Mating interactions of Schistosoma haematobium and S. intercalatum with their hybrid offspring

Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 327-338 ◽  
Author(s):  
B. L. WEBSTER ◽  
V. R. SOUTHGATE
Keyword(s):  
Schistosoma Haematobium ◽  
Parental Species ◽  
Mating Behaviour ◽  
Electrophoretic Analysis ◽  
Hybrid Analysis ◽  
Epidemiological Changes ◽  
Female Hybrid ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Haenszel Test ◽  
Better Than

Experiments were designed to study the mating behaviour between the Schistosoma haematobium [male ]×S. intercalatum [female] hybrid and the 2 parental species S. haematobium and S. intercalatum. Individual worms were identified by electrophoretic analysis of glucose-6-phosphate dehydrogenase, which was characteristic for each isolate. Analysis of the data obtained showed that both heterospecific and homospecific pairs formed between the hybrids and S. haematobium and S. intercalatum. S. haematobium and the hybrid are better than S. intercalatum in forming pairs, and S. haematobium showed a greater homospecific mate preference compared with the hybrid. Analysis of the data using the Mantel-Haenszel test suggests that mating competition does exist between the schistosomes, with the hybrid being dominant over both the parental species and S. haematobium being dominant over S. intercalatum. The hybrid males showed a greater ability than S. intercalatum and S. haematobium males in taking away S. haematobium and S. intercalatum females from their homospecific males when introduced into a pre-established S. haematobium or S. intercalatum infection. They were able to take females from S. intercalatum homospecific pairs more easily compared with females from S. haematobium homospecific pairs. The significance of the results is discussed in relation to the epidemiological changes of schistosomiasis in Cameroon, where hybridization between S. haematobium and S. intercalatum has taken place, with S. haematobium and the hybrid managing to replace the endemic S. intercalatum over the last 30 years.

Isoenzyme analysis of Schistosoma haematobium, S. intercalatum and their hybrids and occurrences of natural hybridization in Cameroon

2003 ◽  
Vol 77 (3) ◽  
pp. 269-274 ◽  
Author(s):  
B.L. Webster ◽  
V.R. Southgate ◽  
L.-A. Tchuem Tchuenté
Keyword(s):  
Isoelectric Focusing ◽  
Schistosoma Haematobium ◽  
Parental Species ◽  
Molecular Data ◽  
Natural Hybridization ◽  
Isoenzyme Analysis ◽  
South West ◽  
Parasitological Survey ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Recombinant Population

AbstractIsoelectric focusing of glucose-6-phosphate dehydrogenase (G6PD) produced clearly identifiable profiles for S. haematobium and S. intercalatum and their hybrids. To provide a more detailed analysis of the interactions of S. haematobium and S. intercalatum in South West Cameroon over the last 12 years, G6PD analyses were carried out on individual schistosomes collected in Kumba in 1990, Loum in 1990, 1999 and 2000 and Barombi Mbo and Barombi Kotto in 1999. Studies were also carried out on the two parental species S. haematobium Barombi Mbo, S. intercalatum Edea and subsequent generations of hybrids resulting from laboratory crosses of the two parental species. The isoenzyme analysis demonstrated that the 1990 isolate from Kumba, was a recombinant of S. intercalatumxS. haematobium, and that 30% of individual schistosomes collected in 1990 in Loum were also recombinants. The remainder gave data indicative of S. haematobium. In 1999, 12.5% of individuals from Loum showed recombination and 10% in 2000. Results from the most recent parasitological survey in October 2000 showed the persistence of the recombinant population in addition to that of S. haematobium. There was also evidence of recombination having taken place in Barombi Kotto but not Barombi Mbo. This study demonstrates how the situation has changed over the last 12 years, and emphasizes the importance of assessing morphological, biological and molecular data together to gain a true picture of the rapidly evolving situation.

