Ping Liang

Professor, Biological Sciences

Ping Liang

Office: Mackenzie Chown F 236
905 688 5550 x5922

My lab is interested in studying the mechanisms of inter- and intra-species genetic diversity and their contribution to the diversity of biological traits, using an integrated approach combining the use of computational and experimental comparative and functional genomics technologies.

Genetic variation underlies the vivid diversity of our own human species and of all other organisms on Earth.  Understanding the mechanisms of genetic diversity and how they lead to phenotype variations continues to be an intriguing and fundamental question in life science research, and it has invaluable implications in medicine and agriculture. The advent of high throughput genome sequencing and functional genomics technologies and the availability of genome sequences for an ever increasing number of species have brought in a golden age for genetics research. By means of computational and experimental comparative genomics approaches, a comprehensive survey of inter- and intra-species genetic diversity now becomes possible, and their functional impacts can be assessed using functional genomics methodologies.

Among the many types of genetic polymorphisms, we are currently focusing on a class of genetic components called transposable elements, which exist very abundantly and evolve actively in the genomes of most organisms, including humans. Our past work includes the development of several computational comparative genomics methodologies for the identification of retrotransposon insertion polymorphisms and retrotransposon-derived genome rearrangements, as well as the development of the database of Retrotransposon Insertion Polymorphisms in humans (dbRIP). In our current research, we are utilizing newly available individual human genome sequences generated by the next-generation sequencing technologies, such as 454 and Illumina, for more comprehensive surveys and documentation of genetic diversity derived from transposable elements. We are also extending our attention to the mechanisms and identification of other types of structural variations, such as copy number variations. We will then start to examine the impact of these genetic variations on gene function and phenotype, including human disease susceptibility and tasting variation.

In addition to those above research activities, we also collaborate with a large number of investigators within and outside Brock campus by providing our bioinformatics expertise. Outside the biology-oriented research, we are also interested in developing novel bioinformatics and genomics analytic tools.

My research lab provides an ideal environment for students who have interest in the exciting emerging field of genomics and bioinformatics, which advance essentially on a daily-basis. Within this group, students have the opportunity to learn and apply computational skills, as well as advanced genomics and molecular techniques. I am look for highly motivated and hard working graduate students either from a biological field with a certain level of computer programming skills or from a computer science background with a minor degree in biology. (Note: Students with interests only for bench research and those with no prior trainings or skills in computer programming will not be considered.)

Bioinformatics (BIOL 4P06BCHM 4P06BTEC 4P06)
Human Molecular Biology (BIOL 4P41BCHM 4P41BTEC 4P41CHSC 4P41)


