Drosophila ananassae: a species characterized by spontaneous male recombination in appreciable frequency

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).

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Effect of Selection on Crossing over in the Males of Drosophila ananassae

The American Naturalist ◽

10.1086/282157 ◽

1961 ◽

Vol 95 (880) ◽

pp. 57-59 ◽

Cited By ~ 16

Author(s):

A. S. Mukherjee

Keyword(s):

Drosophila Ananassae ◽

Crossing Over

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Comparison of long-read sequencing technologies in interrogating bacteria and fly genomes

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab083 ◽

2021 ◽

Author(s):

Eric S Tvedte ◽

Mark Gasser ◽

Benjamin C Sparklin ◽

Jane Michalski ◽

Carl E Hjelmen ◽

...

Keyword(s):

Bacterial Genome ◽

Hybrid Approach ◽

Cost Effective ◽

Fruit Fly ◽

Drosophila Ananassae ◽

Whole Genome Sequencing Data ◽

Sequencing Data ◽

E Coli ◽

Hybrid Approaches ◽

Long Read

Abstract The newest generation of DNA sequencing technology is highlighted by the ability to generate sequence reads hundreds of kilobases in length. Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) have pioneered competitive long read platforms, with more recent work focused on improving sequencing throughput and per-base accuracy. We used whole-genome sequencing data produced by three PacBio protocols (Sequel II CLR, Sequel II HiFi, RS II) and two ONT protocols (Rapid Sequencing and Ligation Sequencing) to compare assemblies of the bacteria Escherichia coli and the fruit fly Drosophila ananassae. In both organisms tested, Sequel II assemblies had the highest consensus accuracy, even after accounting for differences in sequencing throughput. ONT and PacBio CLR had the longest reads sequenced compared to PacBio RS II and HiFi, and genome contiguity was highest when assembling these datasets. ONT Rapid Sequencing libraries had the fewest chimeric reads in addition to superior quantification of E. coli plasmids versus ligation-based libraries. The quality of assemblies can be enhanced by adopting hybrid approaches using Illumina libraries for bacterial genome assembly or polishing eukaryotic genome assemblies, and an ONT-Illumina hybrid approach would be more cost-effective for many users. Genome-wide DNA methylation could be detected using both technologies, however ONT libraries enabled the identification of a broader range of known E. coli methyltransferase recognition motifs in addition to undocumented D. ananassae motifs. The ideal choice of long read technology may depend on several factors including the question or hypothesis under examination. No single technology outperformed others in all metrics examined.

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GENETIC LINKAGE IN THE HORSE. II. DISTRIBUTION OF MALE RECOMBINATION ESTIMATES AND THE INFLUENCE OF AGE, BREED AND SEX ON RECOMBINATION FREQUENCY

Genetics ◽

10.1093/genetics/106.1.109 ◽

1984 ◽

Vol 106 (1) ◽

pp. 109-122

Author(s):

Leif Andersson ◽

Kaj Sandberg

Keyword(s):

Genetic Linkage ◽

Recombination Frequency ◽

Age Effect ◽

Significant Heterogeneity ◽

Male Recombination ◽

Male And Female ◽

Factors Affecting ◽

Individual Male ◽

Breed Differences ◽

Age And Sex

ABSTRACT n the present study an extensive amount of data, comprising more than 30,000 offspring in total, was analyzed to evaluate the influence of age and sex on the recombination frequency in the K-PGD segment of the equine linkage group (LG) I and the influence of age, breed and sex on recombination in the Al-Es segment of LG II. A highly significant sex difference is reported for both segments. Male and female recombination values in the K-PGD segment were estimated at 25.8 ± 0.8 and 33.3 ± 2.5%, respectively. Similarly, recombination was less frequent in the male (36.6 ± 0.7%) than in the female (46.6 ± 1.2%) in the Al-Es segment. Comparison of data from two Swedish horse breeds revealed no significant breed differences in either sex for recombination in the Al-Es segment. No evidence of an age effect was found in any segment or sex. The distribution of individual male recombination estimates was also investigated, and a significant heterogeneity among stallions was revealed in the K-PGD segment. The results are discussed in relation to previous studies on factors affecting recombination in mammals.

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Population Subdivision and Molecular Sequence Variation: Theory and Analysis of Drosophila ananassae Data

Genetics ◽

10.1093/genetics/165.3.1385 ◽

2003 ◽

Vol 165 (3) ◽

pp. 1385-1395

Author(s):

Claus Vogl ◽

Aparup Das ◽

Mark Beaumont ◽

Sujata Mohanty ◽

Wolfgang Stephan

Keyword(s):

Sequence Data ◽

Isolation By Distance ◽

Allele Frequencies ◽

Drosophila Ananassae ◽

Population Subdivision ◽

Variation Theory ◽

Peripheral Populations ◽

Molecular Variation ◽

Data Set ◽

Evolutionary Forces

Abstract Population subdivision complicates analysis of molecular variation. Even if neutrality is assumed, three evolutionary forces need to be considered: migration, mutation, and drift. Simplification can be achieved by assuming that the process of migration among and drift within subpopulations is occurring fast compared to mutation and drift in the entire population. This allows a two-step approach in the analysis: (i) analysis of population subdivision and (ii) analysis of molecular variation in the migrant pool. We model population subdivision using an infinite island model, where we allow the migration/drift parameter 0398; to vary among populations. Thus, central and peripheral populations can be differentiated. For inference of 0398;, we use a coalescence approach, implemented via a Markov chain Monte Carlo (MCMC) integration method that allows estimation of allele frequencies in the migrant pool. The second step of this approach (analysis of molecular variation in the migrant pool) uses the estimated allele frequencies in the migrant pool for the study of molecular variation. We apply this method to a Drosophila ananassae sequence data set. We find little indication of isolation by distance, but large differences in the migration parameter among populations. The population as a whole seems to be expanding. A population from Bogor (Java, Indonesia) shows the highest variation and seems closest to the species center.

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