Chromosomal polymorphism in Drosophila willistoni populations from Uruguay

Valente, Vera Lúcia da Silva; Goñi, Beatriz; Valiati, Victor Hugo; Rohde, Cláudia; Morales, N.B

doi:10.1590/s1415-47572003000200009

Cited by 14 publications

(20 citation statements)

References 29 publications

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“…The presence of these species in urban areas was previously related by Valente et al (1993), by Valiati & Valente (1996), and recently by Silva et al (2005a,b), who sampled it at high abundance in Porto Alegre, southernmost Brazil. Moreover, due to the high abundance of the exotic species in the city, the expressiveness of willistoni subgroup is low in areas of medium and high urbanisation.…”

Section: Discussionsupporting

confidence: 58%

Changes in Brazilian Drosophilidae (Diptera) assemblages across an urbanisation gradient

Gottschalk¹,

Toni²,

Valente³

et al. 2007

Neotrop. entomol.

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Section: Discussionsupporting

confidence: 58%

Changes in Brazilian Drosophilidae (Diptera) assemblages across an urbanisation gradient

Gottschalk¹,

Toni²,

Valente³

et al. 2007

Neotrop. entomol.

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“…This may result from differences in polymorphism levels within species of these subgenera (Sperlich and Pfriem 1986). Members of the obscura and willistoni groups are quite polymorphic for paracentric inversions (Da Cunha et al 1950;Da Cunha and Dobzhansky 1954;Dobzhansky and Sturtevant 1938;Valente and Morales 1985;Krimbas 1992;Valente et al 1993). Thus, the fixed rearrangement differences may result from higher levels of rearrangement polymorphism within these lineages.…”

Section: Discussionmentioning

confidence: 99%

“…species of the subgenus Sophophora, is very close to the split (62.9 MYA) between the two subgenera (Sophophora and Drosophila) of the genus Drosophila . D. willistoni is known to have extensive gene arrangement polymorphism on all chromosomes (Da Cunha et al 1950, 1959Da Cunha and Dobzhansky 1954;Araujo 1985, 1986;Valente et al 1993Valente et al , 2001Valente et al , 2003Rohde 2000;Rohde et al 2005) as observed from chromosomal variability in natural populations.…”

Section: Discussionmentioning

confidence: 99%

Chromosomal Rearrangement Inferred From Comparisons of 12 Drosophila Genomes

et al. 2008

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The availability of 12 complete genomes of various species of genus Drosophila provides a unique opportunity to analyze genome-scale chromosomal rearrangements among a group of closely related species. This article reports on the comparison of gene order between these 12 species and on the fixed rearrangement events that disrupt gene order. Three major themes are addressed: the conservation of syntenic blocks across species, the disruption of syntenic blocks (via chromosomal inversion events) and its relationship to the phylogenetic distribution of these species, and the rate of rearrangement events over evolutionary time. Comparison of syntenic blocks across this large genomic data set confirms that genetic elements are largely (95%) localized to the same Muller element across genus Drosophila species and paracentric inversions serve as the dominant mechanism for shuffling the order of genes along a chromosome. Gene-order scrambling between species is in accordance with the estimated evolutionary distances between them and we find it to approximate a linear process over time (linear to exponential with alternate divergence time estimates). We find the distribution of synteny segment sizes to be biased by a large number of small segments with comparatively fewer large segments. Our results provide estimated chromosomal evolution rates across this set of species on the basis of whole-genome synteny analysis, which are found to be higher than those previously reported. Identification of conserved syntenic blocks across these genomes suggests a large number of conserved blocks with varying levels of embryonic expression correlation in Drosophila melanogaster. On the other hand, an analysis of the disruption of syntenic blocks between species allowed the identification of fixed inversion breakpoints and estimates of breakpoint reuse and lineage-specific breakpoint event segregation. D ROSOPHILA research has a rich history in the study of genome rearrangements that now culminates with the analysis of complete genomic sequences. Comparative genomics in Drosophila began when linkage maps of morphological traits were used to establish the homologies of six chromosomal arms in closely related species (Donald 1936;Sturtevant and Tan 1937;Muller 1940;Sturtevant and Novitski 1941). These early studies established the idea that genes are syntenic or conserved on the same chromosome arm among species. One difficulty encountered with these early comparative genomic analyses was that chromosomal arm nomenclatures varied among species (Crew and Lamy 1935;Sturtevant and Tan 1937). Muller (1940) overcame this problem when he developed a standard nomenclature that assigned a letter to each of the chromosomal arms or elements on the basis of the Drosophila melanogaster genome (chromosomal arm equals Muller element: X ¼ A, 2L ¼ B, 2R ¼ C, 3L ¼ D, 3R ¼ E, 4 ¼ F). Sturtevant and Novitski (1941) showed that the conservation of chromosomal elements extended to species across the entire genus of Drosophila.The conservation of the ...

