scholarly journals MODIFICATIONS OF MEAN OVARIOLE NUMBER, FRESH WEIGHT OF ADULT FEMALES AND DEVELOPMENTAL TIME IN DROSOPHILA MELANOGASTER INDUCED BY DROSOPHILA C VIRUS

Genetics ◽  
1984 ◽  
Vol 107 (4) ◽  
pp. 635-644
Author(s):  
Michele Thomas-Orillard

ABSTRACT Drosophila C virus, a picornavirus that has some influence on ovarian morphogenesis, was discovered in a French strain of Drosophila melanogaster. When the strain was infected by Drosophila C virus (DCV), the mean number of ovarian tubes and weights of the adult females increased, but the developmental time from egg to imago decreased. The maternal effects observed when DCV was present disappeared when the strain was DCV free but were restored by experimental contamination.

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1257-1265 ◽  
Author(s):  
Hsiao-Pei Yang ◽  
Ana Y Tanikawa ◽  
Wayne A Van Voorhies ◽  
Joana C Silva ◽  
Alexey S Kondrashov

Abstract We induced mutations in Drosophila melanogaster males by treating them with 21.2 mm ethyl methanesulfonate (EMS). Nine quantitative traits (developmental time, viability, fecundity, longevity, metabolic rate, motility, body weight, and abdominal and sternopleural bristle numbers) were measured in outbred heterozygous F3 (viability) or F2 (all other traits) offspring from the treated males. The mean values of the first four traits, which are all directly related to the life history, were substantially affected by EMS mutagenesis: the developmental time increased while viability, fecundity, and longevity declined. In contrast, the mean values of the other five traits were not significantly affected. Rates of recessive X-linked lethals and of recessive mutations at several loci affecting eye color imply that our EMS treatment was equivalent to ∼100 generations of spontaneous mutation. If so, our data imply that one generation of spontaneous mutation increases the developmental time by 0.09% at 20° and by 0.04% at 25°, and reduces viability under harsh conditions, fecundity, and longevity by 1.35, 0.21, and 0.08%, respectively. Comparison of flies with none, one, and two grandfathers (or greatgrandfathers, in the case of viability) treated with EMS did not reveal any significant epistasis among the induced mutations.


Genetics ◽  
1974 ◽  
Vol 77 (3) ◽  
pp. 569-589
Author(s):  
Martin L Tracey ◽  
Francisco J Ayala

ABSTRACT Recent studies of genetically controlled enzyme variation lead to an estimation that at least 30 to 60% of the structural genes are polymorphic in natural populations of many vertebrate and invertebrate species. Some authors have argued that a substantial proportion of these polymorphisms cannot be maintained by natural selection because this would result in an unbearable genetic load. If many polymorphisms are maintained by heterotic natural selection, individuals with much greater than average proportion of homozygous loci should have very low fitness. We have measured in Drosophila melanogaster the fitness of flies homozygous for a complete chromosome relative to normal wild flies. A total of 37 chromosomes from a natural population have been tested using 92 experimental populations. The mean fitness of homozygous flies is 0.12 for second chromosomes, and 0.13 for third chromosomes. These estimates are compatible with the hypothesis that many (more than one thousand) loci are maintained by heterotic selection in natural populations of D. melanogaster.


Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 975-989 ◽  
Author(s):  
K E Weber

Abstract Five bivariate distributions of wing dimensions of Drosophila melanogaster were measured, in flies 1) subjected to four defined environmental regimes during development, 2) taken directly from nature in seven U.S. states, 3) selected in ten populations for change in wing form, and 4) sampled from 21 long inbred wild-type lines. Environmental stresses during development altered both wing size and the ratios of wing dimensions, but regardless of treatment all wing dimensions fell near a common allometric baseline in each bivariate distribution. The wings of wild-caught flies from seven widely separated localities, and of their laboratory-reared offspring, also fell along the same baselines. However, when flies were selected divergently for lateral offset from these developmental baselines, response to selection was rapid in every case. The mean divergence in offset between oppositely selected lines was 14.68 SD of the base population offset, after only 15 generations of selection at 20%. Measurements of 21 isofemale lines, founded from wild-caught flies and maintained in small populations for at least 22 years, showed large reductions in phenotypic variance of offsets within lines, but a large increase in the variance among lines. The variance of means of isofemale lines within collection localities was ten times the variance of means among localities of newly established wild lines. These observations show that much additive genetic variance exists for individual dimensions within the wing, such that bivariate developmental patterns can be changed in any direction by selection or by drift. The relative invariance of the allometric baselines of wing morphology in nature is most easily explained as the result of continuous natural selection around a local optimum of functional design.


