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Duplication
Kinds of Duplication Terms modified by Duplication Selected AbstractsALLELIC DIVERGENCE PRECEDES AND PROMOTES GENE DUPLICATIONEVOLUTION, Issue 5 2006Stephen R. Proulx Abstract One of the striking observations from recent whole-genome comparisons is that changes in the number of specialized genes in existing gene families, as opposed to novel taxon-specific gene families, are responsible for the majority of the difference in genome composition between major taxa. Previous models of duplicate gene evolution focused primarily on the role that neutral processes can play in evolutionary divergence after the duplicates are already fixed in the population. By instead including the entire cycle of duplication and divergence, we show that specialized functions are most likely to evolve through strong selection acting on segregating alleles at a single locus, even before the duplicate arises. We show that the fitness relationships that allow divergent alleles to evolve at a single locus largely overlap with the conditions that allow divergence of previously duplicated genes. Thus, a solution to the paradox of the origin of organismal complexity via the expansion of gene families exists in the form of the deterministic spread of novel duplicates via natural selection. [source] Phenotypic Characterization of Early Onset Paget's Disease of Bone Caused by a 27-bp Duplication in the TNFRSF11A Gene,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003Kiyoshi Nakatsuka Abstract Three different insertion mutations in the TNFRSF11A gene affecting the signal peptide of RANK have been described. An 18-bp duplication at position 84 (84dup18) is associated with the clinical syndrome of familial expansile osteolysis (FEO), whereas a 15-bp duplication at the same site (84dup15) causes the syndrome of expansile skeletal hyperphosphatasia (ESH). Here we report the phenotype of patients harboring a 27-bp duplication at position 75 (75dup27) in RANK. Affected individuals had hearing impairment and tooth loss beginning in the second or third decade. Radiographs of affected bones showed lytic and sclerotic lesions with bony enlargement and deformity. Serum alkaline phosphatase levels were elevated between 2 and 17 times above the normal range. Most patients had pelvic and skull involvement, and all had involvement of the mandible and maxilla. Most patients also had bony enlargement of the small joints of the hands, and one developed hypercalcemia during a period of immobilization. We conclude that the 75dup27 mutation of RANK causes a Paget's disease of bone-like phenotype that is distinct from, but which overlaps with, FEO and ESH. A particularly striking feature was involvement of the mandible and maxilla, but it remains to be seen if this is a specific feature of the 75dup27 mutation until further kindreds with this mutation are reported. [source] Dual Origin Extracranial Vertebral Artery: Case Report and EmbryologyJOURNAL OF NEUROIMAGING, Issue 2 2008Ajith J. Thomas MD ABSTRACT Duplication of the vertebral artery origin is a rare vascular anomaly. The authors describe this finding in a patient who underwent neurointerventional treatment for a midbasilar aneurysm. The embryology and clinical significance is also presented. [source] CMT1A Associated With The 17p11.2 Duplication: Differential Features And CorrelationJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2001D Pareyson A duplication on chromosome 17p11.2 encompassing the gene coding for the peripheral myelin protein-22 (PMP22) is the most common genetic abnormality underlying Charcot-Marie-Tooth disease (CMT). We report clinical and electrophysiologic features of our series of CMT1A patients harboring the duplication. There were 92 patients from 53 families representing 42% of all CMT index cases (n = 125) and 64% of CMT1 probands (n = 83). In CMT1A patients, mean age at onset was 9.7 ± 11.4 and was significantly lower than in non-duplicated CMT1 cases (12.6 ± 9.7, p < 0.01) and CMT2 cases (21.5 ± 17, p < 0.001). Clinical severity was similar to that of CMT2 patients, but significantly milder than in non-duplicated CMT1 cases. Pes cavus, upper limb involvement, deep tendon reflexes abnormalities, and sensory loss were more frequent compared to CMT2. Electrophysiologic examination revealed motor and sensory conduction velocity (MCV, SCV) slowing below 32 m/s in upper limbs. MCV and SCV were significantly lower than in non-duplicated CMT1 patients. Amplitudes of upper limb compound muscle action potentials (CMAPs) and of upper and lower limb sensory action potentials (SAPs) were significantly lower than in CMT2, paralleling clinical differences. Clinical severity correlated with CMAP amplitudes and with disease duration. On the other hand, MCV slowing was not correlated with either severity or duration of the disease. We found a direct correlation