dMi-2 is a highly conserved ATP-dependent chromatin-remodeling factor that regulates transcription and cell fates by altering the structure or positioning of nucleosomes. Here we report an unanticipated role for dMi-2 in the regulation of higher-order chromatin structure in Drosophila. Loss of dMi-2 function causes salivary gland polytene chromosomes to lose their characteristic banding pattern and appear more condensed than normal. Conversely, increased expression of dMi-2 triggers decondensation of polytene chromosomes accompanied by a significant increase in nuclear volume; this effect is relatively rapid and is dependent on the ATPase activity of dMi-2. Live analysis revealed that dMi-2 disrupts interactions between the aligned chromatids of salivary gland polytene chromosomes. dMi-2 and the cohesin complex are enriched at sites of active transcription; fluorescence-recovery after photobleaching (FRAP) assays showed that dMi-2 decreases stable association of cohesin with polytene chromosomes. These findings demonstrate that dMi-2 is an important regulator of both chromosome condensation and cohesin binding in interphase cells.
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http://dx.doi.org/10.1371/journal.pgen.1002878 | DOI Listing |
Based on the morphology of the polytene chromosomes, 21 species of the genus Chironomus Meigen from Bulgaria have been identified. Original pictures of the polytene chromosomes are presented for each species. "Basic" sequences were determined for each arm of the polytene chromosomes which are used to determine the corresponding arms of the chromosomes, and the cytocomplex to which the species belongs.
View Article and Find Full Text PDFThe polytene chromosomes, larva, pupa, and male are described for the black fly Simulium chaouikaidi n. sp., a member of the Simulium venustum group from Morocco.
View Article and Find Full Text PDFPLoS One
October 2024
Department of Biological Sciences, University of South Alabama, Mobile, Alabama, United States of America.
Invasive species are a threat to ecosystems worldwide, but determining if a species is adventive or native is not always straightforward. The black flies that inhabit the Galapagos Islands, long known as Simulium ochraceum, are blood-feeding pests of humans and livestock. They first came to the attention of residents in 1989, suggesting a recent arrival.
View Article and Find Full Text PDFActa Trop
November 2024
International Center for Island Studies, Kagoshima University, Korimoto 1-21-24, Kagoshima, Japan.
Dokl Biol Sci
October 2024
Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
The transcription factor Z4 (putzig) is one of the key proteins that determine the chromatin structure in Drosophila. Z4 is found at the boundaries of bands on polytene chromosomes, and the bands are currently thought to correlate with chromatin domains. Z4 is a component of a protein complex that additionally includes Chromator and BEAF-32, and a conserved domain is necessary to occur at the N end of Z4 to ensure its interaction with the two proteins.
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