RESUMO
The major histocompatibility complex (MHC) is a genetic region in jawed vertebrates that contains key genes involved in the immune response. Associations between the MHC and avian malaria infections in wild birds have been observed and mainly explored in the Northern Hemisphere, while a general lack of information remains in the Southern Hemisphere. Here, we investigated the associations between the MHC genes and infections with Plasmodium and Haemoproteus blood parasites along a latitudinal gradient in South America. We sampled 93 rufous-collared sparrows (Zonotrichia capensis) individuals from four countries, Colombia, Ecuador, Peru, and Chile, and estimated MHC-I and MHC-II allele diversity. We detected between 1-4 (MHC-I) and 1-6 (MHC-II) amino acidic alleles per individual, with signs of positive selection. We obtained generalized additive mixed models to explore the associations between MHC-I and MHC-II diversity and latitude. We also explored the relationship between infection status and latitude/biome. We found a non-linear association between the MHC-II amino acidic allele diversity and latitude. Individuals from north Chile presented a lower MHC genetic diversity than those from other locations. We also found an association between deserts and xeric shrublands and a lower prevalence of Haemoproteus parasites. Our results support a lower MHC genetic in arid or semi-arid habitats in the region with the lower prevalence of Haemoproteus parasites.
Assuntos
Frutas , Genes de Plantas , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Padrões de Referência , Regulação da Expressão Gênica de Plantas , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
Functional annotation based on Gene Ontology has provided a structured and comprehensive system to access the current knowledge about the function of genes. For model plants such as Arabidopsis thaliana, there is a constant updating and restructuring of the functional annotation that increases the reliability of the analyses that use it. For tomato (Solanum lycopersicum), a crop widely used as a model plant for the study of fleshy fruits, there is no functional annotation, at least not freely accessible, even though its genome has long been sequenced and annotated. In this work, we generated, using a simplified version of the maize GAMER pipeline, a tomato Gene Ontology functional annotation with 72.42% (ITAG3.2) and 74.2% (ITAG4.0) of protein-coding genes with at least one GO term association. With this dataset, we share a reliable and easy-to-use tool with the tomato community.
RESUMO
Forensic genomic systems allow simultaneously analyzing identity informative (iiSNPs), ancestry informative (aiSNPs), and phenotype informative (piSNPs) genetic markers. Among these kits, the ForenSeq DNA Signature prep (Verogen) analyzes identity STRs and SNPs as well as 24 piSNPs from the HIrisPlex system to predict the hair and eye color. We report herein these 24 piSNPs in 88 samples from Monterrey City (Northeast, Mexico) based on the ForenSeq DNA Signature prep. Phenotypes were predicted by genotype results with both Universal Analysis Software (UAS) and the web tool of the Erasmus Medical Center (EMC). We observed predominantly brown eyes (96.5%) and black hair (75%) phenotypes, whereas blue eyes, and blond and red hair were not observed. Both UAS and EMC showed high performance in eye color prediction (p ≥ 96.6%), but a lower accuracy was observed for hair color prediction. Overall, UAS hair color predictions showed better performance and robustness than those obtained with the EMC web tool (when hair shade is excluded). Although we employed a threshold (p > 70%), we suggest using the EMC enhanced approach to avoid the exclusion of a high number of samples. Finally, although our results are helpful to employ these genomic tools to predict eye color, caution is suggested for hair color prediction in Latin American (admixed) populations such as those studied herein, principally when no black color is predicted.
