We have hybridized Drosophila melanogaster DNA sequences to polytene chromosomes of D. silvestris. The results support Muller's hypothesis that the chromosomal elements have been largely conserved in the evolution of the genus Drosophila. As originally suggested by Carson, D. melanogaster elements X, 2L, 2R, 3L, and 3R appear to correspond to chromosomes X, 3, 2, 5, and 4, respectively, in D. s...

We have purified a human histone H4 lysine 20 methyltransferase and cloned the encoding gene, PR/SET07. A mutation in Drosophila pr-set7 is lethal: second instar larval death coincides with the loss of H4 lysine 20 methylation, indicating a fundamental role for PR-Set7 in development. Transcriptionally competent regions lack H4 lysine 20 methylation, but the modification coincided with condense...

The Su(var)3-7 protein is essential for fly viability, and several lines of evidence support its key importance in heterochromatin formation: it binds to pericentric heterochromatin, it potently suppresses variegation and it interacts with HP1. However, the mode of action of Su(var)3-7 is poorly understood. Here we investigate in vivo the consequences of increased Su(var)3-7 expression on fly v...

Linkage groups, as defined by chromosome arms in Drosophila melanogaster, appear to have remained largely intact within the genus Drosophila and, possibly, within the higher Diptera per se. We hypothesized that linkage group conservation might have a functional basis (possibly related to interphase chromosome arrangement). To test this hypothesis, a series of autosomal 2-3 translocations were s...

The investigation was carried out on a small pond situated on a recent mine spoil at Bolesław in the Olkusz region with Zn-Pb ore deposits. Water of the pond had pH 7.2-8.5 and low concentrations of heavy metals. Concentrations of Pb (487 μg g( - 1)) and Zn (1,991 μg g( - 1)) in the sediment were very high and potentially could lead to toxicological effects. In the pond, 48 taxa of macroinverte...

We present a genetic map based on microsatellite polymorphisms for the African human malaria vector, Anopheles gambiae. Polymorphisms in laboratory strains were detected for 89% of the tested microsatellite markers. Genotyping was performed for individual mosquitos from 13 backcross families that included 679 progeny. Three linkage groups were identified, corresponding to the three chromosomes....

The banded portion of Drosophila melanogaster chromosome 4 exhibits euchromatic and heterochromatic characteristics. Reminiscent of heterochromatin, it contains a high percentage of repetitive elements, does not undergo recombination, and exhibits high levels of HP1 and histone-3 lysine-9 dimethylation. However, in the distal 1.2 Mb, the gene density is typical of euchromatin, and this region i...

Chromosomal forms of Anopheles gambiae, given the informal designations Bamako, Mopti, and Savannah, have been recognized by the presence or absence of four paracentric inversions on chromosome 2. Studies of karyotype frequencies at sites where the forms occur in sympatry have led to the suggestion that these forms represent species. We conducted a study of the genetic structure of populations ...

In Drosophila melanogaster and in Sciara ocellaris dosage compensation occurs by hypertranscription of the single male X chromosome. This article reports the cloning and characterization in S. ocellaris of the gene homologous to maleless (mle) of D. melanogaster, which implements dosage compensation. The Sciara mle gene produces a single transcript, encoding a helicase, which is present in both...

The degree of polarization of fluorescence from stretched Chironomus thummi polytene chromosomes, stained with low concentrations of acridine orange (AO), decreases with increasing temperature. The "half temperature" of this decrease (T((1/2)R)) is lower than the expected DNA thermal denaturation temperature (T(m)) by about 20 degrees C. T((1/2)R) is lowered as histone is removed from chromosom...