High impact information on Ste12DOR

• The Ste locus, a component of the parasitic cry-Ste system of Drosophila melanogaster, encodes a protein that forms crystals in primary spermatocytes and mimics properties of the beta subunit of casein kinase 2 [1].
• Expression of the X-linked repeated Stellate (Ste) genes, which code for a protein with 38% similarity to the beta-subunit of casein kinase II, is suppressed by the Su(Ste) locus on the Y chromosome [2].
• DNA sequencing shows that these repeats may be considered as Ste pseudogenes or as damaged variants of a putative gene(s) encoding a protein quite different from the Ste protein as a result of an alternative splicing pattern [2].
• The newly detected "dead family" of cognate repeats on the Y chromosome has contributed to the evolution of Ste and its suppressors via gene conversion [3].
• Ste silencing is mediated by symmetric transcription of the paralogous Y-linked repeats and exerted by an RNA interference (RNAi) mechanism [3].

Biological context of Ste12DOR

• To test whether this is true, we have constructed a Ste-deleted X chromosome and examined the phenotype of Ste(-)/cry(-) males [4].
• Although it is impossible to construct a completely Ste(-) genotype, we find that Ste(-)/cry(-) males have exactly the same phenotype as Ste(+)/cry(-) males [4].
• Moreover, we found that meiosis is disrupted after synapsis and that cry-induced meiotic drive is probably not mediated by Ste [5].
• We found that heterochromatic as well as euchromatic Ste repeats are functional and that the abnormality in chromosome condensation and the frequency of nondisjunction are related to Ste copy number [5].

Anatomical context of Ste12DOR

• Drosophila melanogaster males deficient for the crystal (cry) locus of the Y chromosome that carry between 15 and 60 copies of the X-linked Stellate (Ste) gene are semisterile, have elevated levels of nondisjunction, produce distorted sperm genotype ratios (meiotic drive), and evince hyperactive transcription of Ste in the testes [4].

Other interactions of Ste12DOR

• In a vicinity of 12E Stellate cluster the undamaged, recently originated euchromatic Stellate orphon was found at 12D, providing the poly(A) signal for the bendless gene [6].

References