Agrivet ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 17
Author(s):  
Siti Dailah ◽  
Mofit Eko Poerwanto ◽  
Supono Budi Sutoto

The productivity of chili in terms of both quality and quantity is suppressed by the attacks of anthracnose disease caused by Colletotrichum spp. Pesticides is commonly used to control the disease. Researched was conducted to determine the antagonistic fungi and the effective dose in inhibiting the growth of the Colletotrichum spp. Antagonistic tests were performed in vivo using the direct method with three replicates. Inhibition test was arranged in a Complete Randomized Block Design (RCBD) with 7 treatments: Control, Gliocladium sp (150, 250, and 350 mL/plant) and T. harzianum (150, 250, and 350 mL/plant) with four replicates and three samples out of 20 plants per treatment. The results showed that the percentage of inhibition of T. harzianum against Colletotrichum sp. is 55% while Gliocladium sp. is 70.33% in antagonistic test. The mean of disease intensity at 11 up to 32 DAI on control is 5.61 ± 0.71% up to 20.30 ± 1.35 % respectively. It is significantly higher than Gliocladium sp. 350 mL/Plant (1.94 ± 0.45 % up to 11.15 ± 0.87 %), T. harzianum 350 mL/Plant (1.10 ± 0.58 % up to 8.68 ± 0.91 %), and T. harzianum 250 mL/Plant (2.28 ± 0.43 % up to 8.75 ± 0.79 %). No significant different is observed on mean of fresh weight of red chili fruit yield per plant. T. harzianum and Gliocladium sp. fungi are effective in controlling the attack of anthracnose disease in chili. The most efficient dose to control anthracnose disease is the application of T. Harzianum or Gliocladium sp at the dose of 250 mL/plant.Key Words: Chilli, Anthracnose, Gliocladium, Trichoderma, Colletotrichum.


Author(s):  
Sudhakar Rao M. S. ◽  
Navneeth T. P. ◽  
John C. J.

<p class="abstract"><strong>Background:</strong> Thyroid gland disorders form one of the most common endocrinal and surgical problems encountered in clinical practice. FNNAC is widely accepted as the primary and better method than FNAC for investigation but has its disadvantages. Colour Doppler is a non-invasive, low cost, easily available and repeatable investigation with least patient discomfort and can be valuable in detection of benign and malignant thyroid enlargements.</p><p class="abstract"><strong>Methods:</strong> Forty cases of adult females with WHO grade 2 thyroid enlargement attending the department of otorhinolaryngology selected on simple random basis were included in this study. Following written consent, Colour Doppler scanning and FNNAC test were done on the thyroid swelling and the results were analysed.  </p><p class="abstract"><strong>Results:</strong> The mean age of patients was 32.44 years. The mean age of malignancy was 44.66 years and showed statistically significant association. The Resistive and Pulsatility index and combination of both were found to have statistically significant results in detecting malignant and benign lesions The sensitivity, specificity, positive and negative predictive values of RI and PI were 83.33%, 94.12%, 71.43%, 96.97% and 50%, 94.12%, 60% and 91.43% respectively. On combining both the indices, the sensitivity was 91.67% and the positive predictive value was 97.06%.</p><p class="abstract"><strong>Conclusions:</strong> Colour Doppler can differentiate between benign and malignant thyroid enlargements using Resistive index (of&gt;0.75) and Pulsatility Index (of&gt;1.5) and can be a complementary diagnostic tool in the thyroid enlargement lesions, considering its accuracy, cost-effectiveness, easy availability and non-invasive repeatable nature.</p>


2014 ◽  
Vol 66 (3) ◽  
pp. 1097-1103 ◽  
Author(s):  
Janne Thirstrup ◽  
Cino Pertoldi ◽  
Peter Larsen ◽  
Vivi Nielsen

Litter sizes in a cross between Brown and Black mink color types were observed through six generations. Litter size was significantly affected by yearly environmental variations. After adjusting for year effects, we found significant increases in litter size in the second and third generations (F2 and F3) after crossing. Thereafter, in the following generations, litter size dropped to a level comparable to the mean litter size of the midparent. Increased litter size in F2 compared to F1 indicated that maternal effects influenced litter size more than non-maternal effects. The heterosis was mainly caused by an increase in litter size compared to the Black parental line. This indicates that the Black line was affected by inbreeding depression prior to crossing. We also found that two-year old F1 females had significantly more offspring compared to one-year old F1 females.


1991 ◽  
Vol 69 (9) ◽  
pp. 2410-2413 ◽  
Author(s):  
J. Mallefet ◽  
F. Baguet

Modifications in oxygen consumption and luminescence of isolated luminescent organs of the mesopelagic fish Argyropelecus hemigymnus following glucose and pyruvate administration were studied before and during light emission triggered by adrenaline. Isolated photophores (mean fresh weight 13.5 ± 0.9 mg) at rest, i.e., in the absence of light emission, in saline (20 °C) exhibit a respiration rate of 1.045 ± 0.082 (SE) nmol O2/min (n = 35). A significant decrease (p = 0.05) in oxygen consumption was observed after the addition of 5.5 mM glucose. Instead of the oxygen decrease usually observed as a result of control stimulations using adrenaline, photophores pretreated with glucose increased their oxygen uptake in response to adrenaline, and maximal light emission was reduced by 85% (p = 0.01). The addition of 5.5 mM pyruvate induced a significant transient increase (p = 0.05) in oxygen uptake of isolated photophores, though this treatment did not statistically modify the mean time course of oxygen consumption and light emission in response to adrenaline. The hypothesis of a hypometabolic state of the isolated photophores of A. hemigymnus during light emission is discussed.


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