scholarly journals A deep dive into the ancestral chromosome number and genome size of flowering plants

2020 ◽  
Vol 228 (3) ◽  
pp. 1097-1106 ◽  
Author(s):  
Angelino Carta ◽  
Gianni Bedini ◽  
Lorenzo Peruzzi
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Flowering Plants ◽  
Deep Dive ◽  
Ancestral Chromosome

scholarly journals A deep dive into the ancestral chromosome number and genome size of flowering plants

2020 ◽  
Author(s):  
Angelino Carta ◽  
Gianni Bedini ◽  
Lorenzo Peruzzi
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Common Ancestor ◽  
Flowering Plants ◽  
Recent Common Ancestor ◽  
List Type ◽  
Deep Dive ◽  
Haploid Chromosome Number ◽  
Ancestral Chromosome ◽  
Genome Size Evolution

SummaryChromosome number and genome variation in flowering plants has stimulated a blossoming number of speculations about the ancestral chromosome number of angiosperms, but estimates so far remain equivocal.We used a probabilistic approach to model haploid chromosome number (n) changes along a phylogeny embracing more than 10 thousands taxa, to reconstruct the ancestral chromosome number of the common ancestor of extant angiosperms and the most recent common ancestor for single angiosperm families. Independently, we carried out an analysis of 1C genome size evolution, including over 5 thousands taxa.Our inferences revealed an ancestral haploid chromosome number for angiosperms n = 7, a diploid status, and an ancestral 1C = 1.73 pg. For 160 families, inferred ancestral n are provided for the first time.Both descending dysploidy and polyploidy played crucial roles in chromosome number evolution. While descending dysploidy is equally distributed early and late across the phylogeny, polyploidy is detected mainly towards the tips. Similarly, also 1C genome size significantly increases (or decreases) in late-branching lineages. Therefore, no evidence exists for a clear link between ancestral chromosome numbers and ancient polyploidization events, suggesting that further insights are needed to elucidate the organization of genome packaging into chromosomes.

B chromosomes and genome size in flowering plants

Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Robert Trivers ◽  
Austin Burt ◽  
Brian G Palestis
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Chromosome Number ◽  
Genome Size ◽  
Breeding System ◽  
Flowering Plants ◽  
B Chromosomes ◽  
Global Level ◽  
Selfish Genetic Elements ◽  
Large Genomes

B chromosomes are extra chromosomes found in some, but not all, individuals within a species, often maintained by giving themselves an advantage in transmission, i.e. they drive. Here we show that the presence of B chromosomes correlates to and varies strongly and positively with total genome size (excluding the Bs and corrected for ploidy) both at a global level and via a comparison of independent taxonomic contrasts. B chromosomes are largely absent from species with small genomes; however, species with large genomes are studied more frequently than species with small genomes and Bs are more likely to be reported in well-studied species. We controlled for intensity of study using logistic regression. This regression analysis also included effects of degree of outbreeding, which is positively associated with Bs and genome size, and chromosome number, which is negatively associated with Bs and genome size, as well as variable ploidy (more than one ploidy level in a species). Genome size, breeding system and chromosome number all contribute independently to the distribution of B chromosomes, while variable ploidy does not have a significant effect. The genome size correlates are consistent with reduced selection against extra DNA in species with large genomes and with increased generation of B sequences from large A genomes.Key words: B chromosomes, genome size, selfish genetic elements, breeding system, ploidy.

scholarly journals Limitation of current probe design for oligo-cross-FISH, exemplified by chromosome evolution studies in duckweeds

Chromosoma ◽  
2021 ◽  
Vol 130 (1) ◽  
pp. 15-25
Author(s):  
Phuong T. N. Hoang ◽  
Jean-Marie Rouillard ◽  
Jiří Macas ◽  
Ivona Kubalová ◽  
Veit Schubert ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chromosome Number ◽  
Chromosome Evolution ◽  
Sequence Similarity ◽  
Flowering Plants ◽  
The Other ◽  
Probe Design ◽  
Congeneric Species ◽  
Specific Design ◽  
Spirodela Polyrhiza