between age at onset and upper limb MCV slowing. Conclusions: CMT1A is an early-onset but slowly progressive disorder, on average milder than other CMT1. Axonal loss rather than demyelination per se underlies disease progression. [source] Duplication of chromosome 2 in association with ventriculomegaly , a case reportPRENATAL DIAGNOSIS, Issue 13 2001W. L. Martin Abstract This is a case report of the prenatal diagnosis of a de novo interstitial duplication of chromosome 2 (46,XX,dup(2)(p13p21) de novo) with an associated phenotypic abnormality. This chromosomal duplication is rare, only one has previously been described prenatally. Postnatal reports of similar duplications in this region have described associated dysmorphic features and significant neurodevelopmental delay. In our case, the only ultrasound finding was moderately severe ventriculomegaly. At post-mortem, ventriculomegaly was confirmed and there was associated macrocephaly (head circumference above the 97th centile) with no dysmorphic features seen. Copyright © 2001 John Wiley & Sons, Ltd. [source] Work Type II First Branchial Cleft Cyst with External Auditory Canal DuplicationTHE LARYNGOSCOPE, Issue S1 2009Sandy Mong BS No abstract is available for this article. [source] Congenital Duplication of the Caudal Region (Monocephalus Dipygus) in a Kid GoatANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2005J. A. Corbera Summary A case of congenital duplication (monocephalus dipygus) in a goat is described. Two pelvis and four pelvic limbs were observed in the kid. Conjoined or fused symmetric twins were diagnosed. Associated abnormalities were cleft palate and anal atresia. Most of the classically recognized teratogens were ruled out by history and serology. However, progenitors were related in the second degree. Thus, genetic factors could be suspected in this case. To the authors' best knowledge, this is the first report of monocephalus dipygus in a goat. [source] CFTR Rearrangements in Spanish Cystic Fibrosis Patients: First New Duplication (35kb) Characterised in the Mediterranean CountriesANNALS OF HUMAN GENETICS, Issue 5 2010María D. Ramos Summary Developments in quantitative PCR technologies have greatly improved our ability to detect large genome rearrangements. In particular oligonucleotide-based array comparative genomic hybridisation has become a useful tool for appropriate and rapid detection of breakpoints. In this work, we have analysed 80 samples (42 unknown CF alleles) applying three quantitative technologies (MLPA, qPCR and array-CGH) to detect recurrent as well as novel large rearrangements in the Spanish CF population. Three deletions and one duplication have been identified in five alleles (12%). Interestingly, we provide the comprehensive characterisation of the first duplication in our CF cohort. The new CFTRdupProm-3 mutation spans 35.7 kb involving the 5,-end of the CFTR gene. Additionally, the RNA analysis has revealed a cryptic sequence with a premature termination codon leading to a disrupted protein. This duplication has been identified in five unrelated families from Spain, France and Italy with all patients showing the same associated haplotype, which is further evidence for its likely common Mediterranean origin. Overall, considering this and other previous studies, CFTR rearrangements account for 1.3% of the Spanish CF alleles. [source] Large Genomic Mutations within the ATM Gene Detected by MLPA, Including a Duplication of 41 kb from Exon 4 to 20ANNALS OF HUMAN GENETICS, Issue 1 2008Simona Cavalieri Summary Mutation detection remains problematic for large genes, primarily because PCR-based methodology fails to detect heterozygous deletions and any duplication. In the ATM gene only a handful of multi-exon deletions have been described to date, and this type of mutation has been considered rare. To address this issue we tested a new MLPA (Multiplex Ligation Probe Amplification) kit that covers 33 of the 66 ATM exons, using for controls two previously characterized genomic deletions in addition to three A-T patients, taken from a survey of nine, who had missing four mutations unidentified after conventional mutation screening. We identified for the first time: 1) a ,41 kb genomic duplication spanning exons 4,20 (c.