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Objectives Pregnant women are likely to experience high levels of stress during the COVID-19 pandemic. However, the factors that might influence the extent of experienced emotional distress are poorly understood. Therefore, we aimed to investigate potential correlates of prenatal emotional distress during the COVID-19 pandemic. Methods In total, N = 1437 pregnant women from Germany and Switzerland participated in an online study during the first wave of the COVID-19 pandemic (May-August 2020). The survey assessed prenatal distress, pandemic-related pregnancy stress, general anxiety, fear of childbirth, and several socio-demographic, pregnancy- and COVID-19-related factors. Linear multivariate regression models were the main analytical strategy. Results The results highlight that several factors such as full-time employment, nulliparity, high-risk pregnancy, emotional problems, cancelled prenatal appointments, and stating that COVID-19 affected the choice of birth mode were significantly associated with elevated prenatal distress, anxiety, pandemic-related pregnancy stress, and fear of childbirth. Conversely, access to an outdoor space was a protective factor for pandemic-related pregnancy stress and prenatal distress. Conclusions for Practice Overall, the study highlights significant correlates influencing the levels of emotional distress pregnant women experienced during the COVID-19 pandemic. These findings may contribute to the improvement of maternal prenatal medical and psychological care during a public health crisis of international concern, such as the COVID-19 pandemic., Author(s): Rita T. Amiel Castro [sup.1] , Nora K. Schaal [sup.2] , Hannah Meyerhoff [sup.1] , Heidi Preis [sup.3] [sup.4] , Brittain Mahaffey [sup.3] , Marci Lobel [sup.3] [sup.4] , [...]

Background Primary hyperoxaluria type 1 (PH1) is an autosomal recessive disease caused by the liver defect of oxalate metabolism, which leads to kidney failure and systemic manifestations. Until recently, liver transplantation was the only definitive treatment. The timing of liver transplantation can be early, while kidney function is still normal (pre-emptive liver transplantation-PLT), or when the patient reaches stage 5 chronic kidney disease (CKD) and needs combined liver-kidney transplantation. We aimed to determine the long-term kidney outcomes of PLT in PH1 patients. Methods A retrospective single-center study of PH1 patients who were followed in our center between 1997 and 2017. We compared the kidney outcomes of patients who underwent PLT to those who presented with preserved kidney function and did not undergo PLT. Results Out of 36 PH1 patients, 18 patients were eligible for PLT (eGFR > 40 mL/min/1.73 m.sup.2 at the time of diagnosis). Seven patients underwent PLT (PLT group), while 11 continued conservative treatments (PLTn group). In the PLT group, the median eGFR at the time of PLT and at the end of the follow-up period (14-20 years) was 72 (range 50-89) and 104 (range 86-108) mL/min/1.73 m.sup.2, respectively, and no patient died or reached stage 5 CKD. In the PLTn group, eight patients (72.7%) reached stage 5 CKD (median time to kidney replacement therapy was 11 years), and two patients died from disease complications (18.2%). Conclusions Pre-emptive liver transplantation preserved kidney function in patients with PH1 in our cohort. Early intervention can prevent kidney failure and systemic oxalosis in PH1. Graphical abstract, Author(s): Hadas Shasha-Lavsky [sup.1] [sup.2] , Aviv Avni [sup.2] , Ziv Paz [sup.2] [sup.3] , Limor Kalfon [sup.4] , Amiel A. Dror [sup.2] [sup.5] , Orly Yakir [sup.6] , Tzipora [...]

