scholarly journals Peripatric speciation associated with genome expansion and female-biased sex ratios in the moss genus Ceratodon

2017 ◽  
Author(s):  
Marta Nieto-Lugilde ◽  
Olaf Werner ◽  
Stuart F. McDaniel ◽  
Petr Koutecký ◽  
Jan Kučera ◽  
...  
Keyword(s):  
New Species ◽  
Genome Size ◽  
Population Divergence ◽  
Size Change ◽  
Pcr Marker ◽  
Mediterranean Populations ◽  
Homogeneous Groups ◽  
A Genome ◽  
Peripatric Speciation ◽  
Well Differentiated

ABSTRACTPREMISE OF THE STUDYA period of allopatry is widely believed to be essential for the evolution of reproductive isolation. However, strict allopatry may be difficult to achieve in some cosmopolitan, spore-dispersed groups, like mosses. Here we examine the genetic and genome size diversity in Mediterranean populations of the moss Ceratodon purpureus s.l. to evaluate the role of allopatry and ploidy change in population divergence.METHODSWe sampled populations of the genus Ceratodon from mountainous areas and lowlands of the Mediterranean region, and from western and central Europe. We performed phylogenetic and coalescent analyses on sequences from five nuclear introns and a chloroplast locus to reconstruct their evolutionary history. We also estimated the genome size using flow cytometry, employing propidium iodide, and determined their sex using a sex-linked PCR marker.KEY RESULTSTwo well differentiated clades were resolved, discriminating two homogeneous groups: the widespread C. purpureus and a local group mostly restricted to the mountains in southern Spain. The latter also possessed a genome size 25% larger than the widespread C. purpureus, and the samples of this group consist entirely of females. We also found hybrids, and some of them had a genome size equivalent to the sum of the C. purpureus and Spanish genome, suggesting that they arose by allopolyploidy.CONCLUSIONSThese data suggest that a new species of Ceratodon arose via peripatric speciation, potentially involving a genome size change and a strong female-biased sex ratio. The new species has hybridized in the past with C. purpureus.

scholarly journals DNA Genome Size Affects the Stability of the Adenovirus Virion

2008 ◽  
Vol 83 (4) ◽  
pp. 2025-2028 ◽  
Author(s):  
Adam C. Smith ◽  
Kathy L. Poulin ◽  
Robin J. Parks
Keyword(s):  
Genome Size ◽  
Critical Role ◽  
Heat Stability ◽  
Helper Virus ◽  
Heat Inactivation ◽  
Similar Relationship ◽  
Viral Dna ◽  
A Genome ◽  
The Stability ◽  
Replication Defective Adenovirus

ABSTRACT Replication-defective adenovirus (Ad) vectors can vary considerably in genome length, but whether this affects virion stability has not been investigated. Helper-dependent Ad vectors with a genome size of ∼30 kb were 100-fold more sensitive to heat inactivation than their parental helper virus (>36 kb), and increasing the genome size of the vector significantly improved heat stability. A similar relationship between genome size and stability existed for Ad with early region 1 deleted. Loss of infectivity was due to release of vertex proteins, followed by disintegration of the capsid. Thus, not only does the viral DNA encode all of the heritable information essential for virus replication, it also plays a critical role in maintaining capsid strength and integrity.

scholarly journals The Arabidopsis lyrata genome sequence and the basis of rapid genome size change

2011 ◽  
Vol 43 (5) ◽  
pp. 476-481 ◽  
Author(s):  
Tina T Hu ◽  
Pedro Pattyn ◽  
Erica G Bakker ◽  
Jun Cao ◽  
Jan-Fang Cheng ◽  
...  
Keyword(s):  
Genome Size ◽  
Genome Sequence ◽  
Size Change ◽  
Arabidopsis Lyrata

