Karyotype evolution in the Pinaceae: implication with molecular phylogeny

Genome ◽  
2012 ◽  
Vol 55 (11) ◽  
pp. 735-753 ◽  
Author(s):  
K.K. Nkongolo ◽  
M. Mehes-Smith

The family Pinaceae is made up mostly of diploid species (2n = 24). Systematization of karyotype analysis was developed to make comparison of intra- and interspecific karyotypes among the Pinaceae more accurate and reliable. Considering all parameters, the genera Pseudotsuga and Pseudolarix have the “most derived” (or advanced) and asymmetric karyotypes in the Pinaceae, followed by Larix, Picea, Abies, and Cedrus. The genus Pinus was the “least derived” (or ancestral) of all the genera of the Pinaceae analyzed. Differences in karyotype formulae and asymmetry indices were found among species within the same genera, suggesting that structural changes may have contributed to the diversification of the genus. This review is a detailed analysis of comparative karyotyping based on similar parameters, including numeric data and cytogenetic information. Telomeric sequence repeats and rDNA distribution in the Pinaceae were surveyed. The role of transposition in rDNA chromosome distribution is analyzed. Cytogenetic implications of hybridization between related species are reported. Likewise, the relationships between molecular phylogenetic and karyotype evolution is discussed in light of several reports. Within many genera, chromosomal organization was conserved despite independent molecular divergence and adaptation through the evolutionary history of the species of the Pinaceae.

2021 ◽  
Author(s):  
Keerthic Aswin ◽  
Srinivasan Ramachandran ◽  
Vivek T Natarajan

AbstractEvolutionary history of coronaviruses holds the key to understand mutational behavior and prepare for possible future outbreaks. By performing comparative genome analysis of nidovirales that contain the family of coronaviruses, we traced the origin of proofreading, surprisingly to the eukaryotic antiviral component ZNFX1. This common recent ancestor contributes two zinc finger (ZnF) motifs that are unique to viral exonuclease, segregating them from DNA proof-readers. Phylogenetic analyses indicate that following acquisition, genomes of coronaviruses retained and further fine-tuned proofreading exonuclease, whereas related families harbor substitution of key residues in ZnF1 motif concomitant to a reduction in their genome sizes. Structural modelling followed by simulation suggests the role of ZnF in RNA binding. Key ZnF residues strongly coevolve with replicase, and the helicase involved in duplex RNA unwinding. Hence, fidelity of replication in coronaviruses is a result of convergent evolution, that enables maintenance of genome stability akin to cellular proofreading systems.


2019 ◽  
Vol 158 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Suziane A. Barcellos ◽  
Rafael Kretschmer ◽  
Marcelo S. de Souza ◽  
Alice L. Costa ◽  
Tiago M. Degrandi ◽  
...  

As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and FISH with 11 microsatellite sequences. The diploid chromosome number was 2n = 76 in all 3 species, and NORs were observed in 2 chromosome pairs each. The microsatellite distribution pattern was similar in both Progne species, whereas P. cyanoleuca presented a distinct organization. These repetitive DNA sequences were found in the centromeric, pericentromeric, and telomeric regions of the macrochromosomes, as well as in 2 interstitial blocks in the W chromosome. Most microchromosomes had mainly telomeric signals. The Z chromosome displayed 1 hybridization signal in P. tapera but none in the other species. In contrast, the W chromosome showed an accumulation of different microsatellite sequences. The swallow W chromosome is larger than that of most Passeriformes. The observed enlargement in chromosome size might be explained by these high amounts of repetitive sequences. In sum, our data highlight the significant role that microsatellite sequences may play in sex chromosome differentiation.


2015 ◽  
Vol 84 (4) ◽  
pp. 275-287 ◽  
Author(s):  
Ole E. Heie

Abstract Several characters of the Lachnidae are discussed, and it is explained why some of them are not plesiomorphies as previously believed, but apomorphies. This applies e.g. to the absence of host alternation in the extant genera, to the short cauda and to the presence of compound eyes in the nymphs and the apterous adults. Some characters are adaptations to attention by ants or ways of feeding. It is concluded that many characters show that the family is relatively young and probably originally had host alternation of the same kind as Aphididae, which is regarded as the sister group. The results of some molecular phylogenetic studies are discussed.


