scholarly journals ИССЛЕДОВАНИЕ РАЗМЕРА ГЕНОМА ПРЕДСТАВИТЕЛЕЙ РОДА POTENTILLA L. (ROSACEAE JUSS.)

Author(s):  
A. A. Kechaykin ◽  
M. V. Skaptsov ◽  
S. V. Smirnov ◽  
M. G. Kutsev ◽  
A. I. Shmakov

<p>In our study, 15 representatives of the genus <em>Potentilla</em> L. were analyzed to obtain the relative DNA content and monoploid genome size in the seeds by flow cytometry method. For these <em>Potentilla</em> species, except <em>P. argentea </em>and<em> P. norvegica</em>, DNA content and genome size are revealed for the first time. As a result, the following data were obtaining: representatives of the older section <em>Desertae</em> are diploids with the large monoploid genome size. The genome of <em>P. asiatica</em> (Chrysanthae section) are decrease up to 0.35 pg, while the ploidy is increased to 4. Representatives of the <em>Multifidae</em> and <em>Supinae</em> section are presented with tetra- and hexaploid species with the 0.3 pg of the monoploid genome size. In section Tanacetifoliae are observed a further decrease of the genome size, representatives basically tetraploids. Thus, in the genome size evolution of a <em>Potentilla </em>genera are observed the increase of ploidy with significant reductions in monoploid genome size. This fact proves the general theory of genome evolution of angiosperms, directed towards its reduction. Linear regression analysis was showed a positive correlation between chromosome number and genome size of the representatives of the <em>Potentilla </em>genera. This suggests that between genome size and the number of chromosomes in <em>Potentilla </em>species are linear dependence. Pearson correlation analysis confirmed this result: the correlation coefficient is 0.97 at P&lt;0.05. </p>

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 111
Author(s):  
Yun-Sang Yu ◽  
Soyeong Jin ◽  
Namjoon Cho ◽  
Jongok Lim ◽  
Cheol-Hak Kim ◽  
...  

We estimated the genome size of a relict longhorn beetle, Callipogon relictus Semenov (Cerambycidae: Prioninae)—the Korean natural monument no. 218 and a Class I endangered species—using a combination of flow cytometry and k-mer analysis. The two independent methods enabled accurate estimation of the genome size in Cerambycidae for the first time. The genome size of C. relictus was 1.8 ± 0.2 Gb, representing one of the largest cerambycid genomes studied to date. An accurate estimation of genome size of a critically endangered longhorned beetle is a major milestone in our understanding and characterization of the C. relictus genome. Ultimately, the findings provide useful insight into insect genomics and genome size evolution, particularly among beetles.


2019 ◽  
Vol 125 (4) ◽  
pp. 543-555 ◽  
Author(s):  
Jillian D Bainard ◽  
Steven G Newmaster ◽  
Jessica M Budke

Abstract Background and Aims Compared with other plant lineages, bryophytes have very small genomes with little variation across species, and high levels of endopolyploid nuclei. This study is the first analysis of moss genome evolution over a broad taxonomic sampling using phylogenetic comparative methods. We aim to determine whether genome size evolution is unidirectional as well as examine whether genome size and endopolyploidy are correlated in mosses. Methods Genome size and endoreduplication index (EI) estimates were newly generated using flow cytometry from moss samples collected in Canada. Phylogenetic relationships between moss species were reconstructed using GenBank sequence data and maximum likelihood methods. Additional 1C-values were compiled from the literature and genome size and EI were mapped onto the phylogeny to reconstruct ancestral character states, test for phylogenetic signal and perform phylogenetic independent contrasts. Key Results Genome size and EI were obtained for over 50 moss taxa. New genome size estimates are reported for 33 moss species and new EIs are reported for 20 species. In combination with data from the literature, genome sizes were mapped onto a phylogeny for 173 moss species with this analysis, indicating that genome size evolution in mosses does not appear to be unidirectional. Significant phylogenetic signal was detected for genome size when evaluated across the phylogeny, whereas phylogenetic signal was not detected for EI. Genome size and EI were not found to be significantly correlated when using phylogenetically corrected values. Conclusions Significant phylogenetic signal indicates closely related mosses have more similar genome sizes and EI values. This study supports that DNA content in mosses is defined by small genomes that are highly endopolyploid, suggesting strong selective pressure to maintain these features. Further research is needed to understand the functional significance of DNA content evolution in mosses.


Evolution ◽  
2001 ◽  
Vol 55 (11) ◽  
pp. 2363 ◽  
Author(s):  
Elizabeth L. Brainerd ◽  
Sandra S. Slutz ◽  
Edward K. Hall ◽  
Randall W. Phillis

2017 ◽  
Vol 178 (5) ◽  
pp. 352-361 ◽  
Author(s):  
Meghan Castelli ◽  
Cathy H. Miller ◽  
Alexander N. Schmidt-Lebuhn

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
C. P. Stelzer ◽  
J. Blommaert ◽  
A. M. Waldvogel ◽  
M. Pichler ◽  
B. Hecox-Lea ◽  
...  

