Identification of a novel null allele of the
            
              KEL
            
            gene in a
            Korean
            patient with the
            Kell
            null phenotype

Abstract REC104 is a gene required for the initiation of meiotic recombination in Saccharomyces cerevisiae. To better understand the role of REC104 in meiosis, we used an in vitro mutagenesis technique to create a set of temperature-conditional mutations in REC104 and used one ts allele (rec104-8) in a screen for highcopy suppressors. An increased dosage of the early exchange gene REC102 was found to suppress the conditional recombinational reduction in rec104-8 as well as in several other conditional rec104 alleles. However, no suppression was observed for a null allele of REC104, indicating that the suppression by REC102 is not “bypass” suppression. Overexpression of the early meiotic genes REC114, RAD50, HOP1, and RED1 fails to suppress any of the rec104 conditional alleles, indicating that the suppression might be specific to REC102.

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Genetic and Molecular Characterization of sting, a Gene Involved in Crystal Formation and Meiotic Drive in the Male Germ Line of Drosophila melanogaster

Genetics ◽

10.1093/genetics/151.2.749 ◽

1999 ◽

Vol 151 (2) ◽

pp. 749-760 ◽

Cited By ~ 2

Author(s):

Armin Schmidt ◽

Gioacchino Palumbo ◽

Maria P Bozzetti ◽

Patrizia Tritto ◽

Sergio Pimpinelli ◽

...

Keyword(s):

Amino Acids ◽

Drosophila Melanogaster ◽

Null Allele ◽

Germ Line ◽

Meiotic Drive ◽

P Element ◽

Crystal Formation ◽

Male Sterile ◽

Male Sterile Mutation

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.

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The Putative RNA Helicase Dbp6p Functionally Interacts With Rpl3p, Nop8p and the Novel trans-acting Factor Rsa3p During Biogenesis of 60S Ribosomal Subunits in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/166.4.1687 ◽

2004 ◽

Vol 166 (4) ◽

pp. 1687-1699

Author(s):

Jesús de la Cruz ◽

Thierry Lacombe ◽

Olivier Deloche ◽

Patrick Linder ◽

Dieter Kressler

Keyword(s):

Saccharomyces Cerevisiae ◽

Ribosome Biogenesis ◽

Null Allele ◽

Ribosomal Subunit ◽

Interaction Network ◽

The Novel ◽

Rna Helicases ◽

Ribosomal Subunits ◽

Synthetic Lethal ◽

Synthetically Lethal

Abstract Ribosome biogenesis requires at least 18 putative ATP-dependent RNA helicases in Saccharomyces cerevisiae. To explore the functional environment of one of these putative RNA helicases, Dbp6p, we have performed a synthetic lethal screen with dbp6 alleles. We have previously characterized the nonessential Rsa1p, whose null allele is synthetically lethal with dbp6 alleles. Here, we report on the characterization of the four remaining synthetic lethal mutants, which reveals that Dbp6p also functionally interacts with Rpl3p, Nop8p, and the so-far-uncharacterized Rsa3p (ribosome assembly 3). The nonessential Rsa3p is a predominantly nucleolar protein required for optimal biogenesis of 60S ribosomal subunits. Both Dbp6p and Rsa3p are associated with complexes that most likely correspond to early pre-60S ribosomal particles. Moreover, Rsa3p is co-immunoprecipitated with protA-tagged Dbp6p under low salt conditions. In addition, we have established a synthetic interaction network among factors involved in different aspects of 60S-ribosomal-subunit biogenesis. This extensive genetic analysis reveals that the rsa3 null mutant displays some specificity by being synthetically lethal with dbp6 alleles and by showing some synthetic enhancement with the nop8-101 and the rsa1 null allele.

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