Mating interactions between Schistosoma haematobium and S. mansoni

1999 ◽  
Vol 73 (4) ◽  
pp. 351-356 ◽  
Author(s):  
B.L. Webster ◽  
V.R. Southgate ◽  
L-A. Tchuem Tchuenté
Keyword(s):  
Schistosoma Haematobium ◽  
Dominant Species ◽  
Mating Behaviour ◽  
Mate Preference ◽  
Mixed Infections ◽  
Preference Analysis ◽  
Mating Competition ◽  
Human Host ◽  
Significant Difference ◽  
Haenszel Test

Schistosoma haematobium and S. mansoni are two medically important schistosomes, commonly occurring sympatrically in Africa and so potentially able to infect the same human host. Experiments were designed to study the mating behaviour of these two species in mixed infections in hamsters. Analysis of the data obtained showed that both heterospecific and homospecific pairs readily form. No significant difference was seen between the two species in their ability in forming pairs, however, S. mansoni showed a greater homospecific mate preference. Analysis of the data using the Mantel-Haenszel test suggests that mating competition does occur between S. haematobium and S. mansoni, the former being the more dominant species. Both species appeared to be able to change mate, with S. haematobium showing a greater ability in taking S. mansoni females away from S. mansoni males when introduced into a pre-established S. mansoni infection highlighting the competitiveness of S. haematobium. The significance of the results is discussed in relation to the epidemiological consequences occurring in Senegal, and other areas where both species are sympatric.

FURTHER STUDIES ON NATURAL SELECTION AMONG HYBRIDS OF CARDUUS ACANTHOIDES AND CARDUUS NUTANS

1964 ◽  
Vol 42 (12) ◽  
pp. 1605-1613 ◽  
Author(s):  
R. J. Moore ◽  
G. A. Mulligan
Keyword(s):  
Natural Selection ◽  
Chromosome Number ◽  
Parental Species ◽  
Experimental Studies ◽  
Great Decrease ◽  
Carduus Acanthoides ◽  
Carduus Nutans ◽  
Experimental Plots ◽  
Better Than ◽  
Made In

A third 5-year survey made in 1962 of Carduus acanthoides, C. nutans, and their hybrids in Grey Co., Ontario, revealed that a great decrease in these populations had occurred. C. acanthoides and hybrids similar to this species had survived better than C. nutans but very little spread of either species seemed to have occurred in 1957–1962. In experimental plots the hybrid has been made and backcrossed to the parental species. The species differ in chromosome number (C. acanthoides, 2n = 22; C. nutans, 2n = 16) and hybrids have intermediate numbers. Evidence was found from field and experimental studies that the progeny of the F1 hybrid included a greater proportion of seedlings with the higher chromosome numbers than with the lower and intermediate numbers. It is suggested that this selection may operate through the rejection of the longer chromosomes received from C. nutans, which, in certain zygotic combinations may constitute an excess of chromatin lethal to the zygote.

Acoustic Communication and Mating Behaviour in the Muellerianella Complex (Homoptera - Delphacidae)

Behaviour ◽  
1985 ◽  
Vol 94 (1-2) ◽  
pp. 183-201 ◽  
Author(s):  
S. Drosopoulos
Keyword(s):  
Mating Behavior ◽  
Acoustic Communication ◽  
Parental Species ◽  
Mating Behaviour ◽  
Interspecific Crosses ◽  
Bisexual Species ◽  
Duration Of Copulation ◽  
Isolating Mechanisms ◽  
Copulation Behavior ◽  
Biological Differences

AbstractSome data on acoustic communication and mating behavior of two biparentally reproducing species and the clonally reproducing pseudogamous "species" of the genus Muellerianella are reported. Although bioacoustic differences were found in the calling songs between the species, these did not prevent pairforming. Also, differences in mating behavior, such as pre-copulation behavior, courtship activities, frequency and duration of copulation were not sufficient to prevent successful hybridization between both the two biparentally reproducing species and between each of these two species and the pseudogamous "species". The data reported here are related to other biological differences reported previously. According to these data there is some evidence that differences in acoustic communication and mating behavior between the two species are established by ecological influences which in turn have established analogous physiological requirements. These differences are rather weak isolating mechanisms. Regarding the behavioral relation of the pseudogamous species with males of the two parental species it was found that these females behave exactly as the females of M. fairmairei with which they coexist in the field. In interspecific crosses mechanical barriers to copulation are more efficient than courtship differences. Finally it is assumed that pseudogamy is a strong isolation mechanism between the not yet fully genetically differentiated bisexual species of Muellerianella.