2021 ◽  
Author(s):  
Chaehee Lee ◽  
In-Su Choi ◽  
Domingos Cardoso ◽  
Haroldo C. de Lima ◽  
Luciano P. de Queiroz ◽  
...  

AbstractThe plastid genome (plastome), while surprisingly constant in gene order and content across most photosynthetic angiosperms, exhibits variability in several unrelated lineages. During the diversification history of the legume family Fabaceae, plastomes have undergone many rearrangements, including inversions, expansion, contraction and loss of the typical inverted repeat (IR), gene loss and repeat accumulation in both shared and independent events. While legume plastomes have been the subject of study for some time, most work has focused on agricultural species in the IR-lacking clade (IRLC) and the plant model Medicago truncatula. The subfamily Papilionoideae, which contains virtually all of the agricultural legume species, also comprises most of the plastome variation detected thus far in the family. In this study 33 newly sequenced plastomes of papilionoid legumes and outgroups were evaluated, along with 34 publicly available sequences, to assess plastome structural evolution in the subfamily. In an effort to examine plastome variation across the subfamily, just ∼20% of the sampling represents the IRLC with the remainder selected to represent the early-branching papilionoid clades. A number of IR-related and repeat-mediated changes were identified and examined in a phylogenetic context. Recombination between direct repeats associated with ycf2 resulted in intraindividual plastome heteroplasmy. Although loss of the inverted repeat has not been reported in legumes outside of the IRLC, one genistoid taxon was found to completely lack the typical plastome IR. The role of the IR and non-IR repeats in driving plastome change is discussed.Significance statementComparative genomic approaches employing plastid genomes (plastomes) have revealed that they are more variable across angiosperms than previously suggested. This study examined 64 species of Fabaceae and outgroups, including 33 newly sequenced taxa, to explore plastome structural evolution of the subfamily Papilionoideae in a phylogenetic context. Several unusual features of the inverted repeat highlight the importance of recombination in plastomic structural changes within and between individuals and species.


2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 163
Author(s):  
Airy Gras ◽  
Oriane Hidalgo ◽  
Ugo D’Ambrosio ◽  
Montse Parada ◽  
Teresa Garnatje ◽  
...  

Studies suggesting that medicinal plants are not chosen at random are becoming more common. The goal of this work is to shed light on the role of botanical families in ethnobotany, depicting in a molecular phylogenetic frame the relationships between families and medicinal uses of vascular plants in several Catalan-speaking territories. The simple quantitative analyses for ailments categories and the construction of families and disorders matrix were carried out in this study. A Bayesian approach was used to estimate the over- and underused families in the medicinal flora. Phylogenetically informed analyses were carried out to identify lineages in which there is an overrepresentation of families in a given category of use, i.e., hot nodes. The ethnobotanicity index, at a specific level, was calculated and also adapted to the family level. Two diversity indices to measure the richness of reported taxa within each family were calculated. A total of 47,630 use reports were analysed. These uses are grouped in 120 botanical families. The ethnobotanicity index for this area is 14.44% and the ethnobotanicity index at the family level is 68.21%. The most-reported families are Lamiaceae and Asteraceae and the most reported troubles are disorders of the digestive and nutritional system. Based on the meta-analytic results, indicating hot nodes of useful plants at the phylogenetic level, specific ethnopharmacological research may be suggested, including a phytochemical approach of particularly interesting taxa.


1990 ◽  
Vol 3 (1) ◽  
pp. 145
Author(s):  
DJ Colgan

This paper is a review of the use of information regarding the presence of duplicate genes and their regulation in systematics. The review concentrates on data derived from protein electrophoresis and restriction fragment length polymorphism analysis. The appearance of a duplication in a subset of a group of species implies that the members of the subset belong to the same clade. Suppression of the duplication may render this clade apparently paraphyletic, but may itself be informative of relations within the lineage through patterns of loss of expression in all, or some tissues, or through restrictions of the formation of functional heteropolymers in polymeric enzymes. Examples are given of studies which have used such information to establish phylogenetic hypotheses at the family level, to identify an auto- or allo-polyploid origin of polyploid species and to determine whether there have been single or multiple origins of such species. The likelihood of homoplasy in the patterns of appearance and regulation of duplicates depends on the molecular basis of the duplication. In particular, the contrast between the expected consequences of tandem duplication and the expression of pseudogenes emphasises the value of determining the mechanism of the original duplication. Many instances of sporadic gene duplication are now known, and polyploidisation is a common event in the evolutionary history of both plants and animals. So the opportunities to discover duplicationrelated characters will arise in many systematic studies. A program is presented to increase the chances that such useful information will be recognisable during the studies.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christophe Duplais ◽  
Vincent Sarou-Kanian ◽  
Dominique Massiot ◽  
Alia Hassan ◽  
Barbara Perrone ◽  
...  

