Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Publication year range
1.
Dev Biol ; 448(2): 119-135, 2019 04 15.
Article in English | MEDLINE | ID: mdl-30661645

ABSTRACT

In a multitude of organisms, transcription factors of the basic helix-loop-helix (bHLH) family control the expression of genes required for organ development and tissue differentiation. The functions of different bHLH transcription factors in the specification of nervous system and paraxial mesoderm have been widely investigated in various model systems. Conversely, the knowledge of the role of these regulators in the development of the axial mesoderm, the embryonic territory that gives rise to the notochord, and the identities of their target genes, remain still fragmentary. Here we investigated the transcriptional regulation and target genes of Bhlh-tun1, a bHLH transcription factor expressed in the developing Ciona notochord as well as in additional embryonic territories that contribute to the formation of both larval and adult structures. We describe its possible role in notochord formation, its relationship with the key notochord transcription factor Brachyury, and suggest molecular mechanisms through which Bhlh-tun1 controls the spatial and temporal expression of its effectors.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Ciona/embryology , Ciona/genetics , Gene Regulatory Networks , Notochord/metabolism , Animals , Base Sequence , Basic Helix-Loop-Helix Transcription Factors/genetics , Body Patterning/genetics , Embryo, Nonmammalian/metabolism , Enhancer Elements, Genetic/genetics , Fetal Proteins/genetics , Fetal Proteins/metabolism , Gene Expression Regulation, Developmental , Notochord/embryology , Reproducibility of Results , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , Up-Regulation/genetics
2.
PLoS Negl Trop Dis ; 8(1): e2594, 2014.
Article in English | MEDLINE | ID: mdl-24416461

ABSTRACT

The bloodsucking hemipteran Rhodnius prolixus is a vector of Chagas' disease, which affects 7-8 million people today in Latin America. In contrast to other hematophagous insects, the triatomine gut is compartmentalized into three segments that perform different functions during blood digestion. Here we report analysis of transcriptomes for each of the segments using pyrosequencing technology. Comparison of transcript frequency in digestive libraries with a whole-body library was used to evaluate expression levels. All classes of digestive enzymes were highly expressed, with a predominance of cysteine and aspartic proteinases, the latter showing a significant expansion through gene duplication. Although no protein digestion is known to occur in the anterior midgut (AM), protease transcripts were found, suggesting secretion as pro-enzymes, being possibly activated in the posterior midgut (PM). As expected, genes related to cytoskeleton, protein synthesis apparatus, protein traffic, and secretion were abundantly transcribed. Despite the absence of a chitinous peritrophic membrane in hemipterans - which have instead a lipidic perimicrovillar membrane lining over midgut epithelia - several gut-specific peritrophin transcripts were found, suggesting that these proteins perform functions other than being a structural component of the peritrophic membrane. Among immunity-related transcripts, while lysozymes and lectins were the most highly expressed, several genes belonging to the Toll pathway - found at low levels in the gut of most insects - were identified, contrasting with a low abundance of transcripts from IMD and STAT pathways. Analysis of transcripts related to lipid metabolism indicates that lipids play multiple roles, being a major energy source, a substrate for perimicrovillar membrane formation, and a source for hydrocarbons possibly to produce the wax layer of the hindgut. Transcripts related to amino acid metabolism showed an unanticipated priority for degradation of tyrosine, phenylalanine, and tryptophan. Analysis of transcripts related to signaling pathways suggested a role for MAP kinases, GTPases, and LKBP1/AMP kinases related to control of cell shape and polarity, possibly in connection with regulation of cell survival, response of pathogens and nutrients. Together, our findings present a new view of the triatomine digestive apparatus and will help us understand trypanosome interaction and allow insights into hemipteran metabolic adaptations to a blood-based diet.


Subject(s)
Insect Proteins/genetics , Rhodnius/genetics , Transcriptome , Animals , Female , Gastrointestinal Tract , Insect Proteins/biosynthesis , Latin America , Male , Molecular Sequence Data , Sequence Analysis, DNA
3.
J Proteomics ; 96: 117-32, 2014 Jan 16.
Article in English | MEDLINE | ID: mdl-24185139

ABSTRACT

In Latin America, Lutzomyia longipalpis is the main vector of the protozoan parasite Leishmania infantum, which is the causal agent of American Visceral Leishmaniasis. This insect uses male-produced pheromones for mate recognition. Elucidation of pheromone biogenesis or its regulation may enable molecular strategies for mating disruption and, consequently, the vector's population management. Motivated by our recent results of the transcriptomic characterization of the L. longipalpis pheromone gland, we performed a proteomic analysis of this tissue combining SDS-PAGE, and mass spectrometry followed by an integrative data analysis. Considering that annotated genome sequences of this sand fly are not available, we designed an alternative workflow searching MS/MS data against two customized databases using three search engines: Mascot, OMSSA and ProLuCID. A total of 542 proteins were confidently characterized, 445 of them using a Uniref100-insect protein database, and 97 using a transcript translated database. In addition, use of PEAKS for de novo peptide sequencing of MS/MS data confirmed ~90% identifications made with the combination of the three search engines. Our results include the identification of six of the seven enzymes of the mevalonate-pathway, plus the enzymes involved in sesquiterpenoid biosynthesis, all of which are proposed to be involved in pheromone production in L. longipalpis. BIOLOGICAL SIGNIFICANCE: L. longipalpis is the main vector of the protozoan parasite L. infantum, which is the causal agent of American Visceral Leishmaniasis. One of the control measures of such disease is focused on vector population control. As this insect uses male-produced pheromones for mate recognition, the elucidation of pheromone biogenesis or its regulating process may enable molecular strategies for mating disruption and, consequently, this vector's population management. On this regard, in this manuscript we report expression evidence, at the protein level, of several molecules potentially involved in the pheromone production of L. longipalpis. Our results include the identification of the mevalonate-pathway enzymes, plus the enzymes involved in sesquiterpenoid biosynthesis, all of which are proposed to be involved in pheromone production in L. longipalpis. In addition, considering that the annotated genome sequences of this sand fly are not yet available, we designed an alternative workflow searching MS/MS data against proteomic and transcript translated customized databases, using three search engines: Mascot, OMSSA, and ProLuCID. In addition, a de novo peptide sequencing software (PEAKS) was used to further analyze the MS/MS data. This approach made it possible to identify and annotate 542 proteins for the pheromone gland of L. longipalpis. Importantly, all annotated protein sequences and raw data are available for the research community in protein repositories that provide free access to the data.


