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Laura Morello

Publications and source records attributed to Laura Morello.

5 recordsLinked to original sources

Genome diversity and evolution of the duckweed section Alatae comprising diploids, polyploids, and interspecific hybrids.

The section Alatae of genus Lemna of the monocotyledonous aquatic duckweed family (Lemnaceae) consists of rather diverse accessions with unknown phylogeny and unclear taxonomic assignment. In contrast to other duckweeds, some Alatae accessions, in addition to mainly vegetative propagation, produce readily flowers and viable seeds. We analyzed the genomic diversity and phylogenetic relationship of 52 Alatae accessions. For this purpose, we applied multiple molecular and cytogenetic approaches, including plastid and nuclear sequence polymorphisms, chromosome counting, genome size determination, and genomic in situ hybridization in combination with geographic distribution. We uncovered ploidy variation, recurrent hybridization, and backcrosses between species and their hybrids. The latter successfully spread over three continents. The results elucidate the evolution of Alatae accessions and explain the difficult taxonomic assignment of distinct accessions. Our study might be an example for analogous studies to resolve the hitherto unclear relationships among accessions of the duckweed genera Wolffiella and Wolffia.

Araceae↗

Functional analysis of DNA sequences controlling the expression of the rice OsCDPK2 gene.

Plant calcium-dependent protein kinases (CDPKs) are involved in calcium-mediated signal transduction pathways. Their expression is finely tuned in different tissues and in response to specific signals, but the mechanism of such a regulation is still largely unknown. OsCDPK2 gene expression is modulated in vivo during rice (Oryza sativa L.) flower development and is downregulated by white light in leaves. In order to identify OsCDPK2 regulatory sequences, we amplified and cloned both the 5' and 3'-flanking regions of the gene. Sequence analysis revealed that the leader sequence is interrupted by an intron, whose regulatory role was investigated. Different ss-gucuronidase (GUS) expression vectors, carrying combinations of the putative OsCDPK2 regulatory regions, were generated and GUS expression was analyzed both in transient assays and in transgenic rice plants. The whole 5'-flanking sequence was able to drive GUS expression in rice calli and leaves transiently transformed with the biolistic technique. Analysis of the GUS expression pattern in transgenic plants revealed strong activity in root tips, leaf veins and mesophyll cells, in flower reproductive organs and in mature pollen grains. Expression was also shown to be subject to an intron-mediated enhancement (IME) mechanism, since the deletion of the leader intron sequence from chimeric OsCDPK2::GUS plasmids almost completely abolished GUS activity. Furthermore, in transiently transformed leaves, GUS expression driven by the OsCDPK2 promoter-leader region was constitutively observed regardless of light or dark exposure. Light-regulated expression was restored by inserting the OsCDPK2 3' untranslated region (3'UTR) downstream of the chimeric OsCDPK2::GUS transcription unit, suggesting that light down-regulation is mediated by a mechanism driven by the 3'UTR.

3' Untranslated Regions↗

Comparing diagnostic checklists for pediatric bipolar disorder in academic and community mental health settings.

OBJECTIVES: To compare six promising mania measures, the Parent Mood Disorder Questionnaire (P-MDQ), the Adolescent self-report MDQ, the 10-item short form of the Parent General Behavior Inventory (PGBI-SF10), the 28-item Adolescent General Behavior Inventory (AGBI), the Parent Young Mania Rating Scale (P-YMRS), and the adolescent YMRS, in a demographically diverse outpatient sample. METHODS: Participants were 262 outpatients (including 164 males and 131 African-Americans) presenting to either an academic medical center (n = 153) or a community mental health center (n = 109). Diagnoses were based on semi-structured interviews with the parent and then youth sequentially. RESULTS: Ninety youths (34%) met criteria for a bipolar spectrum disorder. Parent measures yielded Areas Under the Receiver Operating Curve (AUROC) values of 0.81 for the PGBI-SF10 to 0.66 for the P-YMRS. Adolescent report measures performed significantly less well, with AUROCs ranging from 0.65 to 0.50. There were no significant differences in the diagnostic performance of the measures across the sites or by racial groups, although the reliability of measures tended to be lower in the urban community mental health site. The PGBI-SF10 made a significant contribution to logistic regression models examining all combinations of the instruments. The P-MDQ added information in the younger age group, and no measure improved classification of bipolar cases after controlling for the PGBI-SF10 in the older age group. DISCUSSION: Results replicate previous findings that, in decreasing order of efficiency, the PGBI-SF10, P-MDQ, and P-YMRS significantly discriminate bipolar from non-bipolar cases in youths aged 5-18; and they appear robust in a demographically diverse community setting. Adolescent self-report measures are significantly less efficient, sometimes performing no better than chance at detecting bipolar cases.

Academic Medical Centers↗

A long leader intron of the Ostub16 rice beta-tubulin gene is required for high-level gene expression and can autonomously promote transcription both in vivo and in vitro.

A 2 kb DNA fragment, upstream of the rice beta-tubulin isotype 16 (Ostub16) coding sequence, was isolated using inverse PCR and screening of a tubulin-enriched lambda library. An intron (863 bp) present in the 5' untranslated region (5' UTR) is spliced out to produce the most abundant mRNA species which corresponds to the previously cloned Ostub16 cDNA. Transient expression assays performed on rice embryogenic calluses with chimeric Ostub16::GUS constructs demonstrated that the entire 2 kb upstream sequence has a strong promoter activity, and that the 863 bp intron is required for high-level GUS expression. In addition, the intron sequence is capable per se of sustaining a weak but consistent GUS expression. Two rare Ostub16 transcripts, with a start site mapping within this intron sequence, were detected in rice coleoptile cells. The transcription start site mapped at position -290 with respect to the ATG codon, and the shorter molecule originated from splicing of the same precursor mRNA. Therefore transcriptional expression of rice beta-tubulin isotype 16 results in the synthesis of two premRNA molecules (I and II) encoding for three different mRNA species. We discuss these findings in terms of function and molecular evolution of the mechanisms that control plant beta-tubulin gene expression.

5' Flanking Region↗