AbstractAcross the evolutionary history of insects, the shift from nitrogen-rich carnivore/omnivore diets to nitrogen-poor herbivorous diets was made possible through symbiosis with microbes. The herbivorous turtle ants Cephalotes possess a conserved gut microbiome which enriches the nutrient composition by recycling nitrogen-rich metabolic waste to increase the production of amino acids. This enrichment is assumed to benefit the host, but we do not know to what extent. To gain insights into nitrogen assimilation in the ant cuticle we use gut bacterial manipulation, 15N isotopic enrichment, isotope-ratio mass spectrometry, and 15N nuclear magnetic resonance spectroscopy to demonstrate that gut bacteria contribute to the formation of proteins, catecholamine cross-linkers, and chitin in the cuticle. This study identifies the cuticular components which are nitrogen-enriched by gut bacteria, highlighting the role of symbionts in insect evolution, and provides a framework for understanding the nitrogen flow from nutrients through bacteria into the insect cuticle.


2020 ◽  
Author(s):  
А.Б. Бритаева

В представленной статье на материале произведений Музафера Дзасохова известного современного осетинского писателя, поэта, публициста, переводчика, рассматриваются художественные особенности лирической прозы, а именно, автобиографической повести в осетинской детской литературе. Повесть Весенние звезды (1973) и ее продолжение На берегу Уршдона Барагун (1981) стали началом эпопеи о жизни отдельно взятой семьи, а на их примере всей страны в тяжелые послевоенные годы. В качестве одной из важнейших констант художественного мира писателя рассматривается образ детства. В ходе анализа особое внимание уделяется преобладанию нравственного аспекта, актуализации проблемы регулятивно-воспитательной функции национального этикета, ценностно-нормативных ориентиров осетинской ментальности. С опорой на биографический и историко-генетический методы, основное внимание в исследовании акцентируется на темах послевоенного детства, роли семьи и общества в формировании нравственных ориентиров, в становлении личности, образе матери, теме памяти, а также на художественном осмыслении этих проблем и тем в автобиографических повестях писателя. Типологически воплощение детской темы в творчестве М. Дзасохова во многом опирается на традицию изображения детства в русской автобиографической прозе XX в. В заключительной части сформулированы выводы, отражающие особенности лирической прозы в творчестве М. Дзасохова, обозначено место автобиографических повестей автора в контексте осетинской детской литературы второй половины XX века.Актуальность и научная новизна работы обусловлены недостаточной исследованностью истории и проблем осетинской детской литературы. Результаты исследования могут быть использованы при написании истории осетинской детской литературы. The present article examines the artistic features of lyrical prose, namely, autobiographical story in the Ossetian childrens literature in the works of Muzafer Dzasokhov, a well-known modern Ossetian writer, poet, publicist, translator. The story Spring Stars (1973) and its continuation - On the Bank of Ursdon Baragun ... (1981) marked the beginning of an epic about the life of a family, and via their fates the author shows life of the whole country in the difficult post-war years. The theme of childhood is considered as one of the most important constants of the writers artistic world. In the course of the analysis, special attention is paid to the predominance of the moral aspect, the actualization of the problem of the regulatory and educational function of national etiquette, the value and normative guidelines of the Ossetian mentality. The focus of the study is based on biographical and historical-genetic methods and highlights the themes of post-war childhood, the role of the family and society in the formation of moral guidelines, in the formation of personality, the image of the mother, the theme of memory, as well as on the artistic understanding of these problems and topics in autobiographical novels of the writer. Typologically, the embodiment of the childrens theme in the works of M. Dzasokhov is largely based on the tradition of depicting childhood in Russian autobiographical prose of the XXth century. The formulated conclusions in the final part reflect the peculiarities of lyrical prose in the works of M. Dzasokhov, the place of the authors autobiographical stories is indicated in the context of Ossetian childrens literature of the second half of the XXth century. The relevance and scientific novelty of the work are due to insufficient research on the history and problems of Ossetian childrens literature. The results of the study can be used in writing the history of Ossetian childrens literature