-30_2816dup41kb)(a.k.a., ATM dup 41 kb); 2) a novel genomic deletion including exon 31, and 3) in hemizygosis a point mutation in the non-deleted exon 31. In this study we extended mutation detection to nine new Italian A-T patients, using a combined approach of haplotype analysis, DHPLC and MLPA. Overall we achieved a mutation detection rate of >97%, and can now define a spectrum of ATM mutations based on twenty-one consecutive Italian families with A-T. [source] Duplication, divergence and formation of novel protein topologiesBIOESSAYS, Issue 10 2006Christine Vogel The rearrangement or permutation of protein substructures is an important mode of divergence. Recent work1 explored one possible underlying mechanism called permutation-by-duplication, which produces special forms of motif rearrangements called circular permutations. Permutation-by-duplication, involving gene duplication, fusion and truncation, can produce fully functional intermediate proteins1 and thus represents a feasible mechanism of protein evolution. In spite of this, circular permutations are relatively rare and we discuss possible reasons for their existence. BioEssays 28: 973,978, 2006. © 2006 Wiley Periodicals, Inc. [source] Duplication 8q22.1-q24.1 associated with bipolar disorder and speech delayBIPOLAR DISORDERS, Issue 3 2006JF Macayran Objective:, To report a case of a child with bipolar disorder found to have an unbalanced translocation involving the long arm of chromosome 8, a region that has been previously implicated in genome-wide linkage scans. Case report:, A 7-year-old boy with a complex psychiatric symptom presentation including attention deficits, distractibility, impulsivity, pressured speech, sleep disturbance, aggressive behavior, and hypersexuality diagnosed with bipolar disorder. He also showed evidence of borderline intellectual and adaptive functioning and had mild dysmorphic features with a duplication of distal 8q that arose as an unbalanced chromosomal translocation due to a maternal 15p;8q insertion. Conclusion:, This finding of an unbalanced translocation provides further evidence to support previous linkage studies of a potential causative gene on 8q for bipolar disorder. [source] The Algebra of Geometric Impossibility: Descartes and Montucla on the Impossibility of the Duplication of the Cube and the Trisection of the AngleCENTAURUS, Issue 1 2010Jesper Lützen Today we credit Pierre Wantzel with the first proof (1837) of the impossibility of doubling a cube and trisecting an arbitrary angle by ruler and compass. However two centuries earlier Descartes had put forward what probably counts as the first proof of these impossibilities. In this paper I analyze this proof, as well as the later related proof given by Montucla (1754) and the brief version of this proof published by Condorcet (1775). I discuss the many novelties of these early arguments and highlight the problematic points addressed by Gauss (1801) and Wantzel. In particular I show that although Descartes developed many of the algebraic techniques used in later proofs he failed to provide an algebraic impossibility proof and resorted to a geometric argument. Montucla and Condorcet turned this proof into an algebraic one. I situate the analysis of the early proof of the impossibility of the two classical problems in the general context of early modern mathematics where mathematics was primarily viewed as a problem solving activity. Within such a paradigm of mathematics impossibility results arguably do not play the role of proper mathematical results, but rather the role of meta-results limiting the problem solving activity. [source] A detailed look at 7 million years of genome evolution in a 439 kb contiguous sequence at the barley Hv-eIF4E locus: recombination, rearrangements and repeatsTHE PLANT JOURNAL, Issue 2 2005Thomas Wicker Summary Six overlapping BAC clones covering the Hv-eIF4E gene region in barley were sequenced in their entire length, resulting in a 439.7 kb contiguous sequence. The contig contains only two genes, Hv-eIF4E and Hv-MLL, which are located in a small gene island and more than 88% of the sequence is composed of transposable elements. A detailed analysis of the repetitive component revealed that this chromosomal region was affected by multiple major duplication and deletion events as well as the insertion of numerous transposable elements, resulting in a complete reshuffling of genomic DNA. Resolving this highly complex pattern resulted in a model unraveling evolutionary events that shaped this region over an estimated 7 million years. Duplications and deletions caused by illegitimate recombination and unequal crossing over were major driving forces in the evolution of the Hv-eIF4E region, equaling or exceeding the effects of transposable element activities. In addition to a dramatic reshuffling of the repetitive portion of the sequence, we also found evidence for important contributions of illegitimate recombination and transposable elements to the sequence organization of the gene island containing Hv-eIF4E and Hv-MLL. [source] Prader,Willi syndrome phenocopy due to duplication of Xq21.1,q21.31, with array CGH of the critical regionCLINICAL GENETICS, Issue 4 2008MT Gabbett We report on a 4-year-old male with an interstitial tandem duplication of Xq21.1,q21.31 who presented with clinical features of Prader,Willi syndrome (PWS). The duplication was maternally inherited. Abnormalities of the X chromosome have previously been reported in association with a PWS phenotype, but to date, specific duplications