Natural variation of nutrient homeostasis among laboratory and field strains of Chlamydomonas reinhardtii.

Natural variation among individuals and populations exists in all species, playing key roles in response to environmental stress and adaptation. Micro- and macronutrients have a wide range of functions in photosynthetic organisms, and mineral nutrition thus plays a sizable role in biomass production. To maintain nutrient concentrations inside the cell within physiological limits and prevent the detrimental effects of deficiency or excess, complex homeostatic networks have evolved in photosynthetic cells. The microalga Chlamydomonas reinhardtii (Chlamydomonas) is a unicellular eukaryotic model for studying such mechanisms. In this work, 24 Chlamydomonas strains, comprising field isolates and laboratory strains, were examined for intraspecific differences in nutrient homeostasis. Growth and mineral content were quantified in mixotrophy, as full nutrition control, and compared with autotrophy and nine deficiency conditions for macronutrients (-Ca, -Mg, -N, -P, and -S) and micronutrients (-Cu, -Fe, -Mn, and -Zn). Growth differences among strains were relatively limited. However, similar growth was accompanied by highly divergent mineral accumulation among strains. The expression of nutrient status marker genes and photosynthesis were scored in pairs of contrasting field strains, revealing distinct transcriptional regulation and nutrient requirements. Leveraging this natural variation should enable a better understanding of nutrient homeostasis in Chlamydomonas.

Factors Associated with the Patient's Decision to Avoid Healthcare during the COVID-19 Pandemic.

The COVID-19 pandemic has resulted in changes in healthcare use. This study aimed to identify factors associated with a patient's decision to avoid and/or delay healthcare during the COVID-19 pandemic. We used data from a community-based survey in Portugal from July 2020 to August 2021, "COVID-19 Barometer: Social Opinion", which included data regarding health services use, risk perception and confidence in health services. We framed our analysis under Andersen's Behavioural Model of Health Services Use and utilised Poisson regression to identify healthcare avoidance associated factors. Healthcare avoidance was high (44%). Higher prevalence of healthcare avoidance was found among women; participants who reported lower confidence in the healthcare system response to COVID-19 and non-COVID-19; lost income during the pandemic; experienced negative emotions due to physical distancing measures; answered the questionnaire before middle June 2021; and perceived having worse health, the measures implemented by the Government as inadequate, the information conveyed as unclear and confusing, a higher risk of getting COVID-19, a higher risk of complications and a higher risk of getting infected in a health institution. It is crucial to reassure the population that health services are safe. Health services should plan their recovery since delays in healthcare delivery can lead to increased or worsening morbidity, yielding economic and societal costs.

Coordinated homeostasis of essential mineral nutrients: a focus on iron.

In plants, iron (Fe) transport and homeostasis are highly regulated processes. Fe deficiency or excess dramatically limits plant and algal productivity. Interestingly, complex and unexpected interconnections between Fe and various macro- and micronutrient homeostatic networks, supposedly maintaining general ionic equilibrium and balanced nutrition, are currently being uncovered. Although these interactions have profound consequences for our understanding of Fe homeostasis and its regulation, their molecular bases and biological significance remain poorly understood. Here, we review recent knowledge gained on how Fe interacts with micronutrient (e.g. zinc, manganese) and macronutrient (e.g. sulfur, phosphate) homeostasis, and on how these interactions affect Fe uptake and trafficking. Finally, we highlight the importance of developing an improved model of how Fe signaling pathways are integrated into functional networks to control plant growth and development in response to fluctuating environments.

The Anatomic Pathology laboratory adjustments in the era of COVID-19 pandemic: The experience of a laboratory in a Portuguese central hospital.

