High impact information on rn

• The rotund (rn) mutation in Drosophila is unique in that its phenotype is limited to the deletion of specific distal parts, though not the extremities, of all adult appendages [1].
• We have cloned the rn gene, located at cytogenetic position 84D3,4, by chromosomal walking [1].
• Flagellar growth continued within the short rn null cysts to produce large bulbous terminations of intertwined mature flagella [2].
• Our analysis of rotund (rn) null mutations in Drosophila melanogaster revealed that deletion of the rn locus affects both spermatid and retinal differentiation [2].
• Control of Drosophila imaginal disc development by rotund and roughened eye: differentially expressed transcripts of the same gene encoding functionally distinct zinc finger proteins [3].

Biological context of rn

• The rotund (rn) locus of Drosophila melanogaster at cytogenetic position 84D3,4 has been isolated and cloned on the basis of the mutant phenotype: an absence of structures in the subdistal regions of the appendages [4].
• The DNA sequencing of the cloned 5.3 kb element revealed that Tirant possesses an open reading frame (ORF) that shows similarity with the envelope protein encoded by the gypsy and 297 retrotransposons [5].
• The 5.3 kb element present in the fs(2) PM11-19 mt-gs allele possesses a 417 bp long terminal repeat (LTR) at both ends [5].

Associations of rn with chemical compounds

• Circular dichroism spectroscopy, used to monitor thermal denaturations of a heterodimerizing leucine zipper system containing either valine (V) or asparagine (N) in the 'a' position, indicates that the V-N interaction is 2.3 kcal/mole less stable than an N-N interaction and 5.3 kcal/mole less stable than a V-V interaction [6].
• In vitro synthesized MET directly bound to JH III with high affinity (Kd = 5.3 +/- 1.5 nm, mean +/- SD), consistent with the physiological JH concentration [7].

Physical interactions of rn

• We also showed by pull-down assays that Nab binds directly to Rotund and Squeeze via its conserved C-terminal domain [8].

Other interactions of rn

• The rotund (rn) gene in Drosophila melanogaster codes for a RacGTPase-activating protein, RnRacGAP [9].
• We have assigned these mutations to 23 complementation groups that include multiple alleles of Star and hedgehog as well as single alleles of Delta, roughened eye, glass and hairy [10].

Analytical, diagnostic and therapeutic context of rn

• Previous sequence analysis of rn genomic DNA and incomplete cDNA clones suggested that at least two differentially spliced forms of the transcript exist, rnRacGAP(1) and rnRacGAP(2) [9].

References