Displaying all 10 publications

Abstract:
Sort:
  1. Choong CY
    Zootaxa, 2016 Sep 28;4171(2):382-388.
    PMID: 27701232 DOI: 10.11646/zootaxa.4171.2.11
    A new species Leptogomphus tioman is described based on male specimens collected from Tioman Island, Peninsular Malaysia. It is close to Leptogomphus risi Laidlaw in thoracic markings but is readily distinguished by its anal appendages and accessory genitalia.
  2. Dow RA, Choong CY
    Zootaxa, 2015;3914(1):89-93.
    PMID: 25661930 DOI: 10.11646/zootaxa.3914.1.8
    M. megabinluyog spec. nov. is described from a location in Brunei on the island of Borneo. Additional illustrations of its sister species M. astamii are provided. 
  3. Ng CY, Wickneswari R, Choong CY
    Genet. Mol. Res., 2014;13(3):6037-49.
    PMID: 25117361 DOI: 10.4238/2014.August.7.18
    Calamus palustris Griff. is an economically important dioecious rattan species in Southeast Asia. However, dioecy and onset of flowering at 3-4 years old render uncertainties in desired female:male seedling ratios to establish a productive seed orchard for this rattan species. We constructed a subtractive library for male floral tissue to understand the genetic mechanism for gender determination in C. palustris. The subtractive library produced 1536 clones with 1419 clones of high quality. Reverse Northern screening showed 313 clones with differential expression, and sequence analyses clustered them into 205 unigenes, including 32 contigs and 173 singletons. The subtractive library was further validated with reverse transcription-quantitative polymerase chain reaction analysis. Homology identification classified the unigenes into 12 putative functional proteins with 83% unigenes showing significant match to proteins in databases. Functional annotations of these unigenes revealed genes involved in male flower development, including MADS-box genes, pollen-related genes, phytohormones for flower development, and male flower organ development. Our results showed that the male floral genes may play a vital role in sex determination in C. palustris. The identified genes can be exploited to understand the molecular basis of sex determination in C. palustris.
  4. Dow RA, Choong CY, Ng YF
    Zootaxa, 2018 Apr 23;4413(2):351-367.
    PMID: 29690113 DOI: 10.11646/zootaxa.4413.2.7
    Coeliccia erici Laidlaw, 1917 is re-described and illustrated for both sexes; its taxonomic history and the confusion surrounding it is discussed. Coeliccia kimurai Asahina, 1990 is shown to be a junior synonym of C. erici. Coelicca sameerae sp. nov. (holotype ♂, small stream near Sungai Lasir, Tasik Kenyir, Terengganu, Malaysia, deposited in the Natural History Museum, London) is described from both sexes from Peninsular Malaysia; this species had been confused with C. erici until now. A remark on the status of Coeliccia simillima Laidlaw, 1917 is made.
  5. Dow RA, Phan QT, Choong CY
    Zootaxa, 2020 Jan 30;4729(3):zootaxa.4729.3.5.
    PMID: 32229851 DOI: 10.11646/zootaxa.4729.3.5
    Protosticta joepani sp. nov. is described from Malaysian Borneo (holotype male Bario, Kelabit Highlands, Miri Division, Sarawak, Malaysia, deposited in the Naturalis Biodiversity Center, Leiden). It is the sister species of P. kinabaluensis Laidlaw, 1915; some descriptive notes and a set of illustrations are provided of the latter species. A COI gene tree for both species is provided. The placement of both P. joepani and P. kinabaluensis is discussed, but although it is very unlikely that they belong in Protosticta sensu stricto, the issue is left open here.
  6. Dow RA, Choong CY, Ng YF
    Zootaxa, 2017 Oct 24;4338(1):44-50.
    PMID: 29245726 DOI: 10.11646/zootaxa.4338.1.2
    Drepanosticta rahmani sp. nov. (holotype ♂, steep tributary to stream in hills between Baling and Gulai, north west Kedah, Malaysia, 15 xi 2016, leg. R.A. Dow, to be deposited in the Natural History Museum, London) is described from both sexes.
  7. Pang SL, Ong SS, Lee HH, Zamri Z, Kandasamy KI, Choong CY, et al.
    Genet. Mol. Res., 2014;13(3):7217-38.
    PMID: 25222227 DOI: 10.4238/2014.September.5.7
    This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.
  8. Bunawan H, Choong CY, Md-Zain BM, Baharum SN, Noor NM
    Int J Mol Sci, 2011;12(11):7626-34.
    PMID: 22174621 DOI: 10.3390/ijms12117626
    Plastid trnL-trnF and nuclear ribosomal ITS sequences were obtained from selected wild-type individuals of Polygonum minus Huds. in Peninsular Malaysia. The 380 bp trnL-trnF sequences of the Polygonum minus accessions were identical. Therefore, the trnL-trnF failed to distinguish between the Polygonum minus accessions. However, the divergence of ITS sequences (650 bp) among the Polygonum minus accessions was 1%, indicating that these accessions could be distinguished by the ITS sequences. A phylogenetic relationship based on the ITS sequences was inferred using neighbor-joining, maximum parsimony and Bayesian inference. All of the tree topologies indicated that Polygonum minus from Peninsular Malaysia is unique and different from the synonymous Persicaria minor (Huds.) Opiz and Polygonum kawagoeanum Makino.
  9. Loh HC, Tang PY, Tee SF, Chow TJ, Choong CY, Lim SY, et al.
    Psychiatry Res, 2013 Jul 30;208(2):186-8.
    PMID: 23489597 DOI: 10.1016/j.psychres.2013.01.022
    Neuregulin-1 is widely investigated due to its hypothesised association with schizophrenia. Single-nucleotide polymorphisms rs764059, rs2954041 and rs3924999 were investigated (417 patients with schizophrenia and 429 controls). We failed to demonstrate a significant association between rs2954041 and rs3924999 with schizophrenia in the three ethnic groups studied (Malay, Chinese, and Indian), while rs764059 was found to be monomorphic.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links