of Xq21.1,q21.31 have not. We refined the chromosomal breakpoints seen on initial G-banded karyotyping in our case with comparative genomic hybridization by microarray (array CGH). The duplication was between 11.1 and 14.4 Mb in length and overlaps with three loci to which mental retardation with PWS-like features have been previously mapped, showing the utility of array CGH in helping to identify candidate genes. We conclude that duplication of chromosomal region Xq21.1,q21.31 potentially results in a PWS-like phenotype. Reviewing the literature on similar duplications, we further conclude that distal Xq duplications can result in features typically seen in infants with PWS, while proximal duplications can result in features typically seen in older children and adults with PWS. Duplications of chromosome Xq should be considered in the differential diagnosis of PWS, especially in males. [source] Microdeletion/duplication at the Xq28 IP locus causes a de novo IKBKG/NEMO/IKKgamma exon4_10 deletion in families with incontinentia pigmenti,HUMAN MUTATION, Issue 9 2009Fusco Francesca Abstract The Incontinentia Pigmenti (IP) locus contains the IKBKG/NEMO/IKKgamma gene and its truncated pseudogene copy, IKBKGP/deltaNEMO. The major genetic defect in IP is a heterozygous exon4_10 IKBKG deletion (IKBKGdel) caused by a recombination between two consecutive MER67B repeats. We analyzed 91 IP females carrying the IKBKGdel, 59 of whom carrying de novo mutations (65%). In eight parents, we found two recurrent nonpathological variants of IP locus, which were also present as rare polymorphism in control population: the IKBKGPdel, corresponding to the exon4_10 deletion in the pseudogene, and the MER67Bdup, that replicates the exon4_10 region downstream of the normal IKBKG gene. Using quantitative DNA analysis and microsatellite mapping, we established that both variants might promote the generation of the pathological IKBKGdel. Indeed, in family IP-516, the exon4_10 deletion was repositioned in the same allele from the pseudogene to the gene, whereas in family IP-688, the MER67Bdup generated the pathological IKBKGdel by recombination between two direct nonadjacent MER67Bs. Moreover, we found an instance of somatic recombination in a MER67Bdup variant, creating the IKBKGdel in an IP male. Our data suggest that the IP locus undergoes recombination producing recurrent variants that might be "at risk" of generating de novo IKBKGdel by NAHR during either meiotic or mitotic division. Hum Mutat 30:1,8, 2009. © 2009 Wiley-Liss, Inc. [source] Absence of large intragenic rearrangements in the DPYD gene in a large cohort of colorectal cancer patients treated with 5-FU-based chemotherapyBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 2 2010Laia Paré WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT , Dihydropyrimidine dehydrogenase (DPD) is the enzyme responsible for the elimination of approximately 80% of the administered dose of 5-fluorouracil (5-FU). , Mutations in the DPD-coding gene have been shown to increase the risk of severe toxicity in 5-FU treated patients. , The IVS14+1G>A is the most common DPYD mutation. WHAT THIS STUDY ADDS , The intragenic rearrangements of DPYD using multiplex ligation-dependent probe amplification (MLPA) were studied for the first time in a large series of 234 colorectal cancer patients treated with 5-FU-containing chemotherapy. , No deletions or duplications of one or more DPYD exons were detected. The presence of the IVS14+1G>A mutation was also excluded. , These data show that neither the large genomic rearrangements in the DPYD gene nor the IVS14+1G>A mutation are responsible for the serious toxicity associated with a 5-FU containing regimen in this cohort of Spanish patients. AIMS To study the relationship between the toxicity associated with a 5-FU-based therapy and the presence of (i) the large intragenic rearrangements in the DPYD gene and (ii) the IVS14+1G>A mutation. METHODS We used the multiplex ligation-dependent probe amplification technique (MLPA) to study genomic DNA from 234 colorectal cancer patients treated with 5-FU-based chemotherapy. RESULTS We did not detect any deletion/duplication in the DPYD gene. The presence of the IVS14+1G>A mutation was also excluded. CONCLUSIONS Neither the large genomic rearrangements in the DPYD gene nor the IVS14+1G>A mutation play a significant role in the development of serious toxicity associated with a 5-FU containing regimen. [source] Deletions of SCN1A 5, genomic region with promoter activity in Dravet syndrome,HUMAN MUTATION, Issue 7 2010Tojo Nakayama Abstract Mutations involving the voltage-gated sodium channel ,I gene SCN1A are major genetic causes of childhood epileptic disorders, as typified by Dravet syndrome. Here we investigated the upstream regions of the SCN1A 5, noncoding exons and found two major regions with promoter activity. These two major promoters were