scholarly journals Reciprocal differences in female recombination associated with hybrid dysgenesis in Drosophila Melanogaster

1977 ◽  
Vol 30 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Margaret Gale Kidwell
Keyword(s):  
Close Association ◽  
Hybrid Dysgenesis ◽  
F1 Hybrids ◽  
Crossing Over ◽  
Clear Trend ◽  
Female Progeny ◽  
Male Recombination ◽  
Reciprocal Differences ◽  
Component Traits ◽  
Chromosome Iii

SUMMARYLarge reciprocal differences in recombination frequencies were observed in F1 female progeny of a number of strain crosses. These reciprocal effects on recombination were found in several intervals of all three major chromosomes; they were greatest in intervals proximal to or spanning the centromere but were also found in some distal regions. The direction of recombination change was not consistent over different chromosomal intervals. There was no clear trend for reciprocal recombination differences to be associated with change of interference values between adjacent intervals. A close association was found between reciprocal female recombination effects, male recombination and other component traits of hybrid dysgenesis. However, reciprocal differences in female recombination were not restricted to dysgenic crosses. Backcross experiments demonstrated that reciprocal differences in the centromeric region of chromosome III were the result of increased crossing-over in dysgenic F1 hybrids rather than decreased crossing-over in the reciprocal hybrids. It is concluded that genotype-cytoplasm interaction can be a major factor influencing recombination frequencies and that the use of interstrain hybrids for recombination measurement may lead to errors in the estimation of intrastrain frequencies.

scholarly journals HYBRID DYSGENESIS IN DROSOPHILA MELANOGASTER: A SYNDROME OF ABERRANT TRAITS INCLUDING MUTATION, STERILITY AND MALE RECOMBINATION

Genetics ◽  
1977 ◽  
Vol 86 (4) ◽  
pp. 813-833 ◽  
Author(s):  
Margaret G Kidwell ◽  
James F Kidwell ◽  
John A Sved
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
The United States ◽  
Hybrid Dysgenesis ◽  
Transmission Ratio Distortion ◽  
F1 Hybrids ◽  
Male Recombination ◽  
Maternal Contribution ◽  
Ratio Distortion ◽  
P Type

ABSTRACT A syndrome of associated aberrant traits is described in Drosophila melanogaster. Six of these traits, mutation, sterility, male recombination, transmission ratio distortion, chromosomal aberrations and local increases in female recombination, have previously been reported. A seventh trait, nondisjunction, is described for the first time. All of the traits we have examined are found nonreciprocally in F1 hybrids. We present evidence that at least four of the traits are not found in nonhybrids. Therefore we have proposed the name hybrid dysgenesis to describe this syndrome.—A partition of tested strains into two types, designated P and M, was made according to the paternal or maternal contribution required to produce hybrid dysgenesis. This classification seems to hold for crosses of strains from within the United States and Australia, as well as for crosses between strains from the two countries. Strains collected recently from natural populations are typically of the P type and those having a long laboratory history are generally of the M type. However, a group of six strains collected from the wild in the 1960's are unambiguously divided equally between the P and M types. The dichotomy of this latter group raises interesting questions concerning possible implications for speciation.—Temperature often has a critical effect on the manifestation of hybrid dysgenesis. High F1 developmental temperatures tend to increase the expression of sterility, sometimes to extreme levels. Conversely, low developmental temperatures tend to inhibit the expression of some dysgenic traits.—There are potentially important practical implications of hybrid dysgenesis for laboratory experimentation. The results suggest that care should be exercised in planning experiments involving strain crosses.

scholarly journals Combining Ability and Heterosis for Grain Yield and its Component Traits in Rice(Oryza sativa L.)

