https://hdl.handle.net/11000/415 2026-04-08T14:30:29Z https://hdl.handle.net/11000/39241 Título : Mutations in the microRNA complementarity site of the INCURVATA4 gene perturb meristem function and adaxialize lateral organs in arabidopsis Autor : Ochando, Isabel; Jover-Gil, Sara; Ripoll, Juan-José; Candela, Héctor; Vera, Antonio; Ponce, María Rosa; Martínez-Laborda, Antonio; Micol, José Luis Resumen : Here, we describe how the semidominant, gain-of-function icu4-1 and icu4-2 alleles of the INCURVATA4 (ICU4) gene alter leaf phyllotaxis and cell organization in the root apical meristem, reduce root length, and cause xylem overgrowth in the stem. The ICU4 gene was positionally cloned and found to encode the ATHB15 transcription factor, a class III homeodomain/leucine zipper family member, recently named CORONA. The icu4-1 and icu4-2 alleles bear the same point mutation that affects the microRNA complementarity site of ICU4 and is identical to those of several semidominant alleles of the class III homeodomain/leucine zipper family members PHABULOSA and PHAVOLUTA. The icu4-1 and icu4-2 mutations significantly increase leaf transcript levels of the ICU4 gene. The null hst-1 allele of the HASTY gene, which encodes a nucleocytoplasmic transporter, synergistically interacts with icu4-1, the double mutant displaying partial adaxialization of rosette leaves and carpels. Our results suggest that the ICU4 gene has an adaxializing function and that it is down-regulated by microRNAs that require the HASTY protein for their biogenesis. 2026-02-12T15:02:12Z https://hdl.handle.net/11000/39240 Título : Common regulatory networks in leaf and fruit patterning revealed by mutations in the Arabidopsis ASYMMETRIC LEAVES1 gene Autor : Alonso-Cantabrana, Hugo; Ripoll, Juan José; Ochando, Isabel; Vera, Antonio; Ferrándiz, Cristina; Martínez-Laborda, Antonio Resumen : Carpels and leaves are evolutionarily related organs, as the former are thought to be modified leaves. Therefore, developmental pathways that play crucial roles in patterning both organs are presumably conserved. In leaf primordia of Arabidopsis thaliana, the ASYMMETRIC LEAVES1 (AS1) gene interacts with AS2 to repress the class I KNOTTED1-like homeobox (KNOX) genes BREVIPEDICELLUS (BP), KNAT2 and KNAT6, restricting the expression of these genes to the meristem. In this report, we describe how AS1, presumably in collaboration with AS2, patterns the Arabidopsis gynoecium by repressing BP, which is expressed in the replum and valve margin, interacts in the replum with REPLUMLESS (RPL), an essential gene for replum development, and positively regulates the expression of this gene. Misexpression of BP in the gynoecium causes an increase in replum size, while the valve width is slightly reduced, and enhances the effect of mutations in FRUITFULL (FUL), a gene with an important function in valve development. Altogether, these findings strongly suggest that BP plays a crucial role in replum development. We propose a model for pattern formation along the mediolateral axis of the ovary, whereby three domains (replum, valve margin and valve) are specified by the opposing gradients of two antagonistic factors, valve factors and replum factors, the class I KNOX genes working as the latter. 2026-02-12T14:55:57Z https://hdl.handle.net/11000/39239 Título : Clinical and molecular characterization of a patient with a combination of a deletion and a duplication of 22q13 using array CGH Autor : Ochando, Isabel; Urbano, Antonio; Rubio, Juana; Rueda, Joaquin Resumen : Phelan-McDermid syndrome is caused by the loss of terminal regions of different sizes at 22q13. There is a wide range of severity of symptoms in patients with a 22q13 deletion, but these patients usually show neonatal hypotonia, global developmental delay, and dysmorphic traits. We carried out a clinical and molecular characterization of a patient with neonatal hypotonia and dysmorphic features. Array-based comparative genomic hybridization showed an 8.24 Mb terminal deletion associated with a 0.20 Mb duplication. Characterization of patients with Phelan-McDermid syndrome both clinically and at the molecular level allows genotype-phenotype correlations that provide clues to help elucidate the clinical implications. 