RESUMO
Acidic soils, where aluminum (Al) toxicity is a major agricultural constraint, are globally widespread and are prevalent in developing countries. In sorghum, the root citrate transporter SbMATE confers Al tolerance by protecting root apices from toxic Al3+, but can exhibit reduced expression when introgressed into different lines. We show that allele-specific SbMATE transactivation occurs and is caused by factors located away from SbMATE Using expression-QTL mapping and expression genome-wide association mapping, we establish that SbMATE transcription is controlled in a bipartite fashion, primarily in cis but also in trans Multiallelic promoter transactivation and ChIP analyses demonstrated that intermolecular effects on SbMATE expression arise from a WRKY and a zinc finger-DHHC transcription factor (TF) that bind to and trans-activate the SbMATE promoter. A haplotype analysis in sorghum RILs indicates that the TFs influence SbMATE expression and Al tolerance. Variation in SbMATE expression likely results from changes in tandemly repeated cis sequences flanking a transposable element (a miniature inverted repeat transposable element) insertion in the SbMATE promoter, which are recognized by the Al3+-responsive TFs. According to our model, repeat expansion in Al-tolerant genotypes increases TF recruitment and, hence, SbMATE expression, which is, in turn, lower in Al-sensitive genetic backgrounds as a result of lower TF expression and fewer binding sites. We thus show that even dominant cis regulation of an agronomically important gene can be subjected to precise intermolecular fine-tuning. These concerted cis/trans interactions, which allow the plant to sense and respond to environmental cues, such as Al3+ toxicity, can now be used to increase yields and food security on acidic soils.
Assuntos
Alumínio/toxicidade , Proteínas de Transporte de Ânions/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Sorghum/efeitos dos fármacos , Proteínas de Transporte de Ânions/genética , Cromossomos de Plantas/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Locos de Características Quantitativas/genética , Sorghum/genética , Sorghum/metabolismo , Sequências de Repetição em Tandem/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
A region of 160 kb at Xp21.2 has been defined as dosage-sensitive sex reversal (DSS) and includes the NR0B1 gene, considered to be the candidate gene involved in XY gonadal dysgenesis if overexpressed. We describe a girl with 46,XY partial gonadal dysgenesis carrying a 297 kb duplication at Xp21.2 upstream of NR0B1 initially detected by chromosomal microarray analysis. Fine mapping of the breakpoints by whole-genome sequencing showed a tandem duplication of TASL (CXorf21), GK and partially TAB3, upstream of NR0B1. This is the first description of an Xp21.2 duplication upstream of NR0B1 associated with 46,XY partial gonadal dysgenesis.
Assuntos
Disgenesia Gonadal 46 XY , Feminino , Humanos , Receptor Nuclear Órfão DAX-1/genética , Disgenesia Gonadal 46 XY/genéticaRESUMO
BACKGROUND: Phosphorus (P) fixation on aluminum (Al) and iron (Fe) oxides in soil clays restricts P availability for crops cultivated on highly weathered tropical soils, which are common in developing countries. Hence, P deficiency becomes a major obstacle for global food security. We used multi-trait quantitative trait loci (QTL) mapping to study the genetic architecture of P efficiency and to explore the importance of root traits on sorghum grain yield on a tropical low-P soil. RESULTS: P acquisition efficiency was the most important component of P efficiency, and both traits were highly correlated with grain yield under low P availability. Root surface area was positively associated with grain yield. The guinea parent, SC283, contributed 58% of all favorable alleles detected by single-trait mapping. Multi-trait mapping detected 14 grain yield and/or root morphology QTLs. Tightly linked or pleiotropic QTL underlying the surface area of fine roots (1-2 mm in diameter) and grain yield were detected at positions 1-7 megabase pairs (Mb) and 71 Mb on chromosome 3, respectively, and a root diameter/grain yield QTL was detected at 7 Mb on chromosome 7. All these QTLs were near sorghum homologs of the rice serine/threonine kinase, OsPSTOL1. The SbPSTOL1 genes on chromosome 3, Sb03g006765 at 7 Mb and Sb03g031690 at 60 Mb were more highly expressed in SC283, which donated the favorable alleles at all QTLs found nearby SbPSTOL1 genes. The Al tolerance gene, SbMATE, may also influence a grain yield QTL on chromosome 3. Another PSTOL1-like gene, Sb07g02840, appears to enhance grain yield via small increases in root diameter. Co-localization analyses suggested a role for other genes, such as a sorghum homolog of the Arabidopsis ubiquitin-conjugating E2 enzyme, phosphate 2 (PHO2), on grain yield advantage conferred by the elite parent, BR007 allele. CONCLUSIONS: Genetic determinants conferring higher root surface area and slight increases in fine root diameter may favor P uptake, thereby enhancing grain yield under low-P availability in the soil. Molecular markers for SbPSTOL1 genes and for QTL increasing grain yield by non-root morphology-based mechanisms hold promise in breeding strategies aimed at developing sorghum cultivars adapted to low-P soils.
