Chromosome banding homologies in three species of Aedes (Stegomyia)

1986 ◽  
Vol 28 (2) ◽  
pp. 198-202 ◽  
Author(s):  
A. Marchi ◽  
K. S. Rai

The chromosome complements of the mosquitoes Aedes aegypti, Aedes mascarensis, and Aedes albopictus, belonging to the subgenus Stegomyia, gave a uniform response to the Q-, H-, and R-banding techniques. Of the three homomorphic chromosome pairs, only the shortest or sex pair (I) showed a consistent banding pattern. In the three species, a bright yellow intercalary band was present on one arm of both chromosomes of the sex pair after heat treatment and staining with acridine orange. The rest of the chromosome and the other two pairs fluoresced orange–red. The same intercalary region appeared completely dark with the fluorochromes quinacrine and Hoechst 33258, while the rest of the chromosomes fluoresced dull. The same banding pattern was present in males and females. Size variations of the Q- and H-negative and R-positive intercalary bands were observed within each species. The results are interpreted in terms of structural homology of the sex-determining chromosomes, which is retained within the subgenus.Key words: sex-determining chromosomes, banding (Q, H, R), Aedes, mosquitoes.

2004 ◽  
Vol 82 (5) ◽  
pp. 808-816 ◽  
Author(s):  
Mike Spironello ◽  
Fiona F Hunter

The polytene chromosome banding pattern of Simulium exasperans (Craig, 1987) is described for the first time. Three populations of S. exasperans from Moorea and Tahiti were examined cytologically. Interspecific comparisons revealed that S. exasperans is homosequential in chromosomal banding pattern to Simulium cataractarum (Craig, 1987), but contains three species-characteristic floating inversions: IL-1ex.2ex, IIL-1ex,2ex, and IIIL-1ex. No sex-linked inversions were identified; males and females had undifferentiated sex chromosomes. The IIL-1ex,2ex inversion was in Hardy-Weinberg disequilibrium in two of the three populations. From this preliminary data, two cytotypes may exist: cytotype A (Belvedre Cascade population) and cytotype B (1st Afareaitu Cascade and Jardin Public Vaipahi populations). Contrary to phylogenetic and biogeographic data, it is hypothesized that the Belvedre Cascade population (cytotype A) is ancestral to the populations containing cytotype B. Furthermore, a heterozygote advantage may exist in cytotype B.


2019 ◽  
Vol 70 (4) ◽  
pp. 211-216
Author(s):  
Jim Pateman ◽  
Peter Russell

Two Euphydryas aurinea beckeri females from Sierra Blanca, Malaga, Spain were captured and returned to the U.K.; each laid a single egg batch on Succisa pratensis. Both batches hatched and the resulting larvae were reared through to adulthood. One group of larvae produced butterflies with three different mutations: pupae with spines, legs lacking distal tarsals and claws, and with appendages attached to the genitalia which protruded though the rear of the abdomens in both males and females. The other group of larvae produced normal males and females.


1987 ◽  
Vol 58 (2) ◽  
pp. 175-179 ◽  
Author(s):  
John Calam ◽  
Joanna C. Bojarski ◽  
Caroline J. Springer

1. The aim of the present study was to determine whether oral ingestion of raw soya-bean flour, which contains trypsin inhibitors, alters the release of cholecystokinin (CCK) in man.2. Eleven healthy volunteers ate two mixed meals: one with raw soya-bean flour and the other with soya-bean flour that had been heat-treated. The two flours inhibited 34 and 3 mg trypsin/g flour respectively.3. CCK was measured in plasma using a bioassay based on the release of amylase (EC 3.2.1.1) from dispersed rat pancreatic acini.4. The peak CCK response was 168 (SE 8.1) pmol/l with raw soya-bean flour but 4.9 (SE 2.8) pmol/l with heat-treated flour (P < 0.05).5. We conclude that ingestion of raw soya-bean flour increases CCK release in man and that heat treatment which reduces the trypsin inhibitor content of the flour also diminishes its CCK-releasing effect.


