scholarly journals Male recombination in Brazilian populations of Drosophila ananassae

Genome ◽  
2016 ◽  
Vol 59 (7) ◽  
pp. 493-500 ◽  
Author(s):  
Beatriz Goñi ◽  
Muneo Matsuda ◽  
Yoshiko N. Tobari
Keyword(s):  
Genetic Control ◽  
Genetic Factors ◽  
Regional Distribution ◽  
High Variability ◽  
Drosophila Ananassae ◽  
Crossing Over ◽  
Male Recombination ◽  
Spontaneous Recombination ◽  
Recombination Value ◽  
Brazilian Populations

With few exceptions, spontaneous crossing over does not normally occur in male Drosophila. Drosophila ananassae males show considerable amounts of crossing over. In wild males of D. ananassae from Asian (2008) and Brazilian populations (1986 and 2007) variable frequencies of meiotic crossing over, estimated from chiasmata counts, suggested the existence of factors controlling male crossing over in these populations. To corroborate for such prediction, we present data on spontaneous recombination in F1 males of D. ananassae heterozygous for chromosomes of the same Brazilian populations (1986) and marker chromosomes using three testers stocks. Mean recombination value was low, although high variability existed between individual frequencies. Recombination frequencies between lines in each tester stock were not significantly different, excepting when the 3ple-px and 3ple-cy testers were compared (p < 0.05). These two testers differ in respect to the regional distribution of crossovers. The occurrence of recombination in chromosomes 2 and 3 in F1 males tested with e65 se; bri ru was not related, suggesting they are under independent genetic control. Our data are consistent with proposed genetic factors controlling male crossing over in the tester stocks and to the presence of enhancers and suppressors of male crossing over segregating in the Brazilian populations (1986).

RELATIONS BETWEEN FACTORS CONTROLLING CROSSING OVER AND MUTABILITY IN MALES OF DROSOPHILA ANANASSAE

Genetics ◽  
1983 ◽  
Vol 104 (1) ◽  
pp. 95-112
Author(s):  
Claude W Hinton
Keyword(s):  
Regional Distribution ◽  
The Other ◽  
Drosophila Ananassae ◽  
Crossing Over ◽  
The Third

ABSTRACT Several stocks, selected because they carried previously identified factors governing either crossing over in males or mutability, were examined to determine whether the effects of these factors are restricted to one or the other process. Neither of two dominant enhancers of male crossing over had detectable effects on Minute mutation frequencies among progenies of assayed F1 males. Genetically equivalent F1 males monitored for crossing over showed no unequivocal effect of either of three mutators (two dominant and one extrachromosomal) or of a suppressor of mutability. However, one combination of a dominant crossover enhancer with a dominant mutator showed synergistic increases in both crossover and Minute frequencies, and the possibility exists that a single extrachromosomally transmitted element suppresses both male crossing over and mutability. This suppressor element (or elements) had been previously diagnosed in the pc stock which, in this study, was discovered to have also a dominant enhancer of male crossing over and a dominant mutator occupying separable loci in the third chromosome. The pc enhancer of male crossing over differs from the dominant enhancer in another stock with respect to the regional distribution of crossovers, and the pc mutator is distinguished from another 3-linked mutator by its preferential induction of mutations at the Delta locus.

Crossing over does occur in males of Drosophila ananassae from natural populations

Genome ◽  
2012 ◽  
Vol 55 (7) ◽  
pp. 505-511 ◽  
Author(s):  
Beatriz Goñi ◽  
Muneo Matsuda ◽  
Masa-Toshi Yamamoto ◽  
Carlos R. Vilela ◽  
Yoshiko N. Tobari
Keyword(s):  
Natural Populations ◽  
Drosophila Ananassae ◽  
Crossing Over ◽  
Cytological Analysis ◽  
Wild Type ◽  
Cytological Evidence ◽  
Type Strains ◽  
Chromosome Breakages ◽  
Brazilian Populations

Spontaneous crossing over in males of Drosophila ananassae has been well demonstrated using F1 individuals from crosses between marker stocks and wild type strains. However, the question of its occurrence in males from natural populations remained open. Here we present the cytological evidence that crossing over does occur in males of D. ananassae from two Brazilian populations, sampled nearly 21 years apart, and in two recently sampled populations, one from Indonesia and one from Okinawa, Japan. Cytological analysis of meiosis in males collected from nature and in sons of females from the same population inseminated in nature revealed the presence of chiasmata, inversion chiasmata, and isosite chromosome breakages in the diplotene cells in all sampled populations. These data demonstrate that reciprocal and nonreciprocal exchanges and chromosome breakages, previously reported as related events of male crossing over, do occur at variable frequencies among males from natural populations.

Chiasmata and chromosome breakages are related to crossing over in Drosophila ananassae males

Genome ◽  
2006 ◽  
Vol 49 (11) ◽  
pp. 1374-1383 ◽  
Author(s):  
Beatriz Goñi ◽  
Muneo Matsuda ◽  
Yoshiko N. Tobari
Keyword(s):  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Genetic Factors ◽  
Genetic Recombination ◽  
Paracentric Inversion ◽  
Drosophila Ananassae ◽  
Crossing Over ◽  
Low Frequencies ◽  
Genetic Crossing ◽  
Chromosome Breakages

A cytogenetic analysis of male crossing over in Drosophila ananassae revealed that cytological exchanges resulted in genetic crossing over, and that chiasma frequency and the genetic recombination correlated positively in chromosomes 2 and 3. Furthermore, the frequency of chromosome breakages correlated positively with chiasma frequency. Paracentric inversion heterozygosity had no detectable influence on the chromosome pairing or exchange events within the inversion loop at meiosis. Scoring of the chiasma demonstrated that males homozygous for the previously mapped enhancers of male crossing over had low frequencies of chiasmata, whereas higher frequencies of chiasmata were observed in males heterozygous for enhancers. The results presented here indicate that the genetic factors controlling male crossing over are involved in the origin of chromosome breakages and in exchange events.