2026-02-12T14:48:43Z https://hdl.handle.net/11000/39238 Título : Alteration of the shoot radial pattern in Arabidopsis thaliana by a gain-of-function allele of the class III HD-Zip gene INCURVATA4 Autor : Ochando, Isabel; Gonzalez-Reig, Santiago; Ripoll, Juan José; Vera, Antonio; Martínez-Laborda, Antonio Resumen : Class III HD-Zip (HD-Zip III) family genes play key roles in a number of fundamental developmental programs in Arabidopsis thaliana, such as embryo patterning, meristem initiation and homeostasis, lateral organ polarity and vascular development. Semidominant gain-of-function alleles of the HD-Zip III genes PHABULOSA (PHB), PHAVOLUTA (PHV) and REVOLUTA (REV) disrupt the negative regulation of these genes by a mechanism of microRNA interference. We provide evidence that the gain-of-function icu4-1 allele of INCURVATA4, a gene encoding the HD-Zip III transcription factor ATHB15/CORONA (CNA), stimulates the production of vascular tissues, supporting a role for ICU4 in promoting vascular development. Occasionally, homozygous mutants for this allele show a reduced number of thick shoot vascular bundles, although normal collateral polarity remains unchanged. Genetic analysis of icu4-1 and phb-1D, a gain-of-function allele of the related PHB gene, revealed antagonism in lateral organ polarity between both mutations and a synergistic interaction in shoots, with transformation of the polarized collateral bundles into a radialized amphivasal pattern. These results indicate that the precise regulation of HD-Zip III genes confers positional information which is required to establish the number and pattern of vascular bundles in the stem. In addition, we present results that suggest an interaction between ICU4 function and auxin signaling. 2026-02-12T14:42:48Z https://hdl.handle.net/11000/39118 Título : RPGRIP1L is required for stabilizing epidermal keratinocyte adhesion through regulating desmoglein endocytosis Autor : Choi, Yeon Ja; Laclef, Christine; Yang, Ning; Andreu-Cervera, Abraham; Lewis, Joshua; Mao, Xuming; LI, LI; Snedecor, Elizabeth R.; Takemaru, Ken-Ichi; Quin, Chuan; Schneider-Maunoury, Sylvie; Shroyer, Kenneth; Hannun, yusuf; Koch, Peter J; Clark, Richard Resumen : Cilia-related proteins are believed to be involved in a broad range of cellular processes. Retinitis pigmentosa GTPase regulator interacting protein 1-like (RPGRIP1L) is a ciliary protein required for ciliogenesis in many cell types, including epidermal keratinocytes. Here we report that RPGRIP1L is also involved in the maintenance of desmosomal junctions between keratinocytes. Genetically disrupting the Rpgrip1l gene in mice caused intraepidermal blistering, primarily between basal and suprabasal keratinocytes. This blistering phenotype was associated with aberrant expression patterns of desmosomal proteins, impaired desmosome ultrastructure, and compromised cell-cell adhesion in vivo and in vitro. We found that disrupting the RPGRIP1L gene in HaCaT cells, which do not form primary cilia, resulted in mislocalization of desmosomal proteins to the cytoplasm, suggesting a cilia-independent function of RPGRIP1L. Mechanistically, we found that RPGRIP1L regulates the endocytosis of desmogleins such that RPGRIP1L-knockdown not only induced spontaneous desmoglein endocytosis, as determined by AK23 labeling and biotinylation assays, but also exacerbated EGTA- or pemphigus vulgaris IgG-induced desmoglein endocytosis. Accordingly, inhibiting endocytosis with dynasore or sucrose rescued these desmosomal phenotypes. Biotinylation assays on cell surface proteins not only reinforced the role of RPGRIP1L in desmoglein endocytosis, but also suggested that RPGRIP1L may be more broadly involved in endocytosis. Thus, data obtained from this study advanced our understanding of the biological functions of RPGRIP1L by identifying its role in the cellular endocytic pathway. 