RESUMEN
Gonadal development is a complex process that involves sex determination followed by divergent maturation into either testes or ovaries1. Historically, limited tissue accessibility, a lack of reliable in vitro models and critical differences between humans and mice have hampered our knowledge of human gonadogenesis, despite its importance in gonadal conditions and infertility. Here, we generated a comprehensive map of first- and second-trimester human gonads using a combination of single-cell and spatial transcriptomics, chromatin accessibility assays and fluorescent microscopy. We extracted human-specific regulatory programmes that control the development of germline and somatic cell lineages by profiling equivalent developmental stages in mice. In both species, we define the somatic cell states present at the time of sex specification, including the bipotent early supporting population that, in males, upregulates the testis-determining factor SRY and sPAX8s, a gonadal lineage located at the gonadal-mesonephric interface. In females, we resolve the cellular and molecular events that give rise to the first and second waves of granulosa cells that compartmentalize the developing ovary to modulate germ cell differentiation. In males, we identify human SIGLEC15+ and TREM2+ fetal testicular macrophages, which signal to somatic cells outside and inside the developing testis cords, respectively. This study provides a comprehensive spatiotemporal map of human and mouse gonadal differentiation, which can guide in vitro gonadogenesis.
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Linaje de la Célula , Células Germinativas , Ovario , Diferenciación Sexual , Análisis de la Célula Individual , Testículo , Animales , Cromatina/genética , Cromatina/metabolismo , Femenino , Células Germinativas/citología , Células Germinativas/metabolismo , Células de la Granulosa/citología , Células de la Granulosa/metabolismo , Humanos , Inmunoglobulinas , Macrófagos/metabolismo , Masculino , Glicoproteínas de Membrana , Proteínas de la Membrana , Ratones , Microscopía Fluorescente , Ovario/citología , Ovario/embriología , Factor de Transcripción PAX8 , Embarazo , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Receptores Inmunológicos , Diferenciación Sexual/genética , Testículo/citología , Testículo/embriología , TranscriptomaRESUMEN
Maternal viral infection and immune response are known to increase the risk of altered development of the foetal brain. Given the ongoing global pandemic of coronavirus disease 2019 (COVID-19), investigating the impact of SARS-CoV-2 on foetal brain health is of critical importance. Here, we report the presence of SARS-CoV-2 in first and second trimester foetal brain tissue in association with cortical haemorrhages. SARS-CoV-2 spike protein was sparsely detected within progenitors and neurons of the cortex itself, but was abundant in the choroid plexus of haemorrhagic samples. SARS-CoV-2 was also sparsely detected in placenta, amnion and umbilical cord tissues. Cortical haemorrhages were linked to a reduction in blood vessel integrity and an increase in immune cell infiltration into the foetal brain. Our findings indicate that SARS-CoV-2 infection may affect the foetal brain during early gestation and highlight the need for further study of its impact on subsequent neurological development.
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COVID-19 , Complicaciones Infecciosas del Embarazo , Embarazo , Femenino , Humanos , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus , HemorragiaRESUMEN
Experimental citizen science offers new ways to organize on-farm testing of crop varieties and other agronomic options. Its implementation at scale requires software that streamlines the process of experimental design, data collection and analysis, so that different organizations can support trials. This article considers ClimMob software developed to facilitate implementing experimental citizen science in agriculture. We describe the software design process, including our initial design choices, the architecture and functionality of ClimMob, and the methodology used for incorporating user feedback. Initial design choices were guided by the need to shape a workflow that is feasible for farmers and relevant for farmers, breeders and other decision-makers. Workflow and software concepts were developed concurrently. The resulting approach supported by ClimMob is triadic comparisons of technology options (tricot), which allows farmers to make simple comparisons between crop varieties or other agricultural technologies tested on farms. The software was built using Component-Based Software Engineering (CBSE), to allow for a flexible, modular design of software that is easy to maintain. Source is open-source and built on existing components that generally have a broad user community, to ensure their continuity in the future. Key components include Open Data Kit, ODK Tools, PyUtilib Component Architecture. The design of experiments and data analysis is done through R packages, which are all available on CRAN. Constant user feedback and short communication lines between the development teams and users was crucial in the development process. Development will continue to further improve user experience, expand data collection methods and media channels, ensure integration with other systems, and to further improve the support for data-driven decision-making.
