Schizosaccharomyces versatilis represents a distinct evolutionary lineage of fission yeast.

The fission yeast species Schizosaccharomyces japonicus is currently divided into two varieties-S. japonicus var. japonicus and S. japonicus var. versatilis. Here we examine the var. versatilis isolate CBS5679. The CBS5679 genome shows 88% identity to the reference genome of S. japonicus var. japonicus at the coding sequence level, with phylogenetic analyses suggesting that it has split from the S. japonicus lineage 25 million years ago. The CBS5679 genome contains a reciprocal translocation between chromosomes 1 and 2, together with several large inversions. The products of genes linked to the major translocation are associated with 'metabolism' and 'cellular assembly' ontology terms. We further show that CBS5679 does not generate viable progeny with the reference strain of S. japonicus. Although CBS5679 shares closer similarity to the 'type' strain of var. versatilis as compared to S. japonicus, it is not identical to the type strain, suggesting population structure within var. versatilis. We recommend that the taxonomic status of S. japonicus var. versatilis is raised, with it being treated as a separate species, Schizosaccharomyces versatilis.

Divergence of cytokinesis and dimorphism control by myosin II regulatory light chain in fission yeasts.

Non-muscle myosin II activation by regulatory light chain (Rlc1Sp) phosphorylation at Ser35 is crucial for cytokinesis during respiration in the fission yeast Schizosaccharomyces pombe. We show that in the early divergent and dimorphic fission yeast S. japonicus non-phosphorylated Rlc1Sj regulates the activity of Myo2Sj and Myp2Sj heavy chains during cytokinesis. Intriguingly, Rlc1Sj-Myo2Sj nodes delay yeast to hyphae onset but are essential for mycelial development. Structure-function analysis revealed that phosphorylation-induced folding of Rlc1Sp α1 helix into an open conformation allows precise regulation of Myo2Sp during cytokinesis. Consistently, inclusion of bulky tryptophan residues in the adjacent α5 helix triggered Rlc1Sp shift and supported cytokinesis in absence of Ser35 phosphorylation. Remarkably, unphosphorylated Rlc1Sj lacking the α1 helix was competent to regulate S. pombe cytokinesis during respiration. Hence, early diversification resulted in two efficient phosphorylation-independent and -dependent modes of Rlc1 regulation of myosin II activity in fission yeasts, the latter being conserved through evolution.

Myosin II regulatory light chain phosphorylation and formin availability modulate cytokinesis upon changes in carbohydrate metabolism.

Cytokinesis, the separation of daughter cells at the end of mitosis, relies in animal cells on a contractile actomyosin ring (CAR) composed of actin and class II myosins, whose activity is strongly influenced by regulatory light chain (RLC) phosphorylation. However, in simple eukaryotes such as the fission yeast Schizosaccharomyces pombe, RLC phosphorylation appears dispensable for regulating CAR dynamics. We found that redundant phosphorylation at Ser35 of the S. pombe RLC homolog Rlc1 by the p21-activated kinases Pak1 and Pak2, modulates myosin II Myo2 activity and becomes essential for cytokinesis and cell growth during respiration. Previously, we showed that the stress-activated protein kinase pathway (SAPK) MAPK Sty1 controls fission yeast CAR integrity by downregulating formin For3 levels (Gómez-Gil et al., 2020). Here, we report that the reduced availability of formin For3-nucleated actin filaments for the CAR is the main reason for the required control of myosin II contractile activity by RLC phosphorylation during respiration-induced oxidative stress. Thus, the restoration of For3 levels by antioxidants overrides the control of myosin II function regulated by RLC phosphorylation, allowing cytokinesis and cell proliferation during respiration. Therefore, fine-tuned interplay between myosin II function through Rlc1 phosphorylation and environmentally controlled actin filament availability is critical for a successful cytokinesis in response to a switch to a respiratory carbohydrate metabolism.

Specific Functional Features of the Cell Integrity MAP Kinase Pathway in the Dimorphic Fission Yeast Schizosaccharomyces japonicus.

