Document 0831
 DOCN  M9480831
 TI    Genetic variation within and between human, rat and mouse-derived
       Pneumocystis carinii.
 DT    9410
 AU    Keely SP; Pai HJ; Sunkin SM; Baughman R; Sidman CL; Stringer SL;
       Stringer JR; University of Cincinnati College of Medicine, Ohio.
 SO    Abstr Gen Meet Am Soc Microbiol. 1994;94:590 (abstract no. F-10). Unique
       Identifier : AIDSLINE ASM94/94313114
 AB    Pneumocystis carinii is an opportunistic pulmonary pathogen that causes
       P. carinii pneumonia (PCP) in immunocompromised individuals and is the
       major cause of death in AIDS patients. The organism thrives in a wide
       variety of mammals and is generally referred to as P. carinii regardless
       of host species. Recent reports indicate that genetic differences exist
       between organisms isolated from humans, ferrets and rats and that
       genetically distinct organisms can propagate within a single host. In
       order to further examine this diversity within and between host species
       we have sequenced a portion of the thymidylate synthase (TS) and
       mitochondrial large subunit rRNA (mrRNA) genes of P. carinii. P. carinii
       TS and mrRNA genes were sequenced and compared from organisms derived
       from scid mice, immuno-suppressed rats and AIDS patients. Novel P.
       carinii TS and mrRNA sequences were attained from each of these hosts.
       Nucleotide variation of these two genes within a single host was
       detected in humans and rats, but not in mice. Specifically, TS and mrRNA
       sequences showed deletions and point mutations in P. carinii isolated
       from rats. Sequence at the 3' end of numerous human P. carinii mrRNA
       genes revealed nucleotide base substitutions. Human P. carinii TS and
       mrRNA sequences were shown to be equally divergent from homologous genes
       of P. carinii rat and mouse-derived organisms. Surprisingly, nucleotide
       alignments of the P. carinii TS and mrRNA genes show that P. carinii
       from rats are as equally divergent from each other as they are from
       mouse P. carinii. Taken together, these data show that humans, rats and
       mice harbor distinct forms of P. carinii, that nucleotide polymorphisms
       occur within a single host, and that organisms isolated from these three
       mammalian hosts are probably different species of P. carinii.
 DE    Acquired Immunodeficiency Syndrome/*COMPLICATIONS  Animal  Base Sequence
       Comparative Study  *Genes, Fungal  Human  Mice  Mice, SCID  Pneumocystis
       carinii/*GENETICS/ISOLATION & PURIF  Pneumocystis carinii
       Infections/ETIOLOGY/*MICROBIOLOGY  Point Mutation  Rats  RNA,
       Fungal/GENETICS  Sequence Deletion  Thymidylate Synthetase/GENETICS
       *Variation (Genetics)  MEETING ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).