Innovation, conservation, and repurposing of gene function in root cell type development.

Plant species have evolved myriads of solutions, including complex cell type development and regulation, to adapt to dynamic environments. To understand this cellular diversity, we profiled tomato root cell type translatomes. Using xylem differentiation in tomato, examples of functional innovation, repurposing, and conservation of transcription factors are described, relative to the model plant Arabidopsis. Repurposing and innovation of genes are further observed within an exodermis regulatory network and illustrate its function. Comparative translatome analyses of rice, tomato, and Arabidopsis cell populations suggest increased expression conservation of root meristems compared with other homologous populations. In addition, the functions of constitutively expressed genes are more conserved than those of cell type/tissue-enriched genes. These observations suggest that higher order properties of cell type and pan-cell type regulation are evolutionarily conserved between plants and animals.

Transcriptional regulation of nitrogen-associated metabolism and growth.

Nitrogen is an essential macronutrient for plant growth and basic metabolic processes. The application of nitrogen-containing fertilizer increases yield, which has been a substantial factor in the green revolution1. Ecologically, however, excessive application of fertilizer has disastrous effects such as eutrophication2. A better understanding of how plants regulate nitrogen metabolism is critical to increase plant yield and reduce fertilizer overuse. Here we present a transcriptional regulatory network and twenty-one transcription factors that regulate the architecture of root and shoot systems in response to changes in nitrogen availability. Genetic perturbation of a subset of these transcription factors revealed coordinate transcriptional regulation of enzymes involved in nitrogen metabolism. Transcriptional regulators in the network are transcriptionally modified by feedback via genetic perturbation of nitrogen metabolism. The network, genes and gene-regulatory modules identified here will prove critical to increasing agricultural productivity.

Translational regulation contributes to the elevated CO2 response in two Solanum species.

Understanding the impact of elevated CO2 (eCO2 ) in global agriculture is important given climate change projections. Breeding climate-resilient crops depends on genetic variation within naturally varying populations. The effect of genetic variation in response to eCO2 is poorly understood, especially in crop species. We describe the different ways in which Solanum lycopersicum and its wild relative S. pennellii respond to eCO2 , from cell anatomy, to the transcriptome, and metabolome. We further validate the importance of translational regulation as a potential mechanism for plants to adaptively respond to rising levels of atmospheric CO2 .

Skeletal muscle: from birth to old age, routes to mechanical and metabolic failure. / Músculo esquelético: del nacimiento a la vejez, rutas hacia la falla mecánica y metabólica.

Skeletal muscle (SM) is the most abundant tissue and the largest reservoir of protein in the body. It transports glucose in an insulin dependent manner by the glucose transporter type 4 (GLUT4) and contributes in the maintenance of serum amino acids concentration. By its mass and energetic requirements, it is fundamental for the systemic metabolic balance. In the present work, we present the effect of gestational undernourishment (GU) on the mechanical and metabolic properties of SM at birth and in old age in an animal model. Mechanical studies were performed on isolated muscles, while the GLUT4, amino acid transporters LAT2, SNAT2 and insulin receptors (IR) determination were performed on isolated transverse-tubule membranes (TT). The GU in offspring at birth, results in low muscle mass with increased contraction force and resistance to fatigue. However, in two-years old rats, there was muscle hypotrophy and sarcopenia, the force decreased between 50 and 70% in control rats and rats with GU respectively, accompanied by a lower expression of LAT2, SNAT2 and IR in TT. In conclusion, GU irreversibly affects the SM, an effect that could be similar in humans, which help us to understand the events that associate the GU with the metabolic debacle of SM and the metabolic diseases of human adulthood.

Sexual onset and contraceptive use among adolescents from poor neighbourhoods in Managua, Nicaragua.

BACKGROUND AND OBJECTIVES: The prevalence of teenage pregnancies in Nicaragua is the highest in Latin-America. This study aimed to gain insight into factors which determine the sexual behaviours concerned. METHODS: From July until August 2011, a door-to-door survey was conducted among adolescents living in randomly selected poor neighbourhoods of Managua. Logistic regression was used to analyse factors related to sexual onset and contraceptive use. RESULTS: Data from 2803 adolescents were analysed. Of the 475 and 299 sexually active boys and girls, 43% and 54%, respectively, reported contraceptive use. Sexual onset was positively related to increasing age, male sex, alcohol consumption and not living with the parents. Catholic boys and boys never feeling peer pressure to have sexual intercourse were more likely to report consistent condom use. Having a partner and feeling comfortable talking about sexuality with the partner were associated with hormonal contraception. CONCLUSIONS: Our data identified associates of adolescents' sexual behaviour related to personal characteristics (sex and alcohol use), to the interaction with significant others (parents, partners, peers) and to the environment (housing condition, religion). We interpreted those associates within the context of the rapidly changing society and the recently implemented health system reform in Nicaragua.

Draft Genome Sequences of 16 Halophilic Prokaryotes Isolated from Diverse Environments.

Halophile-specific enzymes have wide-ranging industrial and commercial applications. Despite their importance, there is a paucity of available halophile whole-genome sequences. Here, we report the draft genome sequences of 16 diverse salt-tolerant strains of bacteria and archaea isolated from a variety of high-salt environments.

Molecular Mechanisms Driving Switch Behavior in Xylem Cell Differentiation.