Papers related to analysis of transposable/mobile elements (in reverse chronicle order, underlined authors are trainees from my group)
  • Ali A, Han K, Liang P. Role of transposable elements in gene regulation in the human genome. Life 11:118, 2021. (
  • Jeon S, Kim S, Oh MH, Tang W, Liang P, Han K. A comprehensive analysis of gorilla-specific LINE-1 retrotransposons. Genes Genom 43, 1133–1141, 2021.
  • Hwang SY, Jung H, Mun S, Lee S, Park K, Baek SC, Moon H, Kim H, Kim B, Choi Y, Go YH, Tang W, Choi J Choi JK, Cha HJ, Oark HY, Liang P, Kim VN, Han K, Ann K. L1 retrotransposons exploit RNA m6A modification as an evolutionary driving force. Nat Commun 12: 880, 2021. (
  • Tang W, Liang P. Retro-DNA, a new type of retrotransposons, in the primate genomes. (Deposited as preprint in BioRxiv on March 20, 2020;
  • Tang WLiang P. Alu master copies serve as the drivers of differential SINE transposition in recent primate genomes. Analyt Biochem 606:113825, 2020.
  • Tang W, Liang P. Comparative genomics analysis reveals high levels of differential retrotransposition among primates from the Hominidae and the Cercopithecidae families. Genome Biol Evol 11:3309-3325, 2019. open access
  • Lee S, Tang WLiang P, Han K. A comprehensive analysis of chimpanzee (Pan troglodytes)-specific LINE-1retrotransposons. Gene 693: 46-51, 2019.
  • Lee W, Choi M, Kim S, Tang W, Kim DH, Kim HS, Liang P, Han K. A comprehensive analysis of the Baboon-specific full-length LINE-1 retrotransposons. Genes & Genomics 41:831–837, 2019. Access
  • Tang W, Mun S, Joshi A, Han K, Liang P.  Contribution of mobile elements to the uniqueness of human genome with more than 15,000 human-specific insertions. DNA Res. 25:521-533, 2018. doi: 10.1093/dnares/dsy022. (Open access)
  • Ahmed M, Liang P. Study of modern human evolution via comparative analysis with the Neanderthal genome. Genomics Inform. 11:230-238, 2013.
  • Ahmed M, Li W, Liang P. Identification of three new Alu Yb subfamilies by source tracking of recently integrated Alu Yb elements. Mobile DNA 4:25, 2013.
  • Liang P, Wang T. Database documentation of retrotransposon insertion polymorphisms. In “Mobile DNAs in Mammalian Genomes” in Encyclopedia of Bioscience, Frontiers in Bioscience E4,1542-1555, 2012.
  • Luo X, Dehne F, Liang P. Identification of Transposon Insertion Polymorphisms (TIPs) by computational comparative analysis of next generation personal genome data. AIP Proceedings of the AMMCS-2011 Conference. (Accepted on September 27, 2011
  • Konkel M*, Wang J*, Liang P, Batzer MA. Identification and characterization of novel polymorphic LINE-1 insertions through comparison of two Human genome sequence assemblies. Gene 390:28-38, 2007. PubMed Abstract (*co-first authors)
  • Han K, Lee J, Meyer TJ, Wang J, Sen SK, Srikanta D, Liang P, Batzer MA. Chimpanzee-specific structural variation deriv ed from Alu recombination-mediated deletions. PLOS Genetics 3:1939-1949, 2007. Open Access at PLOS Genetics.Amed M, Liang P. Transposable elements are a significant contributor to tandem repeats in the human genome. Comp Funct Genomics 2012, Article 947089, 2012.
  • Lee, J, Cordaux R, Han K, Wang J, Hedges DJ, Batzer MA*, Liang P*. Different evolutionary fates of recently integrated human and chimpanzee LI NE-1 retrotransposons. Gene 390:18-27, 2007. PubMed Abstract. (*co-senior authors
  • Li L, McVety S, Younan R, Liang P, DuSart D, Gordon P, Hutter P, Hogervorst FB, Chong G, and Foulkes WD. Distinct patterns of Germ-Line Deletions in MLH1 and MSH2 in hereditary non-polyposiscolorectal cancer families: the role of Alu sequences. Human Mutat 27:388, 2006. PubMed Abstract
  • Sen SK*, Han K, Wang J, Lee J, Wang H, Callinan PA, Dyer M, Cordaux R, Liang P, Batzer MA.Human genomic deletions mediated by recombination between Alu elements. Am J Hum Genet 79:41-53, 2006. PubMed Abstract , PDF
  • Callinan PA*, Wang J*, Herke SW*, Garber RK, Liang P, Batzer MA. Alu retrotransposition-mediated deletion. J Mol Biol 348:791-800, 2005. (*co-first authors). PubMed Abstract, PDF, Supplemental Materials.
  • Wang J*, Song L*, Gonder MK, Azrak S, Ray DA, Batzer MA, Tishkoff SA, Liang P. Whole genome computational comparative genomics: a fruitful approach for ascertaining Alu insertion polymorphisms. Gene 365:11-20, 2006. PubMed Abstract, , PDF, Supplemental Data (*co-first authors)
  • Wang, J.*, L. Song*, D. Grover*, S. Azrak, M. A. Batzer, Liang P. dbRIP: A Highly Integrated Database of Retrotransposon Insertion Polymorphism in Human. Human Mutat 27:323-329,2006. PubMed Abstract; PDF (*co-first authors).
  • K*, Sen SK*, Wang J*, Callinan PA, Lee J, Cordaux R, Liang P, Batzer MA. Genomic rearrangements by LINE-1 insertion-mediated deletion in the human and chimpanzee lineages. Nucleic Acids Res 33:4040-4052, 2005. (*co-first authors) PubMed Abstract; Supplemental Data1; Supplemental Data2
  • Charbonnier F, Baert-Desurmont S, Liang P, Di Fiore F, Martin C, Frerot S, Olschwang S, Wang Q, Buisine MP, Gilbert B, Nilbert M, Lindblom A, Frebourg T. The 5′ region of the MSH2 gene involved in hereditary non-polyposis colorectal cancer contains a high density of recombinogenic sequences. Hum Mutat 26:255-261, 2005. PubMed Abstract, PDF
