title: Tosca: a Drosophila gene encoding a nuclease specifically expressed in the female germline.
abstract: We describe here a Drosophila gene, tosca (tos), that is specifically expressed in the female germline. tos mRNA accumulates selectively within the pro-oocyte in germarial region 2 and persists throughout oogenesis. In the early embryo, the maternally supplied tos mRNA is evenly distributed at the syncytial blastoderm stage, but is excluded from the forming cells when cellularization begins. tos product is the first Drosophila member of the RAD2 protein family, a group of related DNA repair nucleases conserved from yeast to humans. Within the family, Tos is more closely related to ExoI, a Schizosaccharomyces pombe 5'-->3' double-stranded DNA exonuclease specifically induced in meiotic prophase I. The definite oocyte localization of tos transcript during meiosis and its ubiquitous distribution in early embryos suggest that tos may play a role in mismatch repair during genetic recombination and early cleavage divisions.
authors.affiliation: Istituto di Biochimica delle Proteine ed Enzimologia, CNR, Naples, Italy.
authors.forename: F A
authors.initials: FA
authors.lastname: Digilio
authors.forename: A
authors.initials: A
authors.lastname: Pannuti
authors.forename: J C
authors.initials: JC
authors.lastname: Lucchesi
authors.forename: M
authors.initials: M
authors.lastname: Furia
authors.forename: L C
authors.initials: LC
authors.lastname: Polito
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000201:enzymology / Q000235:genetics*; D004706:Endodeoxyribonucleases / Q000235:genetics*; D005260:Female; D005656:Fungal Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009866:Oogenesis; D010053:Ovary / Q000737:chemistry; D010063:Ovum / Q000737:chemistry / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D015183:Restriction Mapping; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C073998:RAD2 protein, S cerevisiae; D004706:Endodeoxyribonucleases