IRRADIATION OF SPERM AND OOCYTES IN ONCOPELTUS FASCIATUS (HEMIPTERA: LYGAEIDAE): SEX RATIO, FERTILITY, AND CHROMOSOME ABERRATIONS IN THE F1 PROGENY

1973 ◽  
Vol 15 (4) ◽  
pp. 713-721 ◽  
Author(s):  
L. E. LaChance ◽  
R. D. Richard
Keyword(s):  
Sex Ratio ◽  
Gamma Irradiation ◽  
Chromosome Aberrations ◽  
Oncopeltus Fasciatus ◽  
X Rays ◽  
Virtual Absence ◽  
Chromosome Translocations ◽  
F1 Progeny ◽  
Old Females

Adult Oncopeltus fasciatus were irradiated as 7- to 8-day-old males, and as 3- to 4- or 10- to 12-day-old females with doses of 8 and 20 krad of gamma irradiation and 200 R of X-rays, respectively. Treated bugs were outcrossed to untreated bugs, and F1 progeny derived from irradiated sperm and from prophase and metaphase oocytes were studied. All treated bugs were less fertile than the controls, but none of the treatments produced full sterility. Among the F1 generation from the three types of crosses, there was no significant deviation from a 50:50 sex ratio.When F1 males were outcrossed to untreated females, only the males derived from irradiated sperm were semisterile; F1 males derived from the treated oocytes were as fertile as the controls. The semisterility of the F1 males was correlated with chromosome translocations and fragments in the spermatocytes. The virtual absence of these aberrations in the testes of F1 males derived from irradiated oocytes suggests that these aberrations are not induced in oocytes, are repaired, or are not included in the maternal pronucleus after irradiation of meiotic oocytes.

scholarly journals Increased Chromosome Aberrations in Cells Exposed Simultaneously to Simulated Microgravity and Radiation

2018 ◽  
Vol 20 (1) ◽  
pp. 43 ◽  
Author(s):  
Megumi Hada ◽  
Hiroko Ikeda ◽  
Jordan Rhone ◽  
Andrew Beitman ◽  
Ianik Plante ◽  
...  
Keyword(s):  
Chromosome Aberrations ◽  
Human Fibroblasts ◽  
Static Condition ◽  
Combined Effects ◽  
X Rays ◽  
Carbon Ions ◽  
Space Biology ◽  
Irradiation System ◽  
Effects Of Radiation

Space radiation and microgravity (μG) are two major environmental stressors for humans in space travel. One of the fundamental questions in space biology research is whether the combined effects of μG and exposure to cosmic radiation are interactive. While studies addressing this question have been carried out for half a century in space or using simulated μG on the ground, the reported results are ambiguous. For the assessment and management of human health risks in future Moon and Mars missions, it is necessary to obtain more basic data on the molecular and cellular responses to the combined effects of radiation and µG. Recently we incorporated a μG–irradiation system consisting of a 3D clinostat synchronized to a carbon-ion or X-ray irradiation system. Our new experimental setup allows us to avoid stopping clinostat rotation during irradiation, which was required in all other previous experiments. Using this system, human fibroblasts were exposed to X-rays or carbon ions under the simulated μG condition, and chromosomes were collected with the premature chromosome condensation method in the first mitosis. Chromosome aberrations (CA) were quantified by the 3-color fluorescent in situ hybridization (FISH) method. Cells exposed to irradiation under the simulated μG condition showed a higher frequency of both simple and complex types of CA compared to cells irradiated under the static condition by either X-rays or carbon ions.

Effect of age and hunger on host-feeding behaviour by femaleTrichogramma euproctidis(Hymenoptera: Trichogrammatidae)

2013 ◽  
Vol 145 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Émilie Lessard ◽  
Guy Boivin
Keyword(s):  
Sex Ratio ◽  
Feeding Behaviour ◽  
Strategic Choice ◽  
Host Feeding ◽  
Feeding Frequency ◽  
Duration Distribution ◽  
Adult Parasitoid ◽  
Old Females ◽  
Effect Of Age

AbstractAdult parasitoid females can obtain proteins and lipid by consuming the haemolymph of their host. InTrichogrammaWestwood (Hymenoptera: Trichogrammatidae) species, host feeding on the host egg occurs after oviposition and leads to smaller offspring. We tested the effect of age and hunger on host-feeding behaviour of femaleTrichogramma euproctidisGirault. Young and old females, either starved, water fed, or honey fed, were observed and the host-feeding frequency, duration, distribution, and number of hosts used for nutrition were measured. The sex ratio (proportion of males) allocated to parasitised hosts where host feeding occurred and time taken to parasitise 10 hosts (indicator of female mobility) were also noted. The majority of females host fed on the first host encountered. Age had no impact on frequency, duration, number of hosts used, and mobility ofT. euproctidis. Starved females host fed longer and were less mobile. The sex ratio of the progeny emerging from the first host parasitised was more male biased when host feeding occurred. Host feeding had no effect on the sex ratio deposited elsewhere in the sequence of hosts encountered. Age of female had no effect on host feeding, possibly because host feeding incurs little cost for this species. To host feed on the first host parasitised, in which a male is allocated, is less costly in terms of fitness and represents a strategic choice for the female.

Identification of New Nonrandom Translocations in Multiple Myeloma With Multicolor Spectral Karyotyping

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4269-4278 ◽  
Author(s):  
Jeffrey R. Sawyer ◽  
Janet L. Lukacs ◽  
Nikhil Munshi ◽  
K. Raman Desikan ◽  
Seema Singhal ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
In Situ Hybridization ◽  
Chromosome Aberrations ◽  
Chromosome Morphology ◽  
Spectral Karyotyping ◽  
Chromosome Translocations ◽  
Igh Locus ◽  
Additional Chromosome

Multicolor spectral karyotyping (SKY) was performed on bone marrow samples from 50 patients with multiple myeloma (MM) in anticipation of discovering new previously unidentified translocations. All samples showed complex karyotypes with chromosome aberrations which, in most cases, were not fully characterized by G-banding. Patients of special interest were those who showed add(14)(q32), add(8)(q24) and those whose G-banding karyotypes showed poor chromosome morphology. Three new recurring chromosome translocations not previously reported in MM were identified. Two of the translocations involve recurring aberrations at band 14q32.3, the site of the IgH locus, with different exchange partners. The most frequently recurring rearrangement was a subtle translocation at 14q32.3 designated as a t(14;16)(q32;q22∼23), which was identified in six patients. A second and larger translocation at 14q32, identified in two patients, was designated as a t(9;14)(p13;q32), previously associated with Waldenstrom’s macroglobulinemia and lymphoplasmacytoid lymphoma. A third translocation, identified in two patients, involved a whole-arm t(6;8)(p10;q10) translocation. The SKY technique was able to refine the designations of over 156 aberrations not fully characterized by G-banding in this study and resolved additional chromosome aberrations in every patient studied except two. The t(14;16)(q32;q22∼23) identified by SKY in this study suggests this may be a frequent translocation in MM associated with complex karyotypes and disease progression. Therefore, the SKY technique provides a useful adjunct to routine G-banding and fluorescence in situ hybridization studies in the cytogenetic analysis of MM.

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