Selected papers related to genetic and bioinformatics data analysis and development of bioinformatics tools
  1. Ng WV, Kennedy SP, Mahairas GG, Berquist B, Pan M, Shukla HD, Lasky SR, Baliga NS, Thorsson V, Sbrogna J, Swartzell S, Weir D, Hall J, Dahl TA, Welti R, Goo YA, Leithauser B, Keller K, Cruz R, Danson MJ, Hough DW, Maddocks DG, Jablonski PE, Krebs MP, Angevine CM, Dale H, Isenbarger TA, Peck RF, Pohlschroder M, Spudich JL, Jung KW, Alam M, Freitas T, Hou S, Daniels CJ, Dennis PP, Omer AD, Ebhardt H, Lowe TM, Liang P, Riley M, Hood L, DasSarma S. Genome sequence of a genetically tractable and extremely halophilic archaeon. PNAS 97: 11677-12388, 2000. PubMed Abstract , PDF
  2. Liang P, and M. Riley. Comparative genomics approach for studying ancestral proteins and evolution. Adv Appl Microbiol 50: 39-72, 2001. PubMed Abstract
  3. Liang P, LabedanB, Riley M. Physiological genomics of E. coli protein families. Physiol Genomics 9:15-26, 2002. PubMed Abstract, PDF
  4. Serres M, Gopal S, Nahum LA, Liang P, Gaasterland T, Riley M. A functional update of the Escherichia coli K-12 genome. Genome Biol 2: Research0035.1-7,2002. PubMed Abstract, PDF
  5. Wang J, Liang P. Digi-Northern digital expression analysis of query genes based on ESTs. Bioinformatics 19:653-654, 2003. PubMed Abstract, PDF
  6. Zhang Q, Zhao B, Li W, Oiso N, Novak EK, Rusiniak ME, Gautam R, Chintala S, O’Brien EP, Zhang Y, Roe BA, Elliott RW, Eicher EM, Liang P, Kratz C, Legius E, Spritz RA, O’Sullivan TN, Copeland NG, Jenkins NA, Swank RT. Ru2 and Ru encode mouse orthologs of the genes mutated in human Hermansky-Pudlak syndromes type 5 and 6. Nature Genet 33:145-153, 2003. PubMed Abstract, PDF
  7. Shankar G, Rossi1 MR, McQuaid DE, Conroy JM, Gaile DP, Cowell JK, Nowak NJ, Liang P. 2006. aCGHViewer: a generic visualization tool for aCGH data. Cancer Informatics 2:36-43, 2006.
  8. Lo K, Shankar G, Rossi M, Burkhardt T, Liang P, Cowell JK. 2007. Overlay tool for aCGHViewer: an analysis module built for aCGHViewer used to combine different microarray platforms for visualization. Cancer Informatics 3:309-319, 2007.
  9. Song F, Mahmood S, Ghosh S, Liang P, Smiraglia DJ, Nagase N, Held WA. Tissue specific differentially methylated regions (TDMR): changes in DNA methylation during development. Genomics 93: 130-139, 2009.
  10. Safina AF, Varga AE, Bianchi A, Zheng Q, Kunnev D, Liang P, Bakin AV. Ras alters epithelial-mesenchymal transition in response to TGFβ by reducing actin fibers and cell-matrix adhension. Cell Cycle 8: 284-298, 2009.
  11. Hall BM, Ma CX, Liang P, Singh KK. Fluctuation AnaLysis CalculatOR (FALCOR): a web tool for the determination of mutation rate using Luria-Delbrück fluctuation analysis. Bioinformatics 25:1564-1565, 2009.
  12. Marella N, Malyavantham, K, Wang J, Matsui S, Liang P, Berezney R. Cytogenetic and cDNA Microarray Expression Analysis of MCF10A Human Breast Cancer Progression Cell Lines. Cancer Res. 69: 5946-5953, 2009.
  13. Sood AK, Wang J, Mhawech-Fauceglia P, Jana B, Liang P, Geradts J. Sam-pointed domain containing Ets transcription factor in luminal breast cancer pathogenesis. Cancer Epidemiol Biomarkers Prev. 18:1899-903, 2009.
  14. Huang J, Okuka M, Wang F, Zuo B, Liang P, Kalmbach K, Liu L, Keefe DL. Generation of pluripotent stem cells from eggs of aging mice.  Aging Cell 9:113-125, 2010.
  15. Huang J, Wang F, Okuka M, Liu N, Ji G, Ye X, Zuo B, Li M, Liang P, Ge WW, Tsibris JC, Keefe DL, Liu L.  Association of telomere length with authentic pluripotency of ES/iPS cells. Cell Res. 21,779-92, 2011.
  16. Liu N, Enkenann SA, Liang P, Hesmus R, Zanazzi, C, Huang J, Wu C, Chen, Z, Looijenqa, LHJ, Keefe DL, Liu L. Genome-wide gene expression profiling reveals novel signaling pathways associated with early parthenogenesis. J Mol Cell Biol 2:333-344, 2010.
  17. Huang J, Wang F, Okuka M, Liu N, Ji G, Ye X, Zuo B, Li M, Liang P, Ge WW, Tsibris JC, Keefe DL, Liu L.  Association of telomere length with authentic pluripotency of ES/iPS cells. Cell Res. 21,779-92, 2011. Publisher’s full text
  18. Liu C, Morishima M, Yu T, Pao A, Matsui S, Zhang L, Fu D, Parmacek MS, Liang P,  Baldini A, Yu YE. Genetic analysis of Down syndrome-associated heart defects in mice.  Hum Genet.  130: 623-32, 2011. Free access at PMC
  19. Zhang L, Fu D, Belichenko PV, Liu C,  Kleschevnikov AM, Pao A, Liang P, Clapcote SJ, Mobley WC, Yu YE. Genetic analysis of Down syndrome facilitated by mouse chromosome engineering. Bioengineered Bugs. 3: 2011. Publisher’s full text
  20. Liang P*#, Song F*, Ghosh S, Morien E, Qin M, Mahmood S, Fujiwara K, Igarashi J, Nagase H#,  Held WA. Genome-wide survey reveals dynamic widespread tissue-specific changes in DNA methylation during development. BMC Genomics 12: 231, 2011. (*: co-first author, #: corresponding author; highly accessed article). Open access at the journal.
