Molecular and cytogenic analysis of pericentromeric heterochromatin in ovarian nurse cells of Drosophila melanogaster subgroup species

2009 ◽  
Vol 3 (1) ◽  
pp. 50-55 ◽  
Author(s):  
K. E. Usov ◽  
T. A. Shelkovnikova ◽  
I. E. Wasserlauf ◽  
V. N. Stegniy
Keyword(s):  
Drosophila Melanogaster ◽  
Pericentromeric Heterochromatin ◽  
Nurse Cells ◽  
Drosophila Melanogaster Subgroup

Rates and patterns of scnDNA and mtDNA divergence within the Drosophila melanogaster subgroup.

Genetics ◽  
1988 ◽  
Vol 118 (4) ◽  
pp. 671-683
Author(s):  
A Caccone ◽  
G D Amato ◽  
J R Powell
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Hybridization ◽  
Nuclear Dna ◽  
Single Copy ◽  
Rate Of Change ◽  
Drosophila Genome ◽  
Island Species ◽  
Drosophila Melanogaster Subgroup ◽  
Chromosomal Data ◽  
Group 2

Abstract Levels of DNA divergence among the eight species of the Drosophila melanogaster subgroup and D. takahashii have been determined using the technique of DNA-DNA hybridization. Two types of DNA were used: single-copy nuclear DNA (scnDNA) and mitochondrial DNA (mtDNA). The major findings are: (1) A phylogeny has been derived for the group based on scnDNA which is congruent with chromosomal data, morphology, and behavior. The three homosequential species, simulans, sechellia, and mauritiana, are very closely related; the scnDNA divergence indicate the two island species are a monophyletic group. (2) The rates of change of scnDNA and mtDNA are not greatly different; if anything scnDNA evolves faster than mtDNA. (3) The rates of scnDNA evolution are not closely correlated to chromosomal (inversion) evolution. (4) The Drosophila genome appears to consist of two distinct classes of scnDNA with respect to rate of evolutionary change, a very rapidly evolving fraction and a relatively conservative fraction. (5) The absolute rate of change was estimated to be at least 1.7% nucleotide substitution per one million years. (6) DNA distance estimates based on restriction site variation are correlated with distances based on DNA-DNA hybridization, although the correlation is not very strong.

Evolution of the Gypsy Endogenous Retrovirus in the Drosophila melanogaster Subgroup

2000 ◽  
Vol 17 (6) ◽  
pp. 908-914 ◽  
Author(s):  
Christophe Terzian ◽  
Concepcion Ferraz ◽  
Jacques Demaille ◽  
Alain Bucheton
Keyword(s):  
Drosophila Melanogaster ◽  
Endogenous Retrovirus ◽  
Drosophila Melanogaster Subgroup

Fine Structure of Meiotic Prophase Chromosomes in Lilium Longiflorum

1967 ◽  
Vol 25 ◽  
pp. 88-89
Author(s):  
Peter B. Moens
Keyword(s):  
Electron Microscopy ◽  
Drosophila Melanogaster ◽  
Meiotic Prophase ◽  
Lilium Longiflorum ◽  
Nurse Cells ◽  
Tomato Plants ◽  
Regional Conference ◽  
Mother Cells ◽  
European Regional ◽  
Dipteran Species

The presence of the tripartite ribbon within synapsed homologues has been reported for a large number of sexually reproducing organisms (over one hundred species, including fungi, plants, vertebrates and invertebrates). The absence of the ribbon in some species is associated with uncommon synaptic behaviour of meiotic prophase chromosomes (Drosophila melanogaster males, Drosophila melanogaster females homozygous for synapsis suppressing mutant C3G, and achiasmatic Dipteran species, reported by G. F. Meyer, 1964, Third European Regional Conference on Electron Microscopy). The tripartite ribbon, or synaptinemal complex, may therefore be assumed to be related to pairing of homologues at meiosis. The presence of the complexes and multi-complexes in non-meiotic cells such as insect obcyte nurse cells and spermatids suggests a somewhat broader function of the complexes. This is further supported by the occurrence of complexes in non-homologous paired chromosomes in the pollen mother cells of haploid tomato plants.

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