Loss of YABBY2-Like Gene Expression May Underlie the Evolution of the Laminar Style in Canna and Contribute to Floral Morphological Diversity in the Zingiberales.

The Zingiberales is an order of tropical monocots that exhibits diverse floral morphologies. The evolution of petaloid, laminar stamens, staminodes, and styles contributes to this diversity. The laminar style is a derived trait in the family Cannaceae and plays an important role in pollination as its surface is used for secondary pollen presentation. Previous work in the Zingiberales has implicated YABBY2-like genes, which function in promoting laminar outgrowth, in the evolution of stamen morphology. Here, we investigate the evolution and expression of Zingiberales YABBY2-like genes in order to understand the evolution of the laminar style in Canna. Phylogenetic analyses show that multiple duplication events have occurred in this gene lineage prior to the diversification of the Zingiberales. Reverse transcription-PCR in Canna, Costus, and Musa reveals differential expression across floral organs, taxa, and gene copies, and a role for YABBY2-like genes in the evolution of the laminar style is proposed. Selection tests indicate that almost all sites in conserved domains are under purifying selection, consistent with their functional relevance, and a motif unique to monocot YABBY2-like genes is identified. These results contribute to our understanding of the molecular mechanisms underlying the evolution of floral morphologies.

Molecular basis of floral petaloidy: insights from androecia of Canna indica.

Floral organs that take on the characteristics of petals can occur in all whorls of the monocot order Zingiberales. In Canna indica, the most ornamental or 'petaloid' parts of the flowers are of androecial origin and are considered staminodes. However, the precise nature of these petaloid organs is yet to be determined. In order to gain a better understanding of the genetic basis of androecial identity, a molecular investigation of B- and C-class genes was carried out. Two MADS-box genes GLOBOSA (GLO) and AGAMOUS (AG) were isolated from young inflorescences of C. indica by 3' rapid amplification of cDNA ends polymerase chain reaction (3'-RACE PCR). Sequence characterization and phylogenetic analyses show that CiGLO and CiAG belong to the B- and C-class MADS-box gene family, respectively. CiAG is expressed in petaloid staminodes, the labellum, the fertile stamen and carpels. CiGLO is expressed in petals, petaloid staminodes, the labellum, the fertile stamen and carpels. Expression patterns in mature tissues of CiGLO and CiAG suggest that petaloid staminodes and the labellum are of androecial identity, in agreement with their position within the flower and with described Arabidopsis thaliana expression patterns. Although B- and C-class genes are important components of androecial determination, their expression patterns are not sufficient to explain the distinct morphology observed in staminodes and the fertile stamen in C. indica.

Serviço de radiologia odontológica em municípios da região Centro-Oeste do Estado de Minas Gerais, Brasil / Dental radiologic service in cities of the midwest region of the State of Minas Gerais, Brazil

Objetivo: identificar a existência do serviço público de radiologia odontológica em municípios da região Centro-Oeste vinculados a uma Superintendência Regional de Saúde (SRS) de Minas Gerais, Brasil, e a partir daí conhecer o funcionamento do serviço ou o potencial funcionamento caso fosse implantado. Método: o estudo foi aprovado pelo Comitê de Ética em Pesquisa. Para a coleta de dados aplicou-se questionário aos coordenadores municipais de Saúde Bucal. A análise estatística descritiva foi desenvolvida no SPSS. Participaram 50 municípios de 55 vinculados a uma mesma SRS. Resultados: dos municípios participantes, 27 ofertavam o serviço radiológico em odontologia no setor público e 23 não ofertavam esse serviço. Entre os municípios que oferecem o serviço, 81,5% contam com um aparelho próprio, 11,1% utilizam todas as medidas de radioproteção, 96,3% ofertam a radiografia periapical, sem restrição para indicação (70,4%) e quantidade (96,3%). Dos municípios que não possuem o serviço radiológico público, para grande parte, apenas um aparelho próprio seria suficiente para instalação do serviço (59,1%). A maioria dos coordenadores afirmou que a radiologia ajuda muito na qualidade do serviço odontológico (87,0%), no entanto, somente uma minoria (21,7%) pretendia instalar o serviço. Conclusões: a oferta do serviço de radiologia odontológica no setor público não é uma realidade para todos os municípios avaliados. Dos que ofertam o serviço radiológico, a maioria não segue as legislações brasileiras na adoção de todas as medidas de radioproteção.

Objective: To identify the existence of public dental radiology municipalities in the Midwest region linked to a Regional Superintendent of Health (SRS) of Minas Gerais, Brazil, and from there to understand the operation of the service or the potential operation if it was deployed. Method: The study was approved by the Research Ethics. For data collection questionnaire was applied to municipal coordinators of Oral Health. Descriptive statistical analysis was developed in SPSS. Participated in 50 municipalities of 55 bound to the same SRS. Results: participating municipalities, 27 ofertavam dental radiology service in the public sector and 23 not ofertavam this service. Among the municipalities offering the service, 81.5% have an apparatus, 11.1% use all measures of radioprotection, 96.3% tender the periapical without restriction indication (70.4%) and quantity (96.3%). Municipalities that do not have radiological public service, for the most part, only an apparatus would be enough to install the service (59.1%). Most coordinators said the radiology helps a lot on the quality of dental services (87.0%), however, only a minority (21.7%) planned to install the service. Conclusions: The provision of dental radiology service in the public sector is not a reality for all municipalities assessed. That offer the service of radiological, most do not follow the laws Brazilian adoption of all measures of radioprotection.

