1,720,981 research outputs found
On reconciling the interactions between APETALA2, miR172 and AGAMOUS with the ABC model of flower development.
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Transcriptional and posttranscriptional regulatory networks controlling leaf cell differentiation during drought stress in Brachypodium distachyon
No full textDifferent genomic regions define florets number and spike- related traits in T durum ssp.
Full text linkWheat grain yield is a complex trait that can be further dissected in different components such as the number of grains per spike, the gr size/weight and the number of spike per plant, and each of these factors is in turn composed by several sub-components. These traits have subjected to strong selection during the domestication history of Triticeae and are still the main target of modern breeding.
In this study we focused on yield in terms of grains per spike, considering the number of fertile spikelets per spike and fertile florets per spikelet as main traits.
With the aim of identifying genetic components of these traits, we deployed a segregant population, resulting from the cross of a durum wheat cultivar (Latino) and a cultivated emmer accession (MG5323) that show a variability in the number of grain per spike.
Before performing a classic QTL mapping approach, we dissected at stereomicroscope the developing spikes of the parental lines to determine the morphological traits responsible for a different number of grains per spike. The analysis revealed that a different number of floret meristem set during spike development, and a different developmental timing, is at the basis of the observed differences.
For the QTL mapping analysis, the RIL population was phenotyped for spike morphology and florets-related traits in four environments. A total of 94 QTLs were detected along all chromosomes, grouped in 17 regions, based on their physical position. Five QTL groups were identified for floret number and eight for spikelet number/spike morphology. The QTL regions identified for spikelet and floret number are distinct and non-overlapping suggesting that these traits are under different genetic control. Finally, physical interval of our QTL was defined, and candidate genes proposed. Known genes involved in inflorescence meristem development an spike morphology, such as FUL2, FUL3, PPD -1, VRN-A1, and Q-5A, colocalized in our QTL regions and were investigated by qRT-PCR in parental lines of the segregant population
Characterization of five microRNA families in maize.
Full text linkIn recent years, microRNAs (miRNAs) have polarized
the interest of the scientific community as a new category
of gene expression regulators, present in both
plants and animals. Plant miRNAs are involved in processes
such as plant development, organ identity, and
stress response. Nonetheless, knowledge of their functions
is still incomplete, and it is conceivable that
further new processes in which they are involved will
be discovered. For these reasons, structural and functional
characterization of MIR genes, that are also in
crop species such as Zea mays L., becomes instrumental
in addressing genetic and molecular mechanisms
controlling phenotype determination and
phenotypic adaptation to growing conditions. The
present study contributes to the characterization of
five miRNA families in maize, from the determination
of their expression pattern in different maize tissues
and genotypes, to the identification of putative targets
by bioinformatic means and subsequent experimental
validation of three targets by modified 59 RACE
experiments. Furthermore, 30 different MIR genes
belonging to these five miRNA families were analysed
by their attribution to maize chromosomes using oat–
maize addition lines and by investigating their phylogenetic
relationship with genes from other cereals.
In particular, sequence homology was determined by
the reciprocal best BLAST hit approach, to define
groups of homologous genes between maize, rice,
and sorghum
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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