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Bedford N.M.,University of Cincinnati | Winget G.D.,Center for Conservation and Research of Endangered Wildlife | Srikoundinya P.,University of Cincinnati | Steckl A.J.,University of Cincinnati
Biomacromolecules | Year: 2011

Electrospun fibers consisting of poly(3,4- ethylenedioxythiophene)/ poly(styrene sulfonate) (PEDOT/ PSS) and poly(ethylene oxide) (PEO) have been used to successfully encapsulate and stabilize thylakoid membrane vesicles isolated from spinach. Light-driven electronic properties were measured. Fibers with immobilized thylakoids show higher electrical conductivity compared with fibers without thylakoids under white light conditions. This is attributed to the electron-generating photosynthetic reactions from the thylakoids. Electron and optical microscopy show the presence of thylakoid vesicles within the fibers using lipid-specific stains. After electrospinning into fibers, the thylakoid vesicles still exhibit an ability to produce a light-driven electron gradient, indicating that activity is preserved during the electrospinning process. These electrospun fibers provide an excellent example of incorporating photosynthetic function into an artificial system © 2011 American Chemical Society.


Pence V.C.,Center for Conservation and Research of Endangered Wildlife
International Journal of Plant Sciences | Year: 2014

Cryopreservation of nonseed plant tissues can provide a method for preserving plant genetic diversity ex situ when seeds or spores cannot be adapted to traditional methods of preservation. Shoot tips, somatic embryos, and gametophytes can be used as propagules for long-term storage in liquid nitrogen. Tissue cryo-preservation is particularly important in dealing with "exceptional species," i.e., species that have unbankable seeds or that are producing few or no seeds. In vitro methods can be applied to collecting tissues and establishing cultures as a source of tissue for cryopreservation. The applicability of vitrification/dehydration cryoprocedures has been demonstrated for a wide range of species and types of tissues, and the choice and modifications of methods can be informed by the natural adaptations of the species. While tissues in culture are clonally propagated, preserving tissues from multiple genotypes can provide genetic diversity to a cryopreserved collection. Such collections will ultimately serve to provide materials for restoration if wild populations are lost or severely threatened. There is great potential for the use of in vitro methods and cryopreservation in plant conservation strategies, but there are also both scientific and practical challenges to their application. Whereas in vitro propagation and preservation methods are well established, these methods remain highly empirical in their application to new species. This can be a challenge for conservation, which deals with rare and often unstudied species, which may also have unusual natural adaptations. Because of the labor involved, tissue cryopreservation is also more costly than more traditional ex situ conservation methods, which can limit its use in traditionally underfunded work with endangered plants. However, it is suggested that collaborative efforts can help meet these challenges, bringing together expertise and infrastructure from several sources to facilitate the application of tissue cryopreservation to the ex situ conservation of endangered exceptional species. © 2013 by The University of Chicago. All rights reserved.


Swanson W.F.,Center for Conservation and Research of Endangered Wildlife
Reproduction in Domestic Animals | Year: 2012

Contents: Embryo transfer (ET) and artificial insemination (AI) are potentially invaluable techniques for the propagation and management of genetically valuable domestic cat and endangered nondomestic cat populations. Many of the challenges that impair the effective application of ET and AI in felids may be overcome by using laparoscopic oviductal (LO) approaches. LO-ET and LO-AI are minimally-invasive procedures, requiring only two small skin incisions for insertion of a laparoscope and grasping forceps into the abdominal cavity to permit visualization and catheterization of the oviduct for embryo or semen deposition. With concurrent improvements in embryo culture systems and ovarian synchronization protocols, LO-ET has proven effective over the past decade for propagation of laboratory cats, cat models of hereditary disease and nondomestic cats. To date, viable offspring have been produced following LO-ET of non-frozen and frozen-thawed IVF-derived embryos in eight cat hereditary disease models and two nondomestic cat species, the ocelot and sand cat. LO-AI with low sperm numbers (c. 2-8 million motile) has shown similar efficacy to LO-ET, resulting in high pregnancy percentages (50-70%) following insemination of gonadotropin-treated domestic cats. Multiple kittens also have been produced in two hereditary disease models following LO-AI with frozen semen, and both ocelot and Pallas' cat kittens have been born after LO-AI with freshly-collected semen. The application of LO-ET and LO-AI to felids has resulted in substantial improvement in the efficiency of assisted reproduction for genetic management of these invaluable domestic cat and wild cat populations. © 2012 Blackwell Verlag GmbH.


Pence V.C.,Center for Conservation and Research of Endangered Wildlife
Annals of the Missouri Botanical Garden | Year: 2013

For the majority of plant species of conservation concern, seed banking and traditional propagation methods are the most efficient ways of meeting the ex situ and recovery conservation goals of Global Strategy for Plant Conservation (GSPC) Target 8. However, there are estimated to be 5000 or more endangered species for which these methods will not be adequate conservation tools. These "exceptional" species are those with recalcitrant seeds or those that produce few or no seeds. In vitro methods can provide alternative procedures for propagating and preserving germplasm in the long term for these species. Research at the Center for Conservation and Research of Endangered Wildlife (CREW) with several U.S. endangered species has shown the potential of these methods. In vitro propagation can provide plants for reintroduction and research when traditional propagation methods are not adequate. Phytotissue banking can be used for long-term ex situ conservation when seed or embryo banking is not possible. In vitro methods are also needed for recovery when embryo banking of recalcitrant seeds is possible. The full implementation of in vitro methods is constrained by information, scientific, and economic challenges, but the need for its use in meeting the needs of exceptional species should provide impetus for overcoming these challenges and making these methods an integral part of an overall ex situ conservation strategy.


Pence V.C.,Center for Conservation and Research of Endangered Wildlife
In Vitro Cellular and Developmental Biology - Plant | Year: 2011

In vitro methods provide opportunities for propagating and preserving endangered plant species when seed-based methods are not adequate. Such species include those that produce few or no seeds, as well as species with recalcitrant seeds. Tissue culture propagation methods can be used to produce such plants for reintroduction, research, education, display, and commerce. They can also be the basis for tissue banking as a way to preserve genetic diversity when seeds cannot be banked. With some recalcitrant species, embryo banking, a method which also utilizes in vitro culture for recovery germination, is possible. The number of endangered species that will require in vitro methods is estimated to be at least 5,000 worldwide. Further information is needed to identify these species, and the ongoing collection of information into databases on endangered species and recalcitrant species will help provide this. The costs of these methods are higher than for traditional propagation and preservation, but they may be necessary for species under higher threat. The multiplication rate of a culture, as well as the rates of rooting and acclimatization, has a major effect on the number of transfers needed for producing plants or tissue for banking, and improvements that will increase the efficiency of these steps can help lower costs. Further research into factors affecting the growth of tissues in vitro, as well as coordination of efforts among institutions with infrastructure for in vitro work, should facilitate the application of in vitro methods to the endangered species that cannot be propagated or preserved using seeds. © 2010 The Society for In Vitro Biology.

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