges. Vitellogenin (Vtg), a precursor of yolk protein found in the hepatopancreas and ovary of shrimp, plays a key role in facilitating shrimp's oocyte maturation and embryonic development after oviposition. This study found that FpVtg was specifically expressed in F. penicillatus hepatopancreas and ovary. FpVtg was localized predominantly in the oocyte cytoplasm and distributed uniformly in the hepatopancreas tissue. Silencing FpVtg led to apoptosis in both hepatopancreas and ovary tissues. Furthermore, FpVtg depletion upregulated the expression of ovarian peritrophin 1, ovarian peritrophin 2, serine proteinase inhibitor 6, and juvenile hormone esterase-like carboxylesterase 1, while downregulated that of vitellogenin, delta-9 desaturase, and insulin-like receptor. KEGG pathway analysis implicated such as PI3K-AKT signaling, RNA transport, ECM-receptor interaction, hippo signaling, oocyte meiosis, and apoptosis were enriched and involved in ovarian development. These findings have provided insights into the FpVtg's reproductive role and the associated regulatory genes and pathways in F. penicillatus. This knowledge can contribute to establishing strategies to improve the breeding and aquaculture production of F. penicillatus by elucidating its vitellogenesis regulation in redtail prawn and other penaeid species. Further characterization of the implicated pathways and genes will clarify the intricacies underlying ovarian maturation.
  16. Sensory-mediated feeding behaviour in the larvae of marble goby (Oxyeleotris marmorata)
    Lim LS, Yee CW, Tan KA, Liew HJ, Mukai Y
    Behav Processes, 2023 Nov;213:104969.
    PMID: 37989455 DOI: 10.1016/j.beproc.2023.104969
    This study was conducted to determine the senses that facilitate prey detection in the marble goby (Oxyeleotris marmorata) larvae. The ingestion ratios of live (generate chemical and mechanical stimuli) or frozen Artemia nauplii (generate chemical but no mechanical stimuli) by the intact or free neuromast (mechanoreceptor)-ablated O. marmorata larvae (11 mg/L streptomycin treatment before feeding) under the light or dark (fish vision was obstructed) condition were examined. Vision, mechano-, and chemoreceptions were all found to be essential in prey detection of the O. marmorata larvae. Prey movement has a significant influence as a visual stimuli on the O. marmorata larval feeding as the Artemia nauplii ingestion ratio was approximately 40% higher with significant (p = 0.001, d = 3.0), when the intact larvae were fed with the live (78.1 ± 1.5%), rather than the frozen (40.9 ± 2.8%) Artemia nauplii, under the light condition. This result was assured when no significant difference (p = 0.572, d = 0.2) was found between the ingestion ratios of frozen Artemia nauplii by the intact O. marmorata larvae under light and dark conditions. These findings demonstrate that prey detection in the O. marmorata larvae was facilitated by multi-modal senses, allowing O. marmorata larvae to survive in their natural habitats.
  17. Fulltext Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid) Reinforced with Cellulose Nanocrystals
    Lim LS, Rosli NA, Ahmad I, Mat Lazim A, Mohd Amin MCI
    Nanomaterials (Basel), 2017 Nov 20;7(11).
    PMID: 29156613 DOI: 10.3390/nano7110399
    pH-sensitive poly(acrylic acid) (PAA) hydrogel reinforced with cellulose nanocrystals (CNC) was prepared. Acrylic acid (AA) was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide) with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD) data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system.
  18. Targeting TtVgR via siRNA Knockdown Elicits Ovarian Cell Death in the Tri-spine Horseshoe Crab
    Tan K, Ma X, Su B, Zhan C, Yang X, Waiho K, et al.
    Mar Biotechnol (NY), 2024 Apr 27.
    PMID: 38676851 DOI: 10.1007/s10126-024-10319-7
    The vitellogenin present in the bloodstream undergoes internalization into developing oocytes through the vitellogenin receptor (VgR), a process mediated by receptor-mediated endocytosis. VgR plays a crucial role in facilitating the accumulation of vitellogenin and the maturation of oocytes. In this study, we characterized a Tachypleus tridentatus vitellogenin receptor (TtVgR) gene from the tri-spine horseshoe crab, revealing a length of 1956 bp and encoding 652 amino acid residues with 12 exons. TtVgR has a molecular weight of 64.26 kDa and an isoelectric point of 5.95. Predictions indicate 85 phosphorylation sites and 7 glycosylation sites within TtVgR. Transcriptional analysis demonstrated specific expression of TtVgR in the ovary and yellow connective tissue. TtVgR was identified and distributed in the plasma membrane of oocytes. The siRNA-mediated TtVgR knockdown significantly reduced the transcriptional activity of TtVgR. This depletion induced excessive ROS production, resulting in DNA damage in ovarian primary cells. TUNEL and flow cytometry analyses confirmed ovarian cell apoptosis following TtVgR knockdown, indicating DNA damage in ovarian primary cells. These findings underscore the importance of TtVgR in ovarian cell development, suggesting its potential involvement in vitellogenesis and oocyte maturation. This knowledge may inform innovative breeding strategies and contribute to the sustainable management and conservation of the tri-spine horseshoe crab.