A taxonomic note of Pterocephalus (Caprifoliaceae) from N Iran

Phytotaxa ◽  
2021 ◽  
Vol 494 (1) ◽  
pp. 137-144
Author(s):  
MASSOUD RANJBAR ◽  
ZAHRA RANJBAR
Keyword(s):  
New Species ◽  
Annual Species ◽  
Taxonomic Note ◽  
Golestan Province ◽  
Well Differentiated ◽  
A New Species

Pterocephalus ramianensis (Caprifoliaceae) is described and illustrated as a new species from Golestan Province, north Iran. This species is morphologically and micromorphologically well-differentiated from P. plumosus. The characters that distinguish this new species from P. plumosus are provided along with a key to the Iranian annual species in Pterocephalus.

scholarly journals Matching loci surveyed to questions asked in phylogeography

2016 ◽  
Vol 283 (1826) ◽  
pp. 20152340 ◽  
Author(s):  
Chih-Ming Hung ◽  
Sergei V. Drovetski ◽  
Robert M. Zink
Keyword(s):  
Population Diversity ◽  
Single Locus ◽  
Population Divergence ◽  
Summary Statistics ◽  
Recent Past ◽  
Size Change ◽  
The Caucasus ◽  
Nuclear Loci ◽  
The Difference ◽  
Coalescent Time

Although mitochondrial DNA (mtDNA) has long been used for assessing genetic variation within and between populations, its workhorse role in phylogeography has been criticized owing to its single-locus nature. The only choice for testing mtDNA results is to survey nuclear loci, which brings into contrast the difference in locus effective size and coalescence times. Thus, it remains unclear how erroneous mtDNA-based estimates of species history might be, especially for evolutionary events in the recent past. To test the robustness of mtDNA and nuclear sequences in phylogeography, we provide one of the largest paired comparisons of summary statistics and demographic parameters estimated from mitochondrial, five Z-linked and 10 autosomal genes of 30 avian species co-distributed in the Caucasus and Europe. The results suggest that mtDNA is robust in estimating inter-population divergence but not in intra-population diversity, which is sensitive to population size change. Here, we provide empirical evidence showing that mtDNA was more likely to detect population divergence than any other single locus owing to its smaller N e and thus faster coalescent time. Therefore, at least in birds, numerous studies that have based their inferences of phylogeographic patterns solely on mtDNA should not be readily dismissed.

scholarly journals Review of the dinoflagellate cyst <i>Stephanelytron</i> Sarjeant 1961 emend

1999 ◽  
Vol 18 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Bernard Courtinat
Keyword(s):  
New Species ◽  
New Combinations ◽  
Dinoflagellate Cyst ◽  
Peripatric Speciation ◽  
Two New Species ◽  
Endemic Population ◽  
New Evidence ◽  
Upper Callovian ◽  
Posterior Position ◽  
Stratigraphic Range

Abstract. The stratigraphic distribution of the Late Callovian to Early Oxfordian dinoflagellate cyst Stephanelytron Sarjeant 1961 emend provides new evidence pertaining to its evolution. Middle and Upper Callovian times favoured the development of speciations to a short-ranging Stephanelytron community with corona(s) in ventral–posterior position (Stephanelytron brontes, S. callovianum, S. ceto and S. tabulophorum) from eurytopic species with antapical coronas (S. caytonense, S. membranoidium, S. redcliffense and S. scarburghense). The former group of species (except S. tabulophorum) may represent an example of peripatric speciation from an unfavourable mutation. The reduced stratigraphic range gives the appearance of an endemic population. The genus Lagenadinium Piel, 1985 is a junior synonym of Stephanelytron Sarjeant, 1961. A new emendation of Stephanelytron, two new combinations (S. callovianum and S. membranoidium) and two new species (?S. brontes and S. ceto) are proposed.

scholarly journals Distribution of the rare species of clingfishes — small-headed clingfish Apletodon dentatus (Actinopterygii, Gobiesocidae) — near Crimean coasts