  21. Stuart JA, Liang P, Luo X, Page MM, Gallagher EJ, Robb EL. A comparative cellular and molecular biology of longevity database. Age (advanced online publication on July 27, 2012). Link to PubMed.
  22. Peters D, Luo X, Qiu K, Liang P. Speeding up large-scale next generation sequencing data analysis with pBWA.  J. Biocomput. (accepted on Nov 23, 2012)
  23. Bering AH, Pickering G, Liang P. TAS2R38 Single Nucleotide Polymorphisms Are Associated with PROP—but Not Thermal—Tasting: a Pilot Study. Chemosensory Perception 7:23-30. 2014.
  24. Xie P, Sun Y, Ouyang Q, Hu L, Tan Y, Zhou X, Xiong B, Zhang Q, Yuan D, Pan Y, Liu T, Liang P, Lin G, Lu G. Physiological Oxygen Prevents Frequent Silencing of DLK1-DIO3 Cluster During Human Embryonic Stem Cells Culture. Stem Cells 32:391-401, 2014.
  25. Zhang L, Meng K, Jiang X, Liu C, Pao A, Belichenko PV, Kleshevnikov AM, Josselyn S, Liang P, Ye P, Mobley WC, Yu YE. Human chromosome 21 orthologous region on mouse chromosome 17 is a major determinant of Down syndrome-related developmental cognitive deficits. Hum Mol Genet 23:578-89, 2014.
  26. Belyea BC, Xu F, Pentz ES, Medrano S, Li M, Hu Y, Turner S, Legallo R, Jones CA, Tario JD, Liang P, Gross KW, Sequeira-Lopez MLS, Gomez RA. Renin Progenitors in the Bone Marrow: A Novel Origin for B-Cell Leukemia. Nat Commun 5:3273, 2014. 
  27. Fujiwara L, Ghosh S, Liang P, Morien E, Masayoshi Soma, Nagase N. Genome-wide screening of aberrant DNA methylation which associated with gene expression in mouse skin cancers. Mol Carcinogen 54:178-88, 2015.
  28. Sjaarda C, Patrick Hecht P, McNaughton A, Audrina Zhou A, Hudson M, Liang P, Chen N, Ayub M, Beversdorf D, Liu X. Interplay between maternal Slc6a4 mutation and prenatal stress: a possible mechanism for autistic behaviour development. Scientific Reports  (accepted on June 25, 2017).
  29. Tan Y, Tu C, Meng L, Yuan S, Sjaarda C, Luo A, Du J, Li W, Gong F, Zhong C, Deng HX, Lu G, Liang P*, Lin G*. Loss-of-function mutations TDRD7 lead to a rare novel syndrome combining congenital cataract and non-obstructive azoospermia in humans. Genetics in Medicine (accepted on June 20, 2017) (*co-corresponding authors).
  30. Yuan S, Meng L, Zhang Y, Tu C, Du J, Wen Li, Liang P, Lu G, Tan Y. Genotype-phenotype correlation and identification of two novel SRD5A2 mutations in 33 Chinese patients with hypospadias. Steroids (accepted on June 22, 2017)
  31. He W, Lin G, Liang P, Cheng D, Li W. Genetic analysis of three families affected with split-hand/split-foot malformation. Chinese Journal of Medical Genetics 34:476-480, 2017. (in Chinese)
  32. Qu Y, Thamm AMK, Czerwinski M, Masada S; Kim KH, Jones G, Liang P, De Luca V. Identification and biochemical description of geissoschizine synthase, the gateway enzyme controlling flux for the formation of iboga and aspidosperma monoterpenoid indole alkaloids in Catharanthus roseus”. Planta 247:625-634, 2018.
  33. Aida AM, Sarker LS, Malli RPN, Liang P, Mahmoud S. Discovery of novel structural and regulatory terpenoid biosynthetic genes in Lavandula through RNA-Seq. Planta (accepted on June 2, 2018).
  34. Malli RNP, Adal AM, Saker LS, Liang P*, Mahmoud S*. De novo sequencing of the Lavandula angustifolia genome reveals highly duplicated and optimized features for essential oil production. Planta (accepted on Sept 15, 2018). (*corresponding authors). Advanced online version available at ReadCube.
  35. Li Y, Pan H, Chang Y, Dong N, Zou L, Liang P, Tian W, Chang Z. Identification of key sites determining the cofactor specificity and improvement of catalytic activity of a steroid 5β-reductase from Capsella rubella. Enzyme Microb Technol (advanced publication on Nov 30, 2019).
  36. Callaghan DB, Rogic S, Tan PPC, Calli K, Qiao Y, Baldwin R, Jacobson M, Belmadani M, Holmes N, Yu C, Li Y, Li Y, Kurtzke FE, Kuzeljevic B, Yu A, Hudson M, McNaughton AJM, Xu Y, Dionne-Laporte A, Girard S, Liang P, Separovic ER, Liu X, Rouleau G, Pavlidis P, Lewis MES. Whole genome sequencing and variant discovery in the ASPIRE autism spectrum disorder cohort. Clin Genet 96:199-206, 2019.
  37. Li Y, Pan H, Chang Y, Dong N, Zou L, Liang P, Tian W, Chang Z. Identification of key sites determining the cofactor specificity and improvement of catalytic activity of a steroid 5β-reductase from Capsella rubellaEnzyme Microb Technol 134:109483, 2019.
  38. Giordano BV, Gasparotto A, Liang P. Nelder MP, Russell C, Hunter F. Discovery of an Aedes (Stegomyia) albopictus population and first records of Aedes (Stegomyia) aegypti in Canada. Med Veterrin Entomol. 34:10-16, 2020.
  39. Bagshaw ORM, Moradi F, Moffatt CS, Hettwer HA, Liang P, Goldman J, Drelich JW, Stuart JA. Bioabsorbable metal zinc differentially affects mitochondria in vascular endothelial and smooth muscle cells. Biomat Biosyst 4, 100027, 2021.
  40. Hu K, Liang P. Transcriptome analysis reveals higher levels of mobile element-associated abnormal gene transcripts in temporal lobe epilepsy patients. Frontiers in Genetics 12:767341, 2021. (
  41. Alva R, Gardner GL, Liang P, Stuart JA. Supraphysiological Oxygen Levels in Mammalian Cell Culture: Current State and Future Perspectives. Cells 11, 3123, 2022. (

