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At least 19 recordsLinked to original sources
PubMed1979

Oviposition site preference in Drosophila.

Comparative studies of oviposition site preference (OSP) in Drosophila suggest that choice of oviposition site is an important adaptive behavior which influences individual fitness and the potential of populations for speciation. OSP has been investigated under conditions which provided females with a choice of standard medium or medium containing ethanol for oviposition. OSP is an extremely labile behavior in the laboratory, but a technique has been developed which minimizes variation between replicates and allows the detection of OPS differences between semispecies of a single species. An analysis of the OSP of 14 Drosophila species shows that this behavior is not correlated with phylogenetic relationships. OSP with respect to ethanol may be correlated with the presence of ethanol in the environment and the activity of alcohol dehydrogenase in the species tested.

Animals↗
PubMed1979

Penetration into caterpillar cells of virus-like particles injected during oviposition by parasitoid ichneumonid wasps.

Particles originating from the ovarial calyx epithelium of two different species of ichneumonid wasp are injected into host caterpillars during oviposition. At 1 3/4 h post oviposition, many calyx fluid particles are either associated with or have oenetrated through the basement membranes surrounding various tissues. Shortly thereafter, apparently intact particle nucleocapsids are observed in both the cytoplasm and nucleus of host cells. An unusual tubular protrusion of the viral envelope appears to be involved in either or both of penetration of basement membranes and entry of nucleocapsids into host cells.

Animals↗
PubMed1977

Alteration of structure and penetrability of the vitelline envelope after passage of eggs from coelom to oviduct in Xenopus laevis.

The vitelline envelope (VE) that surrounds an egg released from the ovary into the coelom of Xenopus laevis differs markedly, in structure and penetrability, from the VE surrounding an oviposited egg. In a coelomic egg, the filaments that form the VE are arranged in distinct fascicles or bundles. The exterior surface of the VE is irregular in contour and is permeated by channels. In an oviposited egg, the filaments are evenly dispersed and lack a fasciculated arrangement; the exterior surface is smooth and no channels are present. The fascicular arrangement of fibrils in the coelomic VE is maintained only at neutral pH, and is not visibly altered by the cortical reaction. VEs from coelomic eggs retain their fasciculated morphology after isolation from the egg. In an in vitro test system, sperm penetrated VEs isolated from oviposited eggs, but failed to penetrate VEs isolated from coelomic eggs. The structural transformation of the VE from the coelomic type to the oviposited type occurs in the first 1-cm segment of the oviduct, prior to addition of jelly to the egg. Neither intact jelly, solubilized jelly, nor jelly extracts were capable of altering the structural organization of coelomic VEs, suggesting that the structural transformation of the VE is effected by some oviducal factor other than jelly.

Animals↗
PubMed1978

Relevance of laboratory colonies of the vector in arbovirus research--Culicoides variipennis and bluetongue.

Relevance for laboratory colonies of Culicoides variipennis (Coquillett) in arbovirus research was determined during colonization by comparing a vector-competence characteristic for the parent (P) field and subsequent colonized generations. Three colonies established in 1972-1973 were used to determine whether each was representative of the field population from which it was derived for oral infection to 2 to 4 serotypes of bluetongue virus (BTV). Two colonies that were based on small numbers of females ovipositing did not represent the field population. Both appeared homogeneous to oral infection with different serotypes, and one was resistant to infection whereas the other was susceptible. The third colony, which was based on about 150 P females that had oviposited, was more representative of the field population: 1) oral susceptibility to BTV for the F6 was not greatly different from that of the P generation, and 2) the colony retained some heterogeneity for response to oral infection with different serotypes of BTV. The number and percentage of P females ovipositing and the numerical growth factor from the P to F1 were used to estimate whether a laboratory colony was apt to represent the field population from which it was derived.

Animals↗
PubMed1979

The gonotrophic cycle in Simulium ochraceum.

Oogenesis in Simulium ochraceum is characterized in terms of distinct stages of follicular development following emergence, sugar feeding, and completion of a blood meal. Changes in the ovary following the first oviposition are also described. This black fly species was found to be anautogenous and exhibited gonotrophic concordance. The formation of follicular dilatations after oviposition followed a distinct pattern with traces of cellular debris evident up to 144 hours. The presence of fructose, as detected by the cold Anthrone test, indicated that both parous and nulliparous flies routinely imbibe nectars as part of their foraging behavior. The availability and frequent use of nectar may contribute significantly to longevity of parous flies, hence increasing their vector potential.

Animals↗
PubMed1976

Composition of crop and gizzard contents in the laying hen.