The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed the world over the past weeks, with already 8,25 million infections and 445,000 deaths worldwide, leading to an unprecedented international global effort to contain the virus and prevent its spread. The emergence of novel respiratory viruses such as the SARS-CoV-2 creates dramatic challenges to the healthcare services, including surgical pathology laboratories, despite their extensive daily experience in dealing with biological and chemical hazards. Here, we cover important aspects on the knowledge on COVID-19 gathered during the first six months of the pandemic and address relevant issues on human biological sample handling in the Anatomic Pathology laboratory in the context of COVID-19 global threat. In addition, we detail our strategy to minimize the risk of contamination upon exposure to the different biological products received in the laboratory, which can be of general interest to other laboratories worldwide. Our approach has enabled a safe work environment for laboratory staff, while ensuring the maintenance of high quality standards of the work performed. In times of uncertainty and given the lack of specific guidelines directed at Anatomic Pathology services to better deal with the global COVID-19 public-health emergency, it is essential to share with the community rigorous methodologies that will enable us to better cope with probable novel waves of COVID-19 infection and other viruses that will possibly arise in the near future.

Viewing Target Distance Influences the Vestibulo-Ocular Reflex Gain when Assessed Using the Video Head Impulse Test.

Gaze stabilization during head movements is provided by the vestibulo-ocular reflex (VOR). Clinical assessment of this reflex is performed using the video Head Impulse Test (vHIT). To date, the influence of different fixation distances on VOR gain using the vHIT has not been explored. We assessed the effect of target proximity on the horizontal VOR using the vHIT. Firstly, we assessed the VOR gain in 18 healthy subjects with 5 viewing target distances (150, 40, 30, 20, and 10 cm). The gain increased significantly as the viewing target distance decreased. A second experiment on 10 subjects was performed in darkness whilst the subjects were imagining targets at different distances. There were significant inverse relationships between gain and distance for both the real and the imaginary targets. There was a statistically significant difference between light and dark gains for the 20- and 40-cm distances, but not for the 150-cm distance. Theoretical VOR gains for different target distances were calculated and compared with those found in light and darkness. The increase in gain observed for near targets was lower than predicted by geometrical calculations, implying a physiological ceiling effect on the VOR. The VOR gain in the dark, as assessed with the vHIT, demonstrates an enhancement associated with a reduced target distance.

Evaluation of aesthetic and functional outcomes in rhinoplasty surgery: a prospective study / Avaliação dos desfechos estéticos e funcionais em cirurgia de rinoplastia: um estudo prospectivo

Abstract Introduction: Evaluation of surgery outcome measured by patient satisfaction or quality of life is very important, especially in plastic surgery. There is increasing interest in self-reporting outcomes evaluation in plastic surgery. Objective: The aim of our study was to determine patient satisfaction in regard to nose appearance and function with the use of a validated questionnaire, before and after rhinoplasty surgery. Methods: A prospective study was realized at a tertiary centre. All rhinoplasty surgeries performed in adults between February 2013 and August 2014 were included. Many patients underwent additional nasal surgery such as septoplasty or turbinoplasty. The surgical procedures and patients' characteristics were also recorded. Results: Among 113 patients, 107 completed the questionnaires and the follow-up period. Analysis of pre-operative and post-operative Rhinoplasty Evaluation Outcome showed a significant improvement after 3 and 6 months in functional and aesthetic questions (p < 0.01). In the pre-operative, patients anxious and insecure had a worse score (p < 0.05). Difference in improvement of scores was not significant when groups were divided on basis of other nasal procedures, primary or revision surgery and open versus closed approach. Conclusion: We found that patients with lower literacy degree were more satisfied with the procedure. Rhinoplasty surgery significantly improved patient quality of life regarding nose function and appearance.