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The identification of genetic variants implicated in human developmental disorders has been revolutionized by second-generation sequencing combined with international pooling of cases. Here, we describe seven individuals who have diverse yet overlapping developmental anomalies, and who all have de novo missense FBXW11 variants identified by whole exome or whole genome sequencing and not reported in the gnomAD database. Their phenotypes include striking neurodevelopmental, digital, jaw, and eye anomalies, and in one individual, features resembling Noonan syndrome, a condition caused by dysregulated RAS signaling. FBXW11 encodes an F-box protein, part of the Skp1-cullin-F-box (SCF) ubiquitin ligase complex, involved in ubiquitination and proteasomal degradation and thus fundamental to many protein regulatory processes. FBXW11 targets include ß-catenin and GLI transcription factors, key mediators of Wnt and Hh signaling, respectively, critical to digital, neurological, and eye development. Structural analyses indicate affected residues cluster at the surface of the loops of the substrate-binding domain of FBXW11, and the variants are predicted to destabilize the protein and/or its interactions. In situ hybridization studies on human and zebrafish embryonic tissues demonstrate FBXW11 is expressed in the developing eye, brain, mandibular processes, and limb buds or pectoral fins. Knockdown of the zebrafish FBXW11 orthologs fbxw11a and fbxw11b resulted in embryos with smaller, misshapen, and underdeveloped eyes and abnormal jaw and pectoral fin development. Our findings support the role of FBXW11 in multiple developmental processes, including those involving the brain, eye, digits, and jaw.
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Encéfalo/anomalías , Anomalías del Ojo/genética , Dedos/anomalías , Mutación Missense , Fenotipo , Ubiquitina-Proteína Ligasas/genética , Proteínas con Repetición de beta-Transducina/genética , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , MasculinoRESUMEN
We analyzed transcriptomic data from otic sensory cells differentiated from human induced pluripotent stem cells (hiPSCs) by a previously described method to gain new insights into the early human otic neurosensory lineage. We identified genes and biological networks not previously described to occur in the human otic sensory developmental cell lineage. These analyses identified and ranked genes known to be part of the otic sensory lineage program (SIX1, EYA1, GATA3, etc.), in addition to a number of novel genes encoding extracellular matrix (ECM) (COL3A1, COL5A2, DCN, etc.) and integrin (ITG) receptors (ITGAV, ITGA4, ITGA) for ECM molecules. The results were confirmed by quantitative PCR analysis of a comprehensive panel of genes differentially expressed during the time course of hiPSC differentiation in vitro. Immunocytochemistry validated results for select otic and ECM/ITG gene markers in the in vivo human fetal inner ear. Our screen shows ECM and ITG gene expression changes coincident with hiPSC differentiation towards human otic neurosensory cells. Our findings suggest a critical role of ECM-ITG interactions with otic neurosensory lineage genes in early neurosensory development and cell fate determination in the human fetal inner ear.
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Diferenciación Celular , Oído Interno/citología , Células Madre Pluripotentes Inducidas/citología , Células-Madre Neurales/citología , Células Receptoras Sensoriales/citología , Células Receptoras Sensoriales/metabolismo , Transcriptoma , Linaje de la Célula , Oído Interno/metabolismo , Matriz Extracelular/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Integrinas/genética , Integrinas/metabolismo , Células-Madre Neurales/metabolismo , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismoRESUMEN
BACKGROUND: Spermatogenesis is a complex process characterized by the activation and/or repression of a number of genes in a spatio-temporal manner. Pubertal development in males starts with the onset of the first spermatogenesis and implies the division of primary spermatogonia and their subsequent entry into meiosis. This study is aimed at the characterization of genes involved in the onset of puberty in European sea bass, and constitutes the first transcriptomic approach focused on meiosis in this species. RESULTS: European sea bass testes collected at the onset of puberty (first successful reproduction) were grouped in stage I (resting stage), and stage II (proliferative stage). Transition from stage I to stage II was marked by an increase of 11ketotestosterone (11KT), the main fish androgen, whereas the transcriptomic study resulted in 315 genes differentially expressed between the two stages. The onset of puberty induced 1) an up-regulation of genes involved in cell proliferation, cell cycle and meiosis progression, 2) changes in genes related with reproduction and growth, and 3) a down-regulation of genes included in the retinoic acid (RA) signalling pathway. The analysis of GO-terms and biological pathways showed that cell cycle, cell division, cellular metabolic processes, and reproduction were affected, consistent with the early events that occur during the onset of puberty. Furthermore, changes in the expression of three RA nuclear receptors point at the importance of the RA-signalling pathway during this period, in agreement with its role in meiosis. CONCLUSION: The results contribute to boost our knowledge of the early molecular and endocrine events that trigger pubertal development and the onset of spermatogenesis in fish. These include an increase in 11KT plasma levels and changes in the expression of several genes involved in cell proliferation, cell cycle progression, meiosis or RA-signalling pathway. Moreover, the results can be applied to study meiosis in this economically important fish species for Mediterranean countries, and may help to develop tools for its sustainable aquaculture.