2013 ◽  
Vol 5 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Srikrishna LATHA ◽  
Deepak SHARMA ◽  
Gulzar S. SANGHERA
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Analysis Of Variance ◽  
Combining Ability ◽  
Oryza Sativa L ◽  
F1 Hybrids ◽  
Component Traits ◽  
Standard Heterosis ◽  
High Degree ◽  
Yield Trials

The nature and magnitude of heterosis and combining ability was studied in 18 F1 hybrids involving three CMS lines and six testers using line × tester analysis. The analysis of variance for combining ability of all the traits showed that variances due to treatments, parents, hybrids were highly significant. The line ‘CRMS 32A’ and testers viz. ‘Super rice-8’, ‘R 1099-2569-1-1’ and ‘Jitpiti’ were identified as good general combiners. The significant differences between lines x testers interaction indicates that SCA attributed heavily in the expression of these traits and demonstrates the importance of dominance or non additive variances for all the traits. The hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’ and ‘APMS 6A’/‘Super rice-8’ were promising for grain yield. The magnitude of relative heterosis, heterobeltiosis and standard heterosis were also estimated for different characters. A high degree of relative heterosis was observed for grain yield (20.45- 82.37%) in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘APMS 6A’/‘Super rice-8’, ‘APMS 6A’/‘Jitpiti’ and ‘CRMS 32A’/‘R 1099-2569-1-1’. While, a higher degree of: heterobeltiosis (13.60 -68.37%) was observed for grain yield in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘CRMS 32A’/‘R 1099-2569-1-1’, ‘APMS 6A’/’Super rice-8’ and ‘APMS 6A’/’Jitpiti’. A high degree of standard heterosis was observed for grain yield in the hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’. The hybrid ‘CRMS 32A’/ ‘R 1099-2569-1-1’ recorded a high degree of relative heterosis (62.01%), heterobeltiosis (57.35%) and standard heterosis (15.05 and 25.51% over check hybrids, ‘Mahamaya’ and ‘Indirasona’, respectively) that can be tested on yield trials for its further testing over locations.

scholarly journals Does RNA interference influence meiotic crossing over in Drosophila melanogaster?

2008 ◽  
Vol 90 (3) ◽  
pp. 253-258 ◽  
Author(s):  
ERIC W. CROSS ◽  
MICHAEL J. SIMMONS
Keyword(s):  
Drosophila Melanogaster ◽  
Rna Interference ◽  
X Chromosome ◽  
Maternal Effect ◽  
Crossing Over ◽  
Crossover Frequency ◽  
Chromosome Iii ◽  
Chromosome Ii ◽  
Balancer Chromosomes ◽  
Balancer Chromosome

SummaryMutations in the RNA interference (RNAi) genes aubergine (aub), homeless and piwi were tested for effects on the frequency, distribution and coincidence of meiotic crossovers in the long arm of the X chromosome. Some increases in crossover frequency were seen in these tests, but they may have been due to a maternal effect of the balancer chromosomes that were used to maintain the RNAi mutations in stocks rather than to the RNAi mutations themselves. These same balancers produced strong zygotic interchromosomal effects when tested separately. Mutations in aub and piwi did not affect the frequency of crossing over in the centric heterochromatin of chromosome II; nor did a balancer chromosome III.

MEIOTIC NONDISJUNCTION AND ANEUPLOIDS IN INTERSYNGENIC HYBRIDS OF PARAMECIUM CAUDATUM

Genetics ◽  
1985 ◽  
Vol 111 (4) ◽  
pp. 779-794
Author(s):  
Yuuji Tsukii ◽  
Koichi Hiwatashi
Keyword(s):  
Mating Type ◽  
Genetic Study ◽  
F1 Hybrids ◽  
Crossing Over ◽  
Paramecium Caudatum ◽  
Meiotic Process ◽  
Unequal Crossing Over ◽  
Meiotic Nondisjunction ◽  
Fertile Hybrids

ABSTRACT Artificially induced intersyngenic crosses in Paramecium caudatum can produce viable and fertile hybrids. When F1 hybrids of double E mating type (Mt  1/Mt  3 or Mt  12/Mt  3) were crossed with mating type O (mt/mt), aberrant segregants of double E and single O type were produced. This segregation was not explained by ordinary equal or unequal crossing over. Breeding analyses of these segregants by using linkage between Mt and cnrA (a behavioral mutant) revealed that they were produced by meiotic nondisjunction of bivalent chromosomes carrying Mt genes, and thus the double E and single O segregants were aneuploids: trisomics (Mt  1/Mt  3/mt or Mt  12/Mt  3/mt) and monosomics (mt), respectively. An aberrant segregant was also obtained for another locus, tnd 2, independent of both Mt and cnrA, suggesting the occurrence of meiotic nondisjunction throughout hybrid genomes. These aneuploids will be useful for genetic study in this species. The occurrence of meiotic nondisjunction in the intersyngenic hybrids also suggests that syngens of P. caudatum have been reproductively isolated for long enough to develop chromosomal incompatibility in their meiotic process.

