scholarly journals A Chromosomal Duplication Map of Malformations: Regions of Suspected Haplo- and Triplolethality—and Tolerance of Segmental Aneuploidy—in Humans

1999 ◽  
Vol 64 (6) ◽  
pp. 1702-1708 ◽  
Author(s):  
Carole Brewer ◽  
Susan Holloway ◽  
Paul Zawalnyski ◽  
Albert Schinzel ◽  
David FitzPatrick
Keyword(s):  
Segmental Aneuploidy ◽  
Chromosomal Duplication

scholarly journals A Haplolethal Locus Uncovered by Deletions in the Mouse t Complex

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 675-682
Author(s):  
Victoria L Browning ◽  
Rebecca A Bergstrom ◽  
Sandra Daigle ◽  
John C Schimenti
Keyword(s):  
Gene Dosage ◽  
Es Cells ◽  
Embryonic Stem ◽  
Chromosome 17 ◽  
Mammalian Development ◽  
T Complex ◽  
Segmental Aneuploidy ◽  
Systematic Exploration ◽  
Radiation Induced ◽  
Altered Gene

Abstract Proper levels of gene expression are important for normal mammalian development. Typically, altered gene dosage caused by karyotypic abnormalities results in embryonic lethality or birth defects. Segmental aneuploidy can be compatible with life but often results in contiguous gene syndromes. The ability to manipulate the mouse genome allows the systematic exploration of regions that are affected by alterations in gene dosage. To explore the effects of segmental haploidy in the mouse t complex on chromosome 17, radiation-induced deletion complexes centered at the Sod2 and D17Leh94 loci were generated in embryonic stem (ES) cells. A small interval was identified that, when hemizygous, caused specific embryonic lethal phenotypes (exencephaly and edema) in most fetuses. The penetrance of these phenotypes was background dependent. Additionally, evidence for parent-of-origin effects was observed. This genetic approach should be useful for identifying genes that are imprinted or whose dosage is critical for normal embryonic development.

Genetic Mapping by Duplication Segregation in Salmonella enterica

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 491-502
Author(s):  
Eva M Camacho ◽  
Josep Casadesús
Keyword(s):  
Salmonella Enterica ◽  
Replication Fork ◽  
Limiting Factor ◽  
Multiplicity Of Infection ◽  
Dominant Marker ◽  
Host Chromosome ◽  
Transposon Insertion ◽  
Large Size ◽  
Chromosomal Duplication ◽  
Duplication Segregation

Abstract MudP and MudQ elements were used to induce duplications in Salmonella enterica by formation of a triple crossover between two transduced fragments and the host chromosome. The large size (36 kb) of MudP and MudQ is a favorable trait for duplication formation, probably because homology length is a limiting factor for the central crossover. Additional requirements are a multiplicity of infection of 2 or higher in the infecting phage suspensions (which reflects the need of two transduced fragments) and an exponentially growing recipient (which reflects the need of a chromosome replication fork). We describe a set of 11 strains of S. enterica, each carrying a chromosomal duplication with known endpoints. The collection covers all the Salmonella chromosome except the terminus. For mapping, a dominant marker (e.g., a transposon insertion in or near the locus to be mapped) is transduced into the 11-strain set. Several transductants from each cross are grown nonselectively, and haploid segregants are scored for the presence of the marker. If all the segregants contain the transduced marker, it maps outside the duplication interval. If the marker is found only in a fraction of the segregants, it maps within the duplicated region.

scholarly journals CRISPR-PCDup: a novel approach for simultaneous segmental chromosomal duplication in Saccharomyces cerevisiae

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Naim Hassan ◽  
Yu Sasano ◽  
Shunta Kimura ◽  
Farhana Easmin ◽  
Keisuke Ekino ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Novel Approach ◽  
Chromosomal Duplication

scholarly journals Two Chimeric Chromosomes of Streptomyces coelicolor A3(2) Generated by Single Crossover of the Wild-Type Chromosome and Linear Plasmid SCP1

2004 ◽  
Vol 186 (19) ◽  
pp. 6553-6559 ◽  
Author(s):  
Masayuki Yamasaki ◽  
Haruyasu Kinashi
Keyword(s):  
Genome Evolution ◽  
Streptomyces Coelicolor ◽  
Linear Plasmid ◽  
Nucleotide Sequencing ◽  
Inverted Repeats ◽  
Wild Type ◽  
Linear Chromosome ◽  
Terminal Inverted Repeats ◽  
Type Chromosome ◽  
Chromosomal Duplication