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Lubina/genética , Lubina/fisiología , Secuencia Conservada , Proteínas de Peces/genética , Perfilación de la Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos , Pubertad/genética , Animales , Lubina/metabolismo , Clonación Molecular , Ontología de Genes , Hormonas/metabolismo , Masculino , FilogeniaRESUMEN
Follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) are central endocrine regulators of the gonadal function in vertebrates. They act through specific receptors located in certain cell types found in the gonads. In fish, the differential roles of these hormones are being progressively elucidated due to the development of suitable tools for their study. In European sea bass (Dicentrarchus labrax), isolation of the genes coding for the gonadotropin subunits and receptors allowed in first instance to conduct expression studies. Later, to overcome the limitation of using native hormones, recombinant dimeric gonadotropins, which show different functional characteristics depending on the cell system and DNA construct, were generated. In addition, single gonadotropin beta-subunits have been produced and used as antigens for antibody production. This approach has allowed the development of detection methods for native gonadotropins, with European sea bass being one of the few species where both gonadotropins can be detected in their native form. By administering recombinant gonadotropins to gonad tissues in vitro, we were able to study their effects on steroidogenesis and intracellular pathways. Their administration in vivo has also been tested for use in basic studies and as a biotechnological approach for hormone therapy and assisted reproduction strategies. In addition to the production of recombinant hormones, gene-based therapies using somatic gene transfer have been offered as an alternative. This approach has been tested in sea bass for gonadotropin delivery in vivo. The hormones produced by the genes injected were functional and have allowed studies on the action of gonadotropins in spermatogenesis.
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Lubina/metabolismo , Biotecnología/métodos , Gonadotropinas/metabolismo , Animales , Lubina/genética , Femenino , Gónadas/metabolismo , Masculino , Técnicas de Transferencia Nuclear , Procesos de Determinación del SexoRESUMEN
INTRODUCTION: Thanks to advances in antiretroviral treatment, children with HIV infections through vertical transmission have improved their life expectancy. However, new challenges have emerged. We propose this study in order to determine the psychosocial aspects and knowledge of infections in a cohort of adolescents with vertically transmitted HIV infections. METHODS: Patients with vertically-acquired HIV infection between 12 and 19 years old were included. Data were obtained through semi-structured interviews and a Strengths and Difficulties Questionnaire for emotional and behavioral disorders screening. RESULTS: We evaluated 96 patients (58% females) with a median age of 15 years (11-19.1) and a median age at diagnosis of 1.70 years (0-12.2). The median CD4 count was 626cells/mm(3) (132-998), and the viral load was<50cp/ml in 72% of patients. Among them, 90% attended school and 60% repeated at least one course. Although 81% of them knew of their diagnosis, only 30% understood their disease, with 18.2% having discussed it with friends. Six unwanted pregnancies occurred during the study period. Strengths and Difficulties Questionnaire showed hyperactivity risk in 33%. CONCLUSION: A high percentage of adolescents show difficulties in several areas (disease knowledge, peer relationship, school failure...) that can have an impact on their adult lives. Further studies are needed to evaluate their origin and development in depth, as well as interventions to modify this situation.