simultaneously active in various brain regions and in most neurons. Using multiplex ligation-dependent probe amplification (MLPA) assays with probes for the 5, noncoding exons, their upstream regions, and all coding exons of SCN1A, we investigated 130 epileptic patients who did not show any SCN1A mutations by sequence analysis of all coding exons and exon,intron boundaries. Among 71 Dravet syndrome patients, we found two patients with heterozygous microdeletions removing the 5, noncoding exons and regions with promoter activity but not affecting the coding exons. We also identified four patients with deletions/duplication in the coding region. One patient with symptomatic focal epilepsy also showed a deletion in the coding region. This study provides the first case of microdeletion limited to the SCN1A 5, promoter region with the coding sequence preserved, and indicates the critical involvement of this upstream region in the molecular pathology of Dravet syndrome. Hum Mutat 31:,11, 2010. © 2010 Wiley-Liss, Inc. [source] A Possibilistic Petri Net Model for Diagnosing Cracks in RC StructuresCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2003Kevin F. R. Liu PPN integrates Petri nets with possibilistic reasoning and maintains the advantages of both formalisms. Two major features of PPN include the possibilistic token to carry information to describe an object and its corresponding possibility and necessity measures, and four types of possibilistic transitions,inference, duplication, aggregation, and aggregation-duplication. A reasoning algorithm, based on possibilistic Petri nets, is also developed to execute PPN. The PPN model and the reasoning algorithm are further used to diagnose possible causes of cracking in RC structures, and three basic cases are considered to demonstrate the applicability of the approach. The reliability of the results is increased by explaining the diagnostic process through the movement of tokens. Moreover, the confidence level associated with each possible cause of concrete cracking can be used to determine the relevance of the diagnosis. [source] Centrioles to basal bodies in the spermiogenesis of Mastotermes darwiniensis (Insecta, Isoptera)CYTOSKELETON, Issue 5 2009Maria Giovanna Riparbelli Abstract In addition to their role in centrosome organization, the centrioles have another distinct function as basal bodies for the formation of cilia and flagella. Centriole duplication has been reported to require two alternate assembly pathways: template or de novo. Since spermiogenesis in the termite Mastotermes darwiniensis lead to the formation of multiflagellate sperm, this process represents a useful model system in which to follow basal body formation and flagella assembly. We present evidence of a possible de novo pathway for basal body formation in the differentiating germ cell. This cell also contains typical centrosomal proteins, such as centrosomin, pericentrin-like protein, ,-tubulin, that undergo redistribution as spermatid differentiation proceeds. The spermatid centrioles are long structures formed by nine doublet rather than triplet microtubules provided with short projections extending towards the surrounding cytoplasm and with links between doublets. The sperm basal bodies are aligned in parallel beneath the nucleus. They consist of long regions close to the nucleus showing nine doublets in a cartwheel array devoid of any projections; on the contrary, the short region close to the plasma membrane, where the sperm flagella emerge, is characterized by projections similar to those observed in the centrioles linking the basal body to the plasma membrane. It is hypothesized that this appearance is in connection with the centriole elongation and further with the flagellar axonemal organization. Microtubule doublets of sperm flagellar axonemes are provided with outer dynein arms, while inner arms are rarely visible. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Post-karyokinesis centrosome movement leaves a trail of unanswered questionsCYTOSKELETON, Issue 3 2002Young Y. Ou Abstract The centrosome is a complex structure composed of a large number of proteins (pericentriolar material, PCM) usually organized around a pair of centrioles (or a centriole duplex). This structure is capable of nucleating and organizing microtubules, duplication, and motility. In general, episodes of dramatic centrosome movement correlate with periods of cellular reorganization and nowhere is cellular reorganization more apparent, or more important, than in the periods before and after cell division. It is now clear that centrosome movement occurs not only prior to cell division but also at its completion, in concert with cytokinesis. The focus of this review is the newly emerging picture of centrosome activity during the post-karyokinesis period and the role that this activity might play in the transition of cells from mitosis to interphase. Cell