1989 ◽  
Vol 67 (6) ◽  
pp. 1434-1438 ◽  
Author(s):  
Lynn M. Brodsky ◽  
C. Davison Ankney ◽  
Darrell G. Dennis

The influence of social experience on the preferences for a potential mate in a captive population of black ducks, Anas rubripes, and mallards, Anas platyrhynchos, was examined. Birds were reared from hatching with conspecifics (i.e., female black ducks with male black ducks, female mallards with male mallards), or were cross-fostered with the other species (i.e., female black ducks with male mallards, female mallards with male black ducks). Preferences of individuals were tested in a chamber containing caged black ducks and mallards of the opposite sex. In over 90% (100/109) of the trials, males and females preferred the species that they were raised with since hatching, whether they were of the same species or not. These results demonstrate that social experience influences the social preferences of male and female black ducks and mallards.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1109-1114
Author(s):  
Xin Lei ◽  
Hui Huang ◽  
S.P. Wen

This study investigated the mechanical properties and microstructures of Er-containing Al–Mg alloys. The research found that the H114-T sheet of Er-containing Al–Mg alloys showed a relative good comprehensive performance in mechanical properties. With the special rolling and heat treatment process, this H114-T sheet showed different morphology of microstructures with the other sheets in Er-containing Al–Mg alloys. Grains in H114-T sheet performed irregular shape polygon, a number of subgrains appeared in grains, the amount of dislocations in grains decreased. H114-T sheet possessed a lot of Copper texture, this may be one of important factors influenced the mechanical properties.


1953 ◽  
Vol 27 (1-2) ◽  
pp. 81-94 ◽  
Author(s):  
T. Goodey

1. A detailed morphological study has been made of certain nematodes occurring in the basidiomycetous fungi, Entoloma rhodipolium, Pleurotus corticalus, P. ostreatus, Hygrophorus virgineus and Tricholoma cunifolium.2. From the first three of these, males and females of two species of eelworms have been obtained which are placed in the genus Iotonchium Cobb, 1920. One of these is Iotonchium fungorum (Butschli, 1878) n. comb., originally described by Butschli under the name of Tylenchus fungorum', the other is a new species which is named I. bifurcatum n. sp.3. The males of both species have peculiar lobed, dorso-ventrally flattened heads and a poorly developed mouth spear. The bursa is very large, the spicules have posterior prolongations which arc extruded through the cloaca and ventral post-anal papillae are present. A gubernaculum is absent.


1985 ◽  
Vol 12 (1) ◽  
pp. 45-49 ◽  
Author(s):  
D. L. Ketring ◽  
H. E. Pattee

Abstract Following harvest, peanuts are usually subjected to a period of storage. During storage biochemical changes are known to occur. The objectives of this study were to determine the changes and relationship in ethylene production, germination, and lipoxygenase (LG) activity during cold storage of dormant NC-13 peanut seeds. Two seed lots (SL) were used: one grown in Oklahoma (SL80) and the other grown in N. Carolina (SL81). SL80 and SL81 were stored at 2 to 5 C for 193 and 242 days, respectively. Samples were taken at about 28-day intervals for determination of germination, ethylene production, and LG activity. Seeds of two and three maturities were tested for SL80 and SL81, respectively. As afterripening of stored seeds proceeded, ethylene production gradually increased, with the maximum at 48 hours of germination. Germination showed a concomitant gradual increase. Lipoxygenase activity of both seedlots was less for mature than for immature seeds and showed a sharp increase during storage at 2 to 5 C, particularly for immature seeds. After heat-treatment to break dormancy of sublots from SL81, there was a progessive increase in ethylene production and germination, but most notably for mature seeds. In contrast to ethylene production and germination, after heat-treatment LG activity declined. Linear correlation coefficient (r) values between ethylene production and germination were highly significant for mature seeds from SL80 at 48 and 72 hours of germination, but only at 72 hours for immature seeds. For SL81 as for SL80, significant positive correlations were found between ethylene production and germination. However, correlations between LG activity and the other variables were not significant except for mature seeds from SL81. Significant positive correlations for both ethylene production and germination with LG activity also existed for these seeds. But after heat-treatment these correlations no longer occurred. The data indicate that the metabolic processes related to ethylene production and germination are occurring simultaneously with those of LG activity. The possibility that metabolites from LG activity serve as substrates for ethylene production can not be precluded.


2011 ◽  
Vol 284-286 ◽  
pp. 1431-1434 ◽  
Author(s):  
Jin Rui Zhang ◽  
Ru Wang

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.


Hereditas ◽  
2009 ◽  
Vol 76 (2) ◽  
pp. 305-314 ◽  
Author(s):  
LIISA HALKKA ◽  
O. HALKKA ◽  
U. SKARÉN ◽  
VERONICA SÖDERLUND

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