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Infecciones por VIH/psicología , Infecciones por VIH/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Adolescente , Niño , Femenino , Infecciones por VIH/complicaciones , Humanos , Masculino , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Prevalencia , Adulto JovenRESUMEN
FOXL2 is a forkhead transcription factor involved in mammalian development and regulation of reproduction. Two foxl2 paralogs, foxl2a and foxl2b, have been described in various teleost species and were considered as fish-specific duplicates. Here, we report the isolation and characterization of foxl2a (foxl2) and foxl2b (foxl3) in European sea bass (Dicentrarchus labrax), together with the identification of these two genes in non-teleost genomes. Phylogenetic and synteny analyses indicate that these paralogs originated from an ancient genome duplication event that happened long before the teleost specific duplication. While foxl2/foxl2a has been maintained in most vertebrate lineages, foxl2b, which we propose to rename as foxl3, was repeatedly lost in tetrapods. Gonadal expression patterns of the sea bass genes point to a strong sexual dimorphism, and the mRNA levels of foxl2 in ovary and foxl3 in testis vary significantly during the reproductive cycle. When overexpressed in cultured ovarian follicular cells, foxl2 and foxl3 produced functional transcription factors able to control the expression of reproduction-related genes. Taken together, these data suggest that Foxl2 may play a conserved role in ovarian maturation, while Foxl3 could be involved in testis physiology.
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Lubina/genética , Lubina/metabolismo , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Secuencia de Aminoácidos , Animales , ADN Complementario/genética , Femenino , Proteínas de Peces/química , Masculino , Datos de Secuencia Molecular , Reacción en Cadena en Tiempo Real de la Polimerasa , Homología de Secuencia de AminoácidoRESUMEN
Puberty represents the transition from an immature to a mature reproductive stage. The mechanisms underlying the onset of normal or precocious puberty have not yet been elucidated. With the goal of gaining an understanding of early events that occur in the testes of precocious animals during this process, a hemigonadectomy was performed on male juvenile sea bass and expression levels of candidate mRNAs were determined through quantitative real-time RT-PCR. For this purpose, the gonadal soma-derived factors gsdf1 and gsdf2, the nuclear receptor 5 subfamily members nr5a1a (ff1b), nr5a1b (ff1d), nr5a2 (ff1a) and nr5a5 (ff1c) and the proliferating cell nuclear antigen or pcna, genes with a putative role in the beginning of spermatogenesis, were isolated and cloned. Hemigonadectomy proved to be a suitable strategy for the study of gonadal stages prior to the appearance of histological differences between precocious and non-precocious fish, as it allowed the subsequent classification of these gonads. The upregulation of the gene encoding the steroidogenic acute regulatory protein (Star) in precocious testes indicates that sex steroids could play a role in the onset of spermatogenesis in sea bass. In contrast, the downregulation observed in ff1b expression indicates that this initial surge in star expression is not the result of Ff1b transactivation, suggesting an alternative pathway for this transcriptional activation. Finally, a decrease in gsdf1 expression in precocious animals suggests that this gene may play a role in the onset of puberty, while its correlation with ff1b expression points to gsdf1 as a putative target for Ff1b-mediated transactivation.
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Perciformes/metabolismo , Pubertad Precoz/metabolismo , Testículo/metabolismo , Animales , Masculino , Reactores Nucleares , Fosfoproteínas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Idiopathic scoliosis (IS) is the deformation and/or abnormal curvature of the spine that develops progressively after birth. It is a very common condition, affecting approximately 4% of the general population, yet the genetic and mechanistic causes of IS are poorly understood. Here, we focus on PPP2R3B, which encodes a protein phosphatase 2A regulatory subunit. We found that PPP2R3B is expressed at sites of chondrogenesis within human foetuses, including the vertebrae. We also demonstrated prominent expression in myotome and muscle fibres in human foetuses, and zebrafish embryos and adolescents. As there is no rodent orthologue of PPP2R3B, we used CRIPSR/Cas9-mediated gene-editing to generate a series of frameshift mutations in zebrafish ppp2r3b. Adolescent zebrafish that were homozygous for this mutation exhibited a fully penetrant kyphoscoliosis phenotype which became progressively worse over time, mirroring IS in humans. These defects were associated with reduced mineralisation of vertebrae, resembling osteoporosis. Electron microscopy demonstrated abnormal mitochondria adjacent to muscle fibres. In summary, we report a novel zebrafish model of IS and reduced bone mineral density. In future, it will be necessary to delineate the aetiology of these defects in relation to bone, muscle, neuronal and ependymal cilia function.