Assuntos
Cor de Olho , Cor de Cabelo , Humanos , Cor de Olho/genética , Cor de Cabelo/genética , México , Genótipo , DNA/genéticaRESUMO
The TATA box is a promoter sequence able to interact directly with the components of the basal transcription initiation machinery. We investigate the changes in the electronic and magnetic properties of a TATA-DNA sequence when functionalized with different chemical groups; using the first-principles density functional theory specifically, the TATA-DNA sequences were functionalized with methyl groups (CH3 , methylation), amino groups (NH2 , amination), imine groups (NH, imination), chloroamine groups (NCl2 , chloramination), H-adatom (hydrogenation), and Cl-adatom (chlorination). The functional groups were anchored at nitrogen atoms from adenine and oxygen atoms from thymine at sites pointed as reactive regions. We demonstrated that chemical functionalization induces significant changes in charge transfer, hydrogen bond distance, and hydrogen bond energy. The hydrogenation and imination increased the hydrogen bond energy. Results also revealed that the chemical functionalization of DNA molecules exhibit a ferromagnetic ground state, reaching magnetization up to 4.665 µB and complex magnetic ordering. We further demonstrated that the functionalization could induce tautomerism (proton migration in the base pair systems). The present study provides a theoretical basis for understanding the functionalization further into DNA molecules and visualizing possible future applications.
Assuntos
DNA , Eletrônica , Sequência de Bases , Regiões Promotoras Genéticas , Fenômenos MagnéticosRESUMO
Two divergent genetic lineages have been described for the endangered green turtle in the Pacific Ocean, occurring sympatrically in some foraging grounds. Chile has seven known green turtle foraging grounds, hosting mainly juveniles of different lineages. Unfortunately, anthropic factors have led to the decline or disappearance of most foraging aggregations. We investigated age-class/sex structure, morphological variation, genetic diversity and structure, and health status of turtles from two mainland (Bahia Salado and Playa Chinchorro) and one insular (Easter Island) Chilean foraging grounds. Bahia Salado is composed of juveniles, and with Playa Chinchorro, exclusively harbors individuals of the north-central/eastern Pacific lineage, with Galapagos as the major genetic contributor. Conversely, Easter Island hosts juveniles and adults from both the eastern Pacific and French Polynesia. Morphological variation was found between lineages and foraging grounds, suggesting an underlying genetic component but also an environmental influence. Turtles from Easter Island, unlike Bahia Salado, exhibited injuries/alterations probably related to anthropic threats. Our findings point to establishing legal protection for mainland Chile's foraging grounds, and to ensure that the administrative plan for Easter Island's marine protected area maintains ecosystem health, turtle population viability, and related cultural and touristic activities.
RESUMO
BACKGROUND: STR allele frequency databases from populations are necessary to take full advantage of the increased power of discrimination offered by massively parallel sequencing (MPS) platforms. MATERIAL AND METHODS: For this reason, we sequenced 58 STRs (aSTRs, X-STRs, and Y-STRs) and 94 identity informative SNPs (iiSNPs) on 105 Mestizo (admixed) individuals from Monterrey City (Northeast, Mexico), with the Primer Set-A of the ForenSeq™ DNA Signature Prep Kit. RESULTS: Most of the STR markers were in Hardy Weinberg equilibrium, with a few exceptions. We found 346 different length-based alleles for these 58 STRs; nevertheless, they became 528 alleles when the sequence was assessed. The combined power of discrimination from autosomal STRs (aSTRs) was -virtually- 100% in both length and sequence-based alleles, while the power of exclusion was 99.9999999976065 and 99.9999999999494%, respectively. Haplotypes based on X-STRs and Y-STRs showed 100% of discriminatory capacity. CONCLUSIONS: These results provide -for the first time- forensic genomic population data from Mexico necessary for interpretation in kinship and criminal analyses.
Assuntos
Impressões Digitais de DNA , Polimorfismo de Nucleotídeo Único , DNA , Frequência do Gene/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , México , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNARESUMO
Regulatory factor MBF1 is highly conserved between species and has been described as a cofactor and transcription factor. In plants, several reports associate MBF1 with heat stress response. Nevertheless, the specific physical processes involved in the MBF1-DNA interaction are still far from clearly understood. We thus performed extensive molecular dynamics simulations of DNA with a homology-based modethel of the MBF1 protein. Based on recent experimental data, we proposed two B-DNA sequences, analyzing their interaction with our model of the Arabidopsis MBF1c protein (AtMBF1c) at three different temperatures: 293, 300, and 320 K, maintaining a constant pressure of 1 bar. The simulations suggest that MBF1 binds directly to the DNA, supporting the idea of its role as a transcription factor. We identified two different conformations of the MBF1 protein when bound, and characterized the specific groups of amino acids involved in the formation of the DNA-MBF1 complex. These regions of amino acids are bound mostly to the minor groove of DNA by the attraction of positively charged residues and the negatively charged backbone, but subject to the compatibility of shapes, much in the sense of a lock-and-key mechanism. We found that only with a sequence rich in CTAGA motifs at 300 K does MBF1 bind to DNA in the DNA-binding domain Cro/C1-type HTH predicted. In the rest of the systems tested, we observed non-specific DNA-MBF1 interactions. This study complements findings previously reported by others on the role of CTAGA as a DNA-binding element for MBF1c at a heat stress temperature.
