scholarly journals EXTRACHROMOSOMAL INHERITANCE OF CARBON DIOXIDE SENSITIVITY IN THE MOSQUITO CULEX QUINQUEFASCIATUS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 649-659
Author(s):  
Donald A Shroyer ◽  
Leon Rosen
Keyword(s):  
Carbon Dioxide ◽  
Culex Quinquefasciatus ◽  
Natural Populations ◽  
Infectious Agent ◽  
Maternal Transmission ◽  
Co2 Sensitivity ◽  
Laboratory Colony ◽  
F1 Progeny ◽  
Extrachromosomal Inheritance ◽  
Sigma Virus

ABSTRACT Mosquitoes from a laboratory colony of Culex quinquefasciatus from Matsu Island, China, develop irreversible paralytic symptoms after exposure to carbon dioxide at 1°. This CO2 sensitivity is caused by an inherited infectious agent, probably a virus. Crossing studies between CO2-sensitive and -resistant mosquitoes showed that the sensitivity trait is inherited extrachromosomally in a fashion strictly analogous to the hereditary transmission of sigma virus in Drosophila melanogaster. Sensitivity could be maintained through maternal transmission alone, despite nine generations of backcrossing of "stabilized" CO2-sensitive females to males from a resistant strain. CO2-sensitive males crossed to resistant females transmitted sensitivity to a portion of their F1 progeny, and only the female F1 sensitives were capable of further hereditary transmission.—Matsu, or a very similar hereditary infectious agent, is common in natural populations of Cx. quinquefasciatus on Oahu, Hawaii. Fifty-nine percent of the families reared from field-collected egg rafts contained CO2-sensitive mosquitoes, and some families contained only sensitive mosquitoes.

scholarly journals INDEPENDENT PRODUCTION OF CO2 SENSITIVITY BY NUCLEAR GENE DLY AND A TRANSMISSIBLE AGENT FROM DELAYED-RECOVERY DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 92 (2) ◽  
pp. 503-510
Author(s):  
M A Clark ◽  
W B McCrady ◽  
C L Fielding
Keyword(s):  
Carbon Dioxide ◽  
Drosophila Melanogaster ◽  
Nuclear Gene ◽  
Infectious Agent ◽  
Mutant Gene ◽  
Co2 Sensitivity ◽  
The Third ◽  
Male Line ◽  
Delayed Recovery ◽  
Sigma Virus

ABSTRACT Flies of stocks designated delayed-recovery by MCCRADY and SULERUD (1964) remain temporarily paralyzed after exposure to carbon dioxide. This condition is similar to CO2 sensitivity, which occurs in flies infected with the maternally transmitted sigma virus, but is due, at least in part, to the third chromosome mutant gene DlY. Because earlier work indicated that extracts of delayed-recovery flies could occasionally transmit CO2, sensitivity when injected into resistant recipients, we have tested the possibility that some delayed-recovery stocks contain a sigma-like transmissible virus, in addition to the Dly gene. We found that TDR-orange, a stock derived from the original delayed-recovery line, and temperature-cured populations of the same stock, both contain some agent that is transmissible by injection. TDR-BC3f, a stock derived by backcrossing through the male line to eliminate maternally transmitted factors, does not appear to contain such an infectious agent, but remains sensitive to CO2. These observations lead us to the conclusion that the originally described delayed-recovery stocks harbor an infectious extrachromosomal agent, in addition to possessing the Dly gene, and each is capable of producing a sensitivity to carbon dioxide.

scholarly journals POLYMORPHISM OF THE HEREDITARY SIGMA VIRUS IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1980 ◽  
Vol 95 (2) ◽  
pp. 459-465
Author(s):  
Annie Fleuriet
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Common Type ◽  
Co2 Sensitivity ◽  
Genetic Types ◽  
Sigma Virus

ABSTRACT Previous studies have shown that, in natural French populations of Drosophila melanogaster, 10 to 20% of the flies are infected by the noncontagious, hereditary rhabdovirus sigma responsible for CO2 sensitivity. These populations are also polymorphic for two alleles [ref(2)Po and ref(2)Pp of a gene for resistance to the sigma virus. Evidence is given here that two viral genetic types, differing in their response to the ref(2)Pp allele, are present in these populations of flies; the most common type is only slightly sensitive to the ref(2)Pp allele.