ABSTRACT Streptomyces coelicolor A3(2) strain 2106 carries a 1.85-Mb linear plasmid, SCP1′-cysD, in addition to a 7.2-Mb linear chromosome. Macrorestriction analysis indicated that both linear DNAs are hybrids of the wild-type chromosome and the linear plasmid SCP1 on each side. Nucleotide sequencing of the fusion junctions revealed no homology between the recombination regions. SCP1′-cysD contains an SCP1 telomere and a chromosomal telomere at each end and therefore does not have terminal inverted repeats. In addition, SCP1′-cysD could not be eliminated from strain 2106 by various mutagenic treatments. Thus, we concluded that both the 7.2-Mb chromosome and SCP1′-cysD are chimeric chromosomes generated by a single crossover of the wild-type chromosome and SCP1. This may be regarded as a model of chromosomal duplication in genome evolution.

Gene inactivation system extension into a unique sequence outside of the II →> I insertional duplication in Aspergillus nidulans

1998 ◽  
Vol 44 (11) ◽  
pp. 1037-1044
Author(s):  
M Meilus ◽  
MAA Castro-Prado
Keyword(s):  
Aspergillus Nidulans ◽  
Single Copy ◽  
Unique Sequence ◽  
Gene Inactivation ◽  
Duplicated Genes ◽  
Reversible Inactivation ◽  
Linked Gene ◽  
Copy Gene ◽  
System Extension ◽  
Chromosomal Duplication

The first report of the gene inactivation system (GIS) in Aspergillus nidulans came from crosses involving a II Gene inactivation system extension into a unique sequence outside of the II →> I insertional duplication. Duplicated segments trigger the GIS that acts through the methylation of cytosines present within repeats. Duplicated genes are probably inactivated during the premeiotic period between fertilization and karyogamy, but reactivation may occur spontaneously or after 5-azacytidine treatment. The aim of the present study was to determine the action of GIS on a single copy gene located near a duplicated segment. Aspergillus nidulans strains bearing the Dp(II,I) duplication were used in meiotic crosses homozygous for the y+ gene and yellow (y) segregants were recovered among the progenies. Data show that the GIS can act on a closely linked gene outside the duplicated segment, promoting reversible inactivation. Reduction of ascospore numbers and viability were observed in crosses parented by duplication strains. Inactivation of the w+ gene in a w/w+ duplication strain is also shown.Key words: Aspergillus nidulans, gene inactivation, DNA methylation, chromosomal duplication.

scholarly journals Neuroimaging findings in Pallister-Killian syndrome

2017 ◽  
Vol 31 (4) ◽  
pp. 403-411 ◽  
Author(s):  
Emil Jernstedt Barkovich ◽  
Tarannum Musvee Lateef ◽  
Matthew T Whitehead
Keyword(s):  
Intellectual Disability ◽  
Patient Population ◽  
Medical Literature ◽  
Muscle Tone ◽  
Craniofacial Malformations ◽  
Severe Intellectual Disability ◽  
Signal Abnormality ◽  
Craniofacial Dysmorphism ◽  
New Findings ◽  
Chromosomal Duplication

Pallister-Killian syndrome (PKS) is a rare chromosomal duplication disorder caused by additional copies of the short arm of chromosome 12 (12p). Clinically PKS is characterized by craniofacial dysmorphism with neonatal frontotemporal alopecia, hypertelorism, and low-set ears as well as kyphoscoliosis, severe intellectual disability, epilepsy, and abnormal muscle tone. Comprehensive high-resolution brain MR findings of PKS in childhood have not been previously illustrated in the medical literature. We present detailed neuroimaging findings from a child with PKS and thoroughly review previously reported structural brain abnormalities in this patient population. MRI abnormalities common to PKS include cerebral volume loss, malformations of cortical development, corpus callosum dysgenesis, white matter disease, and craniofacial malformations. In our patient, new findings of perisylvian with occipital polymicrogyria, vermian dysplasia, brachium pontis signal abnormality, dural anomalies, and unilateral atlas assimilation were noted. Micrencephaly and cortical dysplasia provide a likely explanation for severe intellectual disability and epilepsy in this patient population.

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