Motil. Cytoskeleton 51:123,132, 2002. © 2002 Wiley-Liss, Inc. [source] Differing strategies for forming the arthropod body plan: Lessons from Dpp, Sog and Delta in the fly Drosophila and spider AchaearaneaDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 4 2008Hiroki Oda In the insect Drosophila embryo, establishment of maternal transcription factor gradients, rather than cell,cell interactions, is fundamental to patterning the embryonic axes. In contrast, in the chelicerate spider embryo, cell,cell interactions are thought to play a crucial role in the development of the embryonic axes. A grafting experiment by Holm using spider eggs resulted in duplication of the embryonic axes, similar to the Spemann's organizer experiment using amphibian eggs. Recent work using the house spider Achaearanea tepidariorum has demonstrated that the homologs of decapentaplegic (dpp), short gastrulation (sog) and Delta, which encode a bone morphogenetic protein (BMP)-type ligand, its antagonist and a Notch ligand, respectively, are required in distinct aspects of axis formation. Achaearanea Dpp appears to function as a symmetry-breaking signal, which could account for Holm's results to some extent. Experimental findings concerning Achaearanea sog and Delta have highlighted differences in the mechanisms underlying ventral and posterior development between Drosophila and Achaearanea. Achaearanea ventral patterning essentially depends on sog function, in contrast to the Drosophila patterning mechanism, which is based on the nuclear gradient of Dorsal. Achaearanea posterior (or opisthosomal) patterning relies on the function of the caudal lobe, which develops from cells surrounding the blastopore through progressive activation of Delta-Notch signaling. In this review, we describe the differing strategies for forming the arthropod body plan in the fly and spider, and provide a perspective towards understanding the relationship between the arthropod and vertebrate body plans. [source] Anteroposterior patterning in the limb and digit specification: Contribution of mouse geneticsDEVELOPMENTAL DYNAMICS, Issue 9 2006Benoît Robert Abstract The limb has been a privileged object of investigation and reflection for scientists over the past two centuries and continues to provide a heuristic framework to analyze vertebrate development. Recently, accumulation of new data has significantly changed our view on the mechanisms of limb patterning, in particular along the anterior-posterior axis. These data have led us to revisit the mode of action of the zone of polarizing activity. They shed light on the molecular and cellular mechanisms of patterning linked to the Shh-Gli3 signaling pathway and give insights into the mechanism of activation of these cardinal factors, as well as the consequences of their activity. These new data are in good part the result of systematic Application of tools used in contemporary mouse molecular genetics. These have extended the power of mouse genetics by introducing mutational strategies that allow fine-tuned modulation of gene expression, interchromosomal deletions and duplication. They have even made the mouse embryo amenable to cell lineage analysis that used to be the realm of chick embryos. In this review, we focus on the data acquired over the last five years from the analysis of mouse limb development and discuss new perspectives opened by these results. Developmental Dynamics 235:2337,2352, 2006. © 2006 Wiley-Liss, Inc. [source] Comparative genomic and expression analysis of group B1 sox genes in zebrafish indicates their diversification during vertebrate evolutionDEVELOPMENTAL DYNAMICS, Issue 3 2006Yuich Okuda Abstract Group B1 Sox genes encode HMG domain transcription factors that play major roles in neural development. We have identified six zebrafish B1 sox genes, which include pan-vertebrate sox1a/b, sox2, and sox3, and also fish-specific sox19a/b. SOX19A/B proteins show a transcriptional activation potential that is similar to other B1 SOX proteins. The expression of sox19a and sox3 begins at approximately the 1,000-cell stage during embryogenesis and becomes confined to the future ectoderm by the shield stage. This is reminiscent of the epiblastic expression of Sox2 and/or Sox3 in amniotes. As development progresses, these six B1 sox genes display unique expression patterns that overlap distinctly from one region to another. sox19a expression is widespread in the early neuroectoderm, resembling pan-neural Sox2 expression in amniotes, whereas zebrafish sox2 shows anterior-restricted expression. Comparative genomics suggests that sox19a/b and mammalian Sox15 (group G) have an orthologous relationship and that the B1/G Sox genes arose from a common ancestral gene through two rounds of genome duplication. It seems likely, therefore, that each B1/G Sox gene has gained a distinct expression profile and function during vertebrate