Tropical life sciences research最新文献

Non-volant mammals in Peninsular Malaysia face numerous threats, primarily driven by habitat loss, fragmentation and illegal hunting. These threats highlight the importance of conducting wildlife surveys in the available forested areas to enhance the current strategies for conservation and management, particularly for a threatened taxon like non-volant mammals. This study aimed to document and update information of non-volant mammals from four areas: Tasik Bera (Pahang state); Tasik Kenyir, Pulau Redang and Universiti Malaysia Terengganu (UMT) Campus (Terengganu state). Cage traps and Visual Encounter Survey methods were utilised to record non-volant mammals from August 2022 until March 2023. This study successfully documented 123 individuals from 27 non-volant mammal species, representing 11 families from 6 orders. Tasik Bera demonstrated the highest species count at 18, followed by UMT Campus with 6, while Tasik Kenyir and Pulau Redang each recorded 4 species. The species diversity was the highest at Tasik Bera (H' = 2.65) and the lowest at Pulau Redang (H' = 1.01). Macaca fascicularis, Tupaia glis and Paradoxurus hermaphroditus were recorded from three of four sites. This study has added new geographically recorded species for Tasik Bera (11 species) and UMT Campus (4 species). This study has advanced our knowledge of the diversity and distribution of non-volant mammals, enhancing our understanding in this field. This understanding is crucial for implementing efficient conservation and management strategies, aiding in the development of targeted conservation strategies to protect these species and their habitats.

Infection of keratinocytes by high-risk human papillomavirus (HPV) strains, notably HPV16, is responsible for the onset of cervical cancer. The E6 protein serves as a pivotal oncoprotein implicated in the progression of cancer. We utilised a virtual screening method to identify bioactive compounds in a variety of commonly used medicinal plants in Indonesia. All the top five compounds bind to a single binding site on the E6 major hydrophobic groove, which corresponds to the binding site for the E6AP and IRF3's LxxLL motifs. They are expected to function as competitive inhibitors, inhibiting the development of the E6-E6AP and E6-IRF3 complexes, which limit p53 degradation and therefore cell proliferation, thus preserving the innate immune response to HPV16 infection. Asarinin and thiazolo[3,2-a]benzimidazole-3(2H)-one,2-(2-fluorobenzylideno)-7,8-dimethyl were predicted to be the most effective compounds in this research owing to their strong affinity for and persistent interactions with the E6 major hydrophobic groove, particularly in comparison to pharmacological controls.

The investigation of alternative raw materials for gelatine production from fishery industry by-products has gained attention due to the increasing demand for gelatine and the importance for sustainable practices. This study aims to determine the optimal hydrochloric acid (HCl) concentration for mineral removal during pre-treatment, assess hydroxyproline content at various processing stages and characterise the resultant gelatine. The methodology involved pre-treatment of the materials with 0.1 M sodium hydroxide (NaOH) to remove non-collagen proteins, followed by mineral extraction using varying HCl concentrations (0.25, 0.5, 0.75 and 1 M). The process included swelling in 0.2% citric acid for 12 h and gelatine extraction at 65°C for 7 h. The results indicated that 0.25 M HCl was most effective for mineral removal. The hydroxyproline analysis showed an insignificant increase (0.088 mg/mL-0.103 mg/mL) from the pre-treatment stage to the final gelatine product. The physicochemical properties of the liquid gelatine, including yield (6.5 ± 0.39%), pH (6.55 ± 0.11), and gel bloom strength (174 ± 8.54 blooms) conformed to Gelatin Manufacturers Institute of America (GMIA). Functional groups confirmed the presence of gelatine-specific, such as amides A, B, I, II and III. The molecular profile is comparable to commercial gelatine, with α1 chains at 130 kDa, α2 chains at 115 kDa, and β chains at 235 kDa. The gelatine derived from the scaly skin of purple-spotted bigeye exhibits promising attributes, aligning with commercial standards and highlights the potential of fishery by-products as a sustainable and halal source of gelatine.