Abstract Background Eukaryotic genomes are known to display an enormous variation in size, but the evolutionary causes of this phenomenon are still poorly understood. To obtain mechanistic insights into such variation, previous studies have often employed comparative genomics approaches involving closely related species or geographically isolated populations within a species. Genome comparisons among individuals of the same population remained so far understudied—despite their great potential in providing a microevolutionary perspective to genome size evolution. The rotifer Brachionus asplanchnoidis represents one of the most extreme cases of within-population genome size variation among eukaryotes, displaying almost twofold variation within a geographic population. Results Here, we used a whole-genome sequencing approach to identify the underlying DNA sequence differences by assembling a high-quality reference genome draft for one individual of the population and aligning short reads of 15 individuals from the same geographic population including the reference individual. We identified several large, contiguous copy number variable regions (CNVs), up to megabases in size, which exhibited striking coverage differences among individuals, and whose coverage overall scaled with genome size. CNVs were of remarkably low complexity, being mainly composed of tandemly repeated satellite DNA with only a few interspersed genes or other sequences, and were characterized by a significantly elevated GC-content. CNV patterns in offspring of two parents with divergent genome size and CNV patterns in several individuals from an inbred line differing in genome size demonstrated inheritance and accumulation of CNVs across generations. Conclusions By identifying the exact genomic elements that cause within-population genome size variation, our study paves the way for studying genome size evolution in contemporary populations rather than inferring patterns and processes a posteriori from species comparisons.


2016 ◽  
Author(s):  
Aurélie Kapusta ◽  
Alexander Suh ◽  
Cédric Feschotte

AbstractGenome size in mammals and birds shows remarkably little interspecific variation compared to other taxa. Yet, genome sequencing has revealed that many mammal and bird lineages have experienced differential rates of transposable element (TE) accumulation, which would be predicted to cause substantial variation in genome size between species. Thus, we hypothesize that there has been co-variation between the amount of DNA gained by transposition and lost by deletion during mammal and avian evolution, resulting in genome size homeostasis. To test this model, we develop a computational pipeline to quantify the amount of DNA gained by TE expansion and lost by deletion over the last 100 million years (My) in the lineages of 10 species of eutherian mammals and 24 species of birds. The results reveal extensive variation in the amount of DNA gained via lineage-specific transposition, but that DNA loss counteracted this expansion to various extent across lineages. Our analysis of the rate and size spectrum of deletion events implies that DNA removal in both mammals and birds has proceeded mostly through large segmental deletions (>10 kb). These findings support a unified ‘accordion’ model of genome size evolution in eukaryotes whereby DNA loss counteracting TE expansion is a major determinant of genome size. Furthermore, we propose that extensive DNA loss, and not necessarily a dearth of TE activity, has been the primary force maintaining the greater genomic compaction of flying birds and bats relative to their flightless relatives.


2020 ◽  
Author(s):  
Jing Li ◽  
Meiqi Lv ◽  
Lei Du ◽  
A Yunga ◽  
Shijie Hao ◽  
...  

AbstractThe monocot family Melanthiaceae with varying genome sizes in a range of 230-fold is an ideal model to study the genome size fluctuation in plants. Its family member Paris genus demonstrates an evolutionary trend of bearing huge genomes characterized by an average c-value of 49.22 pg. Here, we report a 70.18 Gb genome assembly out of the 82.55 Gb genome of Paris polyphylla var. yunnanensis (PPY), which represents the biggest sequenced genome to date. We annotate 69.53% repetitive sequences in this genome and 62.50% of which are long-terminal repeat (LTR) transposable elements. Further evolution analysis indicates that the giant genome likely results from the joint effect of common and species-specific expansion of different LTR superfamilies, which might contribute to the environment adaptation after speciation. Moreover, we identify the candidate pathway genes for the biogenesis of polyphyllins, the PPY-specific medicinal saponins, by complementary approaches including genome mining, comprehensive analysis of 31 next-generation RNA-seq data and 55.23 Gb single-molecule circular consensus sequencing (CCS) RNA-seq reads, and correlation of the transcriptome and phytochemical data of five different tissues at four growth stages. This study not only provides significant insights into plant genome size evolution, but also paves the way for the following polyphyllin synthetic biology.


Genome ◽  
2017 ◽  
Vol 60 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Catherine E. Newman ◽  
T. Ryan Gregory ◽  
Christopher C. Austin

The genus Plethodon is the most species-rich salamander genus in North America, and nearly half of its species face an uncertain future. It is also one of the most diverse families in terms of genome sizes, which range from 1C = 18.2 to 69.3 pg, or 5–20 times larger than the human genome. Large genome size in salamanders results in part from accumulation of transposable elements and is associated with various developmental and physiological traits. However, genome sizes have been reported for only 25% of the species of Plethodon (14 of 55). We collected genome size data for Plethodon serratus to supplement an ongoing phylogeographic study, reconstructed the evolutionary history of genome size in Plethodontidae, and inferred probable genome sizes for the 41 species missing empirical data. Results revealed multiple genome size changes in Plethodon: genomes of western Plethodon increased, whereas genomes of eastern Plethodon decreased, followed by additional decreases or subsequent increases. The estimated genome size of P. serratus was 21 pg. New understanding of variation in genome size evolution, along with genome size inferences for previously unstudied taxa, provide a foundation for future studies on the biology of plethodontid salamanders.


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