Crop and gizzard contents were analysed at six stages of egg formation. 2. The crop was empty during the day and full during the night while the gizzard contained a constant amount of dry matter. The water content of the crop did not change but that of the gizzard was at a minimum just after the ovulation and at a maximum 18 h later. 3. The osmotic pressure of the gizzard contents remained constant and close to that of the blood; that of the crop contents was almost isotonic at oviposition but hypertonic 18 h later. In both organs the pH of the liquid phase varied cyclicly with the egg formation and was lowest during egg shell deposition. 4. The Na+, K+ and Cl- contents of the crop liquid phase did not vary but Ca2+ increased with decreasing pH.Na+ and K+ were also constant in the gizzard liquid phase but Cl- and Ca2+ increased during shell formation. 5. It is concluded that the amount of HCl secreted by the proventiculus is related to egg shell deposition and that calcium solubilisation depends on microbial fermentation in crop and HCl secretion by proventriculus.

Animals↗
PubMed1975

Initial expression of the genes for fructose 1,6-diphosphatase, malic enzyme, and aspartate aminotransferase in Japanese quail and chicken--quail hybrid embryos.

The initial appearance of a number of enzymes involved in gluconeogenesis was investigated in the early embryogenesis of the Japanese quail (Coturnix coturnix japonica), the domestic chicken (Gallus gallus domesticus), and chicken-quail hybrids. Starch gel electrophoresis and enzyme-specific stains revealed genetic differences between muscle and liver fructose 1,6-diphosphatase (FDPase) as well as malic enzyme (ME) and mitochondrial aspartate aminotransferase (AAT) isozymes of the two species. ME and AAT were present in unfertilized unincubated eggs, indicating maternal storage of these enzymes. The initial expression of the paternally inherited genes in the hybrid occurred before oviposition in the case of ME, and between 12 and 18 hr incubation in the case of AAT. Initial expression of both parental sets of genes for FDPase occurred synchronously between 16 and 24 hr in the hybrid, corresponding to the time of initial appearance of this enzyme in the quail and chicken. Glucose 6-phosphate administration at 0 hr was found to cause no prevention or delay of initial enzyme activation. These results are interpreted in terms of early patterns of enzyme activation regulation and nutrition in the avian embryo.

Animals↗
PubMed1979

Effects of caffeine and various xanthines on hornets and bees.

The effect of caffeine was assessed on Vespa orientalis hornets maintained either in sealed breeding boxes or as entire colonies free to forage, and also on Apis mellifera bees within their hives. In a number of instances the hornets were also used to study the effect of various bodily extracts of queen hornets and of the following xanthines: Purine; hypoxanthine; uric acid; theophylline; and theobromine. The studied materials were found to exert an effect on three categories of activities: (1) Motor motility, flight, and construction; (2) sensory response to light (retinal and extraretinal), noise, irritability, orientation; and (3) physiological changes in appetite, copulation, oviposition, hibernation, resistance to cold, and longevity. Up to a point the produced effects were reversible. Throughout the period of experimentation the test insects did not show signs of tolerance or addiction towards caffeine.

Animals↗
PubMed1978

Influence of beta-alanine on mating and territorialism in Drosophila melanogaster.

Effects of beta-alanine on mating behavior and aggression were studied in Drosophila melanogaster using the following competitive pairs: (1) homozygous black (b/b) flies, in which beta-alanine synthesis is decreased, vs. alanine is blocked vs. wild-type (e+/e+) flies; (2) dark flies, in which beta-alanine incorporation is reduced, owing mainly to chromosome 3, vs. light flies collected from the same population as were the dark flies; (3) homozygous black (b/b) flies, in which beta-alanine synthesis is decreased, vs. beta-alanine-infected b/b flies, which are phenocopies of wild-type flies. The behavior of mixed-sex groups was studied in a large, illumination-graded observation chamber containing food and in small uniformly illuminated cells also containing food. The relative competitive mating abilities of these types were measured in both experimental conditions. Uninjected black flies, but not injected ones, showed weak and unsteady gait and weak wing extension. In ebony these abnormalities were more extreme. Dark flies did not show these abnormalities. Accelerated sexual maturation was indicated in males by early onset of courtship and enhanced territorial aggression and in females by earliness of mating. Such acceleration was observed in ebony and dark flies, compared with light flies, and among beta-alanine-injected b/b flies competing with uninjected black flies. Ebony males, although maturing earlier than wild-type males, were less successful than wild-type males in mating. This difference was even greater when the flies were all allowed to mature before competing. Ebony females outmated wild-type females. Dark flies outmated light flies, and beta-alanine-injected b/b males outmated uninjected black males, especially in bright light. Ebony flies mated much longer than wild-type flies, and black flies mated slightly longer than injected b/b flies. There was some spatial isolation of ebony from wild type, dark from light, and beta-alanine-injected from uninjected b/b flies in the illumination-graded observation chamber. Ebony flies more than wild type concentrated near food. Flies were attracted to the current of moist inlet air. They were also attracted to deposited excrement, and males defended such deposits as a mating area, thus showing rudiments of arena behavior in which a mating area away from the oviposition site is defended. Usually, however, the defended area focused on food.

Aggression↗