Displaying all 5 publications

  1. Ghani Hilmi M, Ikhwanuddin M
    Pak J Biol Sci, 2020 Jan;23(5):708-714.
    PMID: 32363828 DOI: 10.3923/pjbs.2020.708.714
    BACKGROUND AND OBJECTIVE: The accumulation of lipofuscin (LF) is an alternative technique to identify age of crustacean species. However, the exact sites and the level of the LF concentration were unknown especially for different sexes of blue swimming crab, Portunus pelagicus. Thus, the present study was aimed to identify which part of the eyestalk of P. pelagicus contains more LF levels in order to establish a specific target part of samples.

    MATERIALS AND METHODS: Thus, crab samples for this study were sampled from the wild habitat at Setiu wetlands, Terengganu, Malaysia. A total of 100 samples of with the same size (80±5 mm carapace width) were sampled and the eyestalk dissected for LF extraction. The determination of LF sites and levels in the eyestalks organ was taken from the area between the distal tangential layer (DTL) and proximal tangential layer (PTL). The lower part of the eyestalk was taken from the PTL until the end of the eyestalk.

    RESULTS: The upper part of the crab's eyestalk was higher in the males crabs compared to the females crabs. LF index also shown that the upper part of crab's eyestalk have higher concentration compared to the lower part.

    CONCLUSION: The left crab's eyestalk had the higher LF index especially in males compared to females but the total concentration was higher in female crabs. Knowing which part has highly dense accumulation of LF helps in LF detection of the tissue and further helps for age determination for this species.

    Matched MeSH terms: Brachyura/metabolism*
  2. Anandkumar A, Nagarajan R, Prabakaran K, Bing CH, Rajaram R, Li J, et al.
    Mar Pollut Bull, 2019 Aug;145:56-66.
    PMID: 31590824 DOI: 10.1016/j.marpolbul.2019.05.002
    The concentration of nine trace elements were analyzed in the different tissue organs of commonly available crabs (Portunus sanguinolentus, Portunus pelagicus and Scylla serrate) and bivalve (Polymesoda erosa) species collected from the Miri coast, Borneo in order to evaluate the potential health risk by consumption of these aquatic organisms. Among the analyzed organs, metal accumulation was higher in the gill tissues. The essential (Cu and Zn) and non-essential (Pb and Cd) elements showed the highest (i.e. Zn) and lowest concentrations (i.e. Cd) in their tissue organs, respectively. The estimated daily intake and hazard indices of all metals in the muscle indicate that the measured values were below the provisional tolerable daily intake suggested by the joint FAO/WHO Expert Committee on Food Additives. Compared to Malaysian and international seafood guideline values the results obtained from the present study are lower than the permissible limits and safe for consumption.
    Matched MeSH terms: Brachyura/metabolism*
  3. Yang X, Ikhwanuddin M, Li X, Lin F, Wu Q, Zhang Y, et al.
    Mar Biotechnol (NY), 2018 Feb;20(1):20-34.
    PMID: 29152671 DOI: 10.1007/s10126-017-9784-2
    The molecular mechanism underlying sex determination and gonadal differentiation of the mud crab (Scylla paramamosain) has received considerable attention, due to the remarkably biological and economic differences between sexes. However, sex-biased genes, especially non-coding genes, which account for these differences, remain elusive in this crustacean species. In this study, the first de novo gonad transcriptome sequencing was performed to identify both differentially expressed genes and long non-coding RNAs (lncRNAs) between male and female S. paramamosain by using Illumina Hiseq2500. A total of 79,282,758 and 79,854,234 reads were generated from ovarian and testicular cDNA libraries, respectively. After filtrating and de novo assembly, 262,688 unigenes were produced from both libraries. Of these unigenes, 41,125 were annotated with known protein sequences in public databases. Homologous genes involved in sex determination and gonadal development pathways (Sxl-Tra/Tra-2-Dsx/Fru, Wnt4, thyroid hormone synthesis pathway, etc.) were identified. Three hundred and sixteen differentially expressed unigenes were further identified between both transcriptomes. Meanwhile, a total of 233,078 putative lncRNAs were predicted. Of these lncRNAs, 147 were differentially expressed between sexes. qRT-PCR results showed that nine lncRNAs negatively regulated the expression of eight genes, suggesting a potential role in sex differentiation. These findings will provide fundamental resources for further investigation on sex differentiation and regulatory mechanism in crustaceans.
    Matched MeSH terms: Brachyura/metabolism*
  4. Waiho K, Fazhan H, Zhang Y, Afiqah-Aleng N, Moh JHZ, Ikhwanuddin M, et al.
    Genomics, 2020 09;112(5):2959-2969.
    PMID: 32437851 DOI: 10.1016/j.ygeno.2020.05.007
    Infection by the rhizocephalan parasite Sacculina beauforti can have detrimental effects on mud crab Scylla olivacea. However, the molecular changes that occur during rhizocephalan infection are poorly understood. Due to the disruption in the reproductive system after infection, the gonadal transcriptomic profiles of non-infected and infected Scylla olivacea were compared. A total of 686 and 843 unigenes were differentially expressed between non-infected and infected males, and females, respectively. The number of DEGs increased after infection. By comparing shared DEGs of non-infected and infected individuals, potential immune- and reproduction-related of host, and immune- and metabolism-related genes of parasite are highlighted. The only shared KEGG pathway between non-infected and infected individuals was the ribosome pathway. In summary, findings in this study provide new insights into the host-parasite relationship of rhizocephalan parasites and their crustacean hosts.
    Matched MeSH terms: Brachyura/metabolism
  5. Rosmilah M, Shahnaz M, Zailatul HM, Noormalin A, Normilah I
    Trop Biomed, 2012 Sep;29(3):467-78.
    PMID: 23018510
    Crab is an important source of food allergen. Tropomyosin represents the main crab allergen and is responsible for IgE cross-reactivity between various species of crustaceans. Recently, other new crab allergens including arginine kinase have been identified. However, information on allergens of the local Portunidcrab is not available. Thus, the aim of this study was to identify the major allergens of Portunus pelagicus (blue swimming crab) using the allergenomics approach. Raw and cooked extracts of the crab were prepared from the crab meat. Protein profile and IgE binding pattern were demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from 30 patients with crab allergy. The major allergens of the crab were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry analysis of the peptide digests. The SDS-PAGE of raw extract revealed approximately 20 protein fractions over a wide molecular weight range, while cooked extract demonstrated fewer protein bands. The raw extract also demonstrated a higher number of IgE reactive bands than the cooked extract. A heat-resistant protein of 36 kDa has been identified as the major allergen in both raw and cooked extracts. In addition, a heat-sensitive protein of 41 kDa was also recognized as a major allergen in raw crab. The 2-DE gel profile of the raw extract demonstrated about >100 distinct proteins spots and immunoblotting of the 2-DE profile demonstrated at least 12 different major IgE reactive spots with molecular masses between 13 to 250 kDa and isoelectric point (pI) values ranging from 4.0 to 7.0. The 36 and 41 kDa proteins were identified as the crab tropomyosin and arginine kinase, respectively by mass spectrometry. Therefore, this study confirmed that tropomyosin and arginine kinase are the major allergens of the local Portunid crab, P. pelagicus.
    Matched MeSH terms: Brachyura/metabolism*
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