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PubMed1969

Transduction of merodiploidy: induced duplication of recipient genes.

Escherichia coli PB160, which carries a tandem duplication with the gene order metB(+)argH(-)su(159) (+)thi(+): metB(+)argH(+)su(159) (-)thi(+), was used to study the mechanism of P1 transduction of genes in the duplicated region. Transduction of the su(159) (+) allele contained within the duplicated segment yields two kinds of su(159) (+) recombinants: 91% are haploid su(159) (+) and 9% are su(159) (+)/su(159) (-) merodiploids. The duplication in these merodiploid transductants includes the metB locus; however, both copies of the metB locus usually are derived from the recipient. Thus, the requirements for transduction of the "condition of merodiploidy" appear to be the cotransduction of the repeat point (the region where the duplication begins to repeat itself) and, of course, the selected marker (in this case su(159) (+)). A mechanism whereby two recipient chromosomes interact with the transduced "repeat point" region to regenerate the tandem duplication is implicated. It appears that a duplication much larger than the quantity of genetic material carried by a P1 phage can be produced in a transductant.

Chromosomes, Bacterial↗
PubMed2006

Natural history of human respiratory syncytial virus inferred from phylogenetic analysis of the attachment (G) glycoprotein with a 60-nucleotide duplication.

A total of 47 clinical samples were identified during an active surveillance program of respiratory infections in Buenos Aires (BA) (1999 to 2004) that contained sequences of human respiratory syncytial virus (HRSV) with a 60-nucleotide duplication in the attachment (G) protein gene. This duplication was analogous to that previously described for other three viruses also isolated in Buenos Aires in 1999 (A. Trento et al., J. Gen. Virol. 84:3115-3120, 2003). Phylogenetic analysis indicated that BA sequences with that duplication shared a common ancestor (dated about 1998) with other HRSV G sequences reported worldwide after 1999. The duplicated nucleotide sequence was an exact copy of the preceding 60 nucleotides in early viruses, but both copies of the duplicated segment accumulated nucleotide substitutions in more recent viruses at a rate apparently higher than in other regions of the G protein gene. The evolution of the viruses with the duplicated G segment apparently followed the overall evolutionary pattern previously described for HRSV, and this genotype has replaced other prevailing antigenic group B genotypes in Buenos Aires and other places. Thus, the duplicated segment represents a natural tag that can be used to track the dissemination and evolution of HRSV in an unprecedented setting. We have taken advantage of this situation to reexamine the molecular epidemiology of HRSV and to explore the natural history of this important human pathogen.

Amino Acid Sequence↗
PubMed2006

Interaction between ROCK II and nucleophosmin/B23 in the regulation of centrosome duplication.

Nucleophosmin (NPM)/B23 has been implicated in the regulation of centrosome duplication. NPM/B23 localizes between two centrioles in the unduplicated centrosome. Upon phosphorylation on Thr(199) by cyclin-dependent kinase 2 (CDK2)/cyclin E, the majority of centrosomal NPM/B23 dissociates from centrosomes, but some NPM/B23 phosphorylated on Thr(199) remains at centrosomes. It has been shown that Thr(199) phosphorylation of NPM/B23 is critical for the physical separation of the paired centrioles, an initial event of the centrosome duplication process. Here, we identified ROCK II kinase, an effector of Rho small GTPase, as a protein that localizes to centrosomes and physically interacts with NPM/B23. Expression of the constitutively active form of ROCK II promotes centrosome duplication, while down-regulation of ROCK II expression results in the suppression of centrosome duplication, especially delaying the initiation of centrosome duplication during the cell cycle. Moreover, ROCK II regulates centrosome duplication in its kinase and centrosome localization activity-dependent manner. We further found that ROCK II kinase activity is significantly enhanced by binding to NPM/B23 and that NPM/B23 acquires a higher binding affinity to ROCK II upon phosphorylation on Thr(199). Moreover, physical interaction between ROCK II and NPM/B23 in vivo occurs in association with CDK2/cyclin E activation and the emergence of Thr(199)-phosphorylated NPM/B23. All these findings point to ROCK II as the effector of the CDK2/cyclin E-NPM/B23 pathway in the regulation of centrosome duplication.

Animals↗
PubMed1994

Spontaneous duplication loss and breakage in Caenorhabditis elegans.

