Structure, regulation and evolution of the crystal-Stellate system of Drosophila.
The crystal-Stellate system is one of the most known example of interaction between heterochromatin and euchromatin: a heterochromatic locus on the Y chromosome (crystal) 'represses' a euchromatic locus (Stellate) on the X chromosome in Drosophila melanogaster. The molecular mechanism regulating this interaction is not completely understood. It is becoming clear that an RNA interference (RNAi) mechanism could be responsible for the silencing carried out by crystal on the Stellate sequences. Here, a detailed structural analysis of all the sequences involved in the system is reported, demonstrating a their 'puzzling' structure. In addition three autosomal mutations: sting, scratch and sirio are described that interfere with the system. All of them are male sterile mutations and exhibit crystals made by the STELLATE protein in their primary spermatocytes. They are requested during oogenesis and early in embryogenesis as well. Hypothesis on the involvement of these genes in activating the Stellate sequences are discussed.
Tritto
Patrizia
P
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università di Lecce, 73100 Lecce, Italy.
Specchia
Valeria
V
Fanti
Laura
L
Berloco
Maria
M
D'Alessandro
Rosalba
R
Pimpinelli
Sergio
S
Palumbo
Gioacchino
G
Bozzetti
Maria Pia
MP
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002874:Chromosome Mapping; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D022041:Euchromatin; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000235:genetics*; D006570:Heterochromatin; D008969:Molecular Sequence Data; D009154:Mutation; D012097:Repressor Proteins / Q000235:genetics*; D016415:Sequence Alignment
D029721:Drosophila Proteins; D022041:Euchromatin; D006570:Heterochromatin; D012097:Repressor Proteins; C106547:Ssl protein, Drosophila