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“…These genetic maps provide some useful markers for orienting the sequence scaffolds from D. willistoni, but these data must be viewed with caution because it is not always obvious if the new photographic maps developed for this project are homosequential with the Dobzhansky (1950) maps. D. willistoni has extensive gene arrangement polymorphism on all chromosomes, which has been described from chromosomal variability in natural populations (da Cunha et al 1950(da Cunha et al , 1959da Cunha and Dobzhansky 1954;Araujo 1985, 1986;Valente et al 1993Valente et al , 2001Valente et al , 2003Rohde 2000;Rohde et al 2005). Regner et al (1996) developed the first photographic maps for D. willistoni using the Dobzhansky (1950) drawings to demarcate the major chromosomal sections.…”

Section: Willistoni Mapsmentioning

confidence: 99%

Polytene Chromosomal Maps of 11 Drosophila Species: The Order of Genomic Scaffolds Inferred From Genetic and Physical Maps

et al. 2008

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The sequencing of the 12 genomes of members of the genus Drosophila was taken as an opportunity to reevaluate the genetic and physical maps for 11 of the species, in part to aid in the mapping of assembled scaffolds. Here, we present an overview of the importance of cytogenetic maps to Drosophila biology and to the concepts of chromosomal evolution. Physical and genetic markers were used to anchor the genome assembly scaffolds to the polytene chromosomal maps for each species. In addition, a computational approach was used to anchor smaller scaffolds on the basis of the analysis of syntenic blocks. We present the chromosomal map data from each of the 11 sequenced non-Drosophila melanogaster species as a series of sections. Each section reviews the history of the polytene chromosome maps for each species, presents the new polytene chromosome maps, and anchors the genomic scaffolds to the cytological maps using genetic and physical markers. The mapping data agree with Muller's idea that the majority of Drosophila genes are syntenic. Despite the conservation of genes within homologous chromosome arms across species, the karyotypes of these species have changed through the fusion of chromosomal arms followed by subsequent rearrangement events. O NE of the primary strengths of the genus Drosophila as a model system has been the relative ease of generating detailed cytogenetic maps. Indeed, the first definitive mapping of genes to chromosomes Genetics 179: 1601-1655 ( July 2008) was performed in Drosophila melanogaster (Bridges 1916). The subsequent discovery of polytene chromosomes in the salivary glands in this same species (Painter 1934) and their codification into fine-structure genetic/ cytogenetic maps represents perhaps one of the first forays into ''genomics.'' Polytene maps (Bridges 1935;Lefevre 1976) provided an important genetic tool for mapping genes, for detecting genetic diversity within populations, and for inferring phylogenies among related species (Dobzhansky and Sturtevant 1938;Judd et al. 1972;Ashburner and Lemeunier 1976;Lemeunier and Ashburner 1976). Sturtevant and Tan (1937) laid the groundwork for comparative genomics when they established that genes within the chromosomal arms are conserved or syntenic among species. In an insightful melding of the gene mapping and evolutionary studies, H. J. Muller (1940) proposed that the genomes of Drosophila species were subdivided into a set of homologous elements represented by chromosome arms. What Muller (1940) noted, which was subsequently elaborated on by Sturtevant and Novitski (1941), was that the presumed homologs of identified mutant alleles within a chromosome arm of D. melanogaster were also confined to a single arm in other species within the genus where mapping data were available. Using D. melanogaster as a reference, Muller proposed that each of the five major chromosome arms plus the dot chromosome be given a letter designation (A-F) and that this nomenclature be used to identify equivalent linkage groups within the genus.The an...

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Chromosomal polymorphism in Drosophila willistoni populations from Uruguay

Cited by 14 publications

References 29 publications

Changes in Brazilian Drosophilidae (Diptera) assemblages across an urbanisation gradient

Changes in Brazilian Drosophilidae (Diptera) assemblages across an urbanisation gradient

Chromosomal Rearrangement Inferred From Comparisons of 12 Drosophila Genomes

Polytene Chromosomal Maps of 11 Drosophila Species: The Order of Genomic Scaffolds Inferred From Genetic and Physical Maps

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