Duplications in Caenorhabditis elegans spontaneously delete at frequencies ranging from 10(-4) to 10(-5). We have analyzed the structure and mitotic stability of 33 deleted duplications resulting from spontaneous breakage events. (i) Breakage usually occurred at a variety of sites; that is, there were no hot spots for breakage. An exception was the spontaneous breakage of the X chromosome into which hDp14 was inserted. These breaks were close to or at the site of the chromosome I insertion; therefore, the insertion created a type of fragile site. (ii) Spontaneous duplications often had complex structures. In some cases, their structures were most simply resolved by proposing that the progenitor duplication was a ring chromosome with a superimposed inversion. Most of the proposed ring chromosomes were mitotically unstable, suggesting that ring structures increase the frequency of chromosome loss. (iii) Clusters of spontaneous deletion events were rarely observed, suggesting that the majority of spontaneous breakage events probably occurred during meiosis. (iv) A minority of the spontaneous breakage events were associated with linkage to an autosome. Like free duplications of chromosome I, these linked duplications tended to segregate from the X chromosome in males. (v) Three meiotic mutants, him-3, him-6, and him-8, had no effect on somatic loss of the duplications but did reduce the frequency of breakage events. Given the conclusion that chromosome breakage is a meiotic event, these data are consistent with the function of the three meiotic genes being restricted to meiosis.

Animals↗
PubMed1994

Recovery of duplications by drug resistance selection in Caenorhabditis elegans.

We have devised a scheme that facilitates rapid screening for duplications of essential loci. Our scheme takes advantage of the lev-1(x22) mutation, which confers resistance in a recessive fashion to the potent anthelmintic levamisole. We have tested our methodology by recovering two gamma ray induced duplications of let-56, the first essential gene to the left of unc-22. One of the duplications is attached to the fourth chromosome. The other duplication is attached to the X chromosome. This duplication contains a functional copy of the unc-22 gene, as well as functional copies of several essential loci adjacent to unc-22. Results we have obtained during analysis of this duplication are compatible with the notion that the copy of the unc-22 gene located on the duplication is subject to X chromosome dosage compensation.

Animals↗
PubMed1988

Gene duplication in haloaromatic degradative plasmids pJP4 and pJP2.

pJP2 and pJP4 are 2,4-dichlorophenoxyacetic acid catabolic plasmids, and they show DNA sequence homology. Most of the pJP2 molecules (80% or more) isolated from 2,4-dichlorophenoxyacetic acid grown cells of Alcaligenes eutrophus harbor a tandem duplication of a 25-kilobase (kb) segment encoding the catabolic functions. Unlike plasmid pJP4, pJP2 in A. eutrophus gives rise to a 3-chlorobenzoate phenotype without further genetic rearrangement. pJP4 under 3-chlorobenzoate selection contains an inverted duplication of 24.5 kb. Absence of selective pressure results in the prompt loss of one copy of the duplication in pJP4, but not of the tandem duplication in pJP2. In both pJP4 and pJP2, mutation of the duplicated copy, rather than gene dosage, is likely to be the basis of phenotypic change of catabolic functions. Experiments using the cloned DNA suggest that a tandem duplication is more stable than an inverted duplication.

Alcaligenes↗
PubMed1993

Gastrointestinal tract duplications: clinical, pathologic, etiologic, and radiologic considerations.

Gastrointestinal tract duplications are uncommon congenital abnormalities. By definition, they are located in or adjacent to the wall of part of the gastrointestinal tract, have smooth muscle in their walls, and are lined by alimentary tract mucosa. The lining mucosa is not necessarily that of the adjacent segment of the gastrointestinal tract. The only clinically important ectopic tissues are gastric mucosa and pancreatic tissue. Although ectopic gastric mucosa is found in duplications at all levels of the gastrointestinal tract, it is most prevalent (43%) in esophageal duplications. Peptic ulcer within this ectopic tissue can account for unusual, often misleading symptoms. Ectopic pancreatic tissue is most common (37%) in gastric duplications and is associated with pancreatitis and elevated amylase levels. Detection of associated vertebral anomalies is a helpful clue in the radiographic diagnosis of duplications. Barium studies usually reveal an intraluminal, intramural, or extrinsic mass, and ultrasonography (US) demonstrates its cystic nature. When US findings are inconclusive, computed tomography can be used to show the true nature, location, and extent of the lesion, as well as associated vertebral anomalies and possible other duplications. Technetium-99m pertechnetate scintigraphy provides definitive evidence of a duplication when it contains ectopic gastric mucosa and is particularly useful for suspected esophageal, duodenal, and small bowel lesions.

Child↗
PubMedDate not supplied

Ureteral duplication and its complications.

