TY - JOUR
T1 - Schistosoma haematobium and S. japonicum
T2 - Analysis of the ribosomal RNA genes and determination of the "gap" boundaries and sequences
AU - Mertz, Prema M.
AU - Bobek, Libuse A.
AU - Rekosh, David M.
AU - LoVerde, Philip T.
N1 - Funding Information:
We thank Ms. Theresa Wnuk for excellent secretarial assistancea nd Ms. Hong Shi for expert technical assistance.T his work was funded in part by grants from NIAID (R22AI-18867)a nd the Edna McConnell Clark Foundation.D .M.R. is the recipient of a RCDA (CA-000905) fromN CI. This work was conducteda s part of the Center for Applied Molecular Biology and Immunology supported by The State University of New York at Buffalo.
PY - 1991/8
Y1 - 1991/8
N2 - We have determined the intragenic organization of the rRNA genes of Schistosoma haematobium and S. japonicum and found them to be similar to that of S. mansoni and other eukaryotes. An entire ribosomal repeat approximately 10 kbp in size from each species was isolated as a SalI fragment from a genomic library constructed in bacteriophage λ. The segments encoding both the small and large rRNAs have been identified using three cloned EcoRI fragments of S. mansoni as probes. There were three EcoRI fragments (4.2, 3.0, 1.6 kbp) from S. haematobium and four EcoRI fragments (4.6, 2.3, 1.7, 1.0 kbp) from S. japonicum. As in a wide variety of organisms within the protostome phyla, the 28S rRNA in schistosomes contains a "gap" which separates it into two fragments. The length of the gap sequence in S. haematobium is 54 bases and it is identical to that in S. mansoni in both length and sequence. However, in S. japonicum the sequence is between 64-67 bases long. In each case, irrespective of the species, the gap is located at the same position within the 28S rRNA. Secondary structures of the gap sequence derived by computer analysis predict a conformation with the minimum free energy that has an UAAU tract in a hairpin loop for S. haematobium and an UAUU tract for S. japonicum.
AB - We have determined the intragenic organization of the rRNA genes of Schistosoma haematobium and S. japonicum and found them to be similar to that of S. mansoni and other eukaryotes. An entire ribosomal repeat approximately 10 kbp in size from each species was isolated as a SalI fragment from a genomic library constructed in bacteriophage λ. The segments encoding both the small and large rRNAs have been identified using three cloned EcoRI fragments of S. mansoni as probes. There were three EcoRI fragments (4.2, 3.0, 1.6 kbp) from S. haematobium and four EcoRI fragments (4.6, 2.3, 1.7, 1.0 kbp) from S. japonicum. As in a wide variety of organisms within the protostome phyla, the 28S rRNA in schistosomes contains a "gap" which separates it into two fragments. The length of the gap sequence in S. haematobium is 54 bases and it is identical to that in S. mansoni in both length and sequence. However, in S. japonicum the sequence is between 64-67 bases long. In each case, irrespective of the species, the gap is located at the same position within the 28S rRNA. Secondary structures of the gap sequence derived by computer analysis predict a conformation with the minimum free energy that has an UAAU tract in a hairpin loop for S. haematobium and an UAUU tract for S. japonicum.
KW - Gap sequences
KW - Gene organization
KW - Schistosoma haematobium
KW - Schistosoma japonicum 28S rRNA
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U2 - 10.1016/0014-4894(91)90017-Q
DO - 10.1016/0014-4894(91)90017-Q
M3 - Article
C2 - 1889469
AN - SCOPUS:0026210803
SN - 0014-4894
VL - 73
SP - 137
EP - 149
JO - Experimental Parasitology
JF - Experimental Parasitology
IS - 2
ER -