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Escoliosis , Pez Cebra , Animales , Adolescente , Humanos , Pez Cebra/genética , Pez Cebra/metabolismo , Escoliosis/genética , Sistemas CRISPR-Cas , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Proteína Fosfatasa 2/genética , Proteína Fosfatasa 2/metabolismo , MutaciónRESUMEN
The adrenal glands synthesize and release essential steroid hormones such as cortisol and aldosterone, but many aspects of human adrenal gland development are not well understood. Here, we combined single-cell and bulk RNA sequencing, spatial transcriptomics, IHC, and micro-focus computed tomography to investigate key aspects of adrenal development in the first 20 weeks of gestation. We demonstrate rapid adrenal growth and vascularization, with more cell division in the outer definitive zone (DZ). Steroidogenic pathways favored androgen synthesis in the central fetal zone, but DZ capacity to synthesize cortisol and aldosterone developed with time. Core transcriptional regulators were identified, with localized expression of HOPX (also known as Hop homeobox/homeobox-only protein) in the DZ. Potential ligand-receptor interactions between mesenchyme and adrenal cortex were seen (e.g., RSPO3/LGR4). Growth-promoting imprinted genes were enriched in the developing cortex (e.g., IGF2, PEG3). These findings reveal aspects of human adrenal development and have clinical implications for understanding primary adrenal insufficiency and related postnatal adrenal disorders, such as adrenal tumor development, steroid disorders, and neonatal stress.
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Corteza Suprarrenal , Aldosterona , Recién Nacido , Humanos , Aldosterona/metabolismo , Hidrocortisona/metabolismo , Glándulas Suprarrenales/metabolismo , Esteroides , Proteínas de Homeodominio/metabolismoRESUMEN
OBJECTIVE: To analyze mid-term neurodevelopment outcome in children with isolated mild ventriculomegaly (VM) ≤12 mm diagnosed in fetal life, using the Battelle Developmental Inventory Screening Test (BDIST). METHODS: 86 cases of mild VM were identified. 68 were excluded due to: other cerebral anomalies (n = 40), extra-cerebral anomalies (n = 3), chromosomal defects (n = 4), dysmorphic syndromes (n = 4), congenital infections (n = 2), termination of pregnancy (n = 9), stillbirth (n = 2) and incomplete follow-up (n = 4). 18 cases (range 1-8 years) of isolated mild VM were included for analysis. Seven neurodevelopment domains were assessed by BDIST. RESULTS: Routine neuropediatrical evaluation detected neurological disorders in five children (28%; 3 with language impairment, one left hemiparesis and one intellectual retardation). BDIST showed some degree of neurodevelopmental delay in higher proportions: 66% in social-personal skills, 56% in gross motor skills, 39% in adaptive behavior and 28% in fine motor skills. Communicative and cognitive areas were the least affected (11 and 22% had moderate-to-severe involvement, respectively). A general trend towards worse outcomes was observed in the group of ≥4 years, although significant differences were only found for gross motor skills. CONCLUSION: Subtle neurological delays may appear during the infant period in fetuses prenatally diagnosed of isolated mild VM. In consequence, adequate measures should be established for early detection and treatment.
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Desarrollo Infantil , Hidrocefalia/diagnóstico , Diagnóstico Prenatal , Niño , Preescolar , Femenino , Humanos , Hidrocefalia/complicaciones , Lactante , Masculino , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/etiología , Examen Neurológico , Embarazo , Estudios RetrospectivosRESUMEN
BACKGROUND: Primary ovarian insufficiency (POI) affects 1% of women and is associated with significant medical consequences. A genetic cause for POI can be found in up to 30% of women, elucidating key roles for these genes in human ovary development. OBJECTIVE: We aimed to identify the genetic mechanism underlying early-onset POI in 2 sisters from a consanguineous pedigree. METHODS: Genome sequencing and variant filtering using an autosomal recessive model was performed in the 2 affected sisters and their unaffected family members. Quantitative reverse transcriptase PCR (qRT-PCR) and RNA sequencing were used to study the expression of key genes at critical stages of human fetal gonad development (Carnegie Stage 22/23, 9 weeks post conception (wpc), 11 wpc, 15/16 wpc, 19/20 wpc) and in adult tissue. RESULTS: Only 1 homozygous variant cosegregating with the POI phenotype was found: a single nucleotide substitution in zinc finger SWIM-type containing 7 (ZSWIM7), NM_001042697.2: c.173Câ >â G; resulting in predicted loss-of-function p.(Ser58*). qRT-PCR demonstrated higher expression of ZSWIM7 in the 15/16 wpc ovary compared with testis, corresponding to peak meiosis in the fetal ovary. RNA sequencing of fetal gonad samples showed that ZSWIM7 has a similar temporal expression profile in the developing ovary to other homologous recombination genes. MAIN CONCLUSIONS: Disruption of ZSWIM7 is associated with POI in humans. ZSWIM7 is likely to be important for human homologous recombination; these findings expand the range of genes associated with POI in women.
