TY - JOUR
T1 - Physical localization and probable transcriptional activity of 18S-5.8S-26S rRNA gene loci in some Asiatic Cymbidiums (Orchidaceae) from north-east India
AU - Sharma, Santosh Kumar
AU - Mehra, Poonam
AU - Kumari, Jyoti
AU - Kumar, Sundip
AU - Kumaria, Suman
AU - Tandon, Pramod
AU - Rao, Satyawada Rama
N1 - Copyright © 2012 Elsevier B.V. All rights reserved.
PY - 2012/5/15
Y1 - 2012/5/15
N2 - Fluorescence in situ hybridization based physical localization of 45S ribosomal DNA in eight horticulturally important species of Cymbidium (Orchidaceae) from north-east India (South-East Asia) has been carried for the first time. Observations revealed only one pair of chromosomes had NOR loci. Three, out of eight Cymbidiums showed decondensed, dispersed, extended form of hybridization signals of rDNA as dots of fluorescence (transcriptionally active), where as the rest of the Cymbidiums revealed condensed (non-active) forms, hence demonstrated the heteromorphism in size, intensities and their appurtenance which may be under epigenetic control. Except for the ribosomal genes, no other active genes have been reported to reside within the nucleoli. Such observations provide useful chromosome landmarks and provide valuable evidence about the genome evolution, speciation and ploidy both at molecular and chromosomal levels which is more or less highly ambiguous in family Orchidaceae.
AB - Fluorescence in situ hybridization based physical localization of 45S ribosomal DNA in eight horticulturally important species of Cymbidium (Orchidaceae) from north-east India (South-East Asia) has been carried for the first time. Observations revealed only one pair of chromosomes had NOR loci. Three, out of eight Cymbidiums showed decondensed, dispersed, extended form of hybridization signals of rDNA as dots of fluorescence (transcriptionally active), where as the rest of the Cymbidiums revealed condensed (non-active) forms, hence demonstrated the heteromorphism in size, intensities and their appurtenance which may be under epigenetic control. Except for the ribosomal genes, no other active genes have been reported to reside within the nucleoli. Such observations provide useful chromosome landmarks and provide valuable evidence about the genome evolution, speciation and ploidy both at molecular and chromosomal levels which is more or less highly ambiguous in family Orchidaceae.
KW - Cymbidium
KW - FISH
KW - Orchidaceae
KW - RDNA
KW - Transcriptionally active
UR - http://www.scopus.com/inward/record.url?scp=84860238740&partnerID=8YFLogxK
U2 - 10.1016/j.gene.2012.03.007
DO - 10.1016/j.gene.2012.03.007
M3 - Article
C2 - 22425970
AN - SCOPUS:84860238740
SN - 0378-1119
VL - 499
SP - 362
EP - 366
JO - Gene
JF - Gene
IS - 2
ER -