AbstractDuckweeds represent a small, free-floating aquatic family (Lemnaceae) of the monocot order Alismatales with the fastest growth rate among flowering plants. They comprise five genera (Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia) varying in genome size and chromosome number. Spirodela polyrhiza had the first sequenced duckweed genome. Cytogenetic maps are available for both species of the genus Spirodela (S. polyrhiza and S. intermedia). However, elucidation of chromosome homeology and evolutionary chromosome rearrangements by cross-FISH using Spirodela BAC probes to species of other duckweed genera has not been successful so far. We investigated the potential of chromosome-specific oligo-FISH probes to address these topics. We designed oligo-FISH probes specific for one S. intermedia and one S. polyrhiza chromosome (Fig. 1a). Our results show that these oligo-probes cross-hybridize with the homeologous regions of the other congeneric species, but are not suitable to uncover chromosomal homeology across duckweeds genera. This is most likely due to too low sequence similarity between the investigated genera and/or too low probe density on the target genomes. Finally, we suggest genus-specific design of oligo-probes to elucidate chromosome evolution across duckweed genera.

scholarly journals Genome size versus geographic range size in birds

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10868
Author(s):  
Beata Grzywacz ◽  
Piotr Skórka
Keyword(s):  
Natural Selection ◽  
Chromosome Number ◽  
Genome Size ◽  
Body Mass ◽  
Generalized Least Squares ◽  
Geographic Range ◽  
Range Size ◽  
Geographic Ranges ◽  
Brain Mass ◽  
Terrestrial Vertebrates

Why do some species occur in small, restricted areas, while others are distributed globally? Environmental heterogeneity increases with area and so does the number of species. Hence, diverse biotic and abiotic conditions across large ranges may lead to specific adaptations that are often linked to a species’ genome size and chromosome number. Therefore, a positive association between genome size and geographic range is anticipated. Moreover, high cognitive ability in organisms would be favored by natural selection to cope with the dynamic conditions within large geographic ranges. Here, we tested these hypotheses in birds—the most mobile terrestrial vertebrates—and accounted for the effects of various confounding variables, such as body mass, relative brain mass, and geographic latitude. Using phylogenetic generalized least squares and phylogenetic confirmatory path analysis, we demonstrated that range size is positively associated with bird genome size but probably not with chromosome number. Moreover, relative brain mass had no effect on range size, whereas body mass had a possible weak and negative effect, and range size was larger at higher geographic latitudes. However, our models did not fully explain the overall variation in range size. Hence, natural selection may impose larger genomes in birds with larger geographic ranges, although there may be additional explanations for this phenomenon.

Psidium guajava L.: taxonomy, relatives and possible origin.

2021 ◽  
pp. 1-21
Author(s):  
Leslie R. Landrum
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Morphological Characteristics ◽  
Psidium Guajava ◽  
Medicinal Uses ◽  
Species Complexes

Abstract This chapter focuses on the taxonomy and geography of guava (Psidium guajava). Information is given on geography, morphological characteristics, chromosome number and genome size, phytochemistry and medicinal uses, closest relatives, and keys to species complexes.

A new species of Acianthera (Pleurothallidinae, Orchidaceae) from Brazil

Phytotaxa ◽  
2019 ◽  
Vol 402 (1) ◽  
pp. 29
Author(s):  
JAN PONERT ◽  
ZUZANA CHUMOVÁ ◽  
TEREZIE MANDÁKOVÁ ◽  
PAVEL TRÁVNÍČEK
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Molecular Phylogeny ◽  
Genome Size ◽  
Size Estimation ◽  
Abaxial Side ◽  
Phylogenetic Placement ◽  
A New Species ◽  
Half Length

Acianthera sudae is newly described based on cultivated material from Brazil. It belongs to section Cryptophoranthae and differs from all others in this group by the larger flowers and sepals fused apically for more than half length, and a green-brown abaxial side of sepals with purple dots. Chromosome number (2n = 40) and genome size estimation (1C-value = 1.18 pg) is provided and its phylogenetic placement under the genus is supported with reconstruction of a molecular phylogeny using nuclear ribosomal ITS.

scholarly journals Correction to: Genome size and chromosome number of ten plant species from Kerguelen Islands

Polar Biology ◽  
2020 ◽  
Vol 43 (12) ◽  
pp. 2001-2002
Author(s):  
Sonja Siljak-Yakovlev ◽  
Françoise Lamy ◽  
Najat Takvorian ◽  
Nicolas Valentin ◽  
Valérie Gouesbet ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Plant Species ◽  
Kerguelen Islands
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