Molecular cytogenetical effects of some mycotoxins to chromosomes of Triticum durum using RAPD-PCR fluorescence in situ hybridization

Abstract

ABSTRACT. PCR-amplified DNA using the random primer OPB-06 was used as a probe for Fluorescence in situ hybridization (FISH). Signals of hybridized sites were observed in both interphase and metaphase plates after hybridization. The FISH signals of the metaphase chromosomes were confirmed as two yellow-color signals hybridized with the probe on two adjacent loci at interphase of the control plates. FISH analysis of the metaphase plates of 25µg/ml deoxynivlenol (DON) and aflatoxin B 1 (AFB 1 ) treated plants revealed 85.7% and 89.3%, respectively had no signals. Of the metaphase plates of plants treated with AFB 1 , 3.6% had one terminal signal while 7.1% revealed two signals and no signals were observed in 89.3% plates. Regarding the interphase nuclei, only one signal was observed in 42.1% of the plates where two signals were observed in 57.8% interphase plates. 10.7% metaphase plates of plants treated with DON had one terminal signal while 3.6% exhibit two signals and no signals were observed in 85.7% plates of metaphase. 44.1% of the interphase nuclei had one signal while 53.2% plates reveal two signals and four signals were observed in 2.7% interphase nuclei. Disappearance of FISH signals in some metaphase plates of plants treated with the two investigated toxins indicates the toxigenic effect of these mycotoxins on metaphase chromosomes of wheat.

Characterization of chromosome complement in <i>Achillea fragrantissima</i> (Forsk) Schultz-Bip. analyzed by DAPI and FISH

“…In contrast, rDNA FISH gives much higher resolution for detecting chromosome variations among closely related species. Our present results and other studies (Kondo et al 1996;Honda et al 1997;Abd El-Twab and Kondo 2003, 2007, 2008, 2009) have shown that the number and positions of major rDNA sites on chromosomes varied among the closely related genera and even species. This variation should have a phylogenetic implication, since the more similar rDNA FISH patterns are likely to be in the most closely related taxa (Abd El-Twab and Kondo 2003).…”

“…In higher eukaryotes, rDNA's are organized into two distinct gene classes of the major rDNA cluster encoding 45S rDNAs and the minor rDNA cluster encoding 5S rDNAs, which are usually found in loci that are separated from those of the major rDNAs and are not involved in the nucleolus formation (Inafuku et al 2000;Abd El-Twab and Kondo 2002, 2006, 2007, 2009. Fluorescence in situ hybridization (FISH) allows identification of specific sequences in a structurally preserved cell, in metaphase or interphase.…”

“…It is used as a folk medicine for the treatment of gastro-intestinal disturbances (El-Shazly et al 2004) Fluorescent banding methods such as 4-6-diamidino-2-phenylindole (DAPI) to determine the A-T (AdenineThymine)-rich segments in the chromosomes of various plants could provide more details and critical chromosomal data for phylogenetic relationships of species (Sumner 1990;Kondo et al 1995;Hizume et al 1997;Abd El-Twab and Kondo 2009). Therefore, the fluorescent banding techniques have been employed to some chromosome complements of closely related taxa Khaung et al 1995;Abd El-Twab and Kondo 2003, 2009, 2010.…”