Morphological abnormalities in Perinereis aibuhitensis (Grube 1878) (Nereididae) and Diopatra claparedii Grube 1878 (Onuphidae) were observed in the specimens collected from the intertidal habitat around Donan Creek in Cilacap City, Central Java Province, Indonesia. The P. aibuhitensis, which is not supposed to have branchiae, possesses digitate branchiae on its dorsum, and lacks eyes. To our knowledge, the presence of branchiae in the genus Perinereis and the shape of the feature has never been reported anywhere else. Furthermore, the D. claparedii, which is supposed to have the most developed branchiae on its dorsal anterior region, lacks the feature. The species also lacks both prostomial and peristomial appendages, and has various anomalous cirri. While the abnormalities in the P. aibuhitensis are likely to be associated with the hypoxic condition of the animal's habitat, the anomalies in the D. claparedii appear to be more related to the exposure to pollutants, particularly heavy metals. Taxonomic investigations are required to reveal the polychaete species richness in this area, and may identify species that have the potential to be used as biological indicators of coastal water pollution in southern Java.

In Malaysia, the study on autism spectrum disorders (ASD) is limited. Most studies only focus on gene neuroligin 3 (NLGN3), NLGN4X, neurexin 1 (NRXN1) and SH3. This study focuses on the N-methyl-D-aspartate (NMDA) that was believed to have a significant effect on ASD. In this study, potential compounds and drugs that can restore receptor function in autistic patients were analysed. This research used an effective in silico method known as drug-repurposing to discover and rediscover drugs and analyse the binding of potential compounds or drugs to the NMDA receptor. AMPA and DOCK4 were used as controls in this study. Using a trusted server, Drug ReposER, 13 potential compounds or drugs that bind to NMDAR were identified. Then, proceed to the docking of potential compounds or drugs that bind to the NMDA receptor using Autodock Vina, Autodock, Hdock and CB dock and three drugs were selected that have the best binding score to NMDA, AMPA and DOCK4. The drugs were alitretinoin, salicylic acid and indinavir, respectively. Next, molecular dynamics simulations were performed with all selected compounds to study drug-protein binding, with detailed analysis of bond stability using root-mean-square fluctuation (RMSF) oscillations. Finally, ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) predictions identify 4-androstenedione, tryptophan, carbocisteine and vitamin A as having minimal toxic effects. This study showed that alitretinoin, which was known to treat skin lesions from Kaposi's sarcoma, might have the ability to reverse the effect in ASD, particularly in NMDA receptors, potentially making a significant impact on the field of neurology and psychiatry.

The Sunda porcupine (Hystrix javanica, F.Cuvier, 1823) is a rodent-mammal species native to Indonesia and is utilised in traditional medicine for the treatment of various ailments. Some ethnic communities in Indonesia have traditional beliefs regarding Sunda porcupine's quills, which are thought to relieve back pain and toothache. Despite this traditional knowledge, there is limited scientific research on the topic. The aim of this study was to identify active compound in an ethanolic crude extract of Sunda porcupine's quills, and to evaluate its antioxidant and antimicrobial properties. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH)-free radical scavenging assay while the antimicrobial activity was evaluated through microdilution resazurin assay. The total phenolic and flavonoid contents were also determined to support the antioxidant properties. The active compounds were identified using gas chromatography-mass spectrophotometer (GCMS) with the National Institute of Standards and Technology (NIST-11) library. The result showed that the extract possesses antioxidant properties (IC₅₀ 138.93 μg/mL) and antimicrobial properties against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Pseudomonas aeruginosa (P. aeruginosa) and Candida albicans (C. albicans) (IC₅₀ range 0.40 mg/mL-33.05 mg/mL). Total phenolic content (TPC) and total flavonoid content (TFC) were 27.29 ± 2.20 mgGAE/g and 27.09 ± 1.66 mgQE/g, respectively. A total of 24 active compounds from the crude extract were identified. As much as five compounds serve as antioxidant agents, including: butylated hydroxytoluene; eicosane; 1-iodo-hexadecane; methyl ester hexadecanoic acid; and L-(+)-ascorbic acid 2,6-dihexadecanoate. Furthermore, as much as 11 compounds serve as antimicrobial agents, including: tetradecane; pentadecane; 2-isopropyl-5-methyl-1-heptanol; hexadecane; butylated hydroxytoluene; eicosane; 1-iodo-hexadecane; methyl ester hexadecanoic acid; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, methyl ester; L-(+)-ascorbic acid 2,6-dihexadecanoate; and octadecanoic acid. This study provides scientific validation for the use of the Sunda porcupine's quills in traditional medicine and highlights the potential for further research in animal bioprospecting.