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Amenorrea/genética , Proteínas de Unión al ADN/genética , Meiosis/genética , Oogénesis/genética , Insuficiencia Ovárica Primaria/genética , Adolescente , Amenorrea/diagnóstico , Niño , Análisis Mutacional de ADN , Femenino , Humanos , Mutación con Pérdida de Función , Ovario/crecimiento & desarrollo , Linaje , Mutación Puntual , Insuficiencia Ovárica Primaria/complicaciones , Insuficiencia Ovárica Primaria/diagnóstico , RNA-Seq , Dedos de ZincRESUMEN
Primary ovarian insufficiency (POI) affects 1% of women and carries significant medical and psychosocial sequelae. Approximately 10% of POI has a defined genetic cause, with most implicated genes relating to biological processes involved in early fetal ovary development and function. Recently, Ythdc2, an RNA helicase and N6-methyladenosine reader, has emerged as a regulator of meiosis in mice. Here, we describe homozygous pathogenic variants in YTHDC2 in 3 women with early-onset POI from 2 families: c. 2567C>G, p.P856R in the helicase-associated (HA2) domain and c.1129G>T, p.E377*. We demonstrated that YTHDC2 is expressed in the developing human fetal ovary and is upregulated in meiotic germ cells, together with related meiosis-associated factors. The p.P856R variant resulted in a less flexible protein that likely disrupted downstream conformational kinetics of the HA2 domain, whereas the p.E377* variant truncated the helicase core. Taken together, our results reveal that YTHDC2 is a key regulator of meiosis in humans and pathogenic variants within this gene are associated with POI.
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Insuficiencia Ovárica Primaria , ARN Helicasas , Adenosina/análogos & derivados , Adenosina/genética , Adenosina/metabolismo , Femenino , Humanos , Meiosis , Insuficiencia Ovárica Primaria/genética , ARN Helicasas/genéticaRESUMEN
Different yields, biopotency, and in vivo pharmacokinetics are obtained for recombinant sea bass gonadoltropins depending on the production system and DNA construct, but they show specific activation of their corresponding receptors. Gonadotropins (GTHs) are glycoprotein hormones that play a major role in the regulation of gonadal functions. Recently, we succeeded in isolating the native sea bass Fsh from sea bass pituitaries, but to ensure the availability of bioactive GTHs and no cross-contamination with other related glycoproteins, recombinant sea bass GTHs were produced using two expression systems-insect and mammalian cells-and different constructs that yielded tethered or noncovalently bound dimers. Their production levels, binding specificity to their homologous cognate receptors, and bioactivity were investigated and compared. Both expression systems were successful in the generation of bioactive recombinant GTHs, but insect Sf9 cells yielded higher amounts of recombinant proteins than mammalian Chinese Hamster Ovary (CHO) stable clones. All recombinant GTHs activated their cognate receptors without cross-ligand binding and were able to stimulate sea bass gonadal steroidogenesis in vitro, although with different biopotencies. To assess their use for in vivo applications, their half-life in sea bass plasma was evaluated. Sf9-GTHs had a lower in vivo stability compared with CHO-GTHs due to their rapid clearance from the blood circulation. Cell-dependent glycosylation could be contributing to the final in vivo stability and biopotency of these recombinant glycoproteins. In conclusion, both insect and mammalian expression systems produced bioactive sea bass recombinant gonadotropins, although with particular features useful for different proposes (e.g., antibody production or in vivo studies, respectively).