Assuntos
Simulação de Dinâmica Molecular , Fatores de Transcrição , Aminoácidos , DNA , Resposta ao Choque Térmico , Fatores de Transcrição/genéticaRESUMO
Este artigo tem como objetivo discutir os efeitos da escuta do sofrimento a partir do dispositivo da clínica psicanalítica num relato de um caso atendido em um serviço de saúde hospitalar. A urgência médica faz parte da rotina dos profissionais da saúde, que têm a missão de salvar vidas em um curto espaço de tempo seguindo condutas previamente estabelecidas. A urgência subjetiva é um assunto que diz da prática da clínica psicanalítica, especialmente nas instituições de saúde, onde encontramos sujeitos que, ao passar por um momento de adoecimento, muitas vezes desencadeiam uma experiência de intensa angústia. Nessas situações, trabalhar na dimensão do tempo lógico, conforme proposto por Lacan (1945/1998), é um recurso analítico para tratar do sujeito que está num momento de ruptura com o simbólico. A oferta de uma escuta clínica possibilita uma abertura no tempo para a palavra diante do mal-estar subjetivo despertado pelo encontro do real (AU).
The objective in this article is discusses the effects of listening to suffering from the perspective of the psychoanalytic clinic in a report of a case attended in a hospital health service. Medical urgency is part of the routine of health professionals, whose mission is to save lives quickly following previously established protocols. The subjective urgency belongs to the practice of the psychoanalytic clinic, especially in health institutions, where we find subjects who, when passing through a moment of illness, often trigger intense anguish. In these situations, working in the dimension of logical time, as proposed by Lacan (1945/1998), is an analytical resource to treat the subject in a moment of rupture with the symbolic. Clinical listening allows an opening in time for the word in the face of the subjective turmoil aroused by the encounter of the real (AU).
Este artículo tiene como objetivo discutir los efectos de la escucha del sufrimiento desde el dispositivo del psicoanálisis em un reporte de caso atendido en un servicio de salud. La urgencia médica es parte de la rutina del os profesionales de la salud, cuya misión es salvar vidas siguiendo procedimientos previamente establecidos en un corto periodo de tiempo. La urgencia subjetiva es un tema que concierne a la práctica de la clínica psicoanalítica, especialmente em las instituciones de salud, donde encontramos sujetos que están pasando por un período de enfermedad que a menudo desencadena una experiencia de angustia intensa. En estas situaciones, trabajar em la dimensión del tiempo lógico, según el propuesto por Lacan (1945/1998), es un recurso analítico para tratar do sujeto que se encuentra en un momento de ruptura con lo simbólico. La oferta de una escucha clínica permite una apertura em el tempo, para la palabra antes del malestar subjetivo despertado por el encuentro con el real (AU).
Assuntos
Humanos , Ansiedade , Tempo , Vida , Emergências , Instalações de Saúde , Serviços de SaúdeRESUMO
The Multiprotein Bridging Factor 1 (MBF1) proteins are transcription co-factors whose molecular function is to form a bridge between transcription factors and the basal machinery of transcription. MBF1s are present in most archaea and all eukaryotes, and numerous reports show that they are involved in developmental processes and in stress responses. In this review we summarize almost three decades of research on the plant MBF1 family, which has mainly focused on their role in abiotic stress responses, in particular the heat stress response. However, despite the amount of information available, there are still many questions that remain about how plant MBF1 genes, transcripts, and proteins respond to stress, and how they in turn modulate stress response transcriptional pathways.