Duplication of the ureters is a common anomaly and is frequently encountered by radiologists. Duplication may be either complete or incomplete and is often accompanied by various complications. Incomplete duplication is most often associated with ureteroureteral reflux or ureteropelvic junction obstruction of the lower pole of the kidney. Complete duplication is most often associated with vesicoureteral reflux, ectopic ureterocele, or ectopic ureteral insertion, all of which are more common in girls than in boys. Vesicoureteral reflux affects the lower pole and can be outgrown, as in nonduplicated systems. Ectopic ureterocele and ectopic ureteral insertion affect the upper pole. The ectopic ureterocele produces a filling defect of variable size in the bladder; it can be identified with contrast material studies or ultrasound. Ectopic ureters may function poorly, be difficult to detect, and cause enuresis in girls. A fourth complication, ureteropelvic junction obstruction, occurs only in the lower pole and is seen in more boys than girls. Anatomic variants or anomalies as well as suboptimal imaging techniques can either simulate or obscure duplication, making diagnosis difficult. However, familiarity with the embryology of duplication and an awareness of the potential pitfalls of excretory urography and voiding cystourethrography will foster an understanding of the varied appearances and associated complications of both incomplete and complete duplication.

Diagnostic Imaging↗
PubMed1988

Alimentary tract duplications in children: case and literature review.

This report reviews 11 alimentary tract duplications over a 25-year experience at Children's Hospital Medical Center of Akron, Ohio. The cases are compared and contrasted to the literature with respect to lesion, location, and patient presentation. There were no multiple duplications in this series. Clinical presentations were related to obstruction, abdominal pain, and/or hemorrhage. There were four foregut duplications, five midgut duplications, and two hindgut lesions. All patients were treated by surgical removal and all survived. One case was an incidental finding at appendectomy. Pooled data from five large series of duplications revealed the ileal region to be involved in 41 percent of all duplications, followed by esophageal (21%), gastroduodenal (12%), and jejunal (8%). Diverticular, recanalization, and split notochord theories of pathogenesis are discussed. The curious association between duplications and gastric mucosa is explored.

Adolescent↗
PubMed1998

Mitochondrial encephalomyopathy and hypoparathyroidism associated with a duplication and a deletion of mitochondrial deoxyribonucleic acid.

Diabetes mellitus is the most frequent endocrinopathy associated with mitochondrial disorders, particularly in patients with duplications of mitochondrial DNA (mtDNA). Although hypoparathyroidism has also been described in mitochondrial diseases, there have been few molecular studies in these cases, most of which identified the presence of single mtDNA deletions in the patients' tissues. We studied muscle DNA of a 12-yr-old patient with incomplete Kearns-Sayre syndrome and hypoparathyroidism. Southern analysis showed that muscle DNA contained three populations of mtDNA: wild type (26%), deleted (65%), and duplicated (9%). To determine the sequence of the breakpoint region from deleted and duplicated mtDNA independently, we isolated the deleted and duplicated mtDNA by gel fractionation of a PstI-digested total DNA. The breakpoint was located at mtDNA positions 5788 and 15,448 for both duplicated and deleted molecules. Our study reinforces the concept that endocrinopathies other than diabetes can be associated with a duplication of mtDNA and gives additional support to the hypothesis that the duplication and deletion of mtDNA are generated from the same recombination event.

Base Sequence↗
PubMed2006

Short communication: effectiveness of sample duplication to control error in ruminant digestion studies.

Eight ruminally cannulated lactating dairy cows from a study on the effect of dietary rumen-degraded protein on production and digestion of nutrients were used to assess using sample duplication to control day-to-day variation within animals and errors associated with sampling and laboratory analyses. Two consecutive pooled omasal samples, each representing a feeding cycle, were obtained from each cow in each period. The effectiveness of sample duplication in error control was tested by comparing the variance of the difference in treatment means when taking 2 samples from each cow in each period to the variance when taking only one sample. Compared with no duplication, sample duplication improved precision by reducing variance by 50, 40, 31, 23, 23, and 9% for, respectively, rumen-undegraded protein flows, ruminal neutral detergent fiber digestibility, microbial nonammonia N flow, microbial efficiency, organic matter flow, and organic matter truly digested in the rumen. For these same variables, reductions in the standard errors of the difference between treatment means due to sample duplication represented 100, 87, 73, 59, 58, and 27% of the predicted reductions resulting from doubling the number of experimental units without sample duplication. Sample duplication can substantially reduce experimental error originating from day-to-day variation within cows, sample collection, and laboratory analyses, thus improving statistical power in ruminant digestion studies.

Animals↗
PubMed2005

Asymptomatic tubular duplication of the transverse colon in an adult.