Mitogen activated protein kinase (MAPK) signaling pathways execute essential functions in eukaryotic organisms by transducing extracellular stimuli into adaptive cellular responses. In the fission yeast model Schizosaccharomyces pombe the cell integrity pathway (CIP) and its core effector, MAPK Pmk1, play a key role during regulation of cell integrity, cytokinesis, and ionic homeostasis. Schizosaccharomyces japonicus, another fission yeast species, shows remarkable differences with respect to S. pombe, including a robust yeast to hyphae dimorphism in response to environmental changes. We show that the CIP MAPK module architecture and its upstream regulators, PKC orthologs Pck1 and Pck2, are conserved in both fission yeast species. However, some of S. pombe's CIP-related functions, such as cytokinetic control and response to glucose availability, are regulated differently in S. japonicus. Moreover, Pck1 and Pck2 antagonistically regulate S. japonicus hyphal differentiation through fine-tuning of Pmk1 activity. Chimeric MAPK-swapping experiments revealed that S. japonicus Pmk1 is fully functional in S. pombe, whereas S. pombe Pmk1 shows a limited ability to execute CIP functions and promote S. japonicus mycelial development. Our findings also suggest that a modified N-lobe domain secondary structure within S. japonicus Pmk1 has a major influence on the CIP signaling features of this evolutionarily diverged fission yeast.

Negative control of cytokinesis by stress-activated MAPK signaling.

Mitogen-activated protein kinase (MAPK) signalling pathways regulate multiple cellular functions in eukaryotic organisms in response to environmental cues, including the dynamic remodeling of the actin cytoskeleton. The fission yeast S. pombe is an optimal model to investigate the conserved regulatory mechanisms of cytokinesis, which relies in an actomyosin-based contractile ring (CAR) that prompts the physical separation of daughter cells during cellular division. Our group has recently shown that p38 MAPK ortholog Sty1, the core component of the stress-activated pathway (SAPK), negatively modulates CAR assembly and integrity in S. pombe during actin cytoskeletal damage induced with Latrunculin A and in response to environmental stress. This response involves downregulation of protein levels of the formin For3, which assembles actin filaments for cables and the CAR, likely through an ubiquitin-mediated degradation mechanism. Contrariwise, Sty1 function positively reinforces CAR assembly during stress in the close relative dimorphic fission yeast S. japonicus. The opposite effect of SAPK signaling on CAR integrity may represent an evolutionary refined adaptation to cope with the marked differences in cytokinesis onset in both fission yeast species.

Stress-activated MAPK signaling controls fission yeast actomyosin ring integrity by modulating formin For3 levels.

Cytokinesis, which enables the physical separation of daughter cells once mitosis has been completed, is executed in fungal and animal cells by a contractile actin- and myosin-based ring (CAR). In the fission yeast Schizosaccharomyces pombe, the formin For3 nucleates actin cables and also co-operates for CAR assembly during cytokinesis. Mitogen-activated protein kinases (MAPKs) regulate essential adaptive responses in eukaryotic organisms to environmental changes. We show that the stress-activated protein kinase pathway (SAPK) and its effector, MAPK Sty1, downregulates CAR assembly in S. pombe when its integrity becomes compromised during cytoskeletal damage and stress by reducing For3 levels. Accurate control of For3 levels by the SAPK pathway may thus represent a novel regulatory mechanism of cytokinesis outcome in response to environmental cues. Conversely, SAPK signaling favors CAR assembly and integrity in its close relative Schizosaccharomyces japonicus, revealing a remarkable evolutionary divergence of this response within the fission yeast clade.

RNA-Binding Protein Rnc1 Regulates Cell Length at Division and Acute Stress Response in Fission Yeast through Negative Feedback Modulation of the Stress-Activated Mitogen-Activated Protein Kinase Pathway.

