Reference : Remarkable conservation of internally transcribed spacer sequences of Arthrospira ("S...
Scientific journals : Article
Life sciences : Phytobiology (plant sciences, forestry, mycology...)
Life sciences : Aquatic sciences & oceanology
http://hdl.handle.net/2268/18266
Remarkable conservation of internally transcribed spacer sequences of Arthrospira ("Spirulina") (Cyanophyceae, Cyanobacteria) strains from four continents and of recent and 30-year-old dried samples from Africa
English
Baurain, Denis mailto [Université de Liège - ULiège > Département de Botanique > > >]
Renquin, Laurent [Université de Liège - ULiège > Département de Botanique > > >]
Grubisic, Stana mailto [Université de Liège - ULiège > Département de Botanique > > >]
Scheldeman, Patsy [Université de Liège - ULiège > Département de Botanique > > >]
Belay, Amha [Earthrise Nutritionals, Inc. > > > >]
Wilmotte, Annick mailto [Université de Liège - ULiège > Département de Botanique > > >]
Apr-2002
Journal of Phycology
Blackwell Publishing Inc
38
2
384-393
Yes (verified by ORBi)
International
0022-3646
Malden
[en] Arthrospira ; "dihe" ; evolution ; ITS ; molecular taxonomy ; rRNA ; sequences ; Spirulina
[en] The internally transcribed spacer (ITS) sequences of 21 Arthrospira clonal strains from four continents and assigned to four different species (A. platensis, A. maxima, A. fusiformis, A. indica) in the culture collections were determined. Two main clusters, I and H, were differentiated by 49 positions out of 475 nt or 477 nt, respectively. Each cluster was further subdivided into two subclusters. Subclusters LA and I.B were separated by two substitutions, whereas subclusters II.A, and II.B were distinguished by four substitutions. After direct sequencing of the PCR products, three dried samples from Chad aged between 3 months and 35 years yielded a sequence belonging to subcluster I.A, as did a recent commercial product. The strains grown in production plants belonged to the same (sub)clusters as strains from culture collections, mainly LA and II. PCR primers specific for each cluster and subcluster were designed and tested with crude cell lysates of Arthrospira strains. One dried sample ("dihe' 1) and a herbarium sample from Lake Sonachi (Kenya) only contained I.A sequences, whereas the commercial product was a mixture of the four genotypes and the other two dried samples contained minor polymorphisms characteristic of different clusters. Five clonal Arthrospira strains, thought to be duplicates, showed the simultaneous presence of the two :Forms of the four diagnostic positions that distinguish subclusters genotype H.A and genotype II.B. This is likely to be caused by multiple copies of the rDNA operon, in a intermediate stage of homogenization between subcluster II.A and subcluster II.B. The high conservation of ITS sequences is in contrast with the assignment to four different species, the great morphological variability of the strains, and their wide geographic distribution.
Earthrise Farms, Calipatria, California, USA
Molecular diversity of the Arthrospira genus
Researchers ; Professionals
http://hdl.handle.net/2268/18266
10.1046/j.1529-8817.2002.01010.x
http://www3.interscience.wiley.com/cgi-bin/fulltext/118910802/PDFSTART

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