RADIATION INDUCED RECIPROCAL TRANSLOCATIONS AND INVERSIONS IN ANOPHELES ALBIMANUS

1982 ◽  
Vol 24 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. E. Kaiser ◽  
J. A. Seawright ◽  
M. Q. Benedict ◽  
S. Narang ◽  
S. G. Suguna
Keyword(s):  
X Rays ◽  
Anopheles Albimanus ◽  
Reciprocal Translocations ◽  
Pericentric Inversions ◽  
Radiation Induced ◽  
Homozygous Translocation ◽  
Paracentric Inversions ◽  
Heterozygous Translocation

Reciprocal translocations and inversions were induced in Anopheles albimanus Wiedemann by irradiation of males with X rays. A total of 1669 sperm were assayed, and 175 new aberrations were identified as follows: 102 reciprocal translocations (67 autosomal and 35 sex-linked), 45 pericentric inversions, and 28 paracentric inversions. Eleven of the translocations were nearly whole-arm interchanges, and these were selected for the construction of "capture systems" for compound chromosomes. Two double-heterozygous translocation strains and four homozygous translocation strains were established. Anopheles albimanus females were irradiated, and a pseudolinkage scheme involving mutant markers was employed to identify reciprocal translocations. The irradiation of females was very inefficient: only one translocation was recovered from 1080 ova tested.

HOMOZYGOUS PERICENTRIC INVERSIONS AND OTHER STUDIES OF INVERSIONS ON CHROMOSOME 3 IN THE MOSQUITO ANOPHELES ALBIMANUS

1981 ◽  
Vol 23 (1) ◽  
pp. 57-64 ◽  
Author(s):  
S. G. Suguna ◽  
J. A. Seawright ◽  
D. J. Joslyn ◽  
M. G. Rabbani
Keyword(s):  
Genetic Control ◽  
Pericentric Inversion ◽  
Chromosome 3 ◽  
Double Heterozygote ◽  
Anopheles Albimanus ◽  
Control Schemes ◽  
Pericentric Inversions ◽  
Partial Sterility ◽  
Radiation Induced ◽  
Experimental Crosses

Two radiation-induced pericentric inversions on chromosome 3 in Anopheles albimanus Wiedemann have been established in homozygous stocks. In(3)17 and In(3)22 cover about 82% and 42%, respectively, of chromosome 3 and should be very useful as crossover suppressors in genetic crosses. In addition, three double-heterozygote stocks were established by combining inversions that had similar breakpoints but were viable only as heterozygotes. These balanced-lethal double heterozygotes can serve as a source of inversion gametes for use in experimental crosses and can be used in surveying populations for lethal chromosomes. Assays of the partial sterility inherent in males heterozygous for a pericentric inversion and a male-linked translocation indicated that the combination of inversions and translocations could be used in genetic control schemes.

scholarly journals CYTOGENETIC MAPPING OF ENZYME LOCI ON CHROMOSOMES J AND U OF DROSOPHILA SUBOBSCURA

Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 913-926
Author(s):  
W Pinsker ◽  
D Sperlich
Keyword(s):  
Linkage Map ◽  
Banding Pattern ◽  
Recombination Frequency ◽  
Divergent Evolution ◽  
Structural Rearrangements ◽  
Cytogenetic Mapping ◽  
Reciprocal Translocations ◽  
Enzyme Loci ◽  
Pericentric Inversions ◽  
Paracentric Inversions

ABSTRACT Enzyme loci located on chromosome J and U were mapped cytologically by means of a Y translocation technique. A linkage map of the two chromosomes was established in a parallel experiment and the recombination frequency in different regions of the chromosomes determined. A comparison of the cytogenetic localization of the enzyme genes in D. subobscura and D. melanogaster indicates that many paracentric inversions must have taken place in the course of divergent evolution. However, no displacements of genes from one element to another due to pericentric inversions, reciprocal translocations or transposing elements can be observed. In spite of the large number of structural rearrangements that have occurred in the phylogeny of the genus Drosophila, gross similarities of banding pattern in homologous regions of the chromosomes of the two species become apparent.

Chromosome rearrangement patterns of an SD chromosome (SDKona-2) in Drosophila melanogaster caused by hybrid dysgenesis

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 855-863 ◽  
Author(s):  
Jeffrey G. Ault
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Rearrangement ◽  
Chromosome Rearrangements ◽  
Hybrid Dysgenesis ◽  
Reciprocal Translocations ◽  
Segregation Distorter ◽  
Chromosome Mutation ◽  
Pericentric Inversions ◽  
Spontaneous Chromosome ◽  
Paracentric Inversions

