Localization and characteristics of DNA underreplication zone in the 75C region of intercalary heterochromatin in Drosophila melanogaster polytene chromosomes

• Published in: Chromosoma Vol. 118; no. 6; pp. 747 - 761
• Main Authors: Andreyenkova, Natalya G, Kokoza, Elena B, Semeshin, Valery F, Belyaeva, Elena S, Demakov, Sergey A, Pindyurin, Alexey V, Andreyeva, Eugenia N, Volkova, Elena I, Zhimulev, Igor F
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01-12-2009; Springer-Verlag; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Animals; Base Sequence; Biochemistry; Biomedical and Life Sciences; Blotting, Southern; Cell Biology; Developmental Biology; DNA Breaks, Double-Stranded; DNA Replication; DNA-Binding Proteins - metabolism; Drosophila melanogaster; Drosophila melanogaster - metabolism; Drosophila melanogaster - ultrastructure; Drosophila Proteins - metabolism; Eukaryotic Microbiology; Heterochromatin - genetics; Heterochromatin - metabolism; Heterochromatin - ultrastructure; Human Genetics; Life Sciences; Physical Chromosome Mapping; Protein Transport; Research Article; Distal Breakpoint; Pericentric Heterochromatin; Polytene Chromosome; Late Replication; Weak Spot
• ISSN: 0009-5915; 1432-0886
• DOI: 10.1007/s00412-009-0232-6

In Drosophila polytene chromosomes, regions of intercalary heterochromatin are scattered throughout the euchromatic arms. Here, we present data on the first fine analysis of the individual intercalary heterochromatin region, 75C1-2, located in the 3L chromosome. By using electron microscopy, we demonstrated that this region appears as three closely adjacent condensed bands. Mapping of the region on the physical map by means of the chromosomal rearrangements with known breakpoints showed that the length of the region is about 445 kb. Although it seems that the SUUR protein binds to the whole 75C1-2 region, the proximal part of the region is fully polytenized, so the DNA underreplication zone is asymmetric and located in the distal half of the region. Finally, we speculate that intercalary heterochromatin regions of Drosophila polytene chromosomes are organized into three different types with respect to the localization of the underreplication zone.