evolution. Developmental Dynamics 235:811,825, 2006. © 2006 Wiley-Liss, Inc. [source] Groucho corepressor proteins regulate otic vesicle outgrowthDEVELOPMENTAL DYNAMICS, Issue 3 2005Baubak Bajoghli Abstract The Groucho/Tle family of corepressor proteins is known to regulate multiple developmental pathways. Applying the dominant-negative effect of the short member Aes, we demonstrate here a critical role of this gene family also for ear development. Misexpression of Aes in medaka embryos resulted in reduced size or loss of otic vesicles, whereas overexpression of the full-length Groucho protein Tle4 gave the opposite phenotype. These results are in close agreement with phenotypes observed for eye formation, suggesting a similar role for Groucho/Tle proteins in the developmental pathways of both sensory organs. Furthermore, by using the heat-inducible HSE promoter, we observed reversible branching of the embryonic axis upon Aes misexpression, indicating a transient duplication of the organizer. Groucho proteins, therefore, are critical for organizer maintenance. Developmental Dynamics 233:760,771, 2005 © 2005 Wiley-Liss, Inc. [source] Studies on epidermal growth factor receptor signaling in vertebrate limb patterningDEVELOPMENTAL DYNAMICS, Issue 2 2005Minoru Omi Abstract The epidermal growth factor receptor (EGFR) regulates multiple patterning events in Drosophila limb development, but its role in vertebrate limb morphogenesis has received little attention. The EGFR and several of its ligands are expressed in developing vertebrate limbs in manners consistent with potential patterning roles. To gain insight into functions of EGFR signaling in vertebrate limb development, we expressed a constitutively active EGFR in developing chick limbs in ovo. Expression of activated EGFR causes pre- and postaxial polydactyly, including mirror-image,type digit duplication, likely due to induction of ectopic expression and/or modulation of genes involved in anterior,posterior (AP) patterning such as Sonic hedgehog (Shh), dHand, Patched (Ptc), Gli3, Hoxd13, Hoxd11, bone morphogenetic protein 2 (Bmp2), Gremlin, and FGF4. Activation of EGFR signaling dorsalizes the limb and alters expression of the dorsal,ventral (DV) patterning genes Wnt7a, Lmx, and En1. Ectopic and/or extended FGF8 expressing apical ectodermal ridges (AERs) are also seen. Interdigital regression is inhibited and the digits fail to separate, leading to syndactyly, likely due to antiapoptotic and pro-proliferative effects of activated EGFR signaling on limb mesoderm, and/or attenuation of interdigital Bmp4 expression. These findings suggest potential roles for EGFR signaling in AP and DV patterning, AER formation, and cell survival during limb morphogenesis. Developmental Dynamics 233:288,300, 2005. © 2005 Wiley-Liss, Inc. [source] Expression of a novel zebrafish zinc finger gene, gli2b, is affected in Hedgehog and Notch signaling related mutants during embryonic developmentDEVELOPMENTAL DYNAMICS, Issue 2 2005Zhiyuan Ke Abstract Gli zinc-finger proteins are known as downstream mediators of the evolutionary conserved Hedgehog pathway. In zebrafish, gli2 functions differently from Gli2 in mammals. This difference could be due to the gli2 duplication in teleosts evolution and partial redundancy between two duplicated genes. Here, we report a novel zebrafish gli2 -like cDNA. Its structure, genetic location, and distinct expression pattern in the central nervous system suggested that this gene might represent a second gli2 of teleosts, and we named it gli2b. gli2b was expressed in the neural keel, excluding the forebrain,midbrain boundary, while gli2 expression complemented this pattern. After 24 hours postfertilization, several specific domains of gli2b expression were observed in the lateral and medial hindbrain and hypothalamus. In mutants affecting the Hedgehog and Notch signaling pathways, gli2b expression was either disrupted or extended in different regions. Developmental Dynamics 232:479,486, 2005. © 2005 Wiley-Liss, Inc. [source] Genome duplication, subfunction partitioning, and lineage divergence: Sox9 in stickleback and zebrafishDEVELOPMENTAL DYNAMICS, Issue 3 2003William A. Cresko Abstract Teleosts are the most species-rich group of vertebrates, and a genome duplication (tetraploidization) event in ray-fin fish appears to have preceded this remarkable explosion of biodiversity. What is the relationship of the ray-fin genome duplication to the teleost radiation? Genome duplication may have facilitated lineage divergence by partitioning different ancestral gene subfunctions among co-orthologs of tetrapod genes in different teleost lineages. To test this hypothesis, we investigated gene expression patterns for Sox9 gene duplicates in stickleback and zebrafish, teleosts whose lineages diverged early in Euteleost evolution. Most expression domains appear to have been partitioned between Sox9a and Sox9b