Resumo Introdução: A avaliação do desfecho de cirurgia medido pela satisfação ou qualidade de vida do paciente é muito importante, especialmente em cirurgia plástica. Existe um interesse crescente na autoavaliação de desfechos nesta especialidade cirúrgica. Objetivo: O objetivo deste estudo foi determinar a satisfação do paciente em relação à aparência e função do nariz com o uso de um questionário validado, antes e depois da cirurgia de rinoplastia. Método: Estudo prospectivo realizado em um centro terciário. Todas as cirurgias de rinoplastia feitas em adultos entre fevereiro de 2013 e agosto de 2014 foram incluídas. Muitos pacientes foram submetidos à cirurgia nasal adicional, como septoplastia ou turbinoplastia. Os procedimentos cirúrgicos e as características dos pacientes também foram registrados. Resultados: Entre 113 pacientes, 107 completaram os questionários e o período de acompanhamento. A análise da avaliação do desfecho de rinoplastia (ADR) no pré-operatório e pós-operatório mostrou uma melhoria significativa após 3 e 6 meses em questões funcionais e estéticas (p < 0,01). No pré-operatório, os pacientes ansiosos e inseguros apresentaram um escore pior (p < 0,05). A diferença na melhoria dos escores não foi significativa quando os grupos foram divididos com base em outros procedimentos nasais, cirurgia primária ou revisão e abordagem aberta versus fechada. Conclusão: Verificou-se que pacientes com menor grau de alfabetização estavam mais satisfeitos com o procedimento. A cirurgia de rinoplastia melhorou significativamente a qualidade de vida do paciente quanto à função e ao aspecto do nariz.

Can we predict diatoms herbicide sensitivities with phylogeny? Influence of intraspecific and interspecific variability.

Diatoms are used as indicators of freshwater ecosystems integrity. Developing diatom-based tools to assess impact of herbicide pollution is expected by water managers. But, defining sensitivities of all species to multiple herbicides would be unattainable. The existence of a phylogenetic signal of herbicide sensitivity was shown among diatoms and should enable prediction of new species sensitivity. However, diatoms present a cryptic diversity that may lead to variation in their sensitivity to herbicides that would need to be taken into account. Using bioassays, the sensitivity to four herbicides (Atrazine, Terbutryn, Diuron, Isoproturon) was evaluated for 11 freshwater diatom taxa and intraspecific variability was assessed for two of them (Nitzschia palea and Achnanthidium spp.). Intraspecific variability of herbicide sensitivity was always smaller than interspecific variability, but intraspecific variability was more important in N. palea than in Achnanthidium spp. Indeed, one species showed no intraspecific phylogenetic signal (N. palea) whereas the other did (Achnanthidium spp.). On one hand, species boundaries are not set properly for Achnanthidium spp. which encompass several taxa. On the other hand, there is a higher phenotypic plasticity for N. palea. Finally, a phylogenetic signal of herbicide sensitivity was measured at the interspecific level, opening up prospects for setting up reliable biomonitoring tools based on sensitivity prediction, insofar as species boundaries are correctly defined.

Evaluation of aesthetic and functional outcomes in rhinoplasty surgery: a prospective study.

INTRODUCTION: Evaluation of surgery outcome measured by patient satisfaction or quality of life is very important, especially in plastic surgery. There is increasing interest in self-reporting outcomes evaluation in plastic surgery. OBJECTIVE: The aim of our study was to determine patient satisfaction in regard to nose appearance and function with the use of a validated questionnaire, before and after rhinoplasty surgery. METHODS: A prospective study was realized at a tertiary centre. All rhinoplasty surgeries performed in adults between February 2013 and August 2014 were included. Many patients underwent additional nasal surgery such as septoplasty or turbinoplasty. The surgical procedures and patients' characteristics were also recorded. RESULTS: Among 113 patients, 107 completed the questionnaires and the follow-up period. Analysis of pre-operative and post-operative Rhinoplasty Evaluation Outcome showed a significant improvement after 3 and 6 months in functional and aesthetic questions (p<0.01). In the pre-operative, patients anxious and insecure had a worse score (p<0.05). Difference in improvement of scores was not significant when groups were divided on basis of other nasal procedures, primary or revision surgery and open versus closed approach. CONCLUSION: We found that patients with lower literacy degree were more satisfied with the procedure. Rhinoplasty surgery significantly improved patient quality of life regarding nose function and appearance.