Compatibility of Schistosoma haematobium, S. intercalatum and their hybrids with Bulinus truncatus and B. forskalii

Parasitology ◽  
2003 ◽  
Vol 127 (3) ◽  
pp. 231-242 ◽  
Author(s):  
B. L. WEBSTER ◽  
V. R. SOUTHGATE
Keyword(s):  
Schistosoma Haematobium ◽  
Parental Species ◽  
Reciprocal Hybrid ◽  
Intermediate Hosts ◽  
Bulinus Truncatus ◽  
Hybrid Offspring ◽  
Species Analysis

Schistosoma haematobium and S. intercalatum readily hybridize with each other producing generations of viable hybrid offspring. Experiments were designed to investigate the infectivity and viability of the S. haematobium×S. intercalatum F1 and F2 hybrid larvae in their two intermediate snail hosts compared with the parental species. Analysis of the data obtained suggested that the S. haematobium [male ]×S. intercalatum [female] F1 hybrid miracidia were more infective to Bulinus truncatus than to B. forskalii, and also more infective to B. truncatus compared with the parental S. haematobium miracidia. This hybrid was also observed to have a greater cercarial productivity from both intermediate hosts and these cercariae were shown to be more infectious and to have a longer longevity compared with the cercariae of S. haematobium, S. intercalatum and the S. haematobium [female]×S. intercalatum [male ] F1 hybrid cercariae. The S. haematobium [female]×S. intercalatum [male ] F1 hybrid was shown not to be very successful in all stages of the investigations. The results indicate that the S. haematobium [male ]×S. intercalatum [female] F1 hybrid may have many reproductive advantages over the reciprocal hybrid and the parental schistosome species. The significance of the results is discussed in relation to the epidemiological consequences occurring in Loum, Cameroon, and other areas where S. haematobium and S. intercalatum are sympatric and able to hybridize.

Hybridization between northern redbelly dace (Phoxinus eos) and finescale dace (Phoxinus neogaeus) (Osteichthyes: Cyprinidae) in Alberta

1989 ◽  
Vol 67 (3) ◽  
pp. 579-584 ◽  
Author(s):  
Mrinal K. Das ◽  
Joseph S. Nelson
Keyword(s):  
Principal Components ◽  
Parental Species ◽  
Introgressive Hybridization ◽  
Morphological Characters ◽  
Allopatric Populations ◽  
Canonical Variates ◽  
Female Hybrid ◽  
Hybrid Group

Hybridization between northern redbelly dace (Phoxinus eos) and finescale dace (Phoxinus neogaeus) was studied in Upper Pierre Grey Lake, Alberta. Sympatric parental and hybrid populations were compared with allopatric populations from Cameron Lake and Tay Lake, Alberta. Canonical variates and principal components analyses, using 31 morphological characters, revealed that the two parental groups were bridged by an intermediate all-female hybrid group in Upper Pierre Grey Lake. Hybrids made up approximately 33% of the individuals of the sympatic population. Neither backcross nor hybrid F2 individuals could be identified from the analyses, although the majority of hybrids were morphologically more similar to P. neogaeus than to P. eos. No clear evidence of introgressive hybridization was found in either of the sympatric parental species.

scholarly journals Spawning behaviour and mating success in hybrids of silver bream (Blicca bjoerkna L.) and rudd (Scardinius erythrophthalmus L.) in an experimental environment

2013 ◽  
Vol 63 (2) ◽  
pp. 119-130 ◽  
Author(s):  
Billy Nzau Matondo ◽  
Michaël Ovidio ◽  
Jean Claude Philippart ◽  
Pascal Poncin
Keyword(s):  
Food Consumption ◽  
Mating Success ◽  
Parental Species ◽  
Mating Behaviour ◽  
Survival Rates ◽  
Spawning Ground ◽  
Scardinius Erythrophthalmus ◽  
Experimental Fish ◽  
Spawning Behaviour ◽  
Dry Food