2026-02-05T09:12:04Z https://hdl.handle.net/11000/39117 Título : The Ciliopathy Gene Ftm/Rpgrip1l Controls Mouse Forebrain Patterning via Region-Specific Modulation of Hedgehog/Gli Signaling Autor : Andreu-Cervera, Abraham; Anselme, Isabelle; Karam, Alice; Laclef, Christine; Catala, Martín; Schneider-Maunoury, Sylvie Resumen : Primary cilia are essential for CNS development. In the mouse, they play a critical role in patterning the spinal cord and telencephalon via the regulation of Hedgehog/Gli signaling. However, despite the frequent disruption of this signaling pathway in human forebrain malformations, the role of primary cilia in forebrain morphogenesis has been little investigated outside the telencephalon. Here we studied development of the diencephalon, hypothalamus and eyes in mutant mice in which the Ftm/Rpgrip1l ciliopathy gene is disrupted. At the end of gestation, Ftm-/- fetuses displayed anophthalmia, a reduction of the ventral hypothalamus and a disorganization of diencephalic nuclei and axonal tracts. In Ftm-/- embryos, we found that the ventral forebrain structures and the rostral thalamus were missing. Optic vesicles formed but lacked the optic cups. In Ftm-/- embryos, Sonic hedgehog (Shh) expression was virtually lost in the ventral forebrain but maintained in the zona limitans intrathalamica (ZLI), the mid-diencephalic organizer. Gli activity was severely downregulated but not lost in the ventral forebrain and in regions adjacent to the Shh-expressing ZLI. Reintroduction of the repressor form of Gli3 into the Ftm-/- background restored optic cup formation. Our data thus uncover a complex role of cilia in development of the diencephalon, hypothalamus and eyes via the region-specific control of the ratio of activator and repressor forms of the Gli transcription factors. They call for a closer examination of forebrain defects in severe ciliopathies and for a search for ciliopathy genes as modifiers in other human conditions with forebrain defects. 2026-02-05T09:11:21Z https://hdl.handle.net/11000/38808 Título : Cerebellar oligodendroglial cells have a mesencephalic origin Autor : Mecklenburg, Nora; García-Lopez, Raquel; Puelles, Eduardo; Sotelo, Constantino; Martínez, Salvador Resumen : While the origin of oligodendroglia in the prosencephalon and spinal cord has been extensively studied and accurately described, the origin of this cell type in the cerebellum is largely unknown. To investigate where cerebellar oligodendrocytes generate and which migratory pathways they follow to reach their final destination in the adult, in ovo transplants were performed using the quail/chick chimeric system. The chimeric embryos were developed up to HH43-49 (17-19 days of incubation) to map the location of donor cells and analyze their phenotype by immunohistochemistry. As a result, mesencephalic homotopic and homochronic transplants generated cellular migratory streams moving from the grafted epithelium into the host cerebellum, crossing the isthmus mainly through the velum medullare and invading the central white matter. From here, these mesencephalic cells invaded all the layers of the cerebellar cortex except the granular layer. The majority of the cells were detected in the central and folial white matter, as well as in superficial regions of the internal granular layer, surrounding the Purkinje cells. In the latter case, the donor cells presented a Bergmann glial morphology and were Vimentin positive, while in other areas they were PLP and Olig2-positive, indicating an oligodendroglial fate. The combinatory analysis of the different grafts allowed us to propose the fate map of chick cerebellar oligodendroglia at the neural tube stage. As a result, the majority of the cerebellar oligodendrocytes originate from the parabasal plate of the mesencephalon 2025-12-16T08:58:15Z https://hdl.handle.net/11000/38805 Título : A high-resolution anatomical atlas of the transcriptome in the mouse embryo Autor : Diez-Roux, Graciana; Banfi, Sandro; Sultan, Marc; Geffers, Lars; Anand, Santosh; Rozado, David; Magen, Alon; Canidio, Elena; Pagani, Massimiliano; Peluso, Ivana; Lin-Marq, Nathalie; Koch, Muriel; Bilio, Marchesa; Cantinello, Inmaculada; Verde, Roberta Resumen : Ascertaining when and where genes are expressed is of crucial importance to understanding or predicting the physiological role of genes and proteins and how they interact to form the complex networks that underlie organ development and function. It is, therefore, crucial to determine on a genome-wide level, the spatio-temporal gene expression profiles at cellular resolution. This information is provided by colorimetric RNA in situ hybridization that can elucidate expression of genes in their native context and does so at cellular resolution. We generated what is to our knowledge the first genome-wide transcriptome atlas by RNA in situ hybridization of an entire mammalian organism, the developing mouse at embryonic day 14.5. This digital transcriptome