Genomics ◽  
1994 ◽  
Vol 22 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Atsushi Fukushima ◽  
Kousaku Okubo ◽  
Hidehiko Sugino ◽  
Naohiro Hori ◽  
Ryo Matoba ◽  
...  

1988 ◽  
Vol 34 (1) ◽  
pp. 50-52
Author(s):  
Chieko Suzuki ◽  
Noriko Tomita ◽  
Eiichi Uchiyama ◽  
Akio Ishii ◽  
Takeshi Nishizaki ◽  
...  

2000 ◽  
Vol 38 (3) ◽  
pp. 1131-1135 ◽  
Author(s):  
D. De Groote ◽  
R. Ducatelle ◽  
L. J. van Doorn ◽  
K. Tilmant ◽  
A. Verschuuren ◽  
...  

Recently, a new 16S ribosomal DNA-based PCR assay was developed for the specific detection of “Candidatus Helicobacter suis” (former “Gastrospirillum suis”) in porcine gastric samples. In the present study, this PCR assay was compared to three other invasive diagnostic methods (rapid urease test, immunohistochemistry, histologic analysis by Giemsa staining). Antral stomach samples from 200 slaughterhouse pigs from Belgium and The Netherlands were examined. Bacterial presence was determined in 77% (154 of 200) of the samples by PCR in combination with Southern blot hybridization, 56% (111 of 200) of the samples by immunohistochemistry, 61% (122 of 200) of the samples by urease testing (20 h postinoculation [p.i.]), 36% (71 of 200) of the samples by urease testing (3 h p.i.), and 33% (65 of 200) of the samples by Giemsa staining. The intrinsic specificity of the PCR assay was assessed by Southern blot analysis with an “Candidatus H. suis”-specific probe and sequencing of PCR products. Interassay sensitivity and specificity values were assessed for each test by pairwise comparisons between tests. Agreement between tests was evaluated by calculating Cohen's kappa coefficient. From that analysis, the PCR assay was considered the most reliable benchmark. Microscopic detection of immunohistochemically labeled or Giemsa-stained “Candidatus H. suis” cells in stomach sections proved to be highly specific (100%) but relatively insensitive (72 and 42%, respectively) compared to the PCR assay. A longer incubation time of the urease test improved its sensitivity considerably (74 versus 55%) but was accompanied by a loss of specificity (72 versus 93%). In conclusion, we found the “Candidatus H. suis”-specific PCR assay to be a sensitive and reliable diagnostic method for the detection of “Candidatus H. suis” in the stomachs of pigs and could prove to be a valuable tool for further epidemiological studies both for “Candidatus H. suis”- and for “Helicobacter heilmannii” type 1-related research.


Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 478-491 ◽  
Author(s):  
Masaki Kuro-o ◽  
Tsutomu Hikida ◽  
Sei-ichi Kohno

Variations in repetitive DNA were examined in nine salamander species of the genera Hynobius and Onychodactylus. The data from Southern blot hybridization were processed by Manhattan distance analysis, and unrooted trees were drawn. The resulting trees suggest that the genus Hynobius can be divided into three groups: group 1 contains only H. retardatus with 40 chromosomes; group 2 contains H. kimurae, which has 58 chromosomes and is a mountain-brook type of Hynobius (this group probably contains all mountain-brook types of Hynobius with 58 chromosomes); and group 3 contains the other six pond-type species examined here, each with 56 chromosomes. Group 3 probably contains all species of Hynobius with 56 chromosomes. Furthermore, group 3 can be further separated into two groups: the first group includes H. leechii, H. tsuensis, H. nebulosus, H. nigrescens, and H. tokyoensis from Chita; and the second group includes H. tokyoensis (except the population from Chita) and H. lichenatus. According to this analysis and other information, it seems that the population from Aichi Prefecture, which belongs to H. tokyoensis, should be identified as H. nebulosus. Furthermore, it appears that the genus Onychodactylus is phylogenetically distant from Hynobius and Salamandrella.Key words: Hynobius, repetitive DNA, Southern blot hybridization, phylogenetics, neighbor-joining method.


1984 ◽  
Vol 4 (11) ◽  
pp. 2389-2395 ◽  
Author(s):  
G N Cox ◽  
J M Kramer ◽  
D Hirsh

We analyzed the number and organization of collagen genes in the nematode Caenorhabditis elegans. Genomic Southern blot hybridization experiments and recombinant phage library screenings indicated that C. elegans has between 40 and 150 distinct collagen genes. A large number of recombinant phages containing collagen genes were isolated from C. elegans DNA libraries. Physical mapping studies indicated that most phage contained a single small collagen gene less than 3 kilobases in size. A few phage contained multiple collagen hybridizing regions and may contain a larger collagen gene or several tightly linked small collagen genes. No overlaps were observed between phages containing different collagen genes, implying that the genes are dispersed in the C. elegans genome. Consistent with the small size of most collagen genes, we found that the predominant class of collagen mRNA in C. elegans is 1.2 to 1.4 kilobases in length. Genomic Southern blot experiments under stringent hybridization conditions revealed considerable sequence diversity among collagen genes. Our data suggest that most collagen genes are unique or are present in only a few copies.


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