Genome Size and Environmental Correlations in Maize (Zea maysssp.mays, Poaceae)

Poggio, Lidia; Rosato, Marcela; Chiavarino, Amilcar M.; Naranjo, Carlos

doi:10.1006/anbo.1998.0757

Cited by 86 publications

(81 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The near doubling in the last 1-2 million years of genome size in Z. luxurians, without polyploidy, as compared to Z. diploperennis and Z. mays, provides an excellent study system (Laurie and Bennett, 1985). Genome size is also known to be quite variable (440%) even within Z. mays, but this is mostly associated with very different quantities of B chromosomes and/or knob repeats (reviewed in Poggio et al, 1998), which can build up by random or selected segregation processes. However, TEs that are scattered about the genome cannot be easily concentrated by simple segregation, so we felt an investigation of repeat content in maize, Z. luxurians and Z. diploperennis would be informative.…”

Section: Discussionmentioning

confidence: 99%

The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution

2013

View full text Add to dashboard Cite

Sample sequence analysis was employed to investigate the repetitive DNAs that were most responsible for the evolved variation in genome content across seven panicoid grasses with 45-fold variation in genome size and different histories of polyploidy. In all cases, the most abundant repeats were LTR retrotransposons, but the particular families that had become dominant were found to be different in the Pennisetum, Saccharum, Sorghum and Zea lineages. One element family, Huck, has been very active in all of the studied species over the last few million years. This suggests the transmittal of an active or quiescent autonomous set of Huck elements to this lineage at the founding of the panicoids. Similarly, independent recent activity of Ji and Opie elements in Zea and of Leviathan elements in Sorghum and Saccharum species suggests that members of these families with exceptional activation potential were present in the genome(s) of the founders of these lineages. In a detailed analysis of the Zea lineage, the combined action of several families of LTR retrotransposons were observed to have approximately doubled the genome size of Zea luxurians relative to Zea mays and Zea diploperennis in just the last few million years. One of the LTR retrotransposon amplification bursts in Zea may have been initiated by polyploidy, but the great majority of transposable element activations are not. Instead, the results suggest random activation of a few or many LTR retrotransposons families in particular lineages over evolutionary time, with some families especially prone to future activation and hyper-amplification.

show abstract

Section: Discussionmentioning

confidence: 99%

The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution

2013

View full text Add to dashboard Cite

show abstract

“…Up to now, the extent of intraspecific genome size variation is hotly debated (Greilhuber 2005) and some authors attribute such variation only to methodological errors or taxa misidentification (Greilhuber 1998;Ohri 1998). However, factors like changes in repetitive DNA and retrotransposon activity (Bennetzen and Kellogg 1997), chromosomal phenomena such as duplications, aneuploidy and the presence of B-chromosomes (Poggio et al 1998) or even the existence of dimorphic sex chromosomes (Costich et al 1991), can be a source of variation within a species, amongst other possibilities. It is believed that changes in genome size within a species can be a true indicator of ongoing processes of speciation or genetic divergence (Price 1976;Murray 2005), although it is also true that speciation can take place without any change in nuclear DNA amounts (Bennett and Leitch 2005).…”

Section: Introductionmentioning

confidence: 99%

Genome size variation in the Artemisia arborescens complex (Asteraceae, Anthemideae) and its cultivars

Garcia¹,

Garnatje²,

Twibell³

et al. 2006

Genome

View full text Add to dashboard Cite

Different wild Mediterranean populations of Artemisia arborescens from diverse locations, representing its geographical distribution, as well as some of its well-known cultivars and some specimens cultivated as omamentals in gardens, streets, roads and nurseries, were analysed for genome size estimation. Other closely related species endemic to Macaronesia, A. canariensis, A. argentea and A. gorgonum, were also measured, and their nuclear DNA amount has been related to the biogeography of this group of species. Additionally, five populations of the closely related A. absinthium were analysed to establish comparisons. Measurements, acquired by flow cytometry, ranged from 8.29 pg to 11.61 pg for 2C values. Statistically significant differences of nuclear DNA amounts with respect to factors such as insularity or domestication have been detected. However, a quite low intraspecific genome size variation has been detected in these species. Furthermore, the study also addressed the possible hybrid origins, and possible misidentifications of some of the supposed cultivars ofA. arborescens..

show abstract

“…The cytogenetic studies conducted by Rosato et al (1998) and Poggio et al (1998) in 21 native populations from northwestern Argentina revealed a negative correlation between the mean number of B's per plant and the number of heterochromatic bands and a positive correlation between the mean number of B's per plant and altitude. According to these authors, B's would be tolerated at high frequencies in those populations with lower numbers of heterochromatic bands, so as to maintain a relatively constant amount of nuclear DNA or an ''optimal'' nucleotype (sensu Bennett 1987).…”

mentioning

confidence: 98%

B Chromosome Polymorphism in Maize Landraces: Adaptivevs. Demographic Hypothesis of Clinal Variation

2007

View full text Add to dashboard Cite

Cytogenetic analysis of maize landraces from northwestern Argentina has revealed an altitudinal cline in the mean number of B chromosomes (B's) per plant, with cultivars growing at higher altitudes exhibiting a higher number of B's. Altitudinal and longitudinal clines are frequently interpreted as evidence of selection, however, they can also be produced by the interplay between drift and spatially restricted gene flow or by admixture between previously isolated populations that have come into secondary contact. Here, we test the adaptive significance of the observed altitudinal gradient by comparing the levels of differentiation in the mean number of B's to those obtained from 18 selectively neutral loci ½simple sequence repeats (SSRs) among seven populations of the cline. The adequacy of alternative genetic-differentiation measures was determined, and associations between cytogenetic, genetic, and altitudinal distances were assessed by means of matrix-correspondence tests. No evidence for association between pairwise F ST and altitudinal distance or B-chromosome differentiation was found. The contrasting pattern of altitudinal divergence between the mean number of B's per plant and the genetic differentiation at SSR loci indicates that demographic processes cannot account for the observed levels of divergence in the mean number of B's.

show abstract

Genome Size and Environmental Correlations in Maize (Zea maysssp.mays, Poaceae)

Cited by 86 publications

References 50 publications

The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution

The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution

Genome size variation in the Artemisia arborescens complex (Asteraceae, Anthemideae) and its cultivars

B Chromosome Polymorphism in Maize Landraces: Adaptivevs. Demographic Hypothesis of Clinal Variation

Contact Info

Product

Resources

About