scholarly journals Characterization of natural populations of Drosophila melanogaster with regard to the hobo system: a new hypothesis on the invasion

1997 ◽  
Vol 69 (3) ◽  
pp. 197-208 ◽  
Author(s):  
ERIC BONNIVARD ◽  
DOMINIQUE HIGUET ◽  
CLAUDE BAZIN
Keyword(s):  
Drosophila Melanogaster ◽  
Reference Strain ◽  
Natural Populations ◽  
Hybrid Dysgenesis ◽  
Molecular Characteristics ◽  
Male Recombination ◽  
System A ◽  
Genetic Level ◽  
New Hypothesis

Until now, with regard to the hobo system of hybrid dysgenesis, natural populations of Drosophila melanogaster have been investigated using only two criteria: at the molecular level, the presence or absence of XhoI fragments 2·6 kb long or smaller; and/or at the genetic level, the ability to induce gonadal dysgenesis sterility in crosses A (females of an E reference strain crossed with males under test) and A* (females under test crossed with males of an H reference strain). Recently, analyses of laboratory strains using these criteria as well as the mobilization of two reporter genes, the male recombination and the number of ‘TPE’ repeats in the S region, revealed a lack of correlation between the different dysgenic parameters themselves, and also between these parameters and the molecular characteristics of the strains. Thirteen current strains derived from world populations were therefore investigated with regard to all these dysgenic traits, to determine discriminating criteria providing a robust method of classifying natural populations and deducing the dynamics of hobo elements in these populations. We show, as in laboratory strains, a lack of correlation between the parameters studied. Therefore, the significance of each of them as well as the nature of hobo hybrid dysgenesis are discussed, to propose an analysis method of the hobo system applicable to natural populations. According to the geographical distribution of hobo activities in world populations and to the variable polymorphism of the number of ‘TPE’ repeats, we propose a new scenario for the invasion of D. melanogaster by hobo elements.

scholarly journals SELECTION FOR A THRESHOLD CHARACTER IN DROSOPHILA IV. CHROMOSOMAL ANALYSES OF PLATEAUED POPULATIONS

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 497-512
Author(s):  
B D H Latter
Keyword(s):  
Genetic Basis ◽  
Major Gene ◽  
Positive Interactions ◽  
Chromosome Substitution ◽  
Bristle Number ◽  
Component Traits ◽  
The Mean ◽  
Selection For ◽  
Chromosome Iii ◽  
Chromosomal Recombination

ABSTRACT Chromosome substitution and intra-chromosomal recombination techniques have been employed to determine the genetic basis of limits to selection in lines selected for high scutellar bristle number from the Canberra population. Three observations indicate the presence of an upper threshold affecting some component traits, which is not readily discernible at the level of the selected phenotype: (1) The variance of the number of anterior + interstitial + posterior bristles is progressively reduced as the mean approaches a total of eight at these sites. Total bristle number, which includes apicals in addition to the above three components, and which was the trait subject to selection, shows little evidence of this phenomenon; (2) the effect of a given chromosome substitution is also greatly reduced as the mean approaches eight anterior + interstitial + posterior bristles, by comparison with its effect in genotypes of lower mean; (3) chromosome substitutions show some evidence of negative interaction as this level is approached, in contrast to the positive interactions evident at higher means. All chromosomes except IV are involved in progress beyond the proposed upper threshold. However, chromosome III has the most important effect, due primarily to a major gene located at approximately 61 cM, which also markedly increases dorsocentral and postvertical bristle numbers.

