Abstract

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.

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Publisher Full Text

Authors

Sharma SK, Mehra P, Kumari J, Kumar S, Kumaria S, Tandon P, Rao SR

Institution

Department of Biotechnology and Bioinformatics, North-Eastern Hill University, Shillong (Meghalaya), India.

Source

Gene 499:2 2012 May 15 pg 362-6

MeSH

Genes, Plant
Genes, rRNA
In Situ Hybridization, Fluorescence
India
Orchidaceae
RNA, Ribosomal
Transcription, Genetic

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22425970