Nuclear Ribosomal DNA Variation among Ramets and Genets of White Clover

Capossela, Angela; Silander, John A.; Jansen, Robert K.; Bergen, Briana; Talbot, Duncan R.

doi:10.2307/2409771

Cited by 7 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Withinindividual variation for polygenic and cytogenetic traits has been documented by several authors (Lewis et al, 1971;Klekowski, 1988;Klekowski and Godfrey, 1989). In addition, molecular genetic variation has been detected among naturally occurring clones in several plant species (Schaal and Learn, 1988;Capossela et al, 1992;Tuskan et al, 1996). Such somatic variation might be expected to be most common at loci with high mutation rates, eg, as reported in some cases for microsatellite DNA sequences (Weber and Wong, 1993;Schlö tterer et al, 1998;Udupa and Baum, 2001).…”

Section: Introductionmentioning

confidence: 89%

Somatic stability of microsatellite loci in Eastern white pine, Pinus strobus L.

et al. 2003

View full text Add to dashboard Cite

Variation at nuclear-and chloroplast-encoded microsatellite loci was studied among and within clonally propagated individuals of Eastern white pine. Total DNA was extracted and assayed from gamete-bearing tissue (megagametophytes) located on six different branch positions on each of 12 individual genets. No within-individual variation was observed among 12 loci studied. Estimates of numbers of mitotic cell divisions required to produce the tissue used as the source of genomic DNA were obtained by combining tree growth and anatomical data. This allowed for the calculation of upper bound estimates of numbers of mutations per locus per somatic cell division. The estimated somatic mutation rate was found to be substantially lower than those published for genomic microsatellite mutation rates in other plant species.

show abstract

Section: Introductionmentioning

confidence: 89%

Somatic stability of microsatellite loci in Eastern white pine, Pinus strobus L.

et al. 2003

View full text Add to dashboard Cite

show abstract

“…The spacer region can be highly variable both among and within given species, while the coding regions are considered highly conserved even in phylogenetically very distant taxa (APPELS and DVORAK 1982) . The number of ribosomal genes is supposed to be directly related to the size of the genome, but it can vary among species and even populations (CAPOSSELA et al 1992;MOSCONE et al 1995). It is known that the number of ribosomal genes could vary even very quickly in response to genetic or environmental stress (KOMMA and ATWOOD 1994;WATERS and SCHAAL 1996); moreover the activity of some rDNA clusters (NORs) could be regulated by evolutionary events or position effects (SCHUBERT and KUNZEL 1990).…”

Section: Discussionmentioning

confidence: 99%

Cytotaxonomic studies inVigna.IV. Variation of the number of active and silent rDNA sites inVigna unguiculatapopulations

Galasso¹,

Saponetti²,

Pignone³

1998

Caryologia

View full text Add to dashboard Cite

SUMMARY-Fluorescent in situ hybridization (FISH) using the pTa71 probe (18S 5.8S-25S rDNA) allowed the physical localization of the rRNA gene clusters on five chromosome pairs in mitotic metaphases of the reference line Tvx3236. Four pairs of these sites, showing high hybridization signal, colocalised with the chromosomal domains identified after Chromomycin A3 (CMA) fluorochrome staining, in telomeric regions. After staining with AgNO3, it was possible to ascertain that these sites had transcriptional activity. The fifth site, showing a lesser signal, had centromeric location and no transcriptional activity. In wild populations of Vigna unguiculata subsp. dekindtiana three major sites were detected with telomeric location and transcriptional activity. In two lines from Southern Italy six sites were observed: five were located telomerically and were genetically active, while the sixth was centromeric and had non activity. No variation was observed for the localization of the 5S rRNA gene clusteys. In all lines analysed it was possible to observe a strict topological correspondence between major rRNA genes sites and CMA stained heterocromatin. Moreover in all cases the regions so identified demonstrated transcriptional activity as assessed by the deposition of silver grains after AgNO3 staining. These results indicate that in cowpea the number of active r-DNA clusters is variable and might suggest that during the domestication/evolution of this crop an increase of these sites occurred.

show abstract

“…While allozyme markers are likely to continue to be the primary tool for population structure analyses, studies using DNA markers have begun to contribute to this database. For example, estimates of levels of genetic diversity and degrees of structuring among plant populations have been made using minisatellite fingerprinting (Wolff et al 1994), RAPDs (Dawson et al 1993, Russell et al 1993, restriction site and length variation in ribosomal DNA (rDNA: Learn and Schaal 1987, Schaal and Learn 1988, King and Schaal 1989, Capossela et al 1992, and restriction site variation in chloroplast DNA (cpDNA: Milligan 1991, Hong et al 1993). Estimates of genetic differentiation among populations (e.g., F st , Wright 1978) can be obtained from levels of band sharing among individuals (e.g., for rDNA and minisatellite techniques: Davis et al 1990, Lynch andMilligan 1994).…”

Section: Genetic Relatedness Within and Among Populationsmentioning

confidence: 99%

Genetic Markers in Plant Evolutionary Ecology

Cruzan

1998

Ecology

View full text Add to dashboard Cite

Genetic markers have provided plant ecologists with a method of assessing levels of genetic relatedness among individuals and populations. In recent years a number of techniques based on DNA sequence variation have been developed to complement allozyme methods that are already widely used. Some of these new markers are more variable than protein‐based markers, allowing more precise estimates of genetic differences among individuals and populations. Other DNA‐based markers are based on organelle genomes that are inherited uniparentally. These cytoplasmic markers can provide a method for assessing the separate effects of seed and pollen dispersal on gene flow within and among populations and species. Studies of hybrid populations have been facilitated by the development of inferential techniques for assessing levels of selection and patterns of introgression between species. Genetic markers have also been used to describe mating patterns within populations and to examine the ecological and genetic mechanisms that contribute to variation in selfing and reproductive success. Integration of ecological methods with genetic marker techniques continues to provide novel approaches to the study of evolutionary processes in plant populations.

show abstract

Nuclear Ribosomal DNA Variation among Ramets and Genets of White Clover

Cited by 7 publications

References 16 publications

Somatic stability of microsatellite loci in Eastern white pine, Pinus strobus L.

Somatic stability of microsatellite loci in Eastern white pine, Pinus strobus L.

Cytotaxonomic studies inVigna.IV. Variation of the number of active and silent rDNA sites inVigna unguiculatapopulations

Genetic Markers in Plant Evolutionary Ecology

Contact Info

Product

Resources

About