Assuntos
Proteínas de Plantas , Plantas/genética , Estresse Fisiológico , Fatores de Transcrição , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Bioinformatic analysis of small RNA sequencing libraries consists of transforming a series of small RNA sequencing experiment fastq files into a table containing small RNA sequences and their abundance. This is achieved by cleaning the reads, aligning the cleaned reads to a reference, and parsing the alignment results. In this protocol we present the most common option, and the rationale, for each of these steps.
Assuntos
MicroRNAs/genética , Algoritmos , Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de RNA/métodos , SoftwareRESUMO
Plants have developed mechanisms that allow them to tolerate different abiotic stresses. Among these mechanisms, the accumulation of specific proteins such as dehydrins (DHNs) and aquaporins (AQPs) can protect other proteins from damage during dehydration and may allow the control of water loss, respectively. Although both types of proteins are involved in plant protection against dehydration stress, a direct interaction between them has not been explored. A previous screen to identify potential OpsDHN1 protein interactions revealed an aquaporin as a possible candidate. Here, we used the Bimolecular Fluorescence Complementation (BiFC) approach to investigate the direct interaction of the cactus OpsDHN1 protein with the Arabidopsis plasma membrane PIP family aquaporin AtPIP2B (At2G37170). Since AtPIP2B is a membrane protein and OpsDHN1 is a cytosolic protein that may be peripherally associated with membranes, we propose that OpsDHN1/AtPIP2B interaction takes place at cellular membranes. Furthermore, we also demonstrate the interaction of AtPIP2B with the three Arabidopsis dehydrins COR47 (AT1G20440), ERD10 (At1g20450), and RAB18 (At5g66400).
Assuntos
Aquaporinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Cactaceae/metabolismo , Proteínas de Plantas/metabolismo , Mapas de Interação de ProteínasRESUMO
Copper (Cu) is an essential micronutrient for all aerobic forms of life. Its oxidation states (Cu+ /Cu2+ ) make this metal an important cofactor of enzymes catalyzing redox reactions in essential biological processes. In gram-negative bacteria, Cu uptake is an unexplored component of a finely regulated trafficking network, mediated by protein-protein interactions that deliver Cu to target proteins and efflux surplus metal to avoid toxicity. Rhizobium etliCFN42 is a facultative symbiotic diazotroph that must ensure its appropriate Cu supply for living either free in the soil or as an intracellular symbiont of leguminous plants. In crop fields, rhizobia have to contend with copper-based fungicides. A detailed deletion analysis of the pRet42e (505 kb) plasmid from an R. etli mutant with enhanced CuCl2 tolerance led us to the identification of the ropAe gene, predicted to encode an outer membrane protein (OMP) with a ß-barrel channel structure that may be involved in Cu transport. In support of this hypothesis, the functional characterization of ropAe revealed that: (I) gene disruption increased copper tolerance of the mutant, and its complementation with the wild-type gene restored its wild-type copper sensitivity; (II) the ropAe gene maintains a low basal transcription level in copper overload, but is upregulated when copper is scarce; (III) disruption of ropAe in an actP (copA) mutant background, defective in copper efflux, partially reduced its copper sensitivity phenotype. Finally, BLASTP comparisons and a maximum likelihood phylogenetic analysis highlight the diversification of four RopA paralogs in members of the Rhizobiaceae family. Orthologs of RopAe are highly conserved in the Rhizobiales order, poorly conserved in other alpha proteobacteria and phylogenetically unrelated to characterized porins involved in Cu or Mn uptake.
Assuntos
Cobre/metabolismo , Porinas/genética , Porinas/metabolismo , Rhizobium etli/genética , Rhizobium etli/metabolismo , Transporte Biológico , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Teste de Complementação GenéticaRESUMO
The whole-genome sequences of three strains of Rhizobium gallicum reported here support the concept that the distinct nodulation host ranges displayed by the symbiovars gallicum and phaseoli can be largely explained by different symbiotic plasmids.