Plant xylem cells conduct water and mineral nutrients. Although most plant cells are totipotent, xylem cells are unusual and undergo terminal differentiation. Many genes regulating this process are well characterized, including the Vascular-related NAC Domain 7 (VND7), MYB46, and MYB83 transcription factors, which are proposed to act in interconnected feedforward loops (FFLs). Less is known regarding the molecular mechanisms underlying the terminal transition to xylem cell differentiation. Here, we generate whole-root and single-cell data, which demonstrate that VND7 initiates sharp switching of root cells to xylem cell identity. Based on these data, we identified 4 candidate VND7 downstream target genes capable of generating this switch. Although MYB46 responds to VND7 induction, it is not among these targets. This system provides an important model to study the emergent properties that may give rise to totipotency relative to terminal differentiation and reveals xylem cell subtypes.

Evolutionary flexibility in flooding response circuitry in angiosperms.

Flooding due to extreme weather threatens crops and ecosystems. To understand variation in gene regulatory networks activated by submergence, we conducted a high-resolution analysis of chromatin accessibility and gene expression at three scales of transcript control in four angiosperms, ranging from a dryland-adapted wild species to a wetland crop. The data define a cohort of conserved submergence-activated genes with signatures of overlapping cis regulation by four transcription factor families. Syntenic genes are more highly expressed than nonsyntenic genes, yet both can have the cis motifs and chromatin accessibility associated with submergence up-regulation. Whereas the flexible circuitry spans the eudicot-monocot divide, the frequency of specific cis motifs, extent of chromatin accessibility, and degree of submergence activation are more prevalent in the wetland crop and may have adaptive importance.

Comportamiento epidemiológico del VIH-SIDA en Panamá / Epidemiological behavior of Hiv-Aids in Panama / Comportamento epidemiológico do vírus da aids no Panamá

La infección por el Virus de la Inmunodeficiencia Humana (VIH) es un problema de salud pública mundial; que tiene efectos a nivel individual, familiar y social; así como sobre los aspectos económicos, políticos y sociales de un país. Requiere la inversión de innumerables recursos, y de la acción conjunta de personas, gobiernos, ONG y sociedad civil, para lograr su control. Es un estudio descriptivo donde se analizaron datos secundarios proporcionados por el departamento de Epidemiología del Ministerio de Salud (MINSA) sobre el comportamiento de las infecciones por VIH para el periodo 1984-2019 en la República de Panamá. Se reportaron un total de 2042 casos de VIH en este intervalo y se observó un aumento de la prevalencia en el año 2018. En Panamá, la transmisión del VIH/SIDA ha ido aumentando desde la aparición del primer caso en Panamá en el año 1984. Y el sexo más afectado son los hombres.

Abstract The Human Immunodeficiency Virus (HIV) infection is a global public health problem that has effects at the individual, family, and social level, as well as on the economic, political and social aspects of a country. It requires the investment of countless resources and the joint action of people, governments, NGOs, and civil society to achieve its control. It is a descriptive study where secondary data on the behavior of HIV infections for the period 1984-2019 in the Republic of Panama, provided by the Department of Epidemiology of the Ministry of Health (MINSA), were analyzed. A total of 2042 HIV cases were reported in this interval, and an increase in prevalence in 2018 was observed. In Panama, the transmission of HIV/AIDS has been increasing since the first case appeared in Panama in 1984, and the sex most affected is men.

Resumo: A infecção pelo Vírus da Imunodeficiência Humana (HIV) é um problema global de saúde pública; que tem efeitos nos níveis individual, familiar e social; bem como sobre os aspectos econômicos, políticos e sociais de um país. Requer o investimento de inúmeros recursos, e a ação conjunta de indivíduos, governos, ONGs e sociedade civil, para alcançar seu controle. O presente trabalho é um estudo descritivo onde foram analisados dados secundários fornecidos pelo Departamento de Epidemiologia do Ministério da Saúde (MINSA) sobre o comportamento das infecções pelo HIV para o período 1984-2019 na República do Panamá. Foram notificados 2.042 casos de HIV nesse intervalo e observado aumento da prevalência em 2018. No Panamá, a transmissão do HIV/AIDS vem aumentando desde que o primeiro caso apareceu no Panamá em 1984. E o sexo mais afetado são os homens.

Primary healthcare providers' views on improving sexual and reproductive healthcare for adolescents in Bolivia, Ecuador, and Nicaragua.

OBJECTIVES: To elicit the views of primary healthcare providers from Bolivia, Ecuador, and Nicaragua on how adolescent sexual and reproductive health (ASRH) care in their communities can be improved. METHODS: Overall, 126 healthcare providers (46 from Bolivia, 39 from Ecuador, and 41 from Nicaragua) took part in this qualitative study. During a series of moderated discussions, they provided written opinions about the accessibility and appropriateness of ASRH services and suggestions for its improvement. The data were analyzed by employing a content analysis methodology. RESULTS: Study participants emphasized managerial issues such as the prioritization of adolescents as a patient group and increased healthcare providers' awareness about adolescent-friendly approaches. They noted that such an approach needs to be extended beyond primary healthcare centers. Schools, parents, and the community in general should be encouraged to integrate issues related to ASRH in the everyday life of adolescents and become 'gate-openers' to ASRH services. To ensure the success of such measures, action at the policy level would be required. For example, decision-makers could call for developing clinical guidelines for this population group and coordinate multisectoral efforts. CONCLUSIONS: To improve ASRH services within primary healthcare institutions in three Latin American countries, primary healthcare providers call for focusing on improving the youth-friendliness of health settings. To facilitate this, they suggested engaging with key stakeholders, such as parents, schools, and decision-makers at the policy level.