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The roughest locus of Drosophila melanogaster encodes a transmembrane protein of the immunoglobulin superfamily required for several developmental processes, including axonal pathfinding in the developing optic lobe, mechanosensory bristle differentiation and myogenesis. In the compound eye, rst was previously shown to be required for establishing the correct number and spacing of secondary and tertiary pigment cells during the final steps of ommatidial assembly. We have further investigated its function in the developing pupal retina by performing a developmental and molecular analysis of a novel dominant rst allele, rst(D). In addition to showing evidence that rst(D) is a regulatory mutant, the results strongly suggest a previously unnoticed role of the rst gene in the differentiation of secondary/tertiary pigment cell fate as well as establishing the correct timing of surplus cell removal by programmed cell death in the compound eye.

BackgroundDrosophila retinal architecture is laid down between 24–48 hours after puparium formation, when some of the still uncommitted interommatidial cells (IOCs) are recruited to become secondary and tertiary pigment cells while the remaining ones undergo apoptosis. This choice between survival and death requires the product of the roughest (rst) gene, an immunoglobulin superfamily transmembrane glycoprotein involved in a wide range of developmental processes. Both temporal misexpression of Rst and truncation of the protein intracytoplasmic domain, lead to severe defects in which IOCs either remain mostly undifferentiated and die late and erratically or, instead, differentiate into extra pigment cells. Intriguingly, mutants not expressing wild type protein often have normal or very mild rough eyes.Methodology/Principal FindingsBy using quantitative real time PCR to examine rst transcriptional dynamics in the pupal retina, both in wild type and mutant alleles we showed that tightly regulated temporal changes in rst transcriptional rate underlie its proper function during the final steps of eye patterning. Furthermore we demonstrated that the unexpected wild type eye phenotype of mutants with low or no rst expression correlates with an upregulation in the mRNA levels of the rst paralogue kin-of-irre (kirre), which seems able to substitute for rst function in this process, similarly to their role in myoblast fusion. This compensatory upregulation of kirre mRNA levels could be directly induced in wild type pupa upon RNAi-mediated silencing of rst, indicating that expression of both genes is also coordinately regulated in physiological conditions.Conclusions/SignificanceThese findings suggest a general mechanism by which rst and kirre expression could be fine tuned to optimize their redundant roles during development and provide a clearer picture of how the specification of survival and apoptotic fates by differential cell adhesion during the final steps of retinal morphogenesis in insects are controlled at the transcriptional level.

The Drosophila roughest (rst) locus encodes an immunoglobulin superfamily transmembrane glycoprotein implicated in a variety of embryonic and postembryonic developmental processes. Here we demonstrate a previously unnoticed role for this gene in the autophagic elimination of larval salivary glands during early pupal stages by showing that overexpression of the Rst protein ectodomain in early pupa leads to persistence of salivary glands up to at least 12 hours after head eversion, although with variable penetrance. The same phenotype is observed in individuals carrying the dominant regulatory allele rst(D), but not in loss of function alleles. Analysis of persistent glands at the ultrastructural level showed that programmed cell death starts at the right time but is arrested at an early stage of the process. Finally we describe the expression pattern and intracellular distribution of Rst in wild type and rst(D) mutants, showing that its downregulation in salivary glands at the beginning of pupal stage is an important factor in the correct implementation of the autophagic program of this tissue in space and time.

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Objective: To evaluate the immunological profile and gene expression of endothelin-1 (ET-1) in mitral valves of patients with rheumatic fever originated from a reference service in cardiovascular surgery.Methods: This was a quantitative, observational and cross-sectional study. Thirty-five subjects (divided into four groups) participated in the study, 25 patients with chronic rheumatic heart disease and ten control subjects. The mean age of the sample studied was 34.5 years. Seventeen of them (48.58%) were male and 18 (51.42%) were female. Inflammatory cytokines (TNF-α, IL-4 and IL-10) were measured and ten mitral valves of patients who underwent first valve replacement were collected for determination of gene expression of endothelin-1 by real time PCR.Results: Among the groups studied (patients vs. controls), there was a statistically significant difference in IL-10 levels (P=0.002), and no differences in other cytokines. Expression of endothelin-1 was observed in 70% of samples. Quantitatively, average of ET-1 expression was 62.85±25.63%.Conclusion: Inflammatory cytokine IL-10 participates in the maintenance of chronicity of rheumatic fever in patients who underwent valve replacement and those who are undergoing medical treatment. The expression of endothelin-1 in heart valve lesions in patients undergoing mitral valve replacement confirms its association with inflammatory activity in rheumatic fever. Rev Bras Cir Cardiovasc 2014;29(1):25-30 Descriptors

Background/Aims: Cytogenetic and molecular genetics play a pivotal role in treatment of acute leukemias. We prospectively evaluated genetic alterations in Brazilian patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) and their association with clinical and laboratorial data. Methods: Flow cytometry, conventional cytogenetics (CC), FISH, PCR, RT-PCR and sequencing were performed on samples from 161 de novo ALL and 155 AML.Results: Main CC findings in AML were t(15;17) (19.4%), +8 (17.4%), complex karyotype (14.6%), t(8;21) (7.6%); in ALL main CC findings were high hyperdiploidy (18.7%), low hyperdiploidy (9.7%), t(1;19) (9.7%), t(9;22) (8.2%). Frequencies of gene fusions and mutations in AML were PML-RARa 21.9%, RUNX1-RUNX1T1 7.1%, CBFB-MYH11 and MLL-AF9 2.6%, FLT3-ITD 14.2%, NPM1mut 13.6%. In ALL, ETV6-RUNX1 and BCR-ABL were present in 11.5% of the cases, TCF3-PBX1 in 10.8% and MLL-AF1 in 1.5%. Results were discordant between CC and RT-PCR in 3.6% of the cases. PML-RARa was associated with younger age, lower WBC and platelet; FLT3-ITD with higher hemoglobin and WBC; NPM1mut with higher platelet and WBC, older age and normal karyotype. BCR-ABL was associated with higher age; MLL-AF1 with higher WBC and EGIL BI-subtype. Conclusions:The incidence of some aberrations in AML differed from international literature. Discrepancies found between methodologies reinforce the importance of both CC and PCR in the diagnosis of leukemias.