Journal Highlights

2012 World Congress

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Journal Highlights

Dr. Fang-sheng Wu at a laminar flow hood with in vitro Paphiopedilum plants in his laboratory.

In Vitro Shoot Induction and Plant Regeneration from Flower Buds in Paphiopedilum Orchids

Species of Paphiopedilum, commonly known as slipper orchids, are extremely diverse in color, shape and size of their flowers, attracting orchid lovers worldwide; however, no explant from mature plants has been successfully mass propagated in vitro. Nearly all slipper orchids are traded as potted plants through in vitro germinated hybrid seeds that lack uniformity and are unpredictable in their traits, which will not be known until many years later when the plants are mature enough to flower.  Using seeds or seedlings as the source material for tissue culture propagation suffers this same serious drawback.    We report here the high-frequency direct induction of shoots and regeneration of plants from sectioned young flower buds (FBs) of fully mature plants in two hybrid species.  The induction rates were 57-75%, and all plants survived in a greenhouse. Because the plants were produced directly from the meristems without going through the callus stage, they are expected to have the same genetic traits as their mother plants. The phenotype of the regenerated plants is therefore predictable and consistent, which is particularly important for the commercial micropropagation production and the conservation of those very few elite or near-extinct Paphiopedilum plants. We also found that the small bract at the FB base harbored a new miniature FB, which further harbored a primitive FB with dome-shaped meristem-like tissues that presumably led to the plant induction. The reiteration of this pattern resulted in a scorpioid cyme inflorescence architecture in the multifloral Paphiopedilum species, and its failure to reiterate resulted in a single flower. This finding offers a lead to further explore both the micropropagation process and the flower organogenesis of Paphiopedilum plants.

Yu-Ching Tsai, Yu-Ju Liao, and Yung-Wei Sun (from left to right) in an orchid tissue culture room.

Yu-Ju Liao, Yu-Ching Tsai, Yung-Wei Sun, Ruey-Song Lin, Fang-Sheng Wu.  In vitro shoot induction and plant regeneration from flower buds in Paphiopedilum orchids. In Vitro Cellular & Developmental Biology-Plant, 47:702-709, 2011.

 

 

 

 

 


 

Dr. Lee’s Lab at Wilfrid Laurier University with some of her students, from left to right: Richelle Monaghan (SIVB Honor Fell Award 2010; Cell Tox Award 2010; Joseph Morgan Award 2009; completed PhD Oct 2011); Bryan Sansom (SIVB Joseph Morgan Award 2010; Cell Tox Award 2009; completed MSc May 2011); Lucy Lee (WLU University Research Professor 2011-12); Michael MacLeod (MSc candidate 2012); Alina Reid and Sarah Gignac (BSc Honours thesis students).   

Misidentification of OLGA-PH-J/92, Believed to be the Only Crustacean Cell Line

Dr. Lee’s lab specializes on the development and use of fish and aquatic invertebrate cell cultures for basic and applied research. Her work with aquatic animal cell lines includes applications in aquaculture, toxicology and biomedical sciences (endocrinology, parasitology, immunology, neurology, nutrition, etc). For all cell culture she ensures that the cell she works with are well characterized in terms of species and tissue origins. The OLGA-PH-J/92 cells behaved very distinctly and did not appear to have much in common to other vertebrate or invertebrate cells she had worked with before, thus the characterization efforts led to the discovery that these cells were not of neural crayfish origin. Lucy E. Lee, Mary Rose Bufalino, Andrew E. Christie, Marc E. Frischer, Thomas Soin, Clement K.M. Tsui, Robert H. Hanner, Guy Smagghe.  Misidentification of OLGA-PH-J/92, believed to be the only crustacean cell line.  In Vitro Cellular and Developmental Biology-Animal, 47:665-474, 2011.

 

 

 

 

This photograph contains the authors that contributed to the manuscript: Asako Matsumoto (1st right), Akiyoshi Taniguchi (2nd left) and our lab group members

Induction of Insulin-like Growth Factor 2 Expression in a Mesenchymal Cell Line Co-cultured with an Ameloblast Cell Line

Various growth factors have been implicated in the regulation of cell proliferation and differentiation during tooth development.  It has been unclear if insulin-like growth factors (IGFs) participate in the epithelium-mesenchyme interactions of tooth development.  We previously produced three-dimensional sandwich co-culture systems (SW) containing a collagen membrane that induce the differentiation of epithelial cells.  In the present study, we used the SW system to analyze the expression of IGFs and IGFRs.  We demonstrate the IGF2 expression in mesenchymal cells was increased by SW.  IGF1R transduces a signal; however, IGF2R does not transduce a signal.  Recombinant IGF2 induces IGF1R and IGF2R expression in epithelial cells. IGF1R expression is increased by SW; however, IGF2R expression did not increase by SW.  Thus, IGF2 signaling works effectively in SW.  These results suggest that IGF signaling acts through the collagen membrane on the interaction between the epithelium and mesenchyme.  In SW, other cytokines may be suppressed to induce IGF2R induction. Our results suggest that IGF2 may play a role in tooth differentiation.  Asako Matsumoto, Hidemitsu Harada, Masahiro Saito, Akiyoshi Taniguchi. Induction of insulin-like growth factor 2 expression in a mesenchymal cell line co-cultured with an ameloblast cell lineIn Vitro Cellular and Developmental Biology-Animal, 47:675-680, 2011.