| dc.contributor |
Corey S . Goodman |
|
| dc.contributor |
Sherry D . Painter |
|
| dc.contributor |
Darrell H . Carney |
|
| dc.contributor |
Jane E . Bottenstein |
|
| dc.contributor |
Gregg T . Nagle |
|
| dc.creator |
Akalal , David -Benjamin Garcia |
|
| dc.date |
2003 -03 -27 |
|
| dc.date.accessioned |
2011 -04 -27T21 :36 :29Z |
|
| dc.date.available |
2011 -04 -27T21 :36 :29Z |
|
| dc.date.issued |
2011 -04 -27T21 :36 :29Z |
|
| dc.identifier |
http : / /etd .utmb .edu /theses /available /etd -01162003 -093008 / |
|
| dc.identifier.uri |
http : / /hdl .handle .net /2249 .1 /35653 |
|
| dc.description |
While the mollusk Aplysia californica has been used as an excellent model for studying the nervous system , no known growth and /or neurotrophic factors had been discovered or characterized in this model . The discovery of an Aplysia growth factor would be important for studying the mechanisms of actions of growth factors and their roles in growth , development , and metamorphosis .
In 1996 , an insect -derived growth factor (IDGF ) was purified from the conditioned medium of an embryonic fleshfly cell line . It had no significant homology to any other protein except for an Aplysia protein of unknown function , atrial gland granule -specific antigen (AGSA ) . Based on its similarity to IDGF , this project was aimed at determining if AGSA functions as a growth factor in Aplysia .
In this study , we cloned an atrial gland cDNA , corrected the reported AGSA nucleotide sequence , and renamed the predicted protein mollusk -derived growth factor (MDGF ) . We have confirmed that there is significant MDGF gene expression in the Aplysia atrial gland and no detectable expression in acutely dissected adult CNS . However , we demonstrate that expression of the MDGF gene begins during embryonic development , and displays distinct temporal patterns of expression in the reproductive tract and CNS during juvenile development suggesting that MDGF may be important during Aplysia development . In addition , MDGF is detected in axotomized adult CNS , suggesting a potential role for MDGF in injury repair . We affinity -purified native MDGF protein from Aplysia atrial glands and showed that it has potent adenosine deaminase (ADA ) and growth factor activity , inducing up to a two -fold increase in an insect cell proliferation assay .
A number of MDGF -related proteins having 30 -50 % sequence identity among themselves have recently been reported including : a human protein involved in cat eye syndrome , several insect growth factors possessing adenosine deaminase activity , and proteins from several other organisms (pig , zebrafish , cow , and slime mold ) . Our findings support the idea that MDGF belongs to a new family of ADA -related growth factors and that it may be important during development and repair of the Aplysia CNS by regulating the levels of extracellular adenosine . MDGF is the first growth factor purified and characterized in Aplysia . |
|
| dc.format |
application /pdf |
|
| dc.language |
en |
|
| dc.publisher |
UTMB |
|
| dc.rights |
unrestricted |
|
| dc.rights |
I hereby certify that , if appropriate , I have obtained and attached hereto a written permission statement from the owner (s ) of each third party copyrighted matter to be included in my thesis , dissertation , or project report , allowing distribution as specified below . I certify that the version I submitted is the same as that approved by my advisory committee . I hereby grant to University of Texas Medical Branch or its agents the non -exclusive license to archive and make accessible , under the conditions specified below , my thesis , dissertation , or project report in whole or in part in all forms of media , now or hereafter known . I retain all other ownership rights to the copyright of the thesis , dissertation or project report . I also retain the right to use in future works (such as articles or books ) all or part of this thesis , dissertation , or project report . |
|
| dc.source |
http : / /etd .utmb .edu /theses /available /etd -01162003 -093008 / |
|
| dc.subject |
Anatomy and Neurosciences Cell Biology Program |
|
| dc.title |
CLONING , EXPRESSION , AND CHARACTERIZATION OF A NOVEL MOLLUSK -DERIVED GROWTH FACTOR IN APLYSIA |
|
| dc.type |
text |
|