: Introduction: Transfeminine adults are impacted by the HIV epidemic in the Philippines, and newly approved modalities of pre‐exposure prophylaxis (PrEP), including long‐acting injectable (LAI‐PrEP), could be beneficial for this group. To inform implementation, we analysed PrEP awareness, discussion and interest in taking LAI‐PrEP among Filipina transfeminine adults. Methods: We utilized secondary data from the #ParaSaAtin survey that sampled Filipina transfeminine adults (n = 139) and conducted a series of multivariable logistic regressions with lasso selection to explore factors independently associated with PrEP outcomes, including awareness, discussion with trans friends and interest in LAI‐PrEP. Results: Overall, 53% of Filipina transfeminine respondents were aware of PrEP, 39% had discussed PrEP with their trans friends and 73% were interested in LAI‐PrEP. PrEP awareness was associated with being non‐Catholic (p = 0.017), having previously been HIV tested (p = 0.023), discussing HIV services with a provider (p Conclusions: Implementing LAI‐PrEP in the Philippines requires addressing systemic improvements across personal, interpersonal, social and structural levels in healthcare access, including efforts to create healthcare settings and environments with providers who are trained and competent in transgender health and can address the social and structural drivers of trans health inequities, including HIV and barriers to LAI‐PrEP., INTRODUCTION Transfeminine adults are disproportionately impacted by the growing HIV epidemic in the Philippines [1]. Based on successful findings from an in‐country pre‐exposure prophylaxis (PrEP) demonstration study showing clinical effectiveness [...]

So far, gene therapies have relied on complex constructs that cannot be finely controlled.sup.1,2. Here we report a universal switch element that enables precise control of gene replacement or gene editing after exposure to a small molecule. The small-molecule inducers are currently in human use, are orally bioavailable when given to animals or humans and can reach both peripheral tissues and the brain. Moreover, the switch system, which we denote X.sup.on, does not require the co-expression of any regulatory proteins. Using X.sup.on, the translation of the desired elements for controlled gene replacement or gene editing machinery occurs after a single oral dose of the inducer, and the robustness of expression can be controlled by the drug dose, protein stability and redosing. The ability of X.sup.on to provide temporal control of protein expression can be adapted for cell-biology applications and animal studies. Additionally, owing to the oral bioavailability and safety of the drugs used, the X.sup.on switch system provides an unprecedented opportunity to refine and tailor the application of gene therapies in humans. A switch system is developed to control the expression of therapeutic genes, involving the administration of a small-molecule drug to induce splicing-mediated control of mRNA translation., Author(s): Alex Mas Monteys [sup.1] [sup.2] , Amiel A. Hundley [sup.1] , Paul T. Ranum [sup.1] , Luis Tecedor [sup.1] , Amy Muehlmatt [sup.1] , Euyn Lim [sup.1] , Dmitriy [...]

Background Co-occurrence of polycystic kidney disease and hyperinsulinemic hypoglycemia has been reported in children in a few families associated with a variant in the promotor of the PMM2 gene, at position -167 upstream of the coding sequence. PMM2 encodes phosphomannomutase 2, a key enzyme in N-glycosylation. While biallelic coding PMM2 mutations are involved in congenital disorder of glycosylation CDG1A, that particular variant in the promoter of the gene, either in the homozygous state or associated with a mutation in the coding exons of the gene, is thought to restrict the N-glycosylation defect to the kidney and the pancreas. Methods Targeted exome sequencing of a panel of genes involved in monogenic kidney diseases. Results We identified a PMM2 variant at position -167 associated with a pathogenic PMM2 variant in the coding exons in 3 families, comprising 6 cases affected with a cystic kidney disease. The spectrum of phenotypes was very broad, from extremely enlarged fetal cystic kidneys in the context of a COACH-like syndrome, to isolated cystic kidney disease with small kidneys, slowly progressing toward kidney failure in adulthood. Hypoglycemia was reported only in one case. Conclusion These data show that the PMM2 promotor variation, in trans of a PMM2 coding mutation, is associated with a wide spectrum of kidney phenotypes, and is not always associated with extra-renal symptoms. When present, extra-renal defects may include COACH-like syndrome. These data prompt screening of PMM2 in unresolved cases of fetal hyperechogenic/cystic kidneys as well as in cystic kidney disease in children and adults., Author(s): Guillaume Dorval [sup.1] [sup.2] , Cécile Jeanpierre [sup.2] , Vincent Morinière [sup.1] , Carole Tournant [sup.1] , Bettina Bessières [sup.3] , Tania Attié-Bittach [sup.3] [sup.4] , Jeanne Amiel [sup.4] [...]

