scholarly journals TECHNIQUES FOR MANIPULATING CHROMOSOMAL REARRANGEMENTS AND THEIR APPLICATION TO DROSOPHILA MELANOGASTER. I. PERICENTRIC INVERSIONS

Genetics ◽  
1981 ◽  
Vol 99 (1) ◽  
pp. 75-97
Author(s):  
Loring Craymer
Keyword(s):  
Drosophila Melanogaster ◽  
Tandem Duplication ◽  
Chromosomal Rearrangements ◽  
Pericentric Inversions ◽  
Derivatives Of ◽  
Tandem Duplications ◽  
Dominant Lethality ◽  
Inversion Loop

ABSTRACT Techniques have been developed for manipulating pericentric inversions in Drosophila that are based on the lethality of grossly aneuploid zygotes and the existence of recombinationally interconvertible genotypes for any heterozygous inversion complex: males of some of these genotypes will produce only aneuploid sperm, which can be used to rescue complementary aneuploid ova and selectively recover recombinational derivatives of inversions. Markers can be recombined into inversions through a sequence of selected single exchanges, and a novel type of duplication can be synthesized from overlapping inversions that has the characteristics of both insertional and tandem duplications; there are also applications to half-tetrad analyses.——Two cytogenetic screens are developed: (1) the dominant lethality of a large insertional-tandem duplication can be reverted by deletional events that give rise to net deficiencies or duplications, and (2) deficiencies and tandem duplications in proximal regions can be selectively recovered as the results of unequal exchanges within an inversion loop. Recombinants have been recovered between breakpoints separated by distances of as little as fifty bands, arguing against the existence of some small number of sites necessary for the initiation of recombinational pairing. In several instances, hyperploids for four to six numbered divisions were observed to be fertile in both sexes.

scholarly journals TECHNIQUES FOR MANIPULATING CHROMOSOMAL REARRANGEMENTS AND THEIR APPLICATION TO DROSOPHILA MELANOGASTER. II. TRANSLOCATIONS

Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 573-587
Author(s):  
Loring Craymer
Keyword(s):  
Tandem Duplication ◽  
Gene Dosage ◽  
Chromosomal Rearrangements ◽  
Region Of Interest ◽  
Reciprocal Translocations ◽  
The Third ◽  
Translocation Breakpoints ◽  
Inversion Breakpoints ◽  
Derivatives Of ◽  
Tandem Duplications

ABSTRACT Translocations have long been valued for their segregational properties. This paper extends the utility of translocations by considering recombinational derivatives of pairs of simple reciprocal translocations. Three major derivative structures are noted. One of these derivatives is suitable for use in half-tetrad experiments. A second should find use in recombining markers with translocation breakpoints. The third is an insertional-tandem duplication: it has a section of one chromosome inserted into a heterologue with a section of the latter chromosome tandemly repeated about the breaks of the insert. All of these structures are contained in "constellations" of chromosomes that regularly segregate aneuploid-1 products (informationally equivalent to nonrecombinant adjacent-1 segregants) for one of the parental translocations but do not segregate euploid products. This is in contrast to the parental T  1/T  2 constellations which segregate euploid products but not aneuploid-1 products. Methods are described for selecting translocation recombinants on the basis of this dichotomy. Several examples of translocation recombinants have been recovered with these techniques, and the recombination frequencies seem to be consistent with those observed for crossovers between inversion breakpoints. Recombinant chromosomes tend to disjoin, but it is observed that the tendency may vary according to the region involved in the recombination, and it is suggested that this difference reflects a difference in chiasmata terminalization times. Special consideration is given to insertional-tandem duplications. Large insertional-tandem duplications are useful in cytogenetic screens. Small insertional-tandem duplications are useful in gene dosage studies and other experiments that require an insert from one chromosome to another. Large duplications can be deleted to form small duplications. To generate a small insert for a specified region, it is only necessary to have one translocation with a breakpoint flanking the region of interest. The second translocation can have a breakpoint quite far from the region: an insertional-tandem duplication containing the region that has one closely flanking breakpoint can be deleted to create a smaller duplication that has two closely flanking breakpoints.