  19. Cloning and functionally characterization of TtVtg2-like in horseshoe crab Tachypleus tridentatus: A special focus on ovarian development
    Yang X, Tan K, Su B, Lim LS, Waiho K, Kwan KY, et al.
    Int J Biol Macromol, 2024 Aug 10;278(Pt 1):134667.
    PMID: 39134189 DOI: 10.1016/j.ijbiomac.2024.134667
    Horseshoe crabs are living fossils. In recent decades, the population of horseshoe crabs, especially the tri-spine horseshoe crab Tachypleus tridentatus, has decreased significantly and was listed as an 'endangered species' under the IUCN Red List in 2019. In order to improve the reproduction of T. tridentatus to facilitate stock enhancement, it is important to understand their ovarian development. In this study, a novel TtVtg2-like gene from T. tridentatus was cloned and functionally characterized. The total legth of TtVtg2-like was 5469 bp, encoding a protein consisting of 1822 amino acid with a pI value of 6.51 and a molecular weight of 208.68 KDa. The TtVtg2-like was highly expressed in the ovary and yellow connective tissues, mainly localized in cytoplasm and endoplasmic reticulum vesicles of oocytes and yellow connective tissues, respectively. RNA interference of TtVtg2-like caused the accumulation of ROS, DNA damage, and apoptosis of ovarian primary cells. The results of this study provide useful baseline information for future studies on ovarian development in horseshoe crabs.
  20. Fulltext Characterisation of full-length cDNA sequences provides insights into the Eimeria tenella transcriptome
    Amiruddin N, Lee XW, Blake DP, Suzuki Y, Tay YL, Lim LS, et al.
    BMC Genomics, 2012 Jan 13;13:21.
    PMID: 22244352 DOI: 10.1186/1471-2164-13-21
    BACKGROUND: Eimeria tenella is an apicomplexan parasite that causes coccidiosis in the domestic fowl. Infection with this parasite is diagnosed frequently in intensively reared poultry and its control is usually accorded a high priority, especially in chickens raised for meat. Prophylactic chemotherapy has been the primary method used for the control of coccidiosis. However, drug efficacy can be compromised by drug-resistant parasites and the lack of new drugs highlights demands for alternative control strategies including vaccination. In the long term, sustainable control of coccidiosis will most likely be achieved through integrated drug and vaccination programmes. Characterisation of the E. tenella transcriptome may provide a better understanding of the biology of the parasite and aid in the development of a more effective control for coccidiosis.

    RESULTS: More than 15,000 partial sequences were generated from the 5' and 3' ends of clones randomly selected from an E. tenella second generation merozoite full-length cDNA library. Clustering of these sequences produced 1,529 unique transcripts (UTs). Based on the transcript assembly and subsequently primer walking, 433 full-length cDNA sequences were successfully generated. These sequences varied in length, ranging from 441 bp to 3,083 bp, with an average size of 1,647 bp. Simple sequence repeat (SSR) analysis identified CAG as the most abundant trinucleotide motif, while codon usage analysis revealed that the ten most infrequently used codons in E. tenella are UAU, UGU, GUA, CAU, AUA, CGA, UUA, CUA, CGU and AGU. Subsequent analysis of the E. tenella complete coding sequences identified 25 putative secretory and 60 putative surface proteins, all of which are now rational candidates for development as recombinant vaccines or drug targets in the effort to control avian coccidiosis.

    CONCLUSIONS: This paper describes the generation and characterisation of full-length cDNA sequences from E. tenella second generation merozoites and provides new insights into the E. tenella transcriptome. The data generated will be useful for the development and validation of diagnostic and control strategies for coccidiosis and will be of value in annotation of the E. tenella genome sequence.

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