Mutations of G protein-coupled receptors (GPCRs) cause various human diseases, but the mechanistic details are limited. Here, we establish p.E303K in the gene encoding the endothelin receptor type A ([ET.sub.A]R/EDNRA) as a recurrent mutation causing mandibulofacial dysostosis with alopecia (MFDA), with craniofacial changes similar to those caused by p.Y129F. Mouse models carrying either of these missense mutations exhibited a partial maxillary-to-mandibular transformation, which was rescued by deleting the ligand endothelin 3 (ET3/EDN3). Pharmacological experiments confirmed the causative [ET.sub.A]R mutations as gain of function, dependent on ET3. To elucidate how an amino acid substitution far from the ligand binding site can increase ligand affinity, we used molecular dynamics (MD) simulations. E303 is located at the intracellular end of transmembrane domain 6, and its replacement by a lysine increased flexibility of this portion of the helix, thus favoring G protein binding and leading to G protein-mediated enhancement of agonist affinity. The Y129F mutation located under the ligand binding pocket reduced the sodium-water network, thereby affecting the extracellular portion of helices in favor of ET3 binding. These findings provide insight into the pathogenesis of MFDA and into allosteric mechanisms regulating GPCR function, which may provide the basis for drug design targeting GPCRs., Introduction G protein-coupled receptor-mediated (GPCR-mediated) signal transduction plays essential roles in various pathophysiological and physiological events. Recent progress in structural biology has accelerated the mechanistic understanding of GPCR activation. In [...]

Purpose To assess the role of left ventricular overload and cumulated fluid balance in the development weaning-induced pulmonary edema (WIPO). Methods Ventilated patients in sinus rhythm with COPD and/or heart failure (ejection fraction [less than or equal to] 40%) were studied. Echocardiography was performed immediately before and during a 30-min spontaneous breathing trial (SBT) using a T-tube. Patients who failed were treated according to echocardiography results before undergoing a second SBT. Results Twelve of 59 patients failed SBT, all of them developing WIPO. Patients who succeeded SBT had lower body weight (- 2.5 kg [- 4.8; - 1] vs. + 0.75 kg [- 2.95; + 5.57]: p = 0.02) and cumulative fluid balance (- 2326 ml [- 3715; + 863] vs. + 143 ml [- 2654; + 4434]: p = 0.007) than those who developed WIPO. SBT-induced central hemodynamic changes were more pronounced in patients who developed WIPO, with higher E wave velocity (122 cm/s [92; 159] vs. 93 cm/s [74; 109]: p = 0.017) and E/A ratio (2.1 [1.2; 3.6] vs. 0.9 [0.8; 1.4]: p = 0.001), and shorter E wave deceleration time (85 ms [72; 125] vs. 147 ms [103; 175]: p = 0.004). After echocardiography-guided treatment, all patients who failed the first SBT were successfully extubated. Fluid balance was then negative (- 2224 ml [- 7056; + 100] vs. + 146 ml [- 2654; + 4434]: p = 0.005). Left ventricular filling pressures were lower (E/E': 7.3 [5; 10.4] vs. 8.9 [5.9; 13.1]: p = 0.028); SBT-induced increase in E wave velocity (+ 10.6% [- 2.7/ + 18] vs. + 25.6% [+ 12.7/ + 49]: p = 0.037) and of mitral regurgitation area were significantly smaller. Conclusion In high-risk patients, WIPO appears related to overloaded left ventricle associated with excessive fluid balance. SBT-induced central hemodynamic changes monitored by CCE help in guiding therapy for successful weaning., Author(s): Marine Goudelin [sup.1] [sup.2], Pauline Champy [sup.1], Jean-Bernard Amiel [sup.1], Bruno Evrard [sup.1] [sup.2], Anne-Laure Fedou [sup.1] [sup.2], Thomas Daix [sup.1] [sup.2], Bruno François [sup.1] [sup.2], Philippe Vignon [sup.1] [...]