Assuntos
Fósforo/metabolismo , Locos de Características Quantitativas/genética , Sorghum/metabolismo , Grão Comestível/metabolismo , Raízes de Plantas/metabolismo , Solo , Sorghum/genéticaRESUMO
Low soil phosphorus (P) availability is a major constraint for crop production in tropical regions. The rice (Oryza sativa) protein kinase, PHOSPHORUS-STARVATION TOLERANCE1 (OsPSTOL1), was previously shown to enhance P acquisition and grain yield in rice under P deficiency. We investigated the role of homologs of OsPSTOL1 in sorghum (Sorghum bicolor) performance under low P. Association mapping was undertaken in two sorghum association panels phenotyped for P uptake, root system morphology and architecture in hydroponics and grain yield and biomass accumulation under low-P conditions, in Brazil and/or in Mali. Root length and root surface area were positively correlated with grain yield under low P in the soil, emphasizing the importance of P acquisition efficiency in sorghum adaptation to low-P availability. SbPSTOL1 alleles reducing root diameter were associated with enhanced P uptake under low P in hydroponics, whereas Sb03g006765 and Sb03g0031680 alleles increasing root surface area also increased grain yield in a low-P soil. SbPSTOL1 genes colocalized with quantitative trait loci for traits underlying root morphology and dry weight accumulation under low P via linkage mapping. Consistent allelic effects for enhanced sorghum performance under low P between association panels, including enhanced grain yield under low P in the soil in Brazil, point toward a relatively stable role for Sb03g006765 across genetic backgrounds and environmental conditions. This study indicates that multiple SbPSTOL1 genes have a more general role in the root system, not only enhancing root morphology traits but also changing root system architecture, which leads to grain yield gain under low-P availability in the soil.
Assuntos
Oryza/enzimologia , Fósforo/análise , Proteínas de Plantas/fisiologia , Solo/química , Sorghum/metabolismo , Desequilíbrio de Ligação , Oryza/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Sorghum/crescimento & desenvolvimentoRESUMO
OBJECTIVE: It was to verify the association between the definition of sex of rearing and, clinical and cytogenetic features among patients with genital ambiguity referred without a sex assignment. METHODS: The sample consisted of 133 patients with genital ambiguity seen at a single reference service. These patients did not have a defined social sex at the first consultation and their etiological diagnosis was obtained during follow-up. RESULTS: A total of 133 cases were included, 74 of which were reared as males and 59 as females. No correlation was found between the year of birth and the year of the first consultation with the definition of sex of rearing. However, the definition of sex of rearing was associated with age at the first consultation, severity of genital ambiguity, presence of palpable gonad(s), presence of uterus on ultrasound, karyotype, and diagnosis. Palpable gonad(s), more virilized genitalia, absence of a uterus on ultrasound, 46, XY karyotype, or a karyotype with sex chromosome abnormalities emerged as strong predictors for defining male sex. All 77 (58 %) patients over 18 years old had a gender identity in accordance with the sex of rearing; though 9 of 77 (12 %) had homo or bisexual orientation, especially girls with Congenital Adrenal Hyperplasia. CONCLUSIONS: Clinical and cytogenetic data were strongly associated with the definition of the sex of rearing of children with genital ambiguity referred to a DSD center without sex assignment. Management in a specialized center allows the establishment of a gender identity in accordance with the sex of rearing.
RESUMO
INTRODUCTION: Although it was common in the 1970s-1990s to assign female gender of rearing to 46,XY infants with limited virilization of varying etiologies, including those with partial androgen insensitivity syndrome (PAIS), long-term data on outcomes for these individuals are sparse. Therefore, our goal was to use the power of an international registry to evaluate clinical features, surgical management, and pubertal data in patients with a molecularly confirmed diagnosis of PAIS who were born before 2008 and were raised as girls. METHODS: The current study interrogated the International Disorders of Sex Development Registry for available data on management and pubertal outcomes in individuals with genetically confirmed PAIS who were raised as girls. RESULTS: Among the 11 individuals who fulfilled the key criteria for inclusion, the external masculinization score (EMS) at presentation ranged from 2 to 6 (median 5); 7 girls underwent gonadectomy before the age of 9 years, whereas 4 underwent gonadectomy in the teenage years (≥ age 13). Clitoral enlargement at puberty was reported for 3 girls (27%) who presented initially at the time of puberty with intact gonads. In the 9 individuals (82%) for whom gonadal pathology data were provided, there was no evidence of germ cell tumor at median age of 8.1 years. All girls received estrogen replacement, and 8/11 had attained Tanner stage 4-5 breast development at the last assessment. CONCLUSION: In general, although it appears that female assignment in PAIS is becoming uncommon, our data provide no evidence to support the practice of prophylactic prepubertal gonadectomy with respect to the risk of a germ cell tumor.
