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dc.contributor.advisorWolniak, Stephen Men_US
dc.contributor.authorTomei, Erika Jeanen_US
dc.date.accessioned2016-09-03T05:35:28Z
dc.date.available2016-09-03T05:35:28Z
dc.date.issued2016en_US
dc.identifierhttps://doi.org/10.13016/M2WZ24
dc.identifier.urihttp://hdl.handle.net/1903/18552
dc.description.abstractThe male gametophyte of the semi-aquatic fern, Marsilea vestita, produces multiciliated spermatozoids in a rapid developmental sequence that is controlled post-transcriptionally when dry microspores are placed in water. Development can be divided into two phases, mitosis and differentiation. During the mitotic phase, a series of nine successive division cycles produce 7 sterile cells and 32 spermatids in 4.5-5 hours. During the next 5-6 hours, each spermatid differentiates into a corkscrew-shaped motile spermatozoid with ~140 cilia. This document focuses on the role of motor proteins in the regulation of male gametophyte development and during ciliogenesis. In order to study the mechanisms that regulate spermatogenesis, RNAseq was used to generate a reference transcriptome that allowed us to assess the abundance of transcripts at different stages of development. Over 120 kinesin-like sequences were identified in the transcriptome that represent 56 unique kinesin transcripts. Members of the kinesin-2, -4, -5, -7, -8, -9, -12, -13, and -14 families, in addition to several plant specific and ‘orphan’ kinesins are present. Most (91%) of these kinesin transcripts change in abundance throughout gametophyte development, with 52% of kinesin mRNAs enriched during the mitotic phase and 39% enriched during differentiation. Functional analyses show that the temporal regulation of kinesin transcripts during gametogenesis directly correlates with kinesin protein function. Specifically, Marsilea makes one kinesin-2 (MvKinesin-2) and two kinesin-9 (MvKinesin-9A and MvKinesin-9B) transcripts, which are present during spermatid differentiation and ciliogenesis. Silencing experiments showed that MvKinesin-2 and MvKinesin-9A are required for ciliogenesis and motility in the Marsilea male gametophyte; however, these kinesins display atypical roles during these processes. In contrast, spermatozoids produced after the silencing of MvKinesin-9B exhibit normal morphology. MvKinesin-2 is necessary for cytokinesis as well as for regulating ciliary length and MvKinesin-9A is needed for the correct orientation of basal bodies, events not typically associated with these proteins. In addition, Marsilea makes motile, ciliated gametophytes without the help of IFT dynein, outer arm dynein, or the BBsome. These results are the first to investigate the kinesin-linked mechanisms that regulate ciliogenesis in a land plant.en_US
dc.language.isoenen_US
dc.titleKINESIN MOTOR PROTEINS ARE ESSENTIAL FOR MALE GAMETOPHYTE DEVELOPMENT IN MARSILEA VESTITAen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentCell Biology & Molecular Geneticsen_US
dc.subject.pqcontrolledCellular biologyen_US
dc.subject.pqcontrolledMolecular biologyen_US
dc.subject.pqcontrolledDevelopmental biologyen_US
dc.subject.pquncontrolledCell Divisionen_US
dc.subject.pquncontrolledCiliogenesisen_US
dc.subject.pquncontrolledIntraflagellar Transporten_US
dc.subject.pquncontrolledKinesin Superfamilyen_US
dc.subject.pquncontrolledMarsilea vestitaen_US
dc.subject.pquncontrolledSpermatogenesisen_US


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