scholarly journals Molecular and Functional Mapping of the Piebald Deletion Complex on Mouse Chromosome 14

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 803-815
Author(s):  
Jeffrey J Roix ◽  
Aaron Hagge-Greenberg ◽  
Dennis M Bissonnette ◽  
Sandra Rodick ◽  
Liane B Russell ◽  
...  

Abstract The piebald deletion complex is a set of overlapping chromosomal deficiencies surrounding the endothelin receptor B locus collected during the Oak Ridge specific-locus-test mutagenesis screen. These chromosomal deletions represent an important resource for genetic studies to dissect the functional content of a genomic region, and several developmental defects have been associated with mice homozygous for distinct piebald deletion alleles. We have used molecular markers to order the breakpoints for 20 deletion alleles that span a 15.7–18-cM region of distal mouse chromosome 14. Large deletions covering as much as 11 cM have been identified that will be useful for regionally directed mutagenesis screens to reveal recessive mutations that disrupt development. Deletions identified as having breakpoints positioned within previously described critical regions have been used in complementation studies to further define the functional intervals associated with the developmental defects. This has focused our efforts to isolate genes required for newborn respiration and survival, skeletal patterning and morphogenesis, and central nervous system development.

2005 ◽  
Vol 25 (23) ◽  
pp. 10407-10418 ◽  
Author(s):  
Zhong-Zhou Yang ◽  
Oliver Tschopp ◽  
Nicolas Di-Poï ◽  
Elisabeth Bruder ◽  
Anne Baudry ◽  
...  

ABSTRACT Akt/protein kinase B (PKB) plays a critical role in the regulation of metabolism, transcription, cell migration, cell cycle progression, and cell survival. The existence of viable knockout mice for each of the three isoforms suggests functional redundancy. We generated mice with combined mutant alleles of Akt1 and Akt3 to study their effects on mouse development. Here we show that Akt1 − / − Akt3 +/ − mice display multiple defects in the thymus, heart, and skin and die within several days after birth, while Akt1 +/ − Akt3 − / − mice survive normally. Double knockout (Akt1 − / − Akt3 − / −) causes embryonic lethality at around embryonic days 11 and 12, with more severe developmental defects in the cardiovascular and nervous systems. Increased apoptosis was found in the developing brain of double mutant embryos. These data indicate that the Akt1 gene is more essential than Akt3 for embryonic development and survival but that both are required for embryo development. Our results indicate isoform-specific and dosage-dependent effects of Akt on animal survival and development.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Brian Head ◽  
Jane La Du ◽  
Robyn L. Tanguay ◽  
Chrissa Kioussi ◽  
Maret G. Traber

Abstract Vitamin E (VitE) deficiency results in embryonic lethality. Knockdown of the gene ttpa encoding for the VitE regulatory protein [α-tocopherol transfer protein (α-TTP)] in zebrafish embryos causes death within 24 h post-fertilization (hpf). To test the hypothesis that VitE, not just α-TTP, is necessary for nervous system development, adult 5D strain zebrafish, fed either VitE sufficient (E+) or deficient (E−) diets, were spawned to obtain E+ and E− embryos, which were subjected to RNA in situ hybridization and RT-qPCR. Ttpa was expressed ubiquitously in embryos up to 12 hpf. Early gastrulation (6 hpf) assessed by goosecoid expression was unaffected by VitE status. By 24 hpf, embryos expressed ttpa in brain ventricle borders, which showed abnormal closure in E− embryos. They also displayed disrupted patterns of paired box 2a (pax2a) and SRY-box transcription factor 10 (sox10) expression in the midbrain-hindbrain boundary, spinal cord and dorsal root ganglia. In E− embryos, the collagen sheath notochord markers (col2a1a and col9a2) appeared bent. Severe developmental errors in E− embryos were characterized by improper nervous system patterning of the usually carefully programmed transcriptional signals. Histological analysis also showed developmental defects in the formation of the fore-, mid- and hindbrain and somites of E− embryos at 24 hpf. Ttpa expression profile was not altered by the VitE status demonstrating that VitE itself, and not ttpa, is required for development of the brain and peripheral nervous system in this vertebrate embryo model.


Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1782
Author(s):  
Sahar I. Da’as ◽  
Waleed Aamer ◽  
Waseem Hasan ◽  
Aljazi Al-Maraghi ◽  
Alya Al-Kurbi ◽  
...  

Recessive mutations in Post-GPI attachment to proteins 3 (PGAP3) cause the rare neurological disorder hyperphosphatasia with mental retardation syndrome 4 type (HPMRS4). Here, we report a novel homozygous nonsense mutation in PGAP3 (c.265C>T-p.Gln89*), in a 3-year-old boy with unique novel clinical features. These include decreased intrauterine fetal movements, dysgenesis of the corpus callosum, olfactory bulb agenesis, dysmorphic features, cleft palate, left ear constriction, global developmental delay, and hypotonia. The zebrafish functional modeling of PGAP3 loss resulted in HPMRS4-like features, including structural brain abnormalities, dysmorphic cranial and facial features, hypotonia, and seizure-like behavior. Remarkably, morphants displayed defective neural tube formation during the early stages of nervous system development, affecting brain morphogenesis. The significant aberrant midbrain and hindbrain formation demonstrated by separation of the left and right tectal ventricles, defects in the cerebellar corpus, and caudal hindbrain formation disrupted oligodendrocytes expression leading to shorter motor neurons axons. Assessment of zebrafish neuromuscular responses revealed epileptic-like movements at early development, followed by seizure-like behavior, loss of touch response, and hypotonia, mimicking the clinical phenotype human patients. Altogether, we report a novel pathogenic PGAP3 variant associated with unique phenotypic hallmarks, which may be related to the gene’s novel role in brain morphogenesis and neuronal wiring.


Author(s):  
М.Е. Лопаткина ◽  
В.С. Фишман ◽  
М.М. Гридина ◽  
Н.А. Скрябин ◽  
Т.В. Никитина ◽  
...  

Проведен анализ генной экспрессии в нейронах, дифференцированных из индуцированных плюрипотентных стволовых клеток пациентов с идиопатическими интеллектуальными нарушениями и реципрокными хромосомными мутациями в регионе 3p26.3, затрагивающими единственный ген CNTN6. Для нейронов с различным типом хромосомных аберраций была показана глобальная дисрегуляция генной экспрессии. В нейронах с вариациями числа копий гена CNTN6 была снижена экспрессия генов, продукты которых вовлечены в процессы развития центральной нервной системы. The gene expression analysis of iPSC-derived neurons, obtained from patients with idiopathic intellectual disability and reciprocal microdeletion and microduplication in 3p26.3 region affecting the single CNTN6 gene was performed. The global gene expression dysregulation was demonstrated for cells with CNTN6 copy number variation. Gene expression in neurons with CNTN6 copy number changes was downregulated for genes, whose products are involved in the central nervous system development.


2008 ◽  
Vol 1 (4) ◽  
pp. A353
Author(s):  
Shenandoah Robinson ◽  
Qing Li

Introduction Many infants born very preterm who suffer brain damage most likely experienced a combined insult from intrauterine infection and placental insufficiency. Damage is thought to be synergistic rather than additive but the mechanisms of combined injury remain elusive. A combination of lipopolysaccharide-induced inflammation and hypoxia-ischemia has been used in rats to model the dual insult that occurs in human infants prenatally. Erythropoietin, a pleiotrophic cytokine that is essential for central nervous system development, ameliorates brain injury after isolated hypoxic-ischemic or inflammatory insults through different intracellular signaling pathways. We hypothesized that exogenous neonatal EPO administration would lessen the damage of a combined prenatal insult in rats. Methods On embryonic Day 18 fetal rats experienced 60 minutes of transient uterine artery occlusion with or without intracervical LPS administration with sham controls receiving surgery but no occlusion and saline for LPS. Survival was recorded and histological biochemical and functional assays were performed. Means were compared with ANOVA with Tukey HSD post hoc analysis. Results After a combined insult of HI and 0.15-mg/kg LPS on E18 the survival of pups by postnatal Day 1 (P1) decreased from 77% with HI alone to 22% for LPS plus HI. When exogenous systemic EPO was administered P1–P3 survival to P9 improved markedly from 40% (2 of 5) for saline-treated insult pups to 100% (6 of 6) for EPO-treated. Initial histological analyses show EPO decreases the number of brain activated caspase 3 and activated microglia by P9. Additional analyses will be presented. Conclusion As at least 60% of placentas from infants born pre-term show evidence of chorioamnionitis, assessment of the impact of exogenous EPO on a model of a combination injury is essential prior to proceeding with a clinical trial. Initial results indicate neonatal exogenous EPO mitigates damage from the combined insult.