RESUMO
The mitochondrial proteome is mostly composed of nuclear-encoded proteins. Such polypeptides are synthesized with signals that guide their intracellular transport to the surface of the organelle and later within the different mitochondrial subcompartments until they reach their functional destination. It has been suggested that the nascent-polypeptide associated complex (NAC) - a cytosolic chaperone that recognizes nascent chains on translationally active ribosomes - has a role in the import of nuclear-encoded mitochondrial proteins. However, the molecular mechanisms that regulate the NAC-mediated cotranslational import are still not clear. Here, we show that a particular NAC heterodimer formed by subunits α and ß' in Saccharomyces cerevisiae is specifically involved in the process of mitochondrial import and functionally cooperates with Sam37, an outer membrane protein subunit of the sorting and assembly machinery complex. Mutants in both components display growth defects, incorrectly accumulate precursor forms of mitochondrial proteins in the cytosol, and have an altered mitochondrial protein content. We propose that αß'-NAC and Sam37 are members of the system that recognizes mitochondrial proteins at early stages of their synthesis, escorting them to the import machinery of mitochondria.
Assuntos
Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/química , Chaperonas Moleculares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Transporte Biológico , Citosol/química , Citosol/metabolismo , Proteínas de Membrana/química , Mitocôndrias/química , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Chaperonas Moleculares/química , Biossíntese de Proteínas/genética , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Ribossomos/química , Ribossomos/metabolismo , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/químicaRESUMO
In most eukaryotic cells mitochondria are essential organelles involved in a great variety of cellular functions. One of the physiological processes linked to mitochondria is aging, a gradual process of damage accumulation that eventually promotes cell death. Aging depends on a balance between mitochondrial biogenesis, function and degradation. It has been previously shown that Tor1, Sch9 and Ras2 are activated in response to nutrient availability and regulate cell growth and division. A deficiency in any of these genes promotes lifespan extension and cell protection during oxidative and heat shock stress. In this work we report that in Saccharomyces cerevisiae, the uncharacterized mitochondrial protein Slm35 is functionally linked with the TOR signaling pathway. A Δtor1Δslm35 strain shows a severe decrease in lifespan and is unable to contend with oxidative and heat shock stresses. Specifically, this mutant shows decreased catalase activity indicating a misregulation of ROS scavenging mechanisms. In this study we show that Slm35 is also relevant for mitochondrial network dynamics and mitophagy. The results presented here suggest that Slm35 plays an important role connecting mitochondrial function with cytosolic responses and cell adaptation to stress and aging.
Assuntos
Longevidade/fisiologia , Mitocôndrias/fisiologia , Proteínas Mitocondriais/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Estresse Fisiológico/fisiologia , Regulação Fúngica da Expressão Gênica , Temperatura Alta , Proteínas Mitocondriais/genética , Oxirredução , Proteínas Serina-Treonina Quinases/genética , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
La hipernatremia crónica se presenta en neonatos con deshidratación secundaria a baja ingesta de leche materna debida a mala técnica de lactancia, se establece progresivamente y se acompaña de gran pérdida de peso. Requiere corrección lenta para evitar complicaciones neurológicas. La rehidratación oral con soluciones de baja osmolaridad constituye una alternativa de tratamiento segura y eficaz, permite la reposición de volumen, recuperación de peso y corrección de los niveles elevados de natremia en forma gradual.
Chronic hypernatremia occurs in infants with dehydration secondary to low breast milk intake due to poor breastfeeding technique, gradually established and is accompanied by severe weight loss. It requires slow correction to avoid neurological complications. Oral Rehydration Solutions (ORS) of low osmolarity are a safe and effective alternative treatment. ORS of low osmolarity allow volume replacement, weight recovery and gradually correction of the elevated serum sodium levels.