scholarly journals PROPERTIES AND EVOLUTIONARY POTENTIAL OF NEWLY INDUCED TANDEM DUPLICATIONS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1982 ◽  
Vol 102 (1) ◽  
pp. 75-89
Author(s):  
Paul A Roberts ◽  
David J Broderick
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Tandem Duplication ◽  
Polytene Chromosomes ◽  
Primary Source ◽  
Evolutionary Potential ◽  
X Ray ◽  
Fitness Effects ◽  
New Genes ◽  
Tandem Duplications

ABSTRACT Most of some 33 X-ray-induced duplications recovered as Suppressors of Minute loci proved to be direct tandem duplications. When heterozygous, most duplications were crossover suppressors, and duplications of short to moderate size did not reduce the fitness of their bearers. Crossover suppression by tandem duplication may be attributed to intrastrand foldbacks of the type regularly seen in somatic polytene chromosomes. As a consequence, linkage disequilibrium between duplicated elements and normal chromosomes should be more profound than has been supposed. Tandem duplications appear to be predisposed by reason of frequency of generation, crossover suppression and fitness effects to serve as the primary source of new genes.

scholarly journals Tandem duplications in Drosophila melanogaster: III. Intrachromosomal exchange of a heterozygous tandem duplication

1975 ◽  
Vol 26 (3) ◽  
pp. 275-282
Author(s):  
Wolf-Ekkehard Kalisch
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Tandem Duplication ◽  
Double Loop ◽  
Exchange Frequency ◽  
Chromosome Distribution ◽  
Interchromosomal Effect ◽  
Tandem Duplications ◽  
Meiotic Event

SUMMARYDuring meiosis the two parts of a tandem duplication are able to pair in a double loop instead of pairing with the corresponding region of the homologous chromosome. The frequency of intrachromosomal exchange within this double loop was measured in heterozygous females of tandem duplication Dp(1; 1)Gr by the phenotypes of the exceptional F1 males. The intrachromosomal exchange frequency is increased significantly by both the ‘interchromosomal effect’ of heterozygous inversions in the autosomes and by a double inversion in the homologous X chromosome. Distribution of the exchange events depends on the pairing situation and its frequency within the double loop. The analysis of clusters of intrachromosomal recombinants observed favours the assumption that this exchange type is exclusively a meiotic event.

scholarly journals A novel transvection phenomenon affecting the white gene of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 167-176
Author(s):  
D Gubb ◽  
M Ashburner ◽  
J Roote ◽  
T Davis
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Tandem Duplication ◽  
Gamma Ray ◽  
Insertion Site ◽  
Hairpin Loop ◽  
Homologous Chromosomes ◽  
Inverted Order ◽  
In Trans ◽  
In Cis

Abstract The zeste mutation of Drosophila melanogaster suppresses the expression of white genes in the eye. This suppression is normally dependent on there being two copies of w+ located close to each other in the genome--they may either be in cis (as in a tandem duplication of w+) or in trans, i.e. on homologous chromosomes. Duplicated w+ genes carried by a giant transposing element, TE146(Z), are suppressed by z whether they are in direct (tandem) or inverted order. The tandem form of the TE is very sensitive to a rearrangement on the homologous chromosome--many rearrangements with breakpoints "opposite" the TE's insertion site prevent the interaction between the white genes on a z background. These aberrations act as dominant suppressors of zeste that are specific to the tandemly duplicated form of TE146(Z). The inverted form of the TE146(Z) presumably pairs as a hairpin loop; this is more stable than the tandem form by the criterion that its zeste phenotype is unaffected by any of the aberrations. This effect of rearrangements has been used as the basis for a screen, gamma-ray induced aberrations with at least one breakpoint opposite the TE site were recovered by their suppression of the zeste phenotype.

scholarly journals Identification, Expression and Evolution of Short-Chain Dehydrogenases/Reductases in Nile Tilapia (Oreochromis niloticus)