Nasal closure for the treatment of epistaxis secondary to hereditary hemorrhagic telangiectasia / Cierre nasal para el tratamiento de la epistaxis secundaria a Telangiectasia Hemorrágica Hereditaria

Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is an autosomal dominant disorder characterised by the presence of multiple arteriovenous malformations (AVMs) affecting multiple organs. Many procedures have been used for epistaxis control in patients with this disorder. The objective of this study was to report the treatment of severe HHT-related epistaxis with the modified Young’s procedure. Materials and methods: We describe the treatment of 4 patients with severe blood-transfusion dependent epistaxis who underwent a modified Young’s procedure in a tertiary hospital. The nasal closure was bilateral and complete in all cases. All patients were followed for 12 months or longer. Results: The procedure was well tolerated and complete cessation of bleeding was achieved in all the patients. Conclusion: Young’s technique is a safe surgical procedure, well tolerated by patients with severe epistaxis and HHT (AU)

La telangiectasia hemorrágica hereditaria (HHT), también conocida por el epónimo síndrome de Osler-Weber-Rendu es un trastorno autosómico dominante caracterizado por la presencia de malformaciones arteriovenosas (MAV) que afectan a múltiplos órganos y sistemas. Un gran número de procedimientos fue utilizado para el control de epistaxis en estos pacientes. El objetivo de este estudio fue reportar el tratamiento de las epistaxis severas relacionadas con HHT con procedimiento de Young modificado. Materiales y métodos: Describimos cuatro pacientes con epistaxis severa, dependientes de transfusiones de sangre, que se sometieron a un procedimiento de Young modificado en un hospital de tercer nivel. El cierre nasal fue bilateral y completo en todos los casos. Se observaron todos los pacientes durante 12 meses o más. Resultados: El procedimiento fue bien tolerado y se logró el cese completo de las hemorragias en todos los pacientes. Conclusión: La cirugía de Young es un procedimiento seguro y bien tolerado por los pacientes con epistaxis severa y HHT (AU)

Intraspecific differences in cadmium tolerance of Nitzschia palea (Kützing) W. Smith: a biochemical approach.

Intraspecific variability occurs in all types of organisms and is a driving force to speciation, conferring genotypic and phenotypic differences that enable adaptive responses to sub-lethal stimuli such as exposure to pollutants (including cadmium, Cd). Thus, differences in biochemical parameters are expected among isolates of the same species. Studying the extent of these differences throughout a stress range, will provide information for the development of approaches to mitigate habitat contamination. This work was designed to identify possible differences in Cd tolerance of five isolates of the freshwater diatom Nitzschia palea from different sampling sites. Each isolate was exposed to five increasing Cd concentrations during 10 days. Growth inhibition was assessed and intracellular accumulation of Cd was quantified. Superoxide dismutase and catalase activities were determined. Glutathione as well as lipid peroxidation (LPO) and intracellular protein content were quantified. The results obtained identified intraspecific differences among isolates. These differences were associated with different approaches of coping with Cd stress. Higher intracellular Cd concentrations induced lower tolerance in isolates, since antioxidant mechanisms were unable to fight effectively against higher oxidative stress. Reversely, lower intracellular accumulation of Cd induced lower oxidative damage and allowed cells to better tolerate exposure to Cd. LPO emerged as an excellent marker of oxidative stress in N. palea and its use can differentiate isolates according to their tolerance.

Nasal closure for the treatment of epistaxis secondary to hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is an autosomal dominant disorder characterised by the presence of multiple arteriovenous malformations (AVMs) affecting multiple organs. Many procedures have been used for epistaxis control in patients with this disorder. The objective of this study was to report the treatment of severe HHT-related epistaxiswith the modified Young's procedure. MATERIALS AND METHODS: We describe the treatment of 4 patients with severe blood-transfusion-dependent epistaxis who underwent a modified Young's procedure in a tertiary hospital. The nasal closure was bilateral and complete in all cases. All patients were followed for 12 months or longer. RESULTS: The procedure was well tolerated and complete cessation of bleeding was achieved in all the patients. CONCLUSION: Young's technique is a safe surgical procedure, well tolerated by patients with severe epistaxis and HHT.

Quality of life in patients submitted to total laryngectomy.