2013 ◽  
Vol 14 (2) ◽  
pp. 160-166
Author(s):  
Diego Gazzolo ◽  
Laura D. Serpero ◽  
Alessandro Frigiola ◽  
Raul Abella ◽  
Alessandro Giamberti ◽  
...  

2020 ◽  
Vol 20 (17) ◽  
pp. 1781-1790
Author(s):  
Noor Anisah Abu Yazit ◽  
Norsham Juliana ◽  
Srijit Das ◽  
Nur Islami Mohd Fahmi Teng ◽  
Nadia Mohd Fahmy ◽  
...  

Postoperative Cognitive Dysfunction (POCD) refers to the condition of neurocognitive decline following surgery in a cognitive and sensory manner. There are several risk factors, which may be life-threatening for this condition. Neuropsychological assessment of this condition is very important. In the present review, we discuss the association of apolipoprotein epsilon 4 (APOE ε4) and few miRNAs with POCD, and highlight the clinical importance for prognosis, diagnosis and treatment of POCD. Microarray is a genome analysis that can be used to determine DNA abnormalities. This current technique is rapid, efficient and high-throughout. Microarray techniques are widely used to diagnose diseases, particularly in genetic disorder, chromosomal abnormalities, mutations, infectious diseases and disease-relevant biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are widely found distributed in eukaryotes. Few miRNAs influence the nervous system development, and nerve damage repair. Microarray approach can be utilized to understand the miRNAs involved and their pathways in POCD development, unleashing their potential to be considered as a diagnostic marker for POCD. This paper summarizes and identifies the studies that use microarray based approaches for POCD analysis. Since the application of microarray in POCD is expanding, there is a need to review the current knowledge of this approach.


2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Melis Savasan Sogut ◽  
Chitra Venugopal ◽  
Basak Kandemir ◽  
Ugur Dag ◽  
Sujeivan Mahendram ◽  
...  

Elk-1, a member of the ternary complex factors (TCFs) within the ETS (E26 transformation-specific) domain superfamily, is a transcription factor implicated in neuroprotection, neurodegeneration, and brain tumor proliferation. Except for known targets, c-fos and egr-1, few targets of Elk-1 have been identified. Interestingly, SMN, SOD1, and PSEN1 promoters were shown to be regulated by Elk-1. On the other hand, Elk-1 was shown to regulate the CD133 gene, which is highly expressed in brain-tumor-initiating cells (BTICs) and used as a marker for separating this cancer stem cell population. In this study, we have carried out microarray analysis in SH-SY5Y cells overexpressing Elk-1-VP16, which has revealed a large number of genes significantly regulated by Elk-1 that function in nervous system development, embryonic development, pluripotency, apoptosis, survival, and proliferation. Among these, we have shown that genes related to pluripotency, such as Sox2, Nanog, and Oct4, were indeed regulated by Elk-1, and in the context of brain tumors, we further showed that Elk-1 overexpression in CD133+ BTIC population results in the upregulation of these genes. When Elk-1 expression is silenced, the expression of these stemness genes is decreased. We propose that Elk-1 is a transcription factor upstream of these genes, regulating the self-renewal of CD133+ BTICs.


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