Siew Woh Choo

Prof. Siew Woh Choo


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 August 2016 in Genome Research
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Journal Article
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SCSiew Woh Choo
Siew Woh Choo
MRMikhail Rayko
Mikhail Rayko
TTTze King Tan
Tze King Tan
RHRanjeev Hari
Ranjeev Hari
AKAleksey Komissarov
Aleksey Komissarov
GWGuat Jah Wong
Guat Jah Wong
Pangolins, unique mammals with scales over most of their body, no teeth, poor vision, and an acute olfactory system, comprise the only placental order (Pholidota) without a whole-genome map. To investigate pangolin biology and evolution, we developed genome assemblies of the Malayan (Manis javanica) and Chinese (M. pentadactyla) pangolins. Strikingly, we found that interferon epsilon (IFNE), exclusively expressed in epithelial cells and important in skin and mucosal immunity, is pseudogenized in all African and Asian pangolin species that we examined, perhaps impacting resistance to infection. We propose that scale development was an innovation that provided protection against injuries or stress and reduced pangolin vulnerability to infection. Further evidence of specialized adaptations was evident from positively selected genes involving immunity-related pathways, inflammation, energy storage and metabolism, muscular and nervous systems, and scale/hair development. Olfactory receptor gene families are significantly expanded in pangolins, reflecting their well-developed olfaction system. This study provides insights into mammalian adaptation and functional diversification, new research tools and questions, and perhaps a new natural IFNE-deficient animal model for studying mammalian immunity.

21 October 2021 in Communications Biology
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DYDingyu Yan
Dingyu Yan
XZXiangyan Zeng
Xiangyan Zeng
MJMiaomiao Jia
Miaomiao Jia
XGXiaobing Guo
Xiaobing Guo
SDSiwei Deng
Siwei Deng
SCSiew Woh Choo
Siew Woh Choo
Pangolins are threatened placental mammals distributed in Africa and Asia. Many efforts have been undertaken in the last century to maintain pangolins in captivity, but only a few of them succeeded in maintaining and keeping this species in a controlled environment. This study reports the first systematic breeding of the Critically Endangered Malayan pangolin (Manis javanica) in captivity. Our captive breeding approach successfully improved the reproductive rate for both wild and captive-born female pangolins. From 2016 to 2020, we had 33 wild pangolins and produced 49 captive-born offspring spanning three filial generations. The female offspring further bred 18 offspring, of which 14 (78%) were conceived during the first time of cohabitation with males, and four offspring were conceived during the second cohabitation event, suggesting that they may practice copulation-induced ovulation. We observed that captive-born female pangolins could reach sexual maturity at 7–9 months (n = 4), and male pangolins could mate and successfully fertilise females at nine months age (n = 1). We also observed a female pangolin conceiving on the eighth day after parturition (the fifth day after the death of its pup). Our captive pangolins had a female-biased sex ratio of 1:0.5 at birth, unlike other known captive-born mammals. Also, captive-born pangolins were generally more viable after successful weaning and had a similar gestation length (~185 days) to wild pangolins. Most importantly, we report the first self-sustaining captive population of Malayan pangolins, and this species has an efficient reproduction strategy. These advances provide more comprehensive information for people to understand pangolins, and have implications for conserving endangered Malayan pangolins and providing scientific guidance to the management of other pangolin species.

28 October 2021 in Applied and Environmental Microbiology
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Journal Article
Open access
SCSiew Woh Choo
Siew Woh Choo
WMWaleed K. Mohammed
Waleed K. Mohammed
Naresh V R MuthaNaresh V R Mutha
Naresh V R Mutha
NRNadia Rostami
Nadia Rostami
HAHalah Ahmed
Halah Ahmed
NJNicholas Jakubovics
Nicholas Jakubovics
Dental plaque is responsible for two of the most prevalent diseases in humans, dental caries and periodontitis. Controlling the formation of dental plaque and preventing the transition from oral health to disease requires a detailed understanding of microbial colonization and biofilm development.