before the divergence of stickleback and zebrafish lineages, but some ancestral expression domains were distributed differentially in each lineage. We conclude that some gene subfunctions, as represented by lineage-specific expression domains, may have assorted differently in separate lineages and that these may have contributed to lineage diversification during teleost evolution. Developmental Dynamics, 2003. © 2003 Wiley-Liss, Inc. [source] Loss of the Tg737 protein results in skeletal patterning defectsDEVELOPMENTAL DYNAMICS, Issue 1 2003Qihong Zhang Abstract Tg737 mutant mice exhibit pathologic conditions in numerous tissues along with skeletal patterning defects. Herein, we characterize the skeletal pathologic conditions and confirm a role for Tg737 in skeletal patterning through transgenic rescue. Analyses were conducted in both the hypomorphic Tg737orpk allele that results in duplication of digit one and in the null Tg737,2-3,Gal allele that is an embryonic lethal mutation exhibiting eight digits per limb. In early limb buds, Tg737 expression is detected throughout the mesenchyme becoming concentrated in precartilage condensations at later stages. In situ analyses indicate that the Tg737orpk mutant limb defects are not associated with changes in expression of Shh, Ihh, HoxD11,13, Patched, BMPs, or Glis. Likewise, in Tg737,2-3,Gal mutant embryos, there was no change in Shh expression. However, in both alleles, Fgf4 was ectopically expressed on the anterior apical ectodermal ridge. Collectively, the data argue for a dosage effect of Tg737 on the limb phenotypes and that the polydactyly is independent of Shh misexpression. Developmental Dynamics 227:78,90, 2003. © 2003 Wiley-Liss, Inc. [source] From genomes to morphology: a view from amphioxusACTA ZOOLOGICA, Issue 1 2010Peter W. H. Holland Abstract Holland, P.W.H. 2010. From genomes to morphology: a view from amphioxus. ,Acta Zoologica (Stockholm) 91: 81,86 As complete genome sequences are determined from an ever-increasing number of animal species, new opportunities are arising for comparative biology. For zoologists interested in the evolution of shape and form, however, there is a problem. The link between genome sequence and morphology is not direct and is obfuscated by complex and evolving genetic pathways, even when conserved regulatory genes are considered. Nonetheless, a large-scale comparison of genome sequences between extant chordates reveals an intriguing parallel between genotypic and phenotypic evolution. Tunicates have highly altered genomes, with loss of ancestral genes and shuffled genetic arrangements, while vertebrate genomes are also derived through gene loss and genome duplication. The recently sequenced amphioxus genome, in contrast, reveals much greater stasis on the cephalochordate lineage, in parallel to a less derived body plan. The opportunities and challenges for relating genome evolution to morphological evolution are discussed. [source] Pre-operative screening for excessive alcohol consumption among patients scheduled for elective surgeryDRUG AND ALCOHOL REVIEW, Issue 2 2007SWATI SHOURIE Abstract Pre-operative intervention for excessive alcohol consumption among patients scheduled for elective surgery has been shown to reduce complications of surgery. However, successful intervention depends upon an effective and practical screening procedure. This study examines current screening practices for excessive alcohol consumption amongst patients scheduled for elective surgery in general hospitals. It also examines the appropriateness of potential sites and staff for pre-operative screening. Forms used routinely to assess alcohol consumption in the pre-admission clinics (PAC) of eight Sydney hospitals were examined. In addition, the appropriateness of six staff categories (surgeons, surgeons' secretaries, junior medical officer, anaesthetists, nurses and a research assistant) and of two sites (surgeons' office and PAC) in conducting additional screening was assessed at two hospitals. Outcomes included observed advantages and disadvantages of sites and personnel, and number of cases with excessive drinking identified. There was duplication in information collected routinely on alcohol use in the PACs in eight Sydney Hospitals. Questions on alcohol consumption in patient self-completion forms were not validated. The PAC provided for efficient screening but time to surgery was typically too short for successful intervention in many cases. A validated tool and efficient screening procedure is required to detect excessive drinking before elective surgery. Patients often present to the PAC too close to the time of surgery for any change in drinking to reverse alcohol's effects. The role of the referring general practitioner and of printed advice from the surgeon in preparing patients for surgery needs further investigation. [source] | |||||||||||||||||||||||||||||||||||||||||||