Purpose To determine the minimum number of supervised transesophageal echocardiography (TEE) that intensivists should perform to reach competence in performing and interpreting a comprehensive hemodynamic assessment in ventilated intensive care unit patients. Methods Prospective and multicentric study. Skills of 41 intensivists (trainees) with no (level 0) or little (level 1) experience in echocardiography was evaluated over a 6-month period, using a previously validated skills assessment score (/40 points). Trainees were evaluated at 1 (M1), 3 (M3) and 6 months (M6) by their tutor while performing 2 TEE examinations in ventilated patients. Competence was a priori defined by a skills assessment score >35/40 points. Results No difference in the score was observed between level 0 and level 1, except at M1 (22.2 ± 6.2 vs. 25.9 ± 4.4 points, p = 0.03). After 6 months, trainees performed a mean of 31 ± 9 supervised TEE. The score gradually increased from M1 to M6 (24 ± 6, 32 ± 3, and 35 ± 3 points, p < 0.001), regardless of trainees' initial level. A correlation was found between the number of supervised TEE and the skills assessment score (r.sup.2 = 0.60; p 35/40 points was 25, with a sensitivity of 81 % and a specificity of 93 % (area under the ROC curve: 0.91 ± 0.04). A number of 31 supervised TEE examinations predicted a score >35/40 points with a specificity close to 100 %. Conclusion The performance of at least 31 supervised examinations over 6 months is required to reach competence in TEE driven hemodynamic evaluation of ventilated patient., Author(s): Cyril Charron [sup.1] [sup.2], Philippe Vignon [sup.3] [sup.4] [sup.5], Gwenaël Prat [sup.6], Alexandre Tonnelier [sup.6], Philippe Aegerter [sup.2] [sup.7], Jean-Michel Boles [sup.6], Jean-Bernard Amiel [sup.3] [sup.4] [sup.5], Antoine Vieillard-Baron [...]

Purpose To evaluate the hemodynamic monitoring capability and safety of a single-use miniaturized transesophageal echocardiography (TEE) probe left in place in ventilated critically ill patients. Methods The probe was inserted in 94 patients and designed to be left in place for up to 72 h. Three views were obtained: the superior vena caval transverse, the mid-esophageal four-chamber, and the transgastric mid-papillary short-axis views. Observational data on the feasibility of insertion, complications, image quality, and influence on management were recorded and analyzed. Results No failure of probe insertion was observed. The nasogastric tube had to be removed in 17 % of cases. Image quality was judged as adequate or optimal in 91/94 (97 %) of cases in the superior vena caval view, 89/94 (95 %) of cases in the four-chamber view, and 86/94 (91 %) of cases in the short-axis view. The duration of monitoring was 32 ± 23 h, allowing 2.8 ± 1.6 hemodynamic evaluations per patient that led to a mean of 1.4 ± 1.5 therapeutic changes per patient. Among the 263 hemodynamic assessments, 132 (50 %) had a direct therapeutic impact in 62 patients (66 %). Two patients developed lip ulceration from the probe, and two patients had self-limited gastric bleeding. Conclusion The single-use miniaturized probe could be inserted in all patients. Image quality was acceptable in the majority of cases, and the information derived from the device was useful in making management decisions in patients with hemodynamic failure on ventilatory support. Further studies are needed to confirm the good tolerance and to compare the new device with other hemodynamic monitoring techniques., Author(s): Antoine Vieillard-Baron [sup.1] [sup.2], Michel Slama [sup.3], Paul Mayo [sup.4], Cyril Charron [sup.1] [sup.2], Jean-Bernard Amiel [sup.5] [sup.6] [sup.7], Cédric Esterez [sup.1] [sup.2], François Leleu [sup.3], Xavier Repesse [sup.1] [...]

