Ignatius Tan Clinical Assistant Professor of Biology; Head of Electron Microscope and Image Analysis Facility Ph.D. 1997 (cell biology), Fordham; M.S. 1986 (bioengineer), Polytechnic; B.A. 1981 (biology), St. Thomas. Office Address: New York University Department of Biology 1009 Silver Center 100 Washington Square East New York, NY 10003-6688 Email: Phone: (212) 998-8295 Fax: (212) 995-4015 List of Publications from Pubmed

Research

My research interests focus on gap junctions which are involved in cell-to-cell communication. Regulating the chemical and physical properties of gap junctions are the different connexin proteins. Unique communication compartments can be formed when gap junctions are assembled from various connexins.

Presently, I am examining the implications of gap junctions on cell differentiation and development using the testis as a model. Organized in the seminiferous tubule and supported by Sertoli cells are some 63 different germ cell types. The germ cells are arranged and organized in the seminiferous epithelium for an ordered development and differentiation into spermatozoa. We are currently determining gap junction’s role in the formation of specific communication compartments and how gap junctions regulate and support specific spermatogenic cells. Gap junction assembly, connexin composition, and the chemical and physical properties of homotypic - heterotypic gap junctions will be examined biochemically and ultrastructurally.

Electron Microscope and Image Analysis Facility:

The facility has a confocal microscope and three electron microscopes: two TEM's and a SEM. Support equipment include ultramicrotomes, paraffin micotome, high vacuum evaporator, sputter coater, critical point dryer, and a low temperature UV chamber for immuno EM. The two modern EM’s are capable of high resolution imaging and capturing digital images. The SEM supports elemental image mapping/analysis and imaging of frozen samples.

Transmission Electron Microscopes:

Phillips E-300
Phillips CM-10. Scanning Electron Microscopes: AMRAY 1850-FE with secondary, Robinson backscatter, and EDX detectors and cryo-chamber

Confocal Microscope System:

Leica TCS SP2 confocal system for available inverted and upright microscopes.
Image analysis workstation.

Confocal Calendar web site: http://www.calsnet.net/confocal_lab

Teaching

Graduate Courses:
Scanning Electron Microscopic Techniques (G23-1029)
Electron Microscopic Techniques (G23-1033).

Undergraduate Courses:
Principles of Light and Electron Microscopy (V23-0033)
Introduction to Recombinant DNA Techniques (V23-0036)
Techniques in Cell Biology (V23-0037).

Lectures given in:
Principles in Biology (V23-0011),
Cell Biology (G23-1051).

Biosketch

Ph.D. 1997 (Cell Biology), Fordham University

M.S. 1986 (Bioengineer), Polytechnic University

B.A. 1981 (Biology), University of St. Thomas

Affiliations:
American Association for the Advancement of Science
Microscopy Society of America
American Society for Cell Biology.

Areas of Research/Interest

Gap junctions; characterization of gap junction proteins in spermatogenesis

External Affiliations

American Association for the Advancement of Science, Microscopy Society of America.

Publications

• Antiviral effects on bacteriophages and rotavirus by cranberry juice.
  Phytomedicine
  Lipson SM, Sethi L, Cohen P, Gordon RE, Tan IP, Burdowski A, Stotzky G
  
  
• Gap junctions with varied permeability properties establish cell-type specific communication pathways in the rat seminiferous epithelium.
  Biol Reprod
  Risley MS, Tan IP, Farrell J
  
  
• Regulated assembly of connexin33 and connexin43 into rat Sertoli cell gap junctions.
  Biol Reprod
  Tan IP, Roy C, Sáez JC, Sáez CG, Paul DL, Risley MS
  
  
• Cell-, age- and stage-dependent distribution of connexin43 gap junctions in testes.
  J Cell Sci
  Risley MS, Tan IP, Roy C, Sáez JC
  
  
• Visualization of myosin exchange between synthetic thick filaments.
  J Muscle Res Cell Motil
  Saad AD, Dennis JE, Tan IP, Fischman DA