atlas, the Eurexpress atlas (http://www.eurexpress.org), consists of a searchable database of annotated images that can be interactively viewed. We generated anatomy-based expression profiles for over 18,000 coding genes and over 400 microRNAs. We identified 1,002 tissue-specific genes that are a source of novel tissue-specific markers for 37 different anatomical structures. The quality and the resolution of the data revealed novel molecular domains for several developing structures, such as the telencephalon, a novel organization for the hypothalamus, and insight on the Wnt network involved in renal epithelial differentiation during kidney development. The digital transcriptome atlas is a powerful resource to determine co-expression of genes, to identify cell populations and lineages, and to identify functional associations between genes relevant to development and disease. 2025-12-15T17:01:31Z https://hdl.handle.net/11000/38803 Título : Genome Wide Conditional Mouse Knockout Resources Autor : kaloff, C; Anastassiadis, Konstantinos; Ayadi, A.; Baldock, R.; Beig, J.; Birling, M-C.; Bradley, A.; Brown, S.; Bürger, A.; Bushell, W.; Chiani, F.; Collins, FS.; Doe, B.; Eppig, JT.; Finnel, RH. Resumen : The International Knockout Mouse Consortium (IKMC) developed high throughput gene trapping and gene targeting pipelines that produced mostly conditional mutations of more than 18,500 genes in C57BL/6N mouse embryonic stem (ES) cells which have been archived and are freely available to the research community as a frozen resource. From this unprecedented resource more than 6,000 mutant mouse strains have been produced by the IKMC and mostly the International Mouse Phenotyping Consortium (IMPC). In addition, a cre-driver resource was established including 250 inducible cre-driver mouse strains in a C57BL/6 background. Complementing the cre-driver resource, a collection of comprising 27 cre-driver rAAVs has also been produced. The resources can be easily accessed at the IKMC/IMPC web portal (www.mousephenotype.org). The IKMC/IMPC resource is a standardized reference library of mouse models with defined genetic backgrounds that enables the analysis of gene-disease associations in mice of different genetic makeup and should therefore have a major impact on biomedical research. 2025-12-15T15:31:04Z https://hdl.handle.net/11000/38791 Título : Dopaminergic control of ADAMTS2 expression through cAMP/CREB and ERK: molecular effects of antipsychotics Autor : Ruso-Julve, Fulgencio; Pombero, Ana; Pilar-Cuellar, Fuencisla; García-Díaz, Nuria; García López, Raquel; Juncal-Ruiz, María; Castro, Elena; Díaz, Alvaro; Vázquez-Bourgon, Javier; García-Blanco, Agustín; Garro-Martínez, Emilio; Helena, PISONERO; Estirado, Alicia; Ayesa-Arriola, Rosa; López-Giménez, Juan Resumen : A better understanding of the molecular mechanisms that participate in the development and clinical manifestations of schizophrenia can lead to improve our ability to diagnose and treat this disease. Previous data strongly associated the levels of deregulated ADAMTS2 expression in peripheral blood mononuclear cells (PBMCs) from patients at first episode of psychosis (up) as well as in clinical responders to treatment with antipsychotic drugs (down). In this current work, we performed an independent validation of such data and studied the mechanisms implicated in the control of ADAMTS2 gene expression. Using a new cohort of drug-naïve schizophrenia patients with clinical follow-up, we confirmed that the expression of ADAMTS2 was highly upregulated in PBMCs at the onset (drug-naïve patients) and downregulated, in clinical responders, after treatment with antipsychotics. Mechanistically, ADAMTS2 expression was activated by dopaminergic signalling (D1-class receptors) and downstream by cAMP/CREB and mitogen-activated protein kinase (MAPK)/ERK signalling. Incubation with antipsychotic drugs and selective PKA and MEK inhibitors abrogated D1-mediated activation of ADAMTS2 in neuronal-like cells. Thus, D1 receptors signalling towards CREB activation might participate in the onset and clinical responses to therapy in schizophrenia patients, by controlling ADAMTS2 expression and activity. The unbiased investigation of molecular mechanisms triggered by antipsychotic drugs may provide a new landscape of novel targets potentially associated with clinical efficacy. 2025-12-15T08:06:19Z