scholarly journals COMPONENTS OF HYBRID DYSGENESIS IN A WILD POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1980 ◽  
Vol 95 (1) ◽  
pp. 111-128
Author(s):  
William R Engels ◽  
Christine R Preston
Keyword(s):  
Large Scale ◽  
Germ Line ◽  
Wild Population ◽  
Hybrid Dysgenesis ◽  
Strongly Correlated ◽  
Low Frequencies ◽  
Male Recombination ◽  
In The Wild ◽  
Wild Strains ◽  
P Factor

ABSTRACT Hybrid dysgenesis is a condition foand in certain interstrain hybrids of Drosophila melanogrrster caused by the interaction of chromosomal and cytoplasmic factors. Germ line abnormalities, including sterility, high mutability and male recombination, appear in the affected individuals. There are at least two distinct systems of hybrid dysgenesis. We examined a Wisconsin wild populetion in two consecutive years to determine the distribution of the chromosomal P factor and the extrachromosomal M cytotype that together cause one kind of hybrid dysgonic sterility. The P factor was found to be very common in the populetion, with all three major chromosomes heing polymorphic for it. This polymorphism was strongly correlated with variability for male recombination elements, suggesting that these two traits are part of the same system of hybrid dysgenesis. There was a slight tendency for the P factor to be lost in lines taken from this population and inbred in the laboratory for many generations. A large-scale search for the M cytotype, which causes susceptibility to the P factor, showed that it is present in the papulation at only very low frequencies. Further evidence that the population is mostly immune to the action of the P factor was our finding of a general lack of dysgenic sterility in the wild flies themselves. However, we were able to isolate several wild strains that consistently showed the M cytotype. In some cases, the frequency of the M cytotype could be maintained in these lines, but it could not usually be increased by artificial sclection. Some possible consequences of hybrid dysgenesis for the evolutional y Siology of Drosophila are suggested.

scholarly journals Germ line aberrations associated with a case of hybrid dysgenesis in Drosophila melanogaster males

1979 ◽  
Vol 33 (2) ◽  
pp. 137-146 ◽  
Author(s):  
William R. Engels
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Ratio ◽  
Germ Line ◽  
Hybrid Dysgenesis ◽  
Transmission Ratio Distortion ◽  
Female Sterility ◽  
Male Recombination ◽  
Ratio Distortion ◽  
Temperature Optima ◽  
Sex Ratio Distortion

SUMMARYMale sterility, male recombination, and transmission ratio distortion – all examples of a syndrome known as hybrid dysgenesis in Drosophila melanogaster – were found to involve chromosome–cytoplasm interactions. The latter two have temperature optima near 25° and involve pre-meiotic events. In addition, sex ratio distortion, and induction of certain translocations of the X and Y chromosomes (but not the autosomes) were found to be part of hybrid dysgenesis. Both are caused by chromosome–cytoplasm interactions with pre-meiotic events playing a crucial role. The results agree with previous data on female sterility in hybrid dysgenesis, which also has cytoplasmic components and premeiotic origins.

scholarly journals ELEMENTS CAUSING MALE CROSSING OVER IN DROSOPHILA MELANOGASTER

Genetics ◽  
1975 ◽  
Vol 81 (2) ◽  
pp. 313-324
Author(s):  
Barton E Slatko ◽  
Yuichiro Hiraizumi
Keyword(s):  
Drosophila Melanogaster ◽  
Major Element ◽  
Large Majority ◽  
Crossing Over ◽  
Male Recombination ◽  
Genetic Elements

ABSTRACT A second chromosome line of Drosophila melanogaster (Symbol: T-007) has previously been shown to be responsible for the induction of male recombination. In the present investigation, the genetic elements responsible for this phenomenon have been partially identified and mapped. A major element (Symbol: Mr, for M ale recombination) locates on the second chromosome between the pr (2L-54.4) and c (2R-75.5) loci and is responsible for the large majority of male recombination. In addition, there appear to be "secondary elements" present which have the ability to induce male recombination in much reduced frequencies and which are diluted out through successive backcross generations when Mr is removed by recombination. The possible nature of these "secondary elements" is discussed.

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