DNA underreplication in intercalary heterochromatin regions in polytene chromosomes of Drosophila melanogaster correlates with the formation of partial chromosomal aberrations and ectopic pairing.
We studied the influence of the Suppressor of Underreplication (SuUR) gene expression on the intercalary heterochromatin (IH) regions of Drosophila melanogaster polytene chromosomes. We observed a strong positive correlation between increased SuUR expression, underreplication extent, amount of DNA truncation, and formation of ectopic contacts in IH regions. SuUR overexpression from heat shock-driven transgene results in the formation of partial chromosomal aberrations whose breakpoints map exclusively to the regions of intercalary and pericentric heterochromatin. It is important to note that all these effects are seen only if SuUR overexpression is induced during early stages of chromosome polytenization. Therefore, we developed the idea that ectopic pairing results from the joining of free DNA ends, which are formed as a consequence of underreplication.
Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Elena S
ES
Belyaeva
Sergey A
SA
Demakov
Galina V
GV
Pokholkova
Artyom A
AA
Alekseyenko
Tatiana D
TD
Kolesnikova
Igor F
IF
Zhimulev
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002869:Chromosome Aberrations; D023902:Chromosome Pairing; D002875:Chromosomes / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect; D018869:Heat-Shock Response; D006570:Heterochromatin / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008957:Models, Genetic; D014960:X Chromosome / Q000235:genetics
D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006570:Heterochromatin; C464850:SuUR protein, Drosophila