RNA-binding proteins (RBPs) play a major role during control of mRNA localization, stability, and translation and are central to most cellular processes. In the fission yeast Schizosaccharomyces pombe, the multiple K homology (KH) domain RBP Rnc1 downregulates the activity of the cell integrity pathway (CIP) via stabilization of pmp1+ mRNA, which encodes the Pmp1 phosphatase that inactivates Pmk1, the mitogen-activated protein kinase (MAPK) component of this signaling cascade. However, Rnc1 likely regulates the half-life/stability of additional mRNAs. We show that Rnc1 downregulates the activity of Sty1, the MAPK of the stress-activated MAPK pathway (SAPK), during control of cell length at division and recovery in response to acute stress. Importantly, this control strictly depends on Rnc1's ability to bind mRNAs encoding activators (Wak1 MAPKKK, Wis1 MAPKK) and downregulators (Atf1 transcription factor, Pyp1 and Pyp2 phosphatases) of Sty1 phosphorylation through its KH domains. Moreover, Sty1 is responsible for Rnc1 phosphorylation in vivo at multiple phosphosites during growth and stress, and these modifications trigger Rnc1 for proper binding and destabilization of the above mRNA targets. Phosphorylation by Sty1 prompts Rnc1-dependent mRNA destabilization to negatively control SAPK signaling, thus revealing an additional feedback mechanism that allows precise tuning of MAPK activity during unperturbed cell growth and stress.IMPORTANCE Control of mRNA localization, stability, turnover, and translation by RNA-binding proteins (RBPs) influences essential processes in all eukaryotes, including signaling by mitogen-activated protein kinase (MAPK) pathways. We describe that in the fission yeast Schizosaccharomyces pombe the RBP Rnc1 negatively regulates cell length at division during unperturbed growth and recovery after acute stress by reducing the activity of the MAPK Sty1, which regulates cell growth and differentiation during environmental cues. This mechanism relies on Rnc1 binding to specific mRNAs encoding both enhancers and negative regulators of Sty1 activity. Remarkably, multiple phosphorylation of Rnc1 by Sty1 favors RBP binding and destabilization of the above mRNAs. Thus, posttranscriptional modulation of MAP kinase signaling by RNA-binding proteins emerges as a major regulatory mechanism that dictates the growth cycle and cellular adaptation in response to the changing environment in eukaryotic organisms.

Functional interaction between Cdc42 and the stress MAPK signaling pathway during the regulation of fission yeast polarized growth.

Cell polarization can be defined as the generation and maintenance of directional cellular organization. The spatial distribution and protein or lipid composition of the cell are not symmetric but organized in specialized domains which allow cells to grow and acquire a certain shape that is closely linked to their physiological function. The establishment and maintenance of polarized growth requires the coordination of diverse processes including cytoskeletal dynamics, membrane trafficking, and signaling cascade regulation. Some of the major players involved in the selection and maintenance of sites for polarized growth are Rho GTPases, which recognize the polarization site and transmit the signal to regulatory proteins of the cytoskeleton. Additionally, cytoskeletal organization, polarized secretion, and endocytosis are controlled by signaling pathways including those mediated by mitogen-activated protein kinases (MAPKs). Rho GTPases and the MAPK signaling pathways are strongly conserved from yeast to mammals, suggesting that the basic mechanisms of polarized growth have been maintained throughout evolution. For this reason, the study of how polarized growth is established and regulated in simple organisms such as the fission yeast Schizosaccharomyces pombe has contributed to broaden our knowledge about these processes in multicellular organisms. We review here the function of the Cdc42 GTPase and the stress activated MAPK (SAPK) signaling pathways during fission yeast polarized growth, and discuss the relevance of the crosstalk between both pathways.

Correction: Quorum sensing and stress-activated MAPK signaling repress yeast to hypha transition in the fission yeast Schizosaccharomyces japonicus.

[This corrects the article DOI: 10.1371/journal.pgen.1008192.].

Quorum sensing and stress-activated MAPK signaling repress yeast to hypha transition in the fission yeast Schizosaccharomyces japonicus.