2021 ◽  
Vol 22 (8) ◽  
pp. 4201
Author(s):  
Shuai Zhang ◽  
Lang Xie ◽  
Shuqing Zheng ◽  
Baoyue Lu ◽  
Wenjing Tao ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Tandem Duplication ◽  
Developmental Stages ◽  
Short Chain ◽  
Sexually Dimorphic ◽  
Physiological Processes ◽  
Genome Wide ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Tandem Duplications

The short-chain dehydrogenases/reductases (SDR) superfamily is involved in multiple physiological processes. In this study, genome-wide identification and comprehensive analysis of SDR superfamily were carried out in 29 animal species based on the latest genome databases. Overall, the number of SDR genes in animals increased with whole genome duplication (WGD), suggesting the expansion of SDRs during evolution, especially in 3R-WGD and polyploidization of teleosts. Phylogenetic analysis indicated that vertebrates SDRs were clustered into five categories: classical, extended, undefined, atypical, and complex. Moreover, tandem duplication of hpgd-a, rdh8b and dhrs13 was observed in teleosts analyzed. Additionally, tandem duplications of dhrs11-a, dhrs7a, hsd11b1b, and cbr1-a were observed in all cichlids analyzed, and tandem duplication of rdh10-b was observed in tilapiines. Transcriptome analysis of adult fish revealed that 93 SDRs were expressed in more than one tissue and 5 in one tissue only. Transcriptome analysis of gonads from different developmental stages showed that expression of 17 SDRs were sexually dimorphic with 11 higher in ovary and 6 higher in testis. The sexually dimorphic expressions of these SDRs were confirmed by in situ hybridization (ISH) and qPCR, indicating their possible roles in steroidogenesis and gonadal differentiation. Taken together, the identification and the expression data obtained in this study contribute to a better understanding of SDR superfamily evolution and functions in teleosts.

Restriction of P-element insertions at the Notch locus of Drosophila melanogaster

1987 ◽  
Vol 7 (4) ◽  
pp. 1545-1548
Author(s):  
M R Kelley ◽  
S Kidd ◽  
R L Berg ◽  
M W Young
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Consensus Sequence ◽  
P Element ◽  
Induced Mutations ◽  
P Elements ◽  
Target Dna ◽  
Complex Locus ◽  
Additional Level ◽  
Derivatives Of

P elements move about the Drosophila melanogaster genome in a nonrandom fashion, preferring some chromosomal targets for insertion over others (J. C. J. Eeken, F. H. Sobels, V. Hyland, and A. P. Schalet, Mutat. Res. 150:261-275, 1985; W. R. Engels, Annu. Rev. Genet. 17:315-344, 1983; M. D. Golubovsky, Y. N. Ivanov, and M. M. Green, Proc. Natl. Acad. Sci. USA 74:2973-2975, 1977; M. J. Simmons and J. K. Lim, Proc. Natl. Acad. Sci. USA 77:6042-6046, 1980). Some of this specificity may be due to recognition of a particular DNA sequence in the target DNA; derivatives of an 8-base-pair consensus sequence are occupied by these transposable elements at many different chromosomal locations (K. O'Hare and G. M. Rubin, Cell 34:25-36, 1983). An additional level of specificity of P-element insertions is described in this paper. Of 14 mutations induced in the complex locus Notch by hybrid dysgenesis, 13 involved P-element insertions at or near the transcription start site of the gene. This clustering was not seen in other transposable element-induced mutations of Notch. DNA sequences homologous to the previously described consensus target for P-element insertion are not preferentially located in this region of the locus. The choice of a chromosomal site for integration appears to be based on more subtle variations in chromosome structure that are probably associated with activation or expression of the target gene.