2017 ◽  
Vol 2 (2) ◽  
pp. 41-48
Author(s):  
E. P. Karpova ◽  
A. R. Boltachev ◽  
O. N. Danylyuk
Keyword(s):  
New Species ◽  
Species Composition ◽  
Coastal Waters ◽  
Taxonomic Status ◽  
Population Characteristics ◽  
The Black Sea ◽  
Mediterranean Populations ◽  
Morphological Studies ◽  
Significant Difference ◽  
A New Species

Cryptobenthic fauna investigations are highly relevant at studying biodiversity of regions. Studies of the species composition of Gobiesocidae family were carried out in order to clarify ichthyofauna of different regions, and a new species for the Black Sea coastal zone of Crimea was found. Information about its morphology, biology, behavior and other characteristics is very important because of weak study and indeterminate taxonomic status of this species. As a result of morphological studies of the Crimean specimens no significant difference with the type of the Atlantic-Mediterranean populations has been proven. Naturalization of small-headed clingfish in coastal waters of Crimea has been confirmed and some population characteristics, such as a length-weight relationship, have been described. Peculiarities of habitat which which small-headed clingfish prefers and features of localization, enabling competitiveness have been identified. Identification keys were compiled and are given in the paper.

Five new species and three new varieties of Begonia section Casparya endemic to Colombia

Phytotaxa ◽  
2021 ◽  
Vol 525 (4) ◽  
pp. 258-280
Author(s):  
ORLANDO ADOLFO JARA-MUÑOZ ◽  
JAMES E. RICHARDSON ◽  
JUAN CARLOS ZABALA-RIVERA
Keyword(s):  
New Species ◽  
Costa Rica ◽  
Conservation Status ◽  
Distribution Maps ◽  
Taxonomic Key ◽  
Colombian Andes ◽  
New Varieties ◽  
Taxonomic Novelties ◽  
Well Differentiated

Casparya, one of the most species-rich sections of Begonia in the Neotropics with 44 species, is distributed from Costa Rica to Peru, with the highest diversity in the Colombian Andes. The section is morphologically well-differentiated and can be distinguished from other Andean cane-like begonias by the 3-horned fruit and multifid or un-divided styles. Here we describe eight taxonomic novelties for Casparya from Colombia, five species and three varieties, descriptions include illustrations, distribution maps, taxonomic comments, and assessments of conservation status. The five species described here are: Begonia diegoi, Begonia galeanoi, Begonia mamapachensis, Begonia perijaensis, and Begonia vinagrera; and the three new varieties are: Begonia kalbreyerii var. orquidensis, Begonia silverstonei var. brevipetiolata, and Begonia vinagrera var. pomecensis. We also present a taxonomic key for the 32 species of Casparya so far known from Colombia.

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 Highly Contiguous Nanopore Genome Assembly of Chlamydomonas reinhardtii CC-1690

2020 ◽  
Vol 9 (37) ◽  
Author(s):  
Samuel O’Donnell ◽  
Frederic Chaux ◽  
Gilles Fischer
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Genome Size ◽  
Genome Assembly ◽  
Reference Genome ◽  
De Novo ◽  
Content Type ◽  
Oxford Nanopore ◽  
A Genome ◽  
Reference Quality

ABSTRACT The current Chlamydomonas reinhardtii reference genome remains fragmented due to gaps stemming from large repetitive regions. To overcome the vast majority of these gaps, publicly available Oxford Nanopore Technology data were used to create a new reference-quality de novo genome assembly containing only 21 contigs, 30/34 telomeric ends, and a genome size of 111 Mb.

scholarly journals Genome Sequence of a T4-like Phage, Escherichia Phage vB_EcoM-Sa45lw, Infecting Shiga Toxin-Producing Escherichia coli Strains

2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Genome Size ◽  
Shiga Toxin ◽  
Open Reading Frames ◽  
Content Type ◽  
E Coli ◽  
Double Stranded Dna ◽  
A Genome ◽  
Reading Frames

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.

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