Introduction Hereditary hearing loss is the most common sensory deficit that affects as many as 0.1-0.3% of newborns (1). Hearing impairment represents a genetically heterogeneous group of disorders that may [...], Hereditary hearing loss is the most common sensory deficit. We determined that progressive high-frequency hearing loss in 2 families of Iraqi Jewish ancestry was due to homozygosity for the protein truncating mutation SYNE4 c.228delAT. SYNE4, a gene not previously associated with hearing loss, encodes nesprin-4 (NESP4), an outer nuclear membrane (ONM) protein expressed in the hair cells of the inner ear. The truncated NESP4 encoded by the families' mutation did not localize to the ONM. NESP4 and SUN domain-containing protein 1 (SUN1), which localizes to the inner nuclear membrane (INM), are part of the linker of nucleoskeleton and cytoskeleton (LINC) complex in the nuclear envelope. Mice lacking either Nesp4 or Sun1 were evaluated for hair cell defects and hearing loss. In both [Nesp4.sup.-/-] and [Sun1.sup.-/-] mice, OHCs formed normally, but degenerated as hearing matured, leading to progressive hearing loss. The nuclei of OHCs from mutant mice failed to maintain their basal localization, potentially affecting cell motility and hence the response to sound. These results demonstrate that the LINC complex is essential for viability and normal morphology of OHCs and suggest that the position of the nucleus in sensory epithelial cells is critical for maintenance of normal hearing.

Introduction Neural crest cells (NCCs) are transient and multipotent progenitors that give rise to various cell types, including neural, endocrine, pigment, craniofacial, and conotruncal cardiac cells (1, 2). Impaired development [...], The most common forms of neurocristopathy in the autonomic nervous system are Hirschsprung disease (HSCR), resulting in congenital loss of enteric ganglia, and neuroblastoma (NB), childhood tumors originating from the sympathetic ganglia and adrenal medulla. The risk for these diseases dramatically increases in patients with congenital central hypoventilation syndrome (CCHS) harboring a nonpolyalanine repeat expansion mutation of the Paired-like homeobox 2b (PHOX2B) gene, but the molecular mechanism of pathogenesis remains unknown. We found that introducing nonpolyalanine repeat expansion mutation of the PHOX2B into the mouse Phox2b locus recapitulates the clinical features of the CCHS associated with HSCR and NB. In mutant embryos, enteric and sympathetic ganglion progenitors showed sustained sex-determining region Y (SRY) box10 (Sox10) expression, with impaired proliferation and biased differentiation toward the glial lineage. Nonpolyalanine repeat expansion mutation of PHOX2B reduced transactivation of wild-type PHOX2B on its known target, dopamine-hydroxylase (DBH), in a dominant-negative fashion. Moreover, the introduced mutation converted the transcriptional effect of PHOX2B on a Sox10 enhancer from repression to transactivation. Collectively, these data reveal that nonpolyalanine repeat expansion mutation of PHOX2B is both a dominant-negative and gain-of-function mutation. Our results also demonstrate that Sox10 regulation by PHOX2B is pivotal for the development and pathogenesis of the autonomic ganglia.

ABSTRACT From 2004 to 2009, aiming to better understand implications for its smelters, Rio Tinto Alcan conducted a detailed study of [PM.sub.2.5] and [PM.sub.10] (particulate matter [PM] ≤ 2.5 and [...]