BACKGROUND: Laryngeal carcinoma accounts for about 80 000 deaths annually worldwide. Despite its aggressiveness, total laryngectomy (TL) is a treatment option with curative intent. This article aims to evaluate its impact on these patients quality of life (QoL). MATERIAL AND METHODS: Thirty-four patients who underwent TL with bilateral neck dissection between 2003 and 2012 responded to the European Organization for Research and Treatment of Cancer QoL Core Questionnaire, the Self-Evaluation of Communication Experiences after Laryngeal Cancer Questionnaire, and the Hospital Anxiety and Depression Scale. RESULTS: Data revealed that QoL is lower in these patients compared with general population. Regarding alaryngeal speech modalities, esophageal speech is associated with a significantly higher physical functional capacity. CONCLUSIONS: TL results in a permanent disability with decreased functional capacity and psychological distress. Close monitoring of these patients and investing in speech rehabilitation are essential to preserve their QoL.

Synphilin-1A is a phosphoprotein phosphatase 1-interacting protein and affects PPP1 sorting to subcellular compartments.

Lewy bodies (LBs) are synphilin-1 (Sph1)-containing aggregates and histological hallmarks of Parkinson's disease. Therefore, understanding processes which modulate the aggregation of Sph1, or its isoform Sph1A, will contribute to our understanding of LBs formation. Protein phosphorylation promotes aggregation, but protein phosphatases with activity towards Sph1 have not been described. The present study documents the identification of a novel Sph1A/phosphoprotein phosphatase 1 (PPP1) complex and unravels its regulatory effect on Sph1A aggregation. Using yeast co-transformation and overlay blot assay, the interaction between Sph1A and PPP1 was mapped to the Sph1A RVTF motif. Then, Sph1A overexpression in human embryonic kidney 293 cells demonstrated that Sph1A specifically targets endogenous PPP1 isoforms to inclusion bodies and that Sph1A/PPP1 complex disruption enhances inclusion bodies formation. Finally, as Sph1A interacted with PPP1CC2, a PPP1 sperm-specific isoform, Sph1 and Sph1A expression was addressed in male germ cells by qRT-PCR, revealing high expression levels in round spermatids. Together, these observations established Sph1A as a novel PPP1-interacting protein able to affect PPP1 sorting to subcellular compartments and Sph1A/PPP1 complex as a negative modulator of LBs formation. Contrarily, in physiological conditions, Sph1 isoforms are pointed as putative participants in vesicle dynamics with implications in neurotransmission and spermiogenesis.

The Toll-dorsal pathway is required for resistance to viral oral infection in Drosophila.

Pathogen entry route can have a strong impact on the result of microbial infections in different hosts, including insects. Drosophila melanogaster has been a successful model system to study the immune response to systemic viral infection. Here we investigate the role of the Toll pathway in resistance to oral viral infection in D. melanogaster. We show that several Toll pathway components, including Spätzle, Toll, Pelle and the NF-kB-like transcription factor Dorsal, are required to resist oral infection with Drosophila C virus. Furthermore, in the fat body Dorsal is translocated from the cytoplasm to the nucleus and a Toll pathway target gene reporter is upregulated in response to Drosophila C Virus infection. This pathway also mediates resistance to several other RNA viruses (Cricket paralysis virus, Flock House virus, and Nora virus). Compared with control, viral titres are highly increased in Toll pathway mutants. The role of the Toll pathway in resistance to viruses in D. melanogaster is restricted to oral infection since we do not observe a phenotype associated with systemic infection. We also show that Wolbachia and other Drosophila-associated microbiota do not interact with the Toll pathway-mediated resistance to oral infection. We therefore identify the Toll pathway as a new general inducible pathway that mediates strong resistance to viruses with a route-specific role. These results contribute to a better understanding of viral oral infection resistance in insects, which is particularly relevant in the context of transmission of arboviruses by insect vectors.

Protein phosphatase 1 catalytic isoforms: specificity toward interacting proteins.

The coordinated and reciprocal action of serine-threonine protein kinases and protein phosphatases produces transitory phosphorylation, a fundamental regulatory mechanism for many biological processes. Phosphoprotein phosphatase 1 (PPP1), a major serine-threonine phosphatase, in particular, is ubiquitously distributed and regulates a broad range of cellular functions, including glycogen metabolism, cell cycle progression, and muscle relaxation. PPP1 has evolved effective catalytic machinery but in vitro lacks substrate specificity. In vivo, its specificity is achieved not only by the existence of different PPP1 catalytic isoforms, but also by binding of the catalytic moiety to a large number of regulatory or targeting subunits. Here, we will address exhaustively the existence of diverse PPP1 catalytic isoforms and the relevance of their specific partners and consequent functions.