The egg-release, mating, courting and aggressive acts for the spawning behaviour as well as the survival rates after spawning at stages of eyed embryos, viable hatchlings, and larvae to dry food consumption for the mating success were studied in cultured silver bream Blicca bjoerkna × rudd Scardinius erythrophthalmus hybrids at their first sexual maturity. Experiments were conducted in experimental environments simulating natural reproductive conditions of the parental species. Spawning behaviour was analysed over 1 day from 8.00 to 18.00 hours using a remote-controlled video. Mating success was assessed from eggs and hatched embryos collected on the spawning ground. The results showed that these hybrids exhibited all the reproductive behaviours of the parental species with significantly more courtship than mating. Each egg-release act was accompanied by mating behaviour, involving all the experimental males. A surprising aggressive behaviour was observed in one male which attacked all other experimental fish. Successful mating resulted in the presence of fertilized eggs, the production of hatched embryos in experiments, and the survival of larvae at the dry food consumption stage. However, the low viable hatchling rate observed could indicate a very low chance of survival for these hybrids in rivers in which the occurrence of post-F1 individuals may be more possible by backcrossing.

Measurement of glucose in plasma by a differential pH technique.

1983 ◽  
Vol 29 (1) ◽  
pp. 80-85 ◽  
Author(s):  
M Luzzana ◽  
G Dossi ◽  
A Mosca ◽  
A Granelli ◽  
D Berger ◽  
...  
Keyword(s):  
Reference Method ◽  
Glass Capillary ◽  
Ph Measurements ◽  
Differential Measurement ◽  
Control Chemical ◽  
Microcomputer Control ◽  
Internal Volume ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Better Than

Abstract A new automatic apparatus based on the differential measurement of pH between two solutions has been developed. Two 25-microL (internal volume) glass capillary electrodes are used to measure the results of automated (under microcomputer control) chemical reactions that lead to the liberation or the uptake of hydrogen ions. The sensitivity of the differential pH measurements is better than +/- 0.0001 pH unit, and the change in H+ concentration that can be detected by such an apparatus is 1 mumol/L for plasma and 3 mumol/L for whole blood. The technique has been applied to the measurement of glucose in plasma, giving results in agreement with the specifications of the Food and Drug Administration reference method for quantitative determination of glucose (hexokinase/glucose-6-phosphate dehydrogenase method).

Comparative growth response in Carduus nutans, C. acanthoides, and their F1 hybrids

1990 ◽  
Vol 68 (8) ◽  
pp. 1675-1679 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
Growth Response ◽  
Parental Species ◽  
Diploid Species ◽  
Dry Weight ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Soil Conditions ◽  
Hybrid Superiority ◽  
Test Models ◽  
Better Than

The growth response of F1 hybrids relative to parental genotypes was compared in a natural hybridization system involving the diploid species Carduus acanthoides L. (2n = 22) and C. nutans L. (2n = 16). The data were used to test models of hybrid intermediacy, superiority, or greater similarity to a single parent in response to variable soil conditions and intra- and inter-genotypic competition. Progeny from paired reciprocal crosses between the two species were used in the experiments. In each of the half-sib families produced, the rapid and early identification of F1 hybrid genotypes and parental genotypes (resulting from selfing) was confirmed using allozyme markers (Pgi-2, Tpi-1, and Tpi-2). Growth of the F1 hybrids was better than C. nutans in poor soil, and both F1 hybrid and C. nutans genotypes produced significantly more dry weight than C. acanthoides in all soil treatments. F1 hybrids grew at least as well as the maternal parental species C. nutans and significantly better than C. acanthoides in the presence of intra- and inter-genotypic competitors. The F1 hybrid genotypes formed a more aggressive competitive environment than C. nutans, as evidenced by the growth of all three genotypes. These data primarily supported the model of greater hybrid similarity to one parental species rather than hybrid intermediacy, with evidence of hybrid superiority under certain extreme conditions.

Mosaicism in female hybrid hares heterozygous for glucose-6-phosphate dehydrogenase

1984 ◽  
Vol 41 (3) ◽  
pp. 354-362 ◽  
Author(s):  
K. Janakidevi ◽  
K.T. Lee ◽  
M. Kroms ◽  
H. Imai ◽  
W.A. Thomas
Keyword(s):  
Female Hybrid ◽  
Glucose 6 Phosphate Dehydrogenase
Sign in / Sign up

Export Citation Format

Share Document