We investigated whether Eastern Ribbon Snakes (Thamnophis sauritus (L., 1766)) use a rise in water level as a cue for emergence from hibernation. We also examined the hypotheses that snakes use temperature gradients or endogenous signals as emergence cues. Twelve artificial hibernacula were used to house 15 Ribbon Snakes. Water level and temperature were regulated. Four Ribbon Snakes emerged from hibernation without any manipulation of water level or temperature. Eight snakes emerged after thermal conditions in their hibernacula changed. Of these, one emerged after the hibernaculum was made warmer on the surface than at depth, four emerged after the room temperature was increased to 9°C, and three emerged after incandescent lights were shone on the surface of each hibernaculum. Three snakes died during hibernation. Eight snakes chose to hibernate fully submerged in water. Although the sample size is too small to draw conclusions that are statistically significant at α = 0.05, our observations collectively suggest that Ribbon Snakes do not use a rise in water level as a cue to emerge. While water-level rise does not appear to be an emergence cue, hibernation below the water table may lead to increased survivorship by decreased metabolism and elimination of the risk of desiccation. Nous cherchons a savoir si les couleuvres minces (Thamnophis sauritus (L., 1766)) utilisent l'elevation du niveau d'eau comme signal pour l'emergence de l'hibernation. Nous examinons aussi les hypotheses selon lesquelles les couleuvres utilisent des gradients thermiques on des reperes endogenes comme signaux d'emergence. Douze hibernacles artificiels ont servi a loger 15 couleuvres minces. Le niveau d'eau et la temperature y etaient contreles. Quatre couleuvres minces sont sorties d'hibernation sans aucune manipulation du niveau d'eau ni de la temperature. Huit couleuvres ont emerge apres que les conditions thermiques de leur hibernacle eurent change. Parmi celles-ci, une a emerge apres que son hibernacle ait ete rechauffe plus en surface qu'en profondeur, quatre apres que la temperature de la piece ait ete elevee a 9°C et trois apres que la surface de leur habitacle ait ete eclaire par des ampoules lumineuses incandescentes. Trois couleuvres sont mortes durant l'hibernation. Huit couleuvres ont choisi d'hiberner completement submergees dans l'eau. Bien que l'echantillon soit trop petit pour en tirer des conclusions statistiquement significatives a α = 0,05, nos observations globales laissent croire que les couleuvres minces n'utilisent pas le niveau d'eau comme signal de l'emergence. Meme si 'augmentation du niveau de 'eau ne semble pas etre un signal pour l'emergence, l'hibernation sous le niveau de la nappe phreatique pent augmenter la survie en diminuant le metabolisme et en eliminant le risque de dessiccation. [Traduit par la Redaction], Introduction Reptiles that live at high latitudes have a much shorter active season than reptiles at lower latitudes. In regions where freezing occurs, a clear signal of when to emerge [...]

Hirschsprung disease (HSCR) is a common, multigenic neurocristopathy characterized by incomplete innervation along a variable length of the gut. The pivotal gene in isolated HSCR cases, either sporadic or familial, is RET. HSCR also presents in various syndromes, including Shah--Waardenburg syndrome (WS), Down (DS), and Bardet--Biedl (BBS). Here, we report 3 families with BBS and HSCR with concomitant mutations in BBS genes and regulatory RET elements, whose functionality is tested in physiologically relevant assays. Our data suggest that BBS mutations can potentiate HSCR predisposing RET alleles, which by themselves are insufficient to cause disease. We also demonstrate that these genes interact genetically in vivo to modulate gut innervation, and that this interaction likely occurs through complementary, yet independent, pathways that converge on the same biological process. Bardet-Biedl | neural crest cells | genetic interaction | zebrafish

MicroRNAs (miRNAs) inhibit the translation of target mRNAs and affect, directly or indirectly, the expression of a large portion of the protein-coding genes. This study focuses on miRNAs that are expressed in the mouse cochlea and vestibule, the 2 inner ear compartments. A conditional knock-out mouse for Dicer1 demonstrated that miRNAs are crucial for postnatal survival of functional hair cells of the inner ear. We identified miRNAs that have a role in the vertebrate developing inner ear by combining miRNA transcriptome analysis, spatial and temporal expression patterns, and bioinformatics. Microarrays revealed similar miRNA profiles in newborn-mouse whole cochleae and vestibules, but different temporal and spatial expression patterns of six miRNAs (miR-15a, miR-18a, miR-30b, miR-99a, miR-182, and miR-199a) may reflect their roles. Two of these miRNAs, miR-15a-1 and miR-18a, were also shown to be crucial for zebrafish inner ear development and morphogenesis. To suggest putative target mRNAs whose translation may be inhibited by selected miRNAs, we combined bioinformatics-based predictions and mRNA expression data. Finally, we present indirect evidence that Slc12a2, Cldn12, and Bdnf mRNAs may be targets for miR-15a. Our data support the hypothesis that inner ear tissue differentiation and maintenance are regulated and controlled by conserved sets of cell-specific miRNAs in both mouse and zebrafish. cochlea | deafness | Dicer | mouse | zebrafish