Quorum sensing (QS), a mechanism of microbial communication dependent on cell density, governs developmental decisions in many bacteria and in some pathogenic and non-pathogenic fungi including yeasts. In these simple eukaryotes this response is mediated by the release into the growth medium of quorum-sensing molecules (QSMs) whose concentration increases proportionally to the population density. To date the occurrence of QS is restricted to a few yeast species. We show that a QS mediated by the aromatic alcohols phenylethanol and tryptophol represses the dimorphic yeast to hypha differentiation in the fission yeast S. japonicus in response to an increased population density. In addition, the stress activated MAPK pathway (SAPK), which controls cell cycle progression and adaptation to environmental changes in this organism, constitutively represses yeast to hypha differentiation both at transcriptional and post-translational levels. Moreover, deletion of its main effectors Sty1 MAPK and Atf1 transcription factor partially suppressed the QS-dependent block of hyphal development under inducing conditions. RNAseq analysis showed that the expression of nrg1+, which encodes a putative ortholog of the transcription factor Nrg1 that represses yeast to hypha dimorphism in C. albicans, is downregulated both by QS and the SAPK pathway. Remarkably, Nrg1 may act in S. japonicus as an activator of hyphal differentiation instead of being a repressor. S. japonicus emerges as an attractive and amenable model organism to explore the QS mechanisms that regulate cellular differentiation in fungi.

Differential functional regulation of protein kinase C (PKC) orthologs in fission yeast.

The two PKC orthologs Pck1 and Pck2 in the fission yeast Schizosaccharomyces pombe operate in a redundant fashion to control essential functions, including morphogenesis and cell wall biosynthesis, as well as the activity of the cell integrity pathway and its core element, the MAPK Pmk1. We show here that, despite the strong structural similarity and functional redundancy of these two enzymes, the mechanisms regulating their maturation, activation, and stabilization have a remarkably distinct biological impact on both kinases. We found that, in contrast to Pck2, putative in vivo phosphorylation of Pck1 within the conserved activation loop, turn, and hydrophobic motifs is essential for Pck1 stability and biological functions. Constitutive Pck activation promoted dephosphorylation and destabilization of Pck2, whereas it enhanced Pck1 levels to interfere with proper downstream signaling to the cell integrity pathway via Pck2. Importantly, although catalytic activity was essential for Pck1 function, Pck2 remained partially functional independent of its catalytic activity. Our findings suggest that early divergence from a common ancestor in fission yeast involved important changes in the mechanisms regulating catalytic activation and stability of PKC family members to allow for flexible and dynamic control of downstream functions, including MAPK signaling.

Embarazo en adolescentes de Jalisco, México: una mirada desde la marginación social / Adolescent pregnancy in Jalisco Mexico: a view from social marginalization

Objetivo: Analizar las condiciones socioculturales, atención prenatal y obstétrica, y del recién nacido, en mujeres adolescentes embarazadas residentes de municipios con muy alta y muy baja marginación, en Jalisco, México durante 2014. Diseño: Estudio cuantitativo, descriptivo transversal. Institución. Secretaría de Salud Jalisco. Participantes: Adolescentes residentes de municipios de muy alta y de muy baja marginación. Metodología: Se revisaron certificados de nacimientos de adolescentes residentes de Jalisco atendidas de parto durante 2014, 140 fueron adolescentes residentes de municipios de muy alta marginación y 21 004 de municipios de muy baja marginación. Principales medidas de resultados: Análisis univariado de condiciones socioculturales, atención prenatal y obstétrica, además de datos del recién nacido. Resultados: Se registraron 28 178 nacimientos; de muy alta marginación (Grupo 1) fueron n=140 (0,5%) y de muy baja marginación (Grupo 2) fueron n=21 004 (74,5%). Del Grupo 1, la media de edad fue 17,1 años, 18,5% tenía 15 años o menos, 41,4% primaria o menos, media del número de embarazos fue 1,35; 20% no recibió atención prenatal, la media del número de consultas era 3,1, el 91% tuvo resolución obstétrica por parto normal, la media del peso de recién nacido fue 3 032,10 gramos. Del Grupo 2 la media de la edad fue 17,5 años, 22,7% era soltera, media del número de embarazos 1,34, media del número de consultas 6,7; el 45,2% tuvo resolución obstétrica por cesárea y la media del peso de recién nacidos fue 3 101,67 gramos. Conclusiones: Existieron diferencias porcentuales y de medias entre los grupos, en características socioculturales (escolaridad, estado civil y seguridad social) y las relacionadas con atención prenatal y obstétrica (control prenatal y resolución del embarazo).