Subject(s)
Diptera/enzymology , Exocrine Glands/enzymology , Insect Proteins/biosynthesis , Insect Vectors/enzymology , Mevalonic Acid/metabolism , Sex Attractants/metabolism , Animals , Diptera/genetics , Diptera/parasitology , Female , Gene Expression Regulation, Enzymologic , Insect Proteins/genetics , Insect Vectors/genetics , Insect Vectors/parasitology , Leishmania infantum , Leishmaniasis, Visceral , Male , Mass Spectrometry , Sex Attractants/genetics
4.
Parasit Vectors ; 6: 56, 2013 Mar 07.
Article in English | MEDLINE | ID: mdl-23497448

ABSTRACT

BACKGROUND: Molecules involved in pheromone biosynthesis may represent alternative targets for insect population control. This may be particularly useful in managing the reproduction of Lutzomyia longipalpis, the main vector of the protozoan parasite Leishmania infantum in Latin America. Besides the chemical identity of the major components of the L. longipalpis sex pheromone, there is no information regarding the molecular biology behind its production. To understand this process, obtaining information on which genes are expressed in the pheromone gland is essential. METHODS: In this study we used a transcriptomic approach to explore the pheromone gland and adjacent abdominal tergites in order to obtain substantial general sequence information. We used a laboratory-reared L. longipalpis (one spot, 9-Methyl GermacreneB) population, captured in Lapinha Cave, state of Minas Gerais, Brazil for this analysis. RESULTS: From a total of 3,547 cDNA clones, 2,502 high quality sequences from the pheromone gland and adjacent tissues were obtained and assembled into 1,387 contigs. Through blast searches of public databases, a group of transcripts encoding proteins potentially involved in the production of terpenoid precursors were identified in the 4th abdominal tergite, the segment containing the pheromone gland. Among them, protein-coding transcripts for four enzymes of the mevalonate pathway such as 3-hydroxyl-3-methyl glutaryl CoA reductase, phosphomevalonate kinase, diphosphomevalonate descarboxylase, and isopentenyl pyrophosphate isomerase were identified. Moreover, transcripts coding for farnesyl diphosphate synthase and NADP+ dependent farnesol dehydrogenase were also found in the same tergite. Additionally, genes potentially involved in pheromone transportation were identified from the three abdominal tergites analyzed. CONCLUSION: This study constitutes the first transcriptomic analysis exploring the repertoire of genes expressed in the tissue containing the L. longipalpis pheromone gland as well as the flanking tissues. Using a comparative approach, a set of molecules potentially present in the mevalonate pathway emerge as interesting subjects for further study regarding their association to pheromone biosynthesis. The sequences presented here may be used as a reference set for future research on pheromone production or other characteristics of pheromone communication in this insect. Moreover, some matches for transcripts of unknown function may provide fertile ground of an in-depth study of pheromone-gland specific molecules.


Subject(s)
Psychodidae/genetics , Transcriptome , Animals , Biosynthetic Pathways/genetics , Brazil , Exocrine Glands , Male , Pheromones/metabolism
7.
J Cosmet Laser Ther ; 10(4): 193-201, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18991154

ABSTRACT

BACKGROUND AND OBJECTIVES: A system that combines bipolar radio frequency (RF) and intense infrared light (IR) together with mechanical massage and suction has recently been reported as being efficient for cellulite treatment. The present split study was designed to evaluate the efficacy of such a system through various treatments of cellulite located on the buttocks. METHODS: Ten patients were enrolled for 12 sessions of 30 minutes each performed over one buttock, the other buttock serving as an untreated control. Sessions were conducted twice a week for a period of 12 weeks. Clinical photography and profilometry were carried out to assess textural changes before (baseline) and 2 months after the final treatment. Histopathology was performed at baseline, 2 hours after the first session, and just before the 12th session and 2 months thereafter. RESULTS: All patients noted improvement in the treated buttock before the final session, which was maintained at the 2-month assessment. Improved skin appearance was noticed after the first session and was maintained throughout the study. All patients were satisfied with the results and requested further treatment in order to balance the results in both buttocks. Random histological analyses suggested dermal firmness, fibre compaction and tightening of skin layers, including the subcutis, as possible reasons for the effects achieved. The authors recognize that the small number of participants limits the statistical power of the study. CONCLUSIONS: Treatment sessions with the combined RF, IR light and mechanical massage and suction system were complication free, produced improvements in the overall cellulite appearance and skin condition, suggesting that further treatment sessions for maintenance could sustain patient satisfaction index (SI) and lead to lasting results. Based on the good results in the limited trial population, further studies with larger patient populations are warranted.


Subject(s)
Adipose Tissue , Buttocks , Infrared Rays/therapeutic use , Lipectomy/methods , Massage/methods , Obesity/therapy , Radiofrequency Therapy , Adult , Combined Modality Therapy , Cosmetic Techniques , Female , Humans , Middle Aged , Skin/cytology
SELECTION OF CITATIONS
SEARCH DETAIL
...