FLT3 Internal Tandem Duplications in Adults with De Novo Acute Myeloid Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4430-4430
Author(s):  
Sandra G. Xavier ◽  
Rocío Hassan ◽  
Nelma C.D. Clementino ◽  
Daniel G. Tabak ◽  
Nelson Spector ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Tandem Duplication ◽  
De Novo ◽  
Univariate Analysis ◽  
Internal Tandem Duplication ◽  
Hematopoietic Stem ◽  
Proliferation And Differentiation ◽  
Polymerase Chain ◽  
De Novo Aml ◽  
Tandem Duplications

Abstract FLT3 is a receptor tyrosine kinase involved in the proliferation and differentiation of hematopoietic stem cells. Recently, internal tandem duplication (ITD) mutations of the FLT3 gene have been described in patients with AML and associated with a poor prognosis. The aim of this study was to analyze the prevalence of FLT3-ITD in a series of 90 adults with de novo AML and correlate the presence of this mutation with biological characteristics and clinical response. We analyzed diagnostic peripheral blood or bone marrow specimens from 43 women and 47 men, with a median age of 38 years (16–83). Polymerase chain reaction was performed on genomic DNA using previously published primers for exons 11 and 12. An FLT3-ITD was found in 22/89 patients (25%). It was present in 37% (9/24) of the patients with acute promyelocytic leukemia (APL) and in only 20% (13/65) of the patients with non-M3-AML (p=0.07). The FLT3-ITD was not detected in patients with M6 (n=1) and M7-AML (n=3), nor in patients with the AML1-ETO (n=2) or with the CBFb-MYH11 (n=4) fusion genes. The median WBC counts were higher in FLT3-ITD patients than in those without the mutation (37 X 109/L vs. 27 X 109/L, p=0.43). In APL, FLT3-ITD was found in 5 out of 6 patients with the short PML-RARa isoform, but in only 4 out of 18 patients with the non-short isoform (p=0.01). Univariate analysis showed an association between the presence of FLT3-ITD and both a lower complete remission (CR) rate (41% vs. 64%; p=0.05) and a shorter overall survival (14% vs. 34%; p=0.03). However, FLT3-ITD was not associated with the CR rate (p=0.18) or the OS (p=0.07) in the multivariate analysis. The clinical significance of FLT3-ITD in adult AML remains uncertain, and further investigation is clearly warranted.

scholarly journals Cis-effects of heterochromatin on heterochromatic and euchromatic gene activity in Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 140 (3) ◽  
pp. 1033-1045
Author(s):  
M Howe ◽  
P Dimitri ◽  
M Berloco ◽  
B T Wakimoto
Keyword(s):  
Chromosomal Rearrangements ◽  
Position Effect ◽  
Position Effect Variegation ◽  
Regulatory Requirements ◽  
Molecular Studies ◽  
Effect Variegation ◽  
Novel Method ◽  
In Cis ◽  
Derivatives Of ◽  
Heterochromatic Genes

Abstract Chromosomal rearrangements that juxtapose heterochromatin and euchromatin can result in mosaic inactivation of heterochromatic and euchromatic genes. This phenomenon, position effect variegation (PEV), suggests that heterochromatic and euchromatic genes differ in their regulatory requirements. This report describes a novel method for mapping regions required for heterochromatic genes, and those that induce PEV of a euchromatic gene. P transposase mutagenesis was used to generate derivatives of a translocation that variegated for the light+ (lt+) gene and carried the euchromatic white+ (w+) gene on a transposon near the heterochromatin-euchromatin junction. Cytogenetic and genetic analyses of the derivatives showed that P mutagenesis resulted in deletions of several megabases of heterochromatin. Genetic and molecular studies showed that the derivatives shared a euchromatic breakpoint but differed in their heterochromatic breakpoint and their effects on seven heterochromatic genes and the w+ gene. Heterochromatic genes differed in their response to deletions. The lt+ gene was sensitive to the amount of heterochromatin at the breakpoint but the heterochromatic 40Fa gene was not. The severity of variegated w+ phenotype did not depend on the amount of heterochromatin in cis, but varied with local heterochromatic environment. These data are relevant for considering mechanisms of PEV of both heterochromatic and euchromatic genes.

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