Cytomolecular Studies in Momordica charantia L. (Cucurbitaceae), a Potential Medicinal Plant

Abstract

SummaryThe cytogenetic of Momordica charantia was studied using CMA 3 /DAPI and fluorescence in situ hybridization (FISH) techniques in order to characterize the features of its heterochromatin and the distribution of rDNA sites. The chromosomes observed were small and symmetrical. DAPI staining presented no band. The tests with CMA 3 staining presented 4 positive bands at chromosome extremities, what indicates the presence of GC rich sites in this species. The studies with FISH showed 4 sites of rDNA 45S located at similar regions of those observed in CMA 3 staining, and 2 sites of rDNA 5S at interstitial positions. Key wordsMomordica charantia L. is an annual dioecious climber plant that grows wild throughout subtropical regions of the world, mainly in South America and Asia. Named by São Caetano melon in Brazil, in world it is known as balsam-apple, karela, cundeamor, bitter melon or bitter gourd. Fruits of M. charantia are widely consumed and has wide commercial distribution in Asia (Ram et al. 2006). This plant has been used as a treatment to diabetes, reduction of adiposity, leprosy, jaundice, rheumatism and gout in several cultures (Leatherdale et al. 1981, Chen et al. 2003, Semiz and Sen 2007. The cytogenetic of this species is poorly studied, basically limited to its chromosome number and some observations in its reproductive biology (Lombello and Forni-Martins 1998, Lenzi et al. 2005). There are studies for the genus Momordica that present some karyological aspects as chromosome measures and karyographs (Agarwal and Roy 1976, Sinha et al. 1996), but with no information about cytomolecular aspects. All the studied species of the genus Momordica presented symmetrical karyomorphology. In such cases cytomolecular techniques, such as fluorochromes DAPI and CMA 3 staining, that evidence heterochromatic regions rich in AT and GC bases respectively, are often used in order to characterize the species cytogenetically (Gupta et al. 1990). Another important cytogenetic assay for karyotype characterization is FISH with rDNA probes (HeslopHarrison 1991). In eukaryotes ribosomal DNA occurs in tandem repeats that codes for ribosomal RNA. These highly repeated DNA families provide karyological markers useful for chromosome identification that are known to be valuable for the investigation of species with small or similarly sized chromosomes and in determination of phylogenetic relationships (Leitch and Heslop-Harrison 1992).In this study we intended to provide new cytogenetic characters to Momordica charantia in order to contribute to phylogenetic studies and grading up programs. Marterial and methodsSeeds and flower buds of Momordica charantia were collected at Santa Eliza farm, experimen-© 2007 The Japan Mendel Society Cytologia 72(4): [415][416][417][418] 2007 * Corresponding author, e-mail: ricardolombello@uol.com.br tal station of Instituto Agronômico de Campinas, state of São Paulo, Southeastern Brazil. Vegetative and reproductive samples of this species were herborized and introducted at IAC herbarium with ...

Chromomycin A3 banding and chromosomal mapping of 45S and 5S ribosomal RNA genes in bottle gourd

“…Chromosomes stained with CMA 3 revealed four bands in terminal regions of chromosomes in this species. Our results of CMA 3 /DAPI staining are in line with those obtained by Lombello and Pinto-Maglio, (2007) and Santos-Sanchês et al, (2019).…”

“…Also FISH with the 45S rDNA probe yielded four signals. In plants, 45S rDNA loci and CMA 3 positive heterochromatic blocks often coincide spatially (Lombello and Pinto-Maglio, 2007;Maragheh et al, 2019;Santos-Sanchês et al, 2019). 5S rDNA sites were not detected by CMA 3 /DAPI banding.…”

“…The 5S rDNA genes consist of a nontranscribed spacer and a conserved coding region of 120 bp (Long and Dawid, 1980). 45S and 5S rDNA genes can be present at one or more positions within a set of chromosomes and be used as chromosomal markers (Long and Dawid, 1980;Lombello and Pinto-Maglio, 2007;Han et al, 2008;Heslop-Harrison and Schwarzacher, 2011;Li et al, 2016;Santos-Sanchês et al, 2019). CMA 3 (chromomycin A3), a GC-rich specific fluorochrome, and DAPI (4'-6-diamidino-2-phenylindole), an AT-rich specific fluorochrome, banding techniques can also be useful to differentiate between chromosomes (Kim et al 2002).…”

A Cytogenetic Study of Three Japanese Cultivars of <i>Momordica charantia</i> L.

“…There are some studies for M. charantia that present karyological information, chromosome measures and karyographs (McKay 1930, Bhaduri and Bose 1947, Lombello and Pinto-Maglio 2007, Zaman and Alam 2009, Bharathi et al 2011, Waminal and Kim 2012, Kausar et al 2014), but not so many. All the studied species presented symmetrical karyomorphology.…”