Effect of CO2 and 100% O2 on cerebral blood flow in preterm infants

1980 ◽  
Vol 48 (3) ◽  
pp. 468-472 ◽  
Author(s):  
F. A. Leahy ◽  
D. Cates ◽  
M. MacCallum ◽  
H. Rigatto
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Preterm Infants ◽  
Cerebral Circulation ◽  
Pressure Change ◽  
Venous Occlusion ◽  
Co2 Sensitivity ◽  
Important Regulator ◽  
Carbon Dioxide Pressure

To determine 1) the effect of arterial CO2 change on the neonatal cerebral circulation and 2) whether 100% O2 would produce significant decrease in cerebral blood flow (CBF), we studied 24 preterm infants to explain the late (5 min) hyperventilation observed in them during hyperoxia. Of these, 12 were studied before and during inhalation of 2-3% CO2 and 12 before and during the inhalation of 100% O2. We measured CBF by a modification of the venous occlusion plethysmography technique and found that CBF increased 7.8% per Torr alveolar carbon dioxide pressure change and that it decreased 15% with 100% O2. These findings suggest that 1) CO2 is an important regulator of CBF in the perterm infant, 2) CBF-CO2 sensitivity in these infants may be greater than in adult subjects, 3) 100% O2 reduced CBF significantly, and 4) a decrease in CBF during administration of 100% O2 may be at least partially responsible for the increase in ventilation with hyperoxia.

scholarly journals REPRODUCTION IN CAGE POPULATIONS OF A POLYMORPHISM REGULARLY OBSERVED IN THE NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER IN FRANCE

Genetics ◽  
1978 ◽  
Vol 88 (4) ◽  
pp. 755-759
Author(s):  
Annie Fleuriet
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Rate Of Return ◽  
Rapid Rate ◽  
Experimental Conditions ◽  
Co2 Sensitivity ◽  
In The Wild ◽  
Strong Forces

ABSTRACT Polymorphism for both alleles of a gene ref(2)P, which is a usual trait of French natural populations of Drosophila melanogaster, can be reproduced in experimental conditions. ref(2)P is a gene for resistance to the hereditary, noncontagious Rhabdovirus α, responsible for CO2 sensitivity in Drosophila melanogaster. The equilibrium frequencies observed in cages are the same as in the wild, whether α virus is present or not. The rapid rate of return to these equilibrium frequencies indicates that strong forces, which remain to be determined, are responsible for the maintenance of this polymorphism.

scholarly journals Synergism between nonane and emanations from soil as cues in oviposition-site selection of natural populations of Anopheles gambiae and Culex quinquefasciatus

2021 ◽  
Author(s):  
Victor Saturnus Mwingira ◽  
Leonard E.G. Mboera ◽  
Willem Takken
Keyword(s):  
Synergistic Effect ◽  
Anopheles Gambiae ◽  
Culex Quinquefasciatus ◽  
Site Selection ◽  
Natural Populations ◽  
Breeding Site ◽  
Distilled Water ◽  
Oviposition Site Selection ◽  
Untreated Soil ◽  
Selection Of