The types and frequencies of spontaneous chromosome rearrangements caused by hybrid dysgenesis were studied in a second chromosome autosome of Drosophila melanogaster. This second chromosome, being an SD chromosome, had two important advantages over other autosomes for this study: (i) it had the two inversions characteristic of a standard SD-72 chromosome type, which distinguished it from its homolog in polytene chromosome spreads, and (ii) because of the meiotic drive associated with the segregation distorter system, it was preferentially transmitted to the next generation. The chromosome mutation frequency of this chromosome (given the name SDKona-2) was 8.3 and 11.7% in the F2 and F3 generations, respectively. The types of new chromosome rearrangements observed in the first four generations included paracentric inversions, pericentric inversions, duplications, deletions, reciprocal translocations (involving the third chromosome), and transpositions. Small paracentric inversions were the most common type of new rearrangement. Later, over 35 generations, some of these new rearrangements changed, either by becoming more complex or by being replaced with yet another new chromosome rearrangement. Duplications were unstable and were replaced by paracentric inversions whose breakpoints were on either side of the duplication. Transpositions arose both from a single multibreak event and from a series of two-break events.Key words: chromosome rearrangements, hybrid dysgenesis, segregation distorter, Drosophila melanogaster.

scholarly journals Immunomodulatory Effects of Radiotherapy

2020 ◽  
Vol 21 (21) ◽  
pp. 8151
Author(s):  
Sharda Kumari ◽  
Shibani Mukherjee ◽  
Debapriya Sinha ◽  
Salim Abdisalaam ◽  
Sunil Krishnan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Carbon Particle ◽  
Dna Lesions ◽  
X Rays ◽  
Adaptive Immune ◽  
High Let Radiation ◽  
Different Types ◽  
High Let ◽  
Radiation Induced ◽  
Tumor Death

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.

scholarly journals Differential Effects of Gold Nanoparticles and Ionizing Radiation on Cell Motility between Primary Human Colonic and Melanocytic Cells and Their Cancerous Counterparts

2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Colorectal Adenocarcinoma ◽  
X Rays ◽  
Cell Adherence ◽  
Cancerous Cell ◽  
Primary Colon ◽  
Radiation Induced

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

RADIATION HAZARDS IN THE FIELD OF PEDIATRICS

PEDIATRICS ◽  
1957 ◽  
Vol 20 (5) ◽  
pp. 921-940
Author(s):  
Meinhard Robinow ◽  
Frederic N. Silverman
Keyword(s):  
Radiation Injury ◽  
Radiation Safety ◽  
The United States ◽  
Point Of View ◽  
Public Understanding ◽  
X Rays ◽  
Tissue Destruction ◽  
Radiation Hazards ◽  
External Sources ◽  
Radiation Induced

The different types of injury from external sources of ionizing radiation are briefly described and the manifestations of radiation injury in the fetus, the infant and the child are reviewed. If radiation therapy for malignant disease is excluded from consideration, it is found that x-ray damage to skin, other tissue destruction, and growth impairment are relatively minor radiation hazards compared to the dangers of leukemia and other malignancy and of radiation-induced genetic damage. Consideration is given to somatic radiation injury as largely an individual problem and genetic injury as a population problem. This point of view is reflected in the differing recommendations concerning "permissible doses" for individuals and for populations. Medical radiation represents a major and presumably growing source of exposure to individuals and to the population in the United States. Various ways are shown in which excessive diagnostic exposure to x-rays, especially in children, can be reduced without interference with requirements of diagnosis. Control of avoidable radiation can be accomplished by combined attack from different fronts. The more important approaches to radiation safety are discussed. They include attention to technical detail, personnel monitoring, maintenance of radiation records, radiation safety through legislative control and public education. The responsibility of the physician in promoting public understanding of radiation hazards is emphasized.

RECIPROCAL TRANSLOCATIONS INDUCED BY X-RAYS AND THERMO-NEUTRONS IN WILD SORGHUM (S. PURPUREO-SERICEUM ASCHERS AND SCHWEINF.)

1968 ◽  
Vol 10 (1) ◽  
pp. 152-160 ◽  
Author(s):  
T. P. Wu ◽  
C. P. Pi
Keyword(s):  
Considerable Degree ◽  
Seedling Height ◽  
X Rays ◽  
Wild Sorghum ◽  
Reciprocal Translocations ◽  
Pollen Counts ◽  
Significant Difference ◽  
Radiation Treatments

Dry seeds of S. purpureo-sericeum were irradiated with either X-rays or thermo-neutrons with three exposures each. No difference was shown in germination between the irradiated treatments and the control. The percentage of survival was greatly reduced to 2.2% in seeds treated with X-rays. However, there was no significant difference in survival between the thermo-neutron treatments and the control. Both radiation treatments inhibited seedling height to a considerable degree, and the variability of seedling height increased with higher exposures of irradiation. The types and the frequency of induced interchanges were proportional to the exposure of thermo-neutron irradiations.Twenty six translocation heterozygous plants were analyzed and considered to be semisterile plants. Spore quartet analysis revealed that the two types of adjacent segregations occur with nearly the same frequency.Six plants with pseudo-isochromosomes were detected. Pseudo-isochromosomes were often delayed in anaphase movement. They were excluded from daughter nuclei at telophase stages and eventually became micronuclei in the spore quartets.Two plants with a ring-of-six, and one plant with two pseudo-isochromosomes plus a ring-of-six were also found among the materials irradiated with high exposures of thermo-neutrons. Pollen counts showed that they had the lowest fertility among translocation heterozygous plants and no seed was obtained.

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