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2008.12.007 Byline: Aldine Amiel, Evelyn Houliston Abstract: Egg animal-vegetal polarity in cnidarians is less pronounced than in most bilaterian species, and its normal alignment with the future embryonic axis can be disturbed by low-speed centrifugation. We have analyzed the development of oocyte polarity within the transparent and autonomously functioning gonads of Clytia medusae, focusing on the localization of three recently identified maternal mRNAs coding for axis-directing Wnt pathway regulators. Animal-vegetal polarity was first detectable in oocytes committed to their final growth phase, as the oocyte nucleus (GV) became positioned at the future animal pole. In situ hybridization analyses showed that during this first, microtubule-dependent polarization event, CheFz1 RNA adopts a graded cytoplasmic distribution, most concentrated around the GV. CheFz3 and CheWnt3 RNAs adopt their polarized cortical localizations later, during meiotic maturation. Vegetal localization of CheFz3 RNA was found to require both microtubules and an intact gonad structure, while animal localization of CheWnt3 RNA was microtubule independent and oocyte autonomous. The cortical distribution of both these RNAs was sensitive to microfilament-disrupting drugs. Thus, three temporally and mechanistically distinct RNA localization pathways contribute to oocyte polarity in Clytia. Unlike the two cortical RNAs, CheFz1 RNA was displaced in fertilized eggs upon centrifugation, potentially explaining how this treatment re-specifies the embryonic axis. Author Affiliation: (a) Universite Pierre et Marie Curie (Paris VI), Developmental Biology Unit, Observatoire Oceanologique, 06230 Villefranche sur mer, France (b) Centre Nationale de la Recherche Scientifique UMR 7009, Observatoire Oceanologique, 06230 Villefranche sur mer, France Article History: Received 30 June 2008; Revised 10 November 2008; Accepted 9 December 2008

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2008.12.007 Byline: Aldine Amiel, Evelyn Houliston Keywords: Clytia; Oogenesis; Meiotic maturation; Oocyte polarity; RNA localization; Frizzled; Wnt; Microtubule; Cnidaria Abstract: Egg animal-vegetal polarity in cnidarians is less pronounced than in most bilaterian species, and its normal alignment with the future embryonic axis can be disturbed by low-speed centrifugation. We have analyzed the development of oocyte polarity within the transparent and autonomously functioning gonads of Clytia medusae, focusing on the localization of three recently identified maternal mRNAs coding for axis-directing Wnt pathway regulators. Animal-vegetal polarity was first detectable in oocytes committed to their final growth phase, as the oocyte nucleus (GV) became positioned at the future animal pole. In situ hybridization analyses showed that during this first, microtubule-dependent polarization event, CheFz1 RNA adopts a graded cytoplasmic distribution, most concentrated around the GV. CheFz3 and CheWnt3 RNAs adopt their polarized cortical localizations later, during meiotic maturation. Vegetal localization of CheFz3 RNA was found to require both microtubules and an intact gonad structure, while animal localization of CheWnt3 RNA was microtubule independent and oocyte autonomous. The cortical distribution of both these RNAs was sensitive to microfilament-disrupting drugs. Thus, three temporally and mechanistically distinct RNA localization pathways contribute to oocyte polarity in Clytia. Unlike the two cortical RNAs, CheFz1 RNA was displaced in fertilized eggs upon centrifugation, potentially explaining how this treatment re-specifies the embryonic axis. Author Affiliation: (a) Universite Pierre et Marie Curie (Paris VI), Developmental Biology Unit, Observatoire Oceanologique, 06230 Villefranche sur mer, France (b) Centre Nationale de la Recherche Scientifique UMR 7009, Observatoire Oceanologique, 06230 Villefranche sur mer, France Article History: Received 30 June 2008; Revised 10 November 2008; Accepted 9 December 2008