Abstract BackgroundOlfactory cues have been shown to have an important role in guiding gravid mosquito females to selected sites for egg laying. The objective of this study was to determine the influence of emanations from soil from a breeding site and the putative oviposition pheromone nonane on oviposition-site selection of natural populations of Anopheles gambiae sensu lato (s.l.) and Culex quinquefasciatus.MethodsThis field-based study was conducted in Mvomero District in East-central Tanzania. In a dual-choice experimental set up, clay bowls were dug into the ground and filled with one of the following treatments: (i) distilled water + autoclaved soil (control), (ii) distilled water + soil from a natural mosquito breeding site, (iii) distilled water + nonane and (iv) distilled water + nonane + soil from a natural breeding site. Soil was dried and autoclaved or dried only before use. After five days of incubation, larvae were collected daily for 10 days. The median number of larvae per bowl per day was used as outcome measure.ResultsAutoclaved soil had a significant attractive effect on oviposition behaviour of Cx. quinquefasciatus (median values ± s.e: 8.0±1.1; P<0.005) but no effect on An. gambiae (median value ± s.e: 0.0±0.2; P = 0.18). Nonane and emanations from untreated soil significantly and positively influenced the selection of oviposition sites by both An. gambiae s.l. (median values ± s.e.: 12.0 ± 2.0 and 4.5 ± 1.5, respectively; P< 0.0001) and Cx. quinquefasciatus (median values ± s.e.: 19.0 ± 1.3 and 17.0 ± 2.0, respectively; P<0.0001). A mixture of nonane and untreated soil caused a synergistic effect on oviposition behaviour in An. gambiae s.l. (median value ± s.e.: 23.5 ± 2.5; P<0.0001) compared to either nonane (median values ± s.e.: 12.0 ± 2.0; P<0.0001) or untreated soil alone (median value ± s.e.: 4.5 ± 1.5; P<0.0001). A synergistic effect of nonane mixed with untreated soil was also found in Cx. quinquefasciatus (median value ± s.e.: 41.0 ± 2.1; P<0.0001) compared to either nonane (median value ± s.e. 19.0 ± 1.3; P<0.0001) or untreated soil alone (median value ± s.e.: 17.0 ± 2.0; P<0.0001). The oviposition activity index for An. gambiae was 0.56 (P< 0.001) and for Cx. quinquefasciatus 0.59 (P<0.0001).ConclusionThe larval pheromone nonane and emanations from breeding-site soil both induced oviposition in wild An. gambiae s.l. and Cx. quinquefasciatus, with a synergistic effect when both stimuli were present simultaneously. This is the first study in which nonane is shown to cause oviposition under natural conditions, suggesting that this compound can potentially be exploited for the management of mosquito vectors.

Concept and measurement of ventilatory sensitivity to carbon dioxide

1965 ◽  
Vol 20 (5) ◽  
pp. 890-897 ◽  
Author(s):  
P. Dejours ◽  
R. Puccinelli ◽  
J. Armand ◽  
M. Dicharry
Keyword(s):  
Carbon Dioxide ◽  
Co2 Concentration ◽  
Control Of Breathing ◽  
Raw Data ◽  
Breathing Control ◽  
Co2 Sensitivity ◽  
Classical Procedure ◽  
True Index ◽  
Normal Respiration

Four resting subjects breathed 0, 1, 2.5, and 4% CO2 diluted in air for 25 min. Ventilation, Po2 and Pco2 of alveolar and expired gases were measured. One can represent on a Po2-Pco2 diagram, as Rahn and Fenn have done, some features of the reaction to CO2, and plot lines of “ventilatory isosensitivity to CO2.” The relation between experimental points and these lines shows why “ventilatory CO2 sensitivity,“ DeltaVa/DeltaPaCOCO2, for normal conditions cannot be quantified by the classical procedure of giving one or several percent CO2 to breathe. CO2 sensitivity nonetheless exists normally, since in subjects breathing mixtures containing a few mm Hg CO2, PaCOCO2 is practically unchanged, while PaOO2 rises by several mm Hg. The difficulties of accurately measuring DeltaVa/DeltaPaCOCO2 suggest caution in accepting some mathematical developments often applied to raw data, and in taking this ratio as a true index of ventilatory CO2 sensitivity, particularly when measurements made with high inspired CO2 concentration are used to interpret the regulation of normal respiration. alveolar pathway during CO2 breathing; control of breathing; hypercapnia; O2-CO2 diagram Submitted on December 11, 1964

scholarly journals Stability, CO2 sensitivity, oil tolerance and displacement efficiency of polymer enhanced foam

RSC Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 6251-6258 ◽  
Author(s):  
Wanfen Pu ◽  
Peng Wei ◽  
Lin Sun ◽  
Song Wang
Keyword(s):  
Carbon Dioxide ◽  
Foam Stability ◽  
Displacement Efficiency ◽  
Co2 Sensitivity ◽  
Foam Flooding

This paper focuses on the benefits of polymers that contribute to foam flooding, such as foam stability, carbon dioxide (CO2) sensitivity, oil tolerance and displacement efficiency.

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