Assuntos
Síndrome de Resistência a Andrógenos , Neoplasias Embrionárias de Células Germinativas , Masculino , Lactente , Adolescente , Humanos , Feminino , Criança , Síndrome de Resistência a Andrógenos/patologia , Gônadas/patologia , Castração , Desenvolvimento Sexual , Neoplasias Embrionárias de Células Germinativas/patologiaRESUMO
INTRODUCTION: The aim of this retrospective study was to verify the association between the time of diagnosis and initial and final sex assignment in a disorder of sex development (DSD) diagnostic group, looking at the age of the patients at first visit, severity of genital ambiguity, and karyotype. METHODS: The time of diagnosis was divided into 3 groups: before 2000, between 2000 and 2006, and after 2006. Data were categorized and analyzed using the χ2 test with α < 0.05. RESULTS: A total of 567 cases were analyzed; 307 were assigned as male, 135 as female, and 125 remained undefined at the first visit. After clinical and laboratory evaluations, 369 patients were male and 198 were female. Neither initial nor final sex assignment proportions changed over time, but there were significant differences in the age at first visit, with referral occurring at an earlier age, as well as more severe genital ambiguity presentations, a higher proportion of sex chromosome aberrations, and a lower frequency of 46,XX DSD cases. This occurred both in the sample as a whole (567 cases) and in the group of 125 patients without definitive sex assignment at the first visit. The results were similar when only 284 patients aged less than 12 months at the first visit were analyzed. DISCUSSION/CONCLUSION: Over time, there were no changes in sex assignment proportions, but there was an increased awareness of the need for early referral and changes in clinical, cytogenetic, and diagnostic aspects.
Assuntos
Transtornos do Desenvolvimento Sexual , Humanos , Masculino , Feminino , Lactente , Estudos Retrospectivos , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/diagnóstico , Desenvolvimento Sexual , Cariotipagem , CariótipoRESUMO
Aluminum (Al) toxicity on acid soils adversely affects maize yields, which can be overcome by combining soil amendments with genetic tolerance. In maize, ZmMATE1 confers Al tolerance via Al-activated citrate release, whereby citrate forms non-toxic complexes with Al3+ in the rhizosphere. Here, we investigated Al tolerance mechanisms in maize germplasm originated from Kenya based on quantitative trait loci (QTL) mapping. Five QTLs and four epistatic interactions explained ~51% of the phenotypic variation for Al tolerance. The lack of Al tolerance QTL on chromosome 6 and the much lower expression of ZmMATE1 in both Kenyan lines than in Cateto Al237, which donates the superior allele of ZmMATE1, strongly indicate that this gene does not play a significant role in Al tolerance in neither parent. In turn, maize homologs to genes previously implicated in Al tolerance in other species, ZmNrat1, ZmMATE3, ZmWRKY and ZmART1, co-localized with Al tolerance QTL and were more highly expressed in the parent that donate favorable QTL alleles. However, these candidate genes will require further studies for functional validation on maize Al tolerance. The existence of Al tolerance mechanisms independent from ZmMATE1 suggests it is possible to develop highly Al tolerant cultivars by pyramiding complementary Al tolerance genes in maize.
