NUCLEOTIDE SEQUENCES OF SMALL-SUBUNIT AND INTERNAL TRANSCRIBED SPACER REGIONS OF NUCLEAR rRNA GENES SUPPORT THE AUTONOMY OF SOME GENERA OF THE GELIDIALES (RHODOPHYTA)

1998 ◽  
Vol 34 (2) ◽  
pp. 299-305 ◽  
Author(s):  
Mohsin U. Patwary ◽  
Christoph W. Sensen ◽  
Ron M. MacKay ◽  
John P. van der Meer
Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 601-615
Author(s):  
Natsumi Kanzaki ◽  
Ebrahim Shokoohi ◽  
Hendrika Fourie ◽  
Antoinette Swart ◽  
Loureine Muller ◽  
...  

Summary In a survey of nematode damage in groundnut (Arachis hypogaea) (Fabaceae) production areas in the Vaalharts Irrigation Scheme in the Northern Cape Province of South Africa, a nematode was recovered and initially believed to be a member of the genus Robustodorus, i.e., the species has a characteristic robust stylet with very well-developed teardrop-shaped (garlic bulb-like) basal swellings. The specimens were recovered in large numbers from damaged hulls and kernels of field-collected groundnuts and, after thorough morphological and molecular studies, were subsequently identified as Aphelenchoides arachidis. Molecular analysis based on near-full-length small subunit (SSU), internal transcribed spacer (ITS) and D2-D3 expansion segments of the large subunit (LSU) rRNA genes supported the monophyly of A. arachidis, A. subtenuis and R. megadorus within the subfamily Aphelenchoidinae. Based on the typological characters observed in the present study compared with descriptions in the literature, these three species are considered as congeneric, i.e., they share very well-developed basal swellings of the stylet. Accordingly, these two Aphelenchoides species are transferred to Robustodorus as R. arachidis n. comb. and R. subtenuis n. comb. In addition, the male tail characters of Robustodorus and Aphelenchoides are discussed.


1999 ◽  
Vol 37 (6) ◽  
pp. 1985-1993 ◽  
Author(s):  
Takashi Sugita ◽  
Akemi Nishikawa ◽  
Reiko Ikeda ◽  
Takako Shinoda

The nucleotide sequences of the internal transcribed spacer (ITS) 1 and 2 regions in the rRNA gene were determined by directly sequencing PCR-amplified fragments for all of the species (17 species and five varieties) in the genus Trichosporon. Comparative sequence analysis suggests that six medically relevant species, T. asahii, T. asteroides, T. cutaneum,T. inkin, T. mucoides, and T. ovoides, can be readily identified by their ITS sequences. In addition, the sequence analysis showed that conspecific strains have fewer than 1% nucleotide differences in the ITS 1 and 2 regions overall. Molecular phylogenetic trees are also presented.


AIDS ◽  
2001 ◽  
Vol 15 (4) ◽  
pp. 451-459 ◽  
Author(s):  
Jannik Helweg-Larsen ◽  
Chao-Hung Lee ◽  
Shaoling Jin ◽  
John Yi-chung Hsueh ◽  
Thomas L. Benfield ◽  
...  

1998 ◽  
Vol 36 (3) ◽  
pp. 734-741 ◽  
Author(s):  
Chao-Hung Lee ◽  
Jannik Helweg-Larsen ◽  
Xing Tang ◽  
Shaoling Jin ◽  
Baozheng Li ◽  
...  

Pneumocystis carinii f. sp. hominisisolates from 207 clinical specimens from nine countries were typed based on nucleotide sequence variations in the internal transcribed spacer regions I and II (ITS1 and ITS2, respectively) of rRNA genes. The number of ITS1 nucleotides has been revised from the previously reported 157 bp to 161 bp. Likewise, the number of ITS2 nucleotides has been changed from 177 to 192 bp. The number of ITS1 sequence types has increased from 2 to 15, and that of ITS2 has increased from 3 to 14. The 15 ITS1 sequence types are designated types A through O, and the 14 ITS2 types are named types a through n. A total of 59 types of P. carinii f. sp. hominis were found in this study.


Parasitology ◽  
1999 ◽  
Vol 118 (6) ◽  
pp. 541-551 ◽  
Author(s):  
N. E. COLLINS ◽  
B. A. ALLSOPP

We sequenced the rRNA genes and internal transcribed spacers (ITS) of several Theileria parva isolates in an attempt to distinguish between the causative agents of East coast fever and Corridor disease. The small subunit (SSU) and large subunit (LSU) rRNA genes from a cloned T. p. lawrencei parasite were sequenced; the former was identical to that of T. p. parva Muguga, and there were minor heterogeneities in the latter. The 5·8S gene sequences of 11 T. parva isolates were identical, but major differences were found in the ITS. Six characterization oligonucleotides were designed to hybridize within the variable ITS1 region; 93·5% of T. p. parva isolates examined were detected by probe TPP1 and 81·8% of T. p. lawrencei isolates were detected by TPL2 and/or TPL3a. There was no absolute distinction between T. p. parva and T. p. lawrencei and the former hybridized with fewer of the probes than did the latter. It therefore seems that a relatively homogenous subpopulation of T. parva has been selected in cattle from a more diverse gene pool in buffalo. The ITSs of both T. p. parva and T. p. lawrencei contained different combinations of identifiable sequence segments, resulting in a mosaic of segments in any one isolate, suggesting that the two populations undergo genetic recombination and that their gene pools are not completely separate.


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