Benthic foraminifera are unicellular marine micro-organism with a hard exoskeleton and commonly present in the benthic community of marine ecosystem. This study aimed to identify the benthic foraminifera present along the coastal areas of eight municipalities in Biliran Island, Philippines. Quadrat sampling was conducted and three samples per quadrant transect of 1 m × 1 m divided into nine squares were collected. The samples were then observed under the microscope, and the specimens seen were identified by comparing them with the images of the sample species from the website https://marinespecies.org/. The researchers conducted an in-situ collection of the foraminiferal shells from intertidal areas along shallow water coastlines of the island. Results showed that the coastal environment of Biliran Island has the presence of the genera Spirillina, Quinqueloculina, Marginopora and Sorites. The identified species were classified based on their feeding mechanisms as herbivory and passive suspension feeding. The presence of benthic foraminifera species along the coastal environments of Biliran Island provides a record of the environment where they are found, making them natural bioindicators of water quality. This study provides a baseline for further studies on the distribution and abundance of benthic foraminifera in the area and can contribute to the understanding of the environmental conditions of the coastal areas in Biliran Island.

Frequent encounters with the greater bandicoot rats (Bandicota indica) following high rodent damage towards rice crops and lack of information on the species had encouraged this study to be conducted to test the relevance of using first- and second-generation rodenticide in a field efficacy test. This study also attempts to detect any sign of resistance of current rodent pest populations towards chlorophacinone (0.005%) and flucoumafen (0.05%) for the control of field rats predominant rice field agrosystem of the Kedah in northern peninsular Malaysia. Six different treatments over dry and wet rice planting season together with trapping exercise. The observation was evaluated based on the number of active burrows, counting tiller damage due to rodent attack and trapping index. The results indicated that flucoumafen gives better rodent control and has a better impact (p < 0.05) although chlorophacinone is still relevant to be applied (p < 0.05). Treatments during the off-planting season (September-February) are more effective compared to the main planting season (March-August). Rodent control during the early off-planting season is encouraged for better rodent management in the rice field and the use of bait stations to increase the weatherability of the baits.

Limnonectes leporinus, the endemic giant river frog, is a riparian (stream dwelling) species that lives along streams with moderate to steep gradients. The most serious threats to the species are deforestation caused by severe clear cutting, which fragments its distribution, and overhunting for local consumption. Excessive landscape modification alters habitat, making it critical for an organism to maintain heterozygozity for the population to be fit to adapt to a changing environment. The goal of this research was to project suitable habitats and predict the potential for habitat connectivity to allow gene flow across the Sarawak landscape. The presence data file and environmental layers were converted into ASCII format using ArcGIS and then used in MaxEnt modelling to generate the map of suitable habitats. To perform the connectivity model, the potential habitat model and genetic attributes of haplotype data were computerised in Circuitscape software. The findings revealed that suitable habitats corresponded to species distribution in lowland areas with sustainable stream networks as breeding sites, while higher elevations were identified as unsuitable habitats. Gene flow data, on the other hand, revealed that connectivity circuits are mostly found in unprotected forest, which includes development areas and private lands. As a result, prioritising conservation areas should include local governments and landowners in proper landscape management as well as species management strategies. This indirectly sustains and protects Borneo's forests, flora and fauna.

Plants are rich in tandem repeats-containing proteins. It is postulated that the occurrence of tandem repeat gene families facilitates the adaptation and survival of plants in adverse environmental conditions. This study intended to identify the tandem repeats in the transcriptome of a high potential tropical horticultural plant, roselle (Hibiscus sabdariffa L.). A total of 92,974 annotated de novo assembled transcripts were analysed using in silico approach, and 6,541 transcripts that encoded proteins containing tandem repeats with length of 20-60 amino acid residues were identified. Domain analysis revealed a total of nine tandem repeat protein families in the transcriptome of roselle, which are the Ankyrin repeats (ANK), Armadillo repeats (ARM), elongation factor-hand domain repeats (EF-hand), Huntingtin, elongation factor 3, protein phosphatase 2A, yeast kinase TOR1 repeats (HEAT), Kelch repeats (Kelch), leucine rich repeats (LRR), pentatricopeptide repeats (PPR), tetratricopeptide repeats (TPR) and WD40 repeats (WD40). Functional annotation analysis further matched 6,236 transcripts to 1,045 known proteins that contained tandem repeats including proteins implicated in plant development, protein-protein interaction, immunity and abiotic stress responses. The findings provide new insights into the occurrence of tandem repeats in the transcriptome and lay the foundation to elucidate the functional associations between tandem peptide repeats (TRs) and proteins in roselle and facilitate the identification of novel biotic and abiotic response related tandem repeats genes that may be useful in breeding improved varieties.