Assuntos
Hipernatremia , Leite Humano , Redução de Peso , HidrataçãoRESUMO
Elucidating molecular links between cell-fate regulatory networks and dynamic patterning modules is a key for understanding development. Auxin is important for plant patterning, particularly in roots, where it establishes positional information for cell-fate decisions. PIN genes encode plasma membrane proteins that serve as auxin efflux transporters; mutations in members of this gene family exhibit smaller roots with altered root meristems and stem-cell patterning. Direct regulators of PIN transcription have remained elusive. Here, we establish that a MADS-box gene (XAANTAL2, XAL2/AGL14) controls auxin transport via PIN transcriptional regulation during Arabidopsis root development; mutations in this gene exhibit altered stem-cell patterning, root meristem size, and root growth. XAL2 is necessary for normal shootward and rootward auxin transport, as well as for maintaining normal auxin distribution within the root. Furthermore, this MADS-domain transcription factor upregulates PIN1 and PIN4 by direct binding to regulatory regions and it is required for PIN4-dependent auxin response. In turn, XAL2 expression is regulated by auxin levels thus establishing a positive feedback loop between auxin levels and PIN regulation that is likely to be important for robust root patterning.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ácidos Indolacéticos/metabolismo , Proteínas de Domínio MADS/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Arabidopsis/genética , Proteínas de Domínio MADS/genética , Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/fisiologiaRESUMO
The biogenesis of hydrophobic membrane proteins involves their cotranslational membrane integration in order to prevent their unproductive aggregation. In the cytosol of bacteria and eukaryotes, membrane targeting of ribosomes that synthesize membrane proteins is achieved by signal recognition particles (SRPs) and their cognate membrane-bound receptors. As is evident from the genomes of fully sequenced eukaryotes, mitochondria generally lack an SRP system. Instead, mitochondrial ribosomes are physically associated with the protein insertion machinery in the inner membrane. Accordingly, deletion of ribosome-binding sites on the Oxa1 insertase and the Mba1 ribosome receptor in yeast leads to severe defects in cotranslational protein insertion and results in respiration-deficient mutants. In this study, we expressed mitochondria-targeted versions of the bacterial SRP protein Ffh and its receptor FtsY in these yeast mutants. Interestingly, Ffh was found to bind to the large subunit of mitochondrial ribosomes, and could relieve, to some degree, the defect of these insertion mutants. Although FtsY could also bind to mitochondrial membranes, it did not improve membrane protein biogenesis in this strain, presumably because of its inability to interact with Ffh. Hence, mitochondrial ribosomes are still able to interact physically and functionally with the bacterial SRP system. Our observations are consistent with a model according to which the protein insertion system in mitochondria evolved in three steps. The loss of genes for hydrophilic polypeptides (step 1) allowed the development of ribosome-binding sites on membrane proteins (step 2), which finally made the existence of an SRP-mediated system dispensable (step 3).
Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Nucleares/metabolismo , Partícula de Reconhecimento de Sinal/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Western Blotting , Complexo IV da Cadeia de Transporte de Elétrons/genética , Eletroforese em Gel de Poliacrilamida , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mitocôndrias/genética , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Modelos Genéticos , Mutação , Proteínas Nucleares/genética , Ligação Proteica , Biossíntese de Proteínas/genética , Transporte Proteico , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Partícula de Reconhecimento de Sinal/genéticaRESUMO
Flowers are the most complex structures of plants. Studies of Arabidopsis thaliana, which has typical eudicot flowers, have been fundamental in advancing the structural and molecular understanding of flower development. The main processes and stages of Arabidopsis flower development are summarized to provide a framework in which to interpret the detailed molecular genetic studies of genes assigned functions during flower development and is extended to recent genomics studies uncovering the key regulatory modules involved. Computational models have been used to study the concerted action and dynamics of the gene regulatory module that underlies patterning of the Arabidopsis inflorescence meristem and specification of the primordial cell types during early stages of flower development. This includes the gene combinations that specify sepal, petal, stamen and carpel identity, and genes that interact with them. As a dynamic gene regulatory network this module has been shown to converge to stable multigenic profiles that depend upon the overall network topology and are thus robust, which can explain the canalization of flower organ determination and the overall conservation of the basic flower plan among eudicots. Comparative and evolutionary approaches derived from Arabidopsis studies pave the way to studying the molecular basis of diverse floral morphologies.