Science 1949 Mar;109(2828):255
Chromosome Res 2013 Jul 5;21(4):345-60. Epub 2013 Jun 5.
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.
The steroid hormone ecdysone induces DNA amplification and subsequent DNA puff formation in late fourth larval instar salivary gland polytene chromosomes of the fungus fly, Sciara coprophila. Previous in vitro studies on DNA puff II/9A in Sciara demonstrated that the ecdysone receptor (ScEcR-A) efficiently binds an ecdysone response element adjacent to the origin recognition complex binding site within the II/9A amplification origin, implying a role for ScEcR-A in amplification. Here, we extrapolate the molecular details from locus II/9A to the rest of the genome using immunofluorescence with a ScEcR-A-specific antibody. Read More
Chromosoma 2013 Mar 16;122(1-2):103-19. Epub 2013 Jan 16.
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02912, USA.
Regulation of DNA replication is critical, and loss of control can lead to DNA amplification. Naturally occurring, developmentally regulated DNA amplification occurs in the DNA puffs of the late larval salivary gland giant polytene chromosomes in the fungus fly, Sciara coprophila. The steroid hormone ecdysone induces DNA amplification in Sciara, and the amplification origin of DNA puff II/9A contains a putative binding site for the ecdysone receptor (EcR). Read More
Chromosoma 2011 Aug 2;120(4):387-97. Epub 2011 May 2.
Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Nicolás Cabrera, Spain.
Sciara coprophila (Diptera, Nematocera) constitutes a classic model to analyze unusual chromosome behavior such as the somatic elimination of paternal X chromosomes, the elimination of the whole paternal, plus non-disjunction of the maternal X chromosome at male meiosis. The molecular organization of the heterochromatin in S. coprophila is mostly unknown except for the ribosomal DNA located in the X chromosome pericentromeric heterochromatin. Read More
J Morphol 2006 Nov;267(11):1316-25
Department of Anatomy and Cell Biology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37604-0582, USA.
The unique chromosome biology of the fungus fly Sciara coprophila has fascinated investigators for over 80 years. Male meiosis exhibits a monopolar spindle, nonrandom segregation of imprinted chromosomes and nondisjunction of the X chromosome. The unusual mechanism of sex determination requires selective elimination of X chromosomes in embryogenesis. Read More
Dev Biol 2006 Nov 21;299(1):151-63. Epub 2006 Jul 21.
Brown University, 69 Brown St.-J.W. Wilson Laboratory, Providence, RI 02912, USA.
DNA replication is normally tightly regulated to ensure the production of only one copy of the genome per cell cycle. However, DNA puffs of the salivary gland giant polytene chromosomes of Sciara coprophila undergo DNA amplification during the normal course of development, overriding this control. This developmental strategy provides more template for the production of large amounts of protein needed for pupation. Read More