Three-dimensional Structure, Function and Composition of the Kinetochore

点击翻译按钮获取中文摘要

; R o o t E n t r y F _ c C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l . c . c 4 5 6 7 8 9 : ; = F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; 9420772 McEwen The long-term objective of the research in this proposal is to elucidate the molecular mechanisms responsible for chromosome movement during mitosis. When cell of higher animals and plants get ready to divide their DNA condenses from its diffuse state into distinct structures called chromosomes. The number and shape of the chromosomes is characteristic of the species. At the onset of mitosis the chromosomes are composed of two chromatics, each of which contains an identical copy of the genetic information. After their formation chromosomes bind to a fibrous bipolar spindle, which also forms at onset of mitosis, such that the chromatics of a given chromosome kind bind to fibers from opposite spindle poles. Once bound the chromosomes move to the center of the spindle. When all of the chromosomes are lined up at the equator, a signal is sent for the chromatids to split apart and move towards opposite spindle poles. The cell then divides in two with each daughter cell receiving a complete complement of DNA. Thus mitosis is the process that enables a complete copy of the genetic i nformation to be accurately distributed to different cells of a multicellular organism, and for genetic information to be transmitted between generations. For this reason it is one of the critically important vital processes of high organisms otherwise the cell would be damaged. Modern research has demonstrated that most of the force for chromosome motions is generated from the kinetochore. The latter is a specialized structure found on each chromatid that is responsible for its attachment to the spindle fibers. This proposal will use three-dimensional electron microscopy, computer graphics, improved methods of specimen preparation, and video enhanced light microscopy to learn more about how the kinetochore work. %%% This project will seek to determine how the kinetochore is constructed, how it interacts with the spindle fibers during chromosome motion in different directions, and precisely where certain molecular components are located. The latter include molecules known or thought to be capable of generating motion along the spindle fibers. This information is critical for evaluating many of the current hypotheses about how chromosome motion is achieved. *** ; Oh +' 0 $ H l D h R:\WWUSER\TEMPLATE\NORMAL.DOT 9420772 Shirley S u m m a r y I n f o r m a t i o n ( 3 Parker Shirley Parker @ 'q:c @ c @ ?~ c @ Microsoft Word 6.0 2 ; e 3 e j j j j j j j @ 1 " q T 7 @ j @ j j j j ~ j j j j : 9420772 McEwen The long-term objective of the research in this proposal is to elucidate the molecular mechanisms responsible for chromosome movement during mitosis. When cell of higher animals and plants get ready to divide their DNA condenses from its diffuse state into distinct structures called chromosomes. The number and shape of the chromosomes is characteristic of the species. At the onset of mitosis the chromosomes are composed of two chromatics, each of which contains an identical copy of the genetic information. After their formation chromosomes bind to