Colonic duplication is a rare congenital anomaly of the alimentary tract. In most cases, symptomatic duplications of the colon are recognized and treated by childhood. It is uncommon for these lesions to be detected in the adulthood since they present with vague symptoms if at all. We experienced a case of asymptomatic tubular duplication of the transverse colon in a 40-year-old female. Barium enema revealed a tubular duplication of the transverse colon. The duplicated segment arose from the mid ascending colon and incorporated just proximal to the splenic flexure, running parallel to the transverse colon and communicating with it at both ends. Colonoscopy demonstrated a normal colonic mucosa in the duplicated segment. The diameter of its lumen gradually narrowed proximally and the colonoscope could not be passed through the proximal opening of the segment. The patient did not need any treatment. Duplications of the alimentary tract can be found at any age. The possibility of congenital lesions in the adult population should not be overlooked.

Adult↗
PubMed2000

Urethral duplication in the male: review of 16 cases.

PURPOSE: Urethral duplication is a rare congenital anomaly. The clinical presentation varies because of the different anatomical patterns of this abnormality. We describe our experience with 16 male patients with this anomaly. MATERIALS AND METHODS: We retrospectively reviewed the records of 16 male patients treated for urethral duplication in the last 10 years. Age at presentation ranged from newborn to 8 years. Evaluation included ultrasound, voiding cystourethrography, retrograde urethrography and endoscopy. RESULTS: A blind ending duplicated urethra (type I) was present in 4 patients, 2 independent urethras with distinct bladder necks (type IIA1) in 6, 2 urethras originating from a common bladder neck (type IIA2) in 4, and complete urethral and bladder duplication (type III) in 2. Six patients had associated vesicoureteral reflux. Duplication was an incidental finding at epispadias repair in 3 patients with bladder exstrophy, at hypospadias repair in 1 and at hydrocele repair in 1. One patient with bilateral dysplastic kidneys died in the newborn period. Surgical management included excision of the duplicated urethra in 8 cases and urethroplasty using a pedicle flap in 2, while surgical management was not required in 3. CONCLUSIONS: Urethral duplication is a rare congenital anomaly with a variable clinical presentation. This pathological condition may easily be under diagnosed, especially in patients with other associated anomalies, such as hypospadias or bladder exstrophy. Surgical management should be planned individually according to the anatomical findings of the abnormality.

Child↗
PubMed2002

[The usefulness of 3D-CTA for the diagnosis of a ruptured aneurysm at the origin of the duplicated middle cerebral artery: case report].

Duplication of the middle cerebral artery is known as a rare anomalous vessel arising from the internal carotid artery and an aneurysm at the origin of the duplicated middle cerebral artery is very rare. We presented a case of ruptured aneurysm at the origin of the duplicated middle cerebral artery and discussed the usefulness of 3D-CTA (three-dimensional computed tomographic angiography) for its diagnosis. A 34-year-old female suffered from severe headache and was admitted to our hospital. CT scan revealed diffuse subarachnoid hemorrhage and angiography revealed duplication of the right middle cerebral artery and dilatation at its origin. We could not identify it as an aneurysm by angiography, so we performed 3D-CTA. 3D-CTA was able to demonstrate clearly the aneurysm at the origin of the duplicated middle cerebral artery and we performed neck clipping of the ruptured aneurysm. To our knowledge, previously there have been only 14 cases which reported such an aneurysm at the origin of a duplicated middle cerebral artery. We reviewed the 15 cases including ours and found that, in 4 cases, the aneurysm could not be detected by the initial angiography. We suspected that most of these aneurysms were small, so the detection of the aneurysms by angiography was difficult. We conclude that 3D-CTA is useful for diagnosing aneurysms at the origin of the duplicated middle cerebral artery even when thy can't be detected by angiography.

Adult↗
PubMed1992

[Duplication of the alimentary canal in infants and children].

This is a review of 30 duplications of the alimentary tract in 28 patients treated at the Surgical Unit of the Children's Department of the Medical University of Pécs, Hungary and at the Department of Pediatric Surgery of the Medical Academy of Dresden, Germany, from 1964 to 1989. The ages of patients ranged from 1 day to 13 years, 80 per cent were less than 2 years of age at initial presentation. There were 6 thoracic, 20 abdominal and 2 thoracoabdominal duplications. Distended abdomen, vomiting, bowel obstruction and palpable abdominal mass were most frequently encountered. Plain thoracic and abdominal X-rays, ultrasonography, barium esophagogram, barium meal and enema were the most common diagnostic procedures. Emergency operative intervention was required in 18 patients. One infant died of an unrelated disease. Twenty-three duplications were cystic and 3 tubular. One patient had an appendiceal duplication, and another patient a flat lumenless duplication located on the perineum close to the anal opening. The surgical procedure--removal of the duplication--should not be more radical than necessary to eliminate the potential complaints and prevent recurrence. During surgery the common blood supply shared between the duplication and the native bowel must be carefully protected to avoid undue sacrifice of normal bowel.