Genetic and environmental influences on psychological distress in the population: General Health Questionnaire analyses in UK twins

2003 ◽  
Vol 33 (5) ◽  
pp. 793-801 ◽  
Author(s):  
F. V. RIJSDIJK ◽  
H. SNIEDER ◽  
J. ORMEL ◽  
P. SHAM ◽  
D. P. GOLDBERG ◽  
...  
Keyword(s):  
Genetic Control ◽  
General Health ◽  
Genetic Factors ◽  
General Health Questionnaire ◽  
Model Fitting ◽  
Regression Method ◽  
Health Questionnaire ◽  
Twin Data ◽  
Score Distribution ◽  
Shared Genetic

Background. The General Health Questionnaire (GHQ) is the most popular screening instrument for detecting psychiatric disorders in community samples. Using longitudinal data of a large sample of UK twin pairs, we explored (i) heritabilities of the four scales and the total score; (ii) the genetic stability over time; and (iii) the existence of differential heritable influences at the high (ill) and low (healthy) tail of the distribution.Method. At baseline we assessed the GHQ in 627 MZ and 1323 DZ female pairs and at a second occasion (3·5 years later) for a small subsample (90 MZ and 270 DZ pairs). Liability threshold models and raw ordinal maximum likelihood were used to estimate twin correlations and to fit longitudinal genetic models. We estimated extreme group heritabilities of the GHQ distribution by using a model-fitting implementation of the DeFries–Fulker regression method for selected twin data.Results. Heritabilities for Somatic Symptoms, Anxiety, Social Dysfunction, Depression and total score were 0·37, 0·40, 0·20, 0·42 and 0·44, respectively. The contribution of shared genetic factors to the correlations between time points is substantial for the total score (73%). Group heritabilities of 0·48 and 0·43 were estimated for the top and bottom 10% of the total GHQ score distribution, respectively.Conclusion. The overall heritability of the GHQ as a measure of psychosocial distress was substantial (44%), with all scales having significant additive genetic influences that persisted across time periods. Extreme group analyses suggest that the genetic control of resilience is as important as the genetic control of vulnerability.

scholarly journals Synaptonemal Complex and Male Crossing-over in Drosophila ananassae

CYTOLOGIA ◽  
1974 ◽  
Vol 39 (4) ◽  
pp. 829-838 ◽  
Author(s):  
Daigoro Moriwaki ◽  
Mitsuo Tsujita
Keyword(s):  
Synaptonemal Complex ◽  
Drosophila Ananassae ◽  
Crossing Over

The genetics of the mimetic butterfly Papilio memnon L

1968 ◽  
Vol 254 (791) ◽  
pp. 37-89 ◽  
Keyword(s):  
Genetic Control ◽  
Crossing Over ◽  
Supporting Evidence ◽  
South East Asia ◽  
Dominance Relationships ◽  
Sympatric Forms ◽  
Occasional Occurrence ◽  
Wing Patterns ◽  
Industrial Melanism ◽  
Complex Locus

Papilio memnon is a swallowtail butterfly widely distributed in south-east Asia. The females are highly polymorphic and many of them are mimetic. The mode of inheritance of seventeen of the female forms is reported. In contradistinction to earlier work it has been shown that they are controlled by what appears to be a series of at least eleven autosomal alleles at one locus, sexcontrolled to the female in effect. There is evidence, however, that the locus is complex, comprising at least three closely linked loci with occasional occurrence of crossing over between them. Two characters which are not polymorphic and one which may be polymorphic are controlled by genes unlinked to the complex locus (the super-gene). In general, dominance is complete between sympatric forms but absent when they are allopatric. The resemblance between the mimetic forms of P. memnon and their models is greater in the genecomplex of a race in which the allelomorph occurs than in hybrids with a race in which it does not. Thus in no case is the resemblance better in the race cross, in ten cases there is no change and in thirty-five the mimicry is less good. The genetic control of the polymorphism in P. memnon shows remarkable parallels with that in P. dardanus and provides further supporting evidence for Fisher’s and Ford’s view that mimicry evolved gradually by adjustment of the gene-complex as a result of natural selection favouring those wing patterns which most closely resembled the models. Furthermore, as in P. dardanus, the mimicry is controlled by what appears to be a super-gene, adding weight to the conclusion that the genetic control of the polymorphic Batesian mimicry has evolved gradually by the accumulation of closely linked allelomorphs in advantageous combinations. This contrasts with the genetic control of Mullerian mimicry as evidenced in the Heliconids. In P. memnon the dominance relationships of the monomorphic tailed and tailless condition (excluding the form achates ) indicate that dominance can be evolved even when the characters concerned are not polymorphic. In addition, the lower frequency of dominance between allopatric forms than between sympatric ones is strongly in favour of the view that dominance has evolved. Similar evidence has been found from breeding work in the Heliconids and in P. dardanus ; however, the phenomenon is not confined to mimetic situations since there is also evidence for the evolution of dominance in other polymorphisms including industrial melanism.

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