Congenital defects of the middle ear--uncommon cause of pediatric hearing loss.

INTRODUCTION: In children, hypoacusis, or conductive hearing loss, is usually acquired; otitis media with effusion is the most common etiology. However, in some cases this condition is congenital, ranging from deformities of the external and middle ear to isolated ossicular chain malformations. The non-ossicular anomalies of the middle ear, for instance, persistent stapedial artery and anomaly of the facial nerve, are uncommon but may accompany the ossicular defects. OBJECTIVE: This study aimed to describe the clinical presentation, diagnostic tests, and therapeutic options of congenital malformations of the middle ear. METHODS: This was a retrospective study of cases followed in otolaryngologic consultations since 2007 with the diagnosis of congenital malformation of the middle ear according to the Teunissen and Cremers classification. A review of the literature regarding the congenital malformation of the middle ear and its treatment is presented. CONCLUSION: Middle ear malformations are rarely responsible for conductive hearing loss in children. As a result, there is often a late diagnosis and treatment of these anomalies, which can lead to delays in the development of language and learning.

Congenital defects of the middle ear - uncommon cause of pediatric hearing loss / Malformações congênitas da orelha média - causa rara de hipoacusia pediátrica

INTRODUCTION: In children, hypoacusis, or conductive hearing loss, is usually acquired; otitis media with effusion is the most common etiology. However, in some cases this condition is congenital, ranging from deformities of the external and middle ear to isolated ossicular chain malformations. The non-ossicular anomalies of the middle ear, for instance, persistent stapedial artery and anomaly of the facial nerve, are uncommon but may accompany the ossicular defects. OBJECTIVE: This study aimed to describe the clinical presentation, diagnostic tests, and therapeutic options of congenital malformations of the middle ear. METHODS: This was a retrospective study of cases followed in otolaryngologic consultations since 2007 with the diagnosis of congenital malformation of the middle ear according to the Teunissen and Cremers classification. A review of the literature regarding the congenital malformation of the middle ear and its treatment is presented. CONCLUSION: Middle ear malformations are rarely responsible for conductive hearing loss in children. As a result, there is often a late diagnosis and treatment of these anomalies, which can lead to delays in the development of language and learning. .

INTRODUÇÃO: Na criança, a hipoacusia de condução é geralmente adquirida, sendo a otite média com efusão a etiologia mais comum. No entanto, em alguns casos é congênita, decorrente desde de deformidades das orelhas média e externa até malformações isoladas da cadeia ossicular. As anomalias não ossiculares da orelha média, como a persistência da artéria estapédica e a alteração do percurso do nervo facial, são incomuns, podendo acompanhar as malformações ossiculares. OBJETIVO: Este estudo tem como objetivo descrever a apresentação clínica, os meios auxiliares de diagnóstico e opções terapêuticas das malformações congênitas da orelha média. MÉTODOS: Os autores apresentam um estudo retrospectivo de casos de malformação congênita da orelha média diagnosticados de acordo com a classificação de Teunissen e Cremers, acompanhados em consultas otorrinolaringológicas desde 2007. É também apresentada uma revisão da literatura sobre malformações congênitas da orelha média e seu tratamento. CONCLUSÃO: As malformações da orelha média são raramente responsáveis pela hipoacusia de condução nas crianças. A demora no diagnóstico e tratamento pode levar a atrasos na linguagem e na aprendizagem. .

Wolbachia variants induce differential protection to viruses in Drosophila melanogaster: a phenotypic and phylogenomic analysis.

