scholarly journals Genome size variation and species diversity in salamanders

2016 ◽  
Author(s):  
John Herrick ◽  
Bianca Sclavi

AbstractSalamanders (Urodela) have among the largest vertebrate genomes, ranging in size from 10 to 120 pg. Although changes in genome size often occur randomly and in the absence of selection pressure, non-random patterns of genome size variation are evident among specific vertebrate lineages. Several reports suggest a relationship between species richness and genome size, but the exact nature of that relationship remains unclear both within and across different taxonomic groups. Here we report i) a negative relationship between haploid genome size (C-value) and species richness at the family taxonomic level in salamander clades; ii) a correlation of C-value and species richness with clade crown-age but not with diversification rates; iii) strong associations between C-value and either geographical area or climatic niche rate. Finally, we report a relationship between C-value diversity and species diversity at both the family and genus level clades in urodeles.

2020 ◽  
Vol 194 (1) ◽  
pp. 47-68
Author(s):  
Robyn F Powell ◽  
Laura Pulido Suarez ◽  
Anthony R Magee ◽  
James S Boatwright ◽  
Maxim V Kapralov ◽  
...  

Abstract Aizoaceae are one of the most diverse succulent plant families in the world, with c. 2 400 species, and they are a major component of the Greater Cape Floristic Region of South Africa. Despite this diversity, genome size (GS) has only been recorded in three of the c. 144 genera of Aizoaceae. This study provides the first comprehensive assessment of GS in the family with 109 genera measured (76% of genera). GS (2C) is conserved in Aizoaceae, varying from 0.54 to 6.34 pg (0.53–6.20 Gbp), with a mean of 2.6 pg. No significant differences between GS and the ecological and environmental traits tested were recovered. Infrageneric GS was explored in the most diverse stoneplant genus, Conophytum, and was found to be extremely conserved [0.98–2.24 pg (1C)]. Furthermore, the extent of endoreduplication in Conophytum was determined across 46 species. Leaf and flower tissues of Conophytum are highly polysomatic and ploidy states of 2C–64C were typically observed across the genus, with some instances of 128C. The relatively conserved and small GS measured across Aizoaceae and in Conophytum is possibly linked to the recent and rapid radiation of the family.


2002 ◽  
Vol 50 (6) ◽  
pp. 735-749 ◽  
Author(s):  
David C. Hardie ◽  
T. Ryan Gregory ◽  
Paul D.N. Hebert

The study of genome size variation is important from a number of practical and theoretical perspectives. For example, the long-standing “C-value enigma” relating to the more than 200,000-fold range in eukaryotic genome sizes is best studied from a broad comparative standpoint. Genome size data are also required in detailed analyses of genome structure and evolution. The choice of future genome sequencing projects will be dependent on knowledge regarding the sizes of genomes to be sequenced, and so on. To date, genome size data have been acquired primarily by Feulgen microdensitometry or flow cytometry. Each has several advantages but also important limitations. In this review, we provide a practical guide to the new technique of Feulgen image analysis densitometry. The review is designed for those interested in genome size measurements but not extensively experienced in histochemistry, densitometry, or microscopy. Therefore, relevant historical and technical background information is included. For easy reference, we provide recipes for required reagents, guidelines for cell staining, and a checklist of steps for successful image analysis. We hope that the accuracy, rapidity, and cost-effectiveness of Feulgen image analysis demonstrated here will stimulate further surveys of genome sizes in a variety of taxa.


Caryologia ◽  
2013 ◽  
Vol 66 (3) ◽  
pp. 221-235 ◽  
Author(s):  
Joan Vallès ◽  
Miguel Ángel Canela ◽  
Sònia Garcia ◽  
Oriane Hidalgo ◽  
Jaume Pellicer ◽  
...  

2019 ◽  
Vol 32 (3) ◽  
pp. 278-286 ◽  
Author(s):  
Bianca Sclavi ◽  
John Herrick

Genome ◽  
2006 ◽  
Vol 49 (3) ◽  
pp. 244-253 ◽  
Author(s):  
Sònia Garcia ◽  
Teresa Garnatje ◽  
John D Twibell ◽  
Joan Vallès

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 ornamentals in gardens, streets, roads and nurseries, were analysed for genome size. Other closely related species endemic to Macaronesia, Artemisia canariensis, Artemisia argentea, and Artemisia gorgonum, were also analysed, and their nuclear DNA amount has been related to the biogeography of this group of species. Additionally, 5 populations of the closely related Artemisia absinthium were analysed to establish comparisons. Measurements acquired by flow cytometry ranged from 8.29 to 11.61 pg for 2C values. Statistically significant differences of 2C nuclear DNA amounts with respect to factors such as insularity or domestication have been detected. However, quite a low intraspecific genome size variation has been found in these species. Furthermore, the study also addressed the possible hybrid origins and possible misidentifications of some of the supposed cultivars of A. arborescens.Key words: Artemisia arborescens, Artemisia absinthium, Artemisia argentea, Artemisia canariensis, Artemisia gorgonum, C value, Compositae, cultivar, domestication, flow cytometry, genome size, hybridization, interspecific variation, intraspecific variation, speciation.


Crop Science ◽  
2004 ◽  
Vol 44 (1) ◽  
pp. 261 ◽  
Author(s):  
A. Lane Rayburn ◽  
D. P. Biradar ◽  
R. L. Nelson ◽  
R. McCloskey ◽  
K. M. Yeater

2017 ◽  
Vol 4 (9) ◽  
pp. 170862 ◽  
Author(s):  
H. Ritchie ◽  
A. J. Jamieson ◽  
S. B. Piertney

Genome size varies considerably across taxa, and extensive research effort has gone into understanding whether variation can be explained by differences in key ecological and life-history traits among species. The extreme environmental conditions that characterize the deep sea have been hypothesized to promote large genome sizes in eukaryotes. Here we test this supposition by examining genome sizes among 13 species of deep-sea amphipods from the Mariana, Kermadec and New Hebrides trenches. Genome sizes were estimated using flow cytometry and found to vary nine-fold, ranging from 4.06 pg (4.04 Gb) in Paralicella caperesca to 34.79 pg (34.02 Gb) in Alicella gigantea . Phylogenetic independent contrast analysis identified a relationship between genome size and maximum body size, though this was largely driven by those species that display size gigantism. There was a distinct shift in the genome size trait diversification rate in the supergiant amphipod A. gigantea relative to the rest of the group. The variation in genome size observed is striking and argues against genome size being driven by a common evolutionary history, ecological niche and life-history strategy in deep-sea amphipods.


Genome ◽  
2016 ◽  
Vol 59 (6) ◽  
pp. 393-402 ◽  
Author(s):  
Nicholas W. Jeffery ◽  
Kristin Hultgren ◽  
Solomon Tin Chi Chak ◽  
T. Ryan Gregory ◽  
Dustin R. Rubenstein

Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.


Caryologia ◽  
2015 ◽  
Vol 68 (2) ◽  
pp. 92-96 ◽  
Author(s):  
Oriane Hidalgo ◽  
Joan Vallès ◽  
Angel Romo ◽  
Miguel-Ángel Canela ◽  
Teresa Garnatje

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