New papers:

  • Arsala Ali (a year PhD student) published a review entitled “The role of transposable elements in gene regulation in humans” in Life 2021, 11(2), 118. The paper is openly available at
  • A paper entitled “Comparative genomics analysis reveals high levels of differential retrotransposition among primates from the Hominidae and the Cercopithecidae families” as part of Daniel Tang’s PhD thesis has been published as an open access article at Genome Biol Evol. Among many new findings from this study, we demonstrated that crab-eating macaque genome has an extremely low level of DNA transposition, while the human genome was shown to be a very young and actively evolving genome by DNA transposition among the eight primate genomes we examined for the great ape and old world monkey groups of primates.
  • Our work (Part of Radesh’s PhD thesis) in sequencing the lavender genome was recently accepted for publication in journal, Planta, with its online version of the paper available at here and via ReadCube.  Paper title: “De novo sequencing of the Lavandula angustifolia genome reveals highly duplicated and optimized features for essential oil production”.
  • A paper titled “Mobile elements contribute to the uniqueness of human genome with 15,000 human-specific insertions and 14 Mbp sequence increase” was accepted on June 20, 2018 and is now available for reading at DNA Research. This paper is based on Daniel W. Tang’s MSc thesis work. In addition to the main discoveries reported in the paper, we also revised the content of transposable elements in the human reference genome from originally reported 49% to 52%.

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