2 September 2020 in Conservation Letters
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Journal Article
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SCSiew Woh Choo
Siew Woh Choo
JZJinfeng Zhou
Jinfeng Zhou
Xuechen TianXuechen Tian
Xuechen Tian
SZSiyuan Zhang
Siyuan Zhang
SQShen Qiang
Shen Qiang
FSFrankie Thomas Sitam
Frankie Thomas Sitam
The COVID‐19 outbreak has infected over 6 million people across the world. The origin of COVID‐19 coronavirus (CoV) remains unknown, although pangolins have been suggested as potential hosts. We investigated two pangolins seized in Guangdong Province, China. Molecular screening revealed CoV in one pangolin (“Dahu”), while another (“Meidong”) was infected by Ehrlichia ruminantium . Dahu exhibited difficulty breathing, infections of lung, intestines, and nostrils, as revealed by computed tomography imaging and necropsy. Previous phylogenetic analyses showed bat coronavirus RaTG13 is closer to COVID‐19 CoV compared to pangolin coronavirus. Over 20 caregivers have had close physical contact with CoV‐positive Dahu, but none became infected with CoV. Our data suggest that pangolins are unlikely the natural reservoir or secondary hosts of COVID‐19 CoV. Pangolins seems to be victims infected by CoV carried by a not yet unidentified natural reservoir host species, perhaps due to their weakened immune system.

1 November 2012 in Journal of Bacteriology
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Open access
YNYun Fong Ngeow
Yun Fong Ngeow
WWWei Yee Wee
Wei Yee Wee
YWYan Ling Wong
Yan Ling Wong
JTJoon Liang Tan
Joon Liang Tan
COChia Su Ongi
Chia Su Ongi
SCSiew Woh Choo
Siew Woh Choo
Mycobacterium abscessus is a ubiquitous, rapidly growing species of nontuberculous mycobacteria that colonizes organic surfaces and is frequently associated with opportunistic infections in humans. We report here the draft genome sequence of Mycobacterium abscessus strain M139, which shows genomic features reported to be characteristic of both Mycobacterium abscessus subsp. abscessus and Mycobacterium abscessus subsp. massiliense .

29 June 2022 in Genomics
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Journal Article
Open access
SCSiew Woh Choo
Siew Woh Choo
YZYu Zhong
Yu Zhong
ESEdward Sendler
Edward Sendler
AGAnton-Scott Goustin
Anton-Scott Goustin
JCJuan Cai
Juan Cai
LEONARD LIPOVICHLEONARD LIPOVICH
LEONARD LIPOVICH
Estrogen drives key transcriptional changes in breast cancer and stimulates breast cancer cells' growth with multiple mechanisms to coordinate transcription and translation. In addition to protein-coding transcripts, estrogen can regulate long non-coding RNA (lncRNA) transcripts, plus diverse non-coding RNAs including antisense, enhancer, and intergenic. LncRNA genes comprise the majority of human genes. The accidental, or regulated, translation of their short open reading frames by ribosomes remains a controversial topic. Here we report for the first time an integrated analysis of RNA abundance and ribosome occupancy level, using Ribo-seq combined with RNA-Seq, in the estrogen-responsive, estrogen receptor α positive, human breast cancer cell model MCF7, before and after hormone treatment. Translational profiling can determine, in an unbiased manner, which fraction of the genome is actually translated into proteins, as well as resolving whether transcription and translation respond concurrently, or differentially, to estrogen treatment. Our data showed specific transcripts more robustly detected in RNA-Seq than in the ribosome-profiling data, and vice versa, suggesting distinct gene-specific estrogen responses at the transcriptional and the translational level, respectively. Here, we showed that estrogen stimulation affects the expression levels of numerous lncRNAs, but not their association with ribosomes, and that most lncRNAs are not ribosome-bound. For the first time, we also demonstrated the transcriptional and translational response of expressed pseudogenes to estrogen, pointing to new perspectives for drug-target development in breast cancer in the future.