Child↗
PubMedDate not supplied

[Duplication of the alimentary tract: report of three cases].

Three cases of duplications of the alimentary tract are presented. Case 1 was a 5-month-old male baby. He was admitted due to copiously painless rectal bleeding. Tc-99m pertechnetate scanning revealed unusual tubular and spherical lesions. Laparotomy findings were that a tubular ileal duplication m assured 100cm or so in length and communicated with ileal lumen by its distal orifice. Moreover, there were 2 spherical duplications like ping-pong ball in morphology located in neighboring mesentery. Case 2 was a 2-day-old male newborn. He was admitted because of persistent bilious vomiting on his second day of life. Plain film x-ray revealed dilated stomach and scanty bowel gas. Laparotomy finding was that a cystic duplication measured 1.5cm in length which located in and obstructed the lumen of proximal jejunum. Also there was a distal orifice of duplication in communication with jejunal lumen. Case 3 was a 4-year-and-4-month-old boy who admitted after intermittently non-projectile vomiting for a period of 1 1/2 year. Sonography showed a calcification lesion at right upper quadrant of abdomen. Panendoscopy saw a refraction at second part of duodenum. The findings of laparotomy were that 2 tumor masses laid upon gastrocolic ligament. One was ossified soft tissue (gastrocolic ligament) with 1.5 x 1 x 0.8cm3 in size, and the other was cystic duplication of transverse colon in contact with beneath mesocolon. All duplications of 3 cases were lined with ectopic gastric and small intestinal mucosa, and ulcerative lesion was found in case 3 only. All lesions were resected and removed with good results.

Child, Preschool↗
PubMed1995

[The diagnosis and prevalence of locus CMT1A duplication in Charcot-Marie-Tooth disease type 1].

BACKGROUND: The Charcot-Marie-Tooth (CMT) disease or hereditary motor-sensitive neuropathy (HMSN) is the most frequent hereditary neuropathy. The demyelinated or type 1 form (CMT1) is the most frequently presented, commonly being of a dominant autosomic inheritance. CMT1 is heterogeneous genetically and the subjacent mutation found in most of the cases is a duplication of 1,500 kb in the CMT1A locus of chromosome 17p11.2. The aim of the present study was to determine the prevalence of CMT1A duplication in patients with CMT1 and evaluate its usefulness as a biological diagnostic marker. METHODS: The study was carried out in a group of patients with HMSN who were not related, and were distributed according to the following diagnostic categories: CMT1 (n = 49), CMT2 (n = 9), untyped CMT (n = 11) and Déjérine-Sottas (DS) disease (n = 4). To detect three alleles confirming the presence of duplication the DNA of the patients was analyzed with four polymorph markers, VAW409R3a, RM11-GT, VAW412R3HEc and EW401HE localized in the CMT1A locus. RESULTS: CMT1A duplication was found in 68.7% of the patients with CMT1 and in 27.2% of untyped CMT patients. None of the individuals in the CMT2 and DS categories showed duplication. Cases pertaining to families with dominant autosomic inheritance and genetically sporadic cases were confirmed to show a high prevalence of duplication, being of 83.3% and 85.7%, respectively. CONCLUSIONS: Duplication of the CMT1A locus is the most prevalent mutation found in Charcot-Marie-Tooth type 1 disease. It is a specific mutation of this disease among the different forms of hereditary motor-sensitive neuropathy. This mutation is useful as a biological marker in the diagnosis of these neuropathies.

Alleles↗
PubMed1995

Isolation and characterization of two herpes simplex virus type 1 variants containing duplication of sequences within the unique long component of their genomes.

This paper reports the first spontaneous isolation of two DNA duplication variants in the unique long (UL) component of herpes simplex virus type 1 (HSV-1) strain 17+ genome, one (1719) with a duplication of 7.5 kb DNA sequences centered around OriL and the other (1740In) with a 356 bp DNA duplication between the UL19 (MCP) and UL20 open reading frames (ORFs). The variant 1719 is stable with the rare isolation of a wild type (strain 17+) genome presumably generated by the excision of the duplicated sequences during homologous recombination. Because of the 7.5 kb duplication, UL29 (DBP) is diploid and UL30 (DNA pol) is present as one complete and one partial copy. Although duplication in the variant 1740In involved sequences from the UL20 ORF, the virus produces an intact UL20 gene product. Both variants show normal growth characteristics when compared with the parental viruses. DNA duplications in these variants suggest a link between replication and recombination in HSV-1.

Amino Acid Sequence↗