Wolbachia are intracellular bacterial symbionts that are able to protect various insect hosts from viral infections. This tripartite interaction was initially described in Drosophila melanogaster carrying wMel, its natural Wolbachia strain. wMel has been shown to be genetically polymorphic and there has been a recent change in variant frequencies in natural populations. We have compared the antiviral protection conferred by different wMel variants, their titres and influence on host longevity, in a genetically identical D. melanogaster host. The phenotypes cluster the variants into two groups--wMelCS-like and wMel-like. wMelCS-like variants give stronger protection against Drosophila C virus and Flock House virus, reach higher titres and often shorten the host lifespan. We have sequenced and assembled the genomes of these Wolbachia, and shown that the two phenotypic groups are two monophyletic groups. We have also analysed a virulent and over-replicating variant, wMelPop, which protects D. melanogaster even better than the closely related wMelCS. We have found that a ~21 kb region of the genome, encoding eight genes, is amplified seven times in wMelPop and may be the cause of its phenotypes. Our results indicate that the more protective wMelCS-like variants, which sometimes have a cost, were replaced by the less protective but more benign wMel-like variants. This has resulted in a recent reduction in virus resistance in D. melanogaster in natural populations worldwide. Our work helps to understand the natural variation in wMel and its evolutionary dynamics, and inform the use of Wolbachia in arthropod-borne disease control.

An intriguing shift occurs in the novel protein phosphatase 1 binding partner, TCTEX1D4: evidence of positive selection in a pika model.

T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) contains the canonical phosphoprotein phosphatase 1 (PPP1) binding motif, composed by the amino acid sequence RVSF. We identified and validated the binding of TCTEX1D4 to PPP1 and demonstrated that indeed this protein is a novel PPP1 interacting protein. Analyses of twenty-one mammalian species available in public databases and seven Lagomorpha sequences obtained in this work showed that the PPP1 binding motif 90RVSF93 is present in all of them and is flanked by a palindromic sequence, PLGS, except in three species of pikas (Ochotona princeps, O. dauurica and O. pusilla). Furthermore, for the Ochotona species an extra glycosylation site, motif 96NLS98, and the loss of the palindromic sequence were observed. Comparison with other lagomorphs suggests that this event happened before the Ochotona radiation. The dN/dS for the sequence region comprising the PPP1 binding motif and the flanking palindrome highly supports the hypothesis that for Ochotona species this region has been evolving under positive selection. In addition, mutational screening shows that the ability of pikas TCTEX1D4 to bind to PPP1 is maintained, although the PPP1 binding motif is disrupted, and the N- and C-terminal surrounding residues are also abrogated. These observations suggest pika as an ideal model to study novel PPP1 complexes regulatory mechanisms.

TCTEX1D4, a novel protein phosphatase 1 interactor: connecting the phosphatase to the microtubule network.

Reversible phosphorylation plays an important role as a mechanism of intracellular control in eukaryotes. PPP1, a major eukaryotic Ser/Thr-protein phosphatase, acquires its specificity by interacting with different protein regulators, also known as PPP1 interacting proteins (PIPs). In the present work we characterized a physiologically relevant PIP in testis. Using a yeast two-hybrid screen with a human testis cDNA library, we identified a novel PIP of PPP1CC2 isoform, the T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) that has recently been described as a Tctex1 dynein light chain family member. The overlay assays confirm that TCTEX1D4 interacts with the different spliced isoforms of PPP1CC. Also, the binding domain occurs in the N-terminus, where a consensus PPP1 binding motif (PPP1BM) RVSF is present. The distribution of TCTEX1D4 in testis suggests its involvement in distinct functions, such as TGFß signaling at the blood-testis barrier and acrosome cap formation. Immunofluorescence in human ejaculated sperm shows that TCTEX1D4 is present in the flagellum and in the acrosome region of the head. Moreover, TCTEX1D4 and PPP1 co-localize in the microtubule organizing center (MTOC) and microtubules in cell cultures. Importantly, the TCTEX1D4 PPP1BM seems to be relevant for complex formation, for PPP1 retention in the MTOC and movement along microtubules. These novel results open new avenues to possible roles of this dynein, together with PPP1. In essence TCTEX1D4/PPP1C complex appears to be involved in microtubule dynamics, sperm motility, acrosome reaction and in the regulation of the blood-testis barrier.