Molecular evolution and patterns of duplication in the SEP/AGL6-like lineage of the Zingiberales: a proposed mechanism for floral diversification.

The diversity of floral forms in the plant order Zingiberales has evolved through alterations in floral organ morphology. One striking alteration is the shift from fertile, filamentous stamens to sterile, laminar (petaloid) organs in the stamen whorls, attributed to specific pollination syndromes. Here, we examine the role of the SEPALLATA (SEP) genes, known to be important in regulatory networks underlying floral development and organ identity, in the evolution of development of the diverse floral organs phenotypes in the Zingiberales. Phylogenetic analyses show that the SEP-like genes have undergone several duplication events giving rise to multiple copies. Selection tests on the SEP-like genes indicate that the two copies of SEP3 have mostly evolved under balancing selection, probably due to strong functional restrictions as a result of their critical role in floral organ specification. In contrast, the two LOFSEP copies have undergone differential positive selection, indicating neofunctionalization. Reverse transcriptase-polymerase chain reaction, gene expression from RNA-seq data, and in situ hybridization analyses show that the recovered genes have differential expression patterns across the various whorls and organ types found in the Zingiberales. Our data also suggest that AGL6, sister to the SEP-like genes, may play an important role in stamen morphology in the Zingiberales. Thus, the SEP-like genes are likely to be involved in some of the unique morphogenetic patterns of floral organ development found among this diverse order of tropical monocots. This work contributes to a growing body of knowledge focused on understanding the role of gene duplications and the evolution of entire gene networks in the evolution of flower development.

Tracking the development of the petaloid fertile stamen in Canna indica: insights into the origin of androecial petaloidy in the Zingiberales.

Flowers of the order Zingiberales demonstrate a remarkable trend of reduction in the number of fertile stamens; from five or six fertile, filamentous stamens bearing two thecae each in Musaceae and Strelitziaceae to just a single petaloid stamen bearing a single theca in Cannaceae and Marantaceae. As one progresses from ancestral to derived floral forms, 5-6 fertile stamens are replaced by 4-5 petaloid staminodes. In Cannaceae and Costaceae, all members of the androecial whorls exhibit petaloidy, including the fertile stamen. In Costaceae, a single fertile stamen develops two thecae embedded on a broad petaloid appendage, while in Cannaceae the single fertile stamen is further reduced to a single theca with a prominent, expanded petaloid appendage. Whether petaloidy of the fertile stamen is a synapomorphy of the entire ginger clade (including Cannaceae, Costaceae, Zingiberaceae and Marantaceae), or the result of independent convergent evolution in Cannaceae, Costaceae, and some Zingiberaceae, is unclear. We combine a developmental series of the formation of the petaloid fertile stamen in Canna indica with data on the expression of B- and C-class floral organ identity genes to elucidate the organogenetic identity of the petaloid stamen and staminodes. Our data indicate that the single fertile theca in C. indica and its petaloid appendage are derived from one-half of the primordium of a single stamen, with no contribution from the remaining part of the stamen (i.e. the second theca primordium) which aborts early in development. The petaloid appendage expands later, and develops from the position of the filament/connective of the developing theca. Floral identity gene expression shows that petal identity genes (i.e. B-class genes) are expressed in all floral organs studied while C-class gene AG-1 is expressed in an increasing gradient from sepals to gynoecium, and AG-2 is expressed in all floral organs except the petals. The canonical model for molecular specification of floral organ identity is not sufficient to explain petaloidy in the androecial whorl in Canna sp. Further studies understanding the regulation of gene networks are required.

A method for extracting high-quality RNA from diverse plants for next-generation sequencing and gene expression analyses.

PREMISE OF THE STUDY: To study gene expression in plants, high-quality RNA must be extracted in quantities sufficient for subsequent cDNA library construction. Field-based collections are often limited in quantity and quality of tissue and are typically preserved in RNAlater. Obtaining sufficient and high-quality yield from variously preserved samples is essential to studies of comparative biology. We present a protocol for the extraction of high-quality RNA from even the most recalcitrant plant tissues. • METHODS AND RESULTS: Tissues from mosses, cycads, and angiosperm floral organs and leaves were preserved in RNAlater or frozen fresh at -80°C. Extractions were performed and quality was measured for yield and purity. • CONCLUSIONS: This protocol results in the extraction of high-quality RNA from a variety of plant tissues representing vascular and nonvascular plants. RNA was used for cDNA synthesis to generate libraries for next-generation sequencing and for expression studies using quantitative PCR (qPCR) and semiquantitative reverse transcription PCR (RT-PCR).