Assuntos
Alumínio/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Regulação da Expressão Gênica de Plantas , Zea mays/efeitos dos fármacos , Alelos , Mapeamento Cromossômico , Epistasia Genética , Perfilação da Expressão Gênica , Ligação Genética , Genótipo , Quênia , Modelos Genéticos , Fenótipo , Raízes de Plantas/metabolismo , Locos de Características Quantitativas , Rizosfera , Zea mays/genética , Zea mays/metabolismoRESUMO
OBJECTIVE: To evaluate, in a sample of patients with disorders of sex development (DSD), data related to the age at referral and their correlation with the initial complaints, gender at referral, defined gender after diagnosis and etiological diagnosis. METHODS: Retrospective review of the age at the first consultation and the reason for it, initial social gender and gender after the diagnosis, karyotype and etiological diagnosis of all cases treated at a DSD outpatient clinic between 1989 and 2016. Cases that did not involve DSD and DSD diagnoses that do not usually involve ambiguous genitalia, thus not requiring specialized monitoring, were excluded. RESULTS: Of the 1793 treated cases, 1139 were diagnosed with some type of DSD. This study excluded 430 cases (272 with Turner's syndrome, 66 with Klinefelter syndrome, and 92 with pure gonadal dysgenesis), thus a total 709 individuals were included. Of these, 82.9% were referred due to ambiguous genitalia; only one-quarter were still in the first month of life, and 6.6% were referred due to pubertal delay, with most of them aged 10 years or older. Of these patients, 68.6% had a diagnosis of XY DSD, 22.4% of XX DSD, and 9% of sex chromosome abnormalities. CONCLUSIONS: This study presents the largest series in the literature of patients with DSD treated in a single center. The time of referral of the majority of patients with ambiguous genitalia fell short of the ideal, and milder cases of ambiguous genitalia and many with pubertal manifestations were referred even later. The results reinforce the importance of continuing education for professionals who will have the first contact with these patients, mainly pediatricians and neonatologists.
Assuntos
Transtornos do Desenvolvimento Sexual , Criança , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/terapia , Humanos , Cariótipo , Pediatras , Estudos RetrospectivosRESUMO
Abstract Objective: To evaluate, in a sample of patients with disorders of sex development (DSD), data related to the age at referral and their correlation with the initial complaints, gender at referral, defined gender after diagnosis and etiological diagnosis. Methods: Retrospective review of the age at the first consultation and the reason for it, initial social gender and gender after the diagnosis, karyotype and etiological diagnosis of all cases treated at a DSD outpatient clinic between 1989 and 2016. Cases that did not involve DSD and DSD diagnoses that do not usually involve ambiguous genitalia, thus not requiring specialized monitoring, were excluded. Results: Of the 1793 treated cases, 1139 were diagnosed with some type of DSD. This study excluded 430 cases (272 with Turner's syndrome, 66 with Klinefelter syndrome, and 92 with pure gonadal dysgenesis), thus a total 709 individuals were included. Of these, 82.9% were referred due to ambiguous genitalia; only one-quarter were still in the first month of life, and 6.6% were referred due to pubertal delay, with most of them aged 10 years or older. Of these patients, 68.6% had a diagnosis of XY DSD, 22.4% of XX DSD, and 9% of sex chromosome abnormalities. Conclusions: This study presents the largest series in the literature of patients with DSD treated in a single center. The time of referral of the majority of patients with ambiguous genitalia fell short of the ideal, and milder cases of ambiguous genitalia and many with pubertal manifestations were referred even later. The results reinforce the importance of continuing education for professionals who will have the first contact with these patients, mainly pediatricians and neonatologists.
Resumo Objetivo: Avaliar em uma amostra de pacientes com distúrbios da diferenciação do sexo (DDS), dados relacionados à idade, ao encaminhamento e sua correlação com as queixas iniciais, ao sexo ao encaminhamento e ao sexo final e diagnóstico etiológico. Métodos: Revisão retrospectiva da idade por ocasião da primeira consulta e motivo dela, sexo social inicial e após definição do diagnóstico, cariótipo e diagnóstico etiológico de todos os casos atendidos em um ambulatório especializado em DDS entre 1989 e 2016. Foram excluídos casos que não compreendiam DDS e diagnósticos de DDS que não cursam comumente com ambiguidade genital, não necessitam de acompanhamento especializado. Resultados: Dos 1.793 casos atendidos, 1.139 foram diagnosticados com algum DDS. Excluíram-se 430 (272 síndrome de Turner, 66 síndrome de Klinefelter e 92 disgenesia gonadal pura), totalizando 709. Desses, 82,9% foram encaminhados por ambiguidade genital, somente um quarto ainda no primeiro mês de vida e 6,6% por atraso puberal, a maioria com 10 anos ou mais; 68,6% tiveram diagnóstico de DDS XY; 22,4% DDS XX e 9% de anomalias dos cromossomos sexuais. Conclusões: Este estudo apresenta a maior casuística na literatura de pacientes com DDS atendidos em um único serviço. O momento de encaminhamento da maioria dos pacientes com ambiguidade genital foi aquém do ideal e casos mais leves de ambiguidade e muitos com manifestações puberais foram encaminhados ainda mais tardiamente. Os resultados reforçam a importância do ensino continuado a profissionais que terão o primeiro contato com esses pacientes, principalmente pediatras e neonatologistas.