PHYSICAL AND GENETIC-MAPPING OF CLONED RIBOSOMAL DNA FROM TOXOPLASMA-GONDII - PRIMARY AND SECONDARY STRUCTURE OF THE 5S GENE

被引:53
作者
GUAY, JM [1 ]
HUOT, A [1 ]
GAGNON, S [1 ]
TREMBLAY, A [1 ]
LEVESQUE, RC [1 ]
机构
[1] UNIV LAVAL, FAC MED, DEPT MICROBIOL, GENIE GENET LAB, QUEBEC CITY G1K 7P4, QUEBEC, CANADA
关键词
RECOMBINANT DNA; PHAGE-GAMMA LIBRARY; PROTOZOA; GENE ORGANIZATION; RESTRICTION MAP; EVOLUTION;
D O I
10.1016/0378-1119(92)90570-F
中图分类号
Q3 [遗传学];
学科分类号
071007 ; 090102 ;
摘要
The ribosomal DNA (rDNA encoding rRNA) of the obligately intracellular protozoan parasite, Toxoplasma gon&i, was identified, cloned, physically mapped, its copy number determined, and the 5S gene sequenced. Using total RNA as a probe, a collection of recombinant lambda-phages containing copies of rDNA were isolated from a lambda-2001 tachyzoite genomic library. Northern gel hybridization confirmed specific homology of the 7.5-kb rDNA unit, subcloned into pTZ18R, to T. gondii rRNA. The mapped rDNA found in pTOX1 contained small ribosomal subunit (SS; 18S)- and large ribosomal subunit (LS; 26S)-encoding genes localized using intragenic heterologous probes from the conserved sequences of the SS (18S) and LS (28S) Xenopus laevis genes. The physical mapping data, together with partial digestion experiments and Southern gel hybridization, confirmed a 7.5-kb rDNA unit arranged in a simple head-to-tail fashion that is tandemly repeated. We estimated the rDNA repeat copy number in T. gondii to be 110 copies per haploid tachyzoite genome. Parts of the SS gene and the complete 5S gene were sequenced. The 5S gene was found to be within the rDNA locus, a rare occurrence found only in some fungi and protozoa. Secondary-structure analysis revealed an organization remarkably similar to the 5S RNA of eukaryotes.
引用
收藏
页码:165 / 171
页数:7
相关论文
共 34 条
[1]   GENERAL METHOD FOR ISOLATION OF HIGH MOLECULAR-WEIGHT DNA FROM EUKARYOTES [J].
BLIN, N ;
STAFFORD, DW .
NUCLEIC ACIDS RESEARCH, 1976, 3 (09) :2303-2308
[2]   AN UNUSUALLY COMPACT RIBOSOMAL DNA REPEAT IN THE PROTOZOAN GIARDIA-LAMBLIA [J].
BOOTHROYD, JC ;
WANG, A ;
CAMPBELL, DA ;
WANG, CC .
NUCLEIC ACIDS RESEARCH, 1987, 15 (10) :4065-4084
[3]   MAPPING OF XENOPUS-LAEVIS 5.8S RDNA BY RESTRICTION AND DNA SEQUENCING [J].
BOSELEY, PG ;
TUYNS, A ;
BIRNSTIEL, ML .
NUCLEIC ACIDS RESEARCH, 1978, 5 (04) :1121-1137
[4]   DIRECT AND SENSITIVE DETECTION OF A PATHOGENIC PROTOZOAN, TOXOPLASMA-GONDII, BY POLYMERASE CHAIN-REACTION [J].
BURG, JL ;
GROVER, CM ;
POULETTY, P ;
BOOTHROYD, JC .
JOURNAL OF CLINICAL MICROBIOLOGY, 1989, 27 (08) :1787-1792
[5]   UNUSUAL ORGANIZATION AND LACK OF RECOMBINATION IN THE RIBOSOMAL-RNA GENES OF COPRINUS-CINEREUS [J].
CASSIDY, JR ;
MOORE, D ;
LU, BC ;
PUKKILA, PJ .
CURRENT GENETICS, 1984, 8 (08) :607-613
[6]   ISOLATION OF BIOLOGICALLY-ACTIVE RIBONUCLEIC-ACID FROM SOURCES ENRICHED IN RIBONUCLEASE [J].
CHIRGWIN, JM ;
PRZYBYLA, AE ;
MACDONALD, RJ ;
RUTTER, WJ .
BIOCHEMISTRY, 1979, 18 (24) :5294-5299
[7]   DETERMINATION OF NUCLEAR-DNA OF 5 EUCOCCIDIAN PARASITES, ISOSPORA (TOXOPLASMA) GONDII, SARCOCYSTIS-CRUZI, EIMERIA-TENELLA, EIMERIA-ACERVULINA AND PLASMODIUM-BERGHEI, WITH SPECIAL REFERENCE TO GAMONTOGENESIS AND MEIOSIS IN I (T) GONDII [J].
CORNELISSEN, AWCA ;
OVERDULVE, JP ;
VANDERPLOEG, M .
PARASITOLOGY, 1984, 88 (JUN) :531-+
[8]   CHARACTERIZATION OF THE NUCLEAR RIBOSOMAL DNA OF EUGLENA-GRACILIS [J].
CURTIS, SE ;
RAWSON, JRY .
GENE, 1981, 15 (2-3) :237-247
[9]   PURIFICATION OF TOXOPLASMA-GONDII FROM HOST-CELLS [J].
DAHL, RJ ;
JOHNSON, AM .
JOURNAL OF CLINICAL PATHOLOGY, 1983, 36 (05) :602-604
[10]   A COMPREHENSIVE SET OF SEQUENCE-ANALYSIS PROGRAMS FOR THE VAX [J].
DEVEREUX, J ;
HAEBERLI, P ;
SMITHIES, O .
NUCLEIC ACIDS RESEARCH, 1984, 12 (01) :387-395