Objective: To analyze the sociocultural conditions, prenatal and obstetrical care, and data of the newborn, in pregnant young women residing in municipalities with very high and very low marginalization in Jalisco, Mexico, in 2014. Design: Quantitative, descriptive cross-sectional study. Institution: Jalisco Health Secretariat. Participants: Adolescents residents of both highly and very low marginalization municipalities. Methodology: Birth certificates of 140 adolescents residing in highly marginalized municipalities (Group 1) and 21 004 residing in municipalities with very low marginalization (Group 2) in Jalisco, Mexico, and who delivered a child during 2014, were reviewed. Main outcome measures: Univariate analysis of social and cultural conditions, prenatal and obstetrical care, data of the newborn. Results: From 28 178 births, 140 (0.5%) adolescents belonged to highly marginalized births (Group 1) and 21 004 (74.5%) occurred in adolescentes of very low marginalization adolescents (Group 2). The average age in Group 1 was 17.1 years, 18.5% were 15 years or less; 41.4% had elementary school or care, the mean number of pregnancies was 1.35; 20% did not receive prenatal care, the mean number of consultations was 3.1, 91% had normal delivery, the average newborn birth weight was 3 032.10 grams. The second group's mean age was 17,5 years , 22.7 % were single, the average number of pregnancies 1.34, the mean number of consultations 6.6 , 45.2% had caesarean section, and the average weight of newborns was 3 101.67 grams. Conclusions: There were differences between groups in sociocultural characteristics (education, marital status and social security) and those related to prenatal and obstetrical care (prenatal and pregnancy resolution).

Newborns and low to moderate prenatal environmental lead exposure: might fathers be the key?

This study is part of the BioMadrid Project, a bio-monitoring study designed to assess pollutants in the environment surrounding children born in the Madrid region. Our aim in this report is to evaluate the association between prenatal lead exposure and fetal development using three biological samples (maternal and paternal blood lead at around 34 weeks of gestation as well as cord blood lead levels), three biomarkers of effect in cord blood peripheral lymphocytes (micronucleus in binucleated cells, nucleoplasmic bridges, and nuclear buds), and different anthropometrical characteristics at birth. Maternal and cord blood lead were not associated with newborn measurements or genotoxicity biomarkers. In contrast, increases in father blood lead were coupled with lower weight (mean difference (MD), -110.8 g; 95% confidence intervals (95%CI), -235.6 to 6.00; p < 0.10) and shorter abdominal (MD, -0.81 cm; 95%CI, -1.64 to 0.00; p < 0.05) and cephalic (MD, -0.32 cm; 95%CI, -0.65 to 0.00; p < 0.05) circumferences at birth as well as with the presence of nucleoplasmic bridges (odds ratio, 1.03; 95%CI, 1.00 to 1.06; p < 0.05) and nuclear buds (odds ratio, 1.02; 95%CI, 0.99 to 1.04; p < 0.10). These associations were mainly confined to female babies, in whom paternal lead was also inversely associated with length. Our results support the hypothesis that paternal lead exposure may be affecting the development of newborns.

Lead, mercury and cadmium in umbilical cord blood and its association with parental epidemiological variables and birth factors.

BACKGROUND: In Spain, few studies have evaluated prenatal exposure to heavy metals. The objective of this study was to describe lead, mercury and cadmium concentrations in blood from a sample of newborn-mother-father trios, as well as to investigate the association between metals in cord blood and parental variables. We also explored the relationship between cord blood metal concentrations and child characteristics at birth. METHODS: Metal correlations among family members were assessed using Spearman Rank Correlation Coefficient. Linear regression was used to explore the association between parental variables and log-transformed cord blood lead and cord blood mercury concentrations. In the case of cadmium, tobit regression was used due to the existence of samples below the detection limit. The association between cord blood metal concentrations and child characteristics at birth was evaluated using linear regression. RESULTS: Geometric means for lead, mercury and cadmium were 14.09 µg/L, 6.72 µg/L and 0.27 µg/L in newborns; 19.80 µg/L, 3.90 µg/L and 0.53 µg/L in pregnant women; and 33.00 µg/L, 5.38 µg/L and 0.49 µg/L in men. Positive correlations were found between metal concentrations among members of the trio. Lead and cadmium concentrations were 15% and 22% higher in newborns from mothers who smoked during pregnancy, while mercury concentrations were 25% higher in newborns from mothers with greater fish intake. Cord-blood lead levels showed seasonal periodicity, with lower concentrations observed in winter. Cord blood cadmium concentrations over 0.29 µg/L were associated with lower 1-minute and 5-minute Apgar scores. CONCLUSIONS: These results reinforce the need to establish biomonitoring programs in Spain, and provide support for tobacco smoke and fish consumption as important preventable sources of heavy metal exposure in newborns. Additionally, our findings support the hypothesis that cadmium exposure might be deleterious to fetal development.

Mercury, lead and cadmium in human milk in relation to diet, lifestyle habits and sociodemographic variables in Madrid (Spain).

BACKGROUND: Although breastfeeding is the ideal way of nurturing infants, it can be a source of exposure to toxicants. This study reports the concentration of Hg, Pb and Cd in breast milk from a sample of women drawn from the general population of the Madrid Region, and explores the association between metal levels and socio-demographic factors, lifestyle habits, diet and environmental exposures, including tobacco smoke, exposure at home and occupational exposures. METHODS: Breast milk was obtained from 100 women (20 mL) at around the third week postpartum. Pb, Cd and Hg levels were determined using Atomic Absorption Spectrometry. Metal levels were log-transformed due to non-normal distribution. Their association with the variables collected by questionnaire was assessed using linear regression models. Separate models were fitted for Hg, Pb and Cd, using univariate linear regression in a first step. Secondly, multivariate linear regression models were adjusted introducing potential confounders specific for each metal. Finally, a test for trend was performed in order to evaluate possible dose-response relationships between metal levels and changes in variables categories. RESULTS: Geometric mean Hg, Pb and Cd content in milk were 0.53 µg L(-1), 15.56 µg L(-1), and 1.31 µg L(-1), respectively. Decreases in Hg levels in older women and in those with a previous history of pregnancies and lactations suggested clearance of this metal over lifetime, though differences were not statistically significant, probably due to limited sample size. Lead concentrations increased with greater exposure to motor vehicle traffic and higher potato consumption. Increased Cd levels were associated with type of lactation and tended to increase with tobacco smoking. CONCLUSIONS: Surveillance for the presence of heavy metals in human milk is needed. Smoking and dietary habits are the main factors linked to heavy metal levels in breast milk. Our results reinforce the need to strengthen national food safety programs and to further promote avoidance of unhealthy behaviors such as smoking during pregnancy.

Cytogenetic status in newborns and their parents in Madrid: the BioMadrid study.

Monitoring cytogenetic damage is frequently used to assess population exposure to environmental mutagens. The cytokinesis-block micronucleus assay is one of the most widely used methods employed in these studies. In the present study we used this assay to assess the baseline frequency of micronuclei in a healthy population of father-pregnant woman-newborn trios drawn from two Madrid areas. We also investigated the association between micronucleus frequency and specific socioeconomic, environmental, and demographic factors collected by questionnaire. Mercury, arsenic, lead, and cadmium blood levels were measured by atomic absorption spectrometry. The association between micronucleated cell frequency and the variables collected by questionnaire, as well as, the risk associated with the presence of elevated levels of metals in blood, was estimated using Poisson models, taking the number of micronucleated cells in 1,000 binucleated cells (MNBCs) as the dependent variable. Separate analyses were conducted for the 110 newborns, 136 pregnant women, and 134 fathers in whom micronuclei could be assessed. The mean number of micronucleated cells per 1,000 binucleated cells was 3.9, 6.5, and 6.1 respectively. Our results show a statistically significant correlation in MNBC frequency between fathers and mothers, and between parents and newborns. Elevated blood mercury levels in fathers were associated with significantly higher MNBC frequency, compared with fathers who had normal mercury levels (RR:1.21; 95%CI:1.02-1.43). This last result suggests the need to implement greater control over populations which, by reason of their occupation or life style, are among those most exposed to this metal.

Biomonitoring of exposure to environmental pollutants in newborns and their parents in Madrid, Spain (BioMadrid): study design and field work results.

In Spain environmental surveillance has mainly relied on measures of selected pollutants in air, water, food and soil. A study was conducted in Madrid to assess the feasibility of implementing a surveillance system of exposure among the general population to specific environmental pollutants, using bio-markers. The project was basically focused on the environment surrounding newborns. Hence, the study population was made up of 145 triplets of pregnant women at around 8 months' gestation, their partners, and newborns from two areas, representing the two main types of urban environments in the region, i.e., the City of Madrid and its outlying metropolitan belt. Multiple biologic substrates were collected from each participant in order to assess the most suitable samples for an environmental surveillance system. The selected contaminants represent the main agents to which a population like that of Madrid is exposed every day, including certain heavy metals, persistent organic pollutants and polycyclic aromatic hydrocarbons, as well as micronuclei in peripheral blood, a commonly used unspecific index of cytogenetic damage. In addition, passive air samplers were placed around subjects' place of residence. This paper reports in detail on the design and response rates, summarizes field work results, and discusses some lessons learned.

Biomonitorización de la exposición a contaminantes ambientales en recién nacidos y sus progenitores en Madrid [BioMadrid]: diseño del estudio y resultados del trabajo de campo / Biomonitoring of exposure to environmental pollutants in newborns and their parents in Madrid, Spain (BioMadrid): study design and field work results

In Spain environmental surveillance has mainly relied on measuresof selected pollutants in air, water, food and soil. A studywas conducted in Madrid to assess the feasibility of implementinga surveillance system of exposure among the generalpopulation to specific environmental pollutants, using biomarkers.The project was basically focused on the environmentsurrounding newborns. Hence, the study population was madeup of 145 triplets of pregnant women at around 8 months’ gestation,their partners, and newborns from two areas, representingthe two main types of urban environments in the region,i.e., the City of Madrid and its outlying metropolitan belt.Multiple biologic substrates were collected from each participantin order to assess the most suitable samples for an environmentalsurveillance system. The selected contaminantsrepresent the main agents to which a population like that ofMadrid is exposed every day, including certain heavy metals,persistent organic pollutants and polycyclic aromatic hydrocarbons,as well as micronuclei in peripheral blood, a commonlyused unspecific index of cytogenetic damage. In addition,passive air samplers were placed around subjects’ placeof residence. This paper reports in detail on the design andresponse rates, summarizes field work results, and discussessome lessons learned(AU)

En España, la vigilancia medioambiental se basa principalmenteen medidas de ciertos contaminantes en muestrasde aire, agua, alimentos y suelos. En Madrid se ha realizadoun estudio para valorar la posibilidad de poner en marchaun sistema de vigilancia de exposiciones a contaminantesambientales en la población general utilizando biomarcadores.El proyecto ha tenido como eje el estudio del entornode los recién nacidos. Por tanto, la población de estudio laconstituyen 145 ®tríos» formados por mujeres en su octavomes de embarazo, sus parejas y los recién nacidos de dosáreas geográficas, que representan los dos principales entornosurbanos de la región, es decir, Madrid capital y su áreametropolitana. Se recogieron múltiples sustratos biológicosde cada participante con el objeto de valorar las muestrasmás adecuadas para un sistema de vigilancia de exposicionesambientales. Los contaminantes elegidos representan losprincipales agentes tóxicos a los que una población como lade Madrid está expuesta diariamente, e incluyen metales pesados,contaminantes orgánicos persistentes e hidrocarburosaromáticos policíclicos; se ha añadido también una medidainespecífica de daño citogenético, los micronúcleos ensangre periférica. Además, se han colocado muestreadorespasivos de aire en los alrededores del domicilio de los participantes.Este artículo describe en detalle el diseño del estudioy la tasa de respuesta, resume los resultados del trabajode campo y comenta algunas enseñanzas prácticas deéste(AU)