ADDITIONAL INFORMATION PAGE

A computational search for box C/D snoRNA genes in the D. melanogaster genome

Figure 2 (full size figure): A) On the top, genomic arrangement of the Dm SnR48-SnR39/59 cluster at the 45A2 region of D. melanogaster chromosome arm 2R (Flybase SEG: AE003834). The cluster is located in the region between the CG13741 and CG8078 genes and is composed of the highly related DmSnR48c and DmSnR48b genes, separated by two Dm SnR39/59 copies. The sequence of the snoRNA genes is reported below; C, D and D’ boxes are indicated respectively by black, grey and light grey rectangles. The grey arrow below the 3’ end of the DmSnR39/59a represents the 20mer oligonucleotide used in primer extension analysis, and the black arrowhead marks the experimentally determined 5’ end. The antisense sequence complementary to 28S rRNA is underlined. B) Developmental Northern blot profile displayed by DmSnR39/59a. 6 mg of total RNA were loaded in each lane (LI and LIII, first and third instar larvae, respectively). C) The size of the snoRNA DmSnR39/59a was estimated about 90 nt by 6% polyacrilammide gel elettrophoresis (left) (M: molecular weight marker; S: 4mg of total RNA sample) and by primer extension analysis (right), using the primer described in A (TCGA: sequence reaction used as molecular weight marker; P: sample).