DSpace Community:http://hdl.handle.net/10362/44852013-05-23T14:04:11Z2013-05-23T14:04:11ZChromatin dynamics in Arbidopsis development: a live cell imaging approachRosa, Stefaniehttp://hdl.handle.net/10362/68472012-01-20T14:55:05Z2011-10-01T00:00:00ZTitle: Chromatin dynamics in Arbidopsis development: a live cell imaging approach
Authors: Rosa, Stefanie
Abstract: The proper development of multicellular organisms demands the distinct specification
of a variety of specialized cell types. While this is one of the oldest statements of
developmental genetics, how different patterns of gene expression are established in
genetically identical cells and maintained during somatic cell divisions is still an active topic
of research.
Chromatin structure is now recognized to regulate gene activity playing a crucial role
in cell differentiation and development. Chromatin is not simply a packaging tool but a
dynamic entity that reflects the regulatory cues necessary to program appropriate cellular
pathways. There are several ways by which chromatin structure can be remodelled. These
mechanisms include DNA-methylation, post-translational modifications of histone proteins,
histone variants and, nuclear localization. While the dynamic nature of chromatin structure
has been previously described its biological function and repercussions on development are
only now beginning to be revealed. In this work we used in vivo microscopy techniques to
assess how different aspects of chromatin organization play a role on various aspects of development.(...)
Description: Dissertation presented to obtain the Ph.D degree in Biology2011-10-01T00:00:00ZGenetics of berry colour and anthocyanin content variation in grapevine (Vitis vinifera L.subsp. vinifera)Cardoso, Silvana Coelhohttp://hdl.handle.net/10362/61812011-10-27T16:25:16Z2011-01-01T00:00:00ZTitle: Genetics of berry colour and anthocyanin content variation in grapevine (Vitis vinifera L.subsp. vinifera)
Authors: Cardoso, Silvana Coelho
Abstract: Anthocyanin content of grape berry skin determines the colour of
grapes and wine. This trait has been widely studied due to its importance
for grape and wine marketing and also due to the antioxidant properties
of anthocyanins.
In this thesis the variation of this trait was investigated within and
between cultivars. DNA sequence variation and differential gene
expression were studied among clones of the cultivars Aragonez and
Negra Mole. Grape colour phenotyping was explored using different
phenotyping approaches. Association mapping was performed for a
sample of 149 cultivars and association mapping methodologies
considering structure and relatedness in the sample were discussed.
It was observed that no DNA sequence variation was present in the
studied genomic regions between different clones of the same cultivar.
Differential expression between Aragonez clones with contrasting values
of skin total anthocyanin concentration was found to be very subtle not
showing any significant results after correction for multiple testing and
with two fold-change. However, relaxing statistical stringency and
focusing on functional groups of interest (flavonoid metabolism and
transcription factors) a list of 24 genes of interest was identified. This
included two genes involved in the flavonoid metabolism, coding
enzymes related with the glucosylation of flavonoids and transcription
factors of the following families: Myb, Myc, zinc fingers, WRKY, DOF,
GRAS, homeobox domain, YABBY, basic-leucine zipper, pathogenesisrelated
and plant homeodomain finger.(...)
Description: Dissertation presented in fulfillment of the requirements for the Degree of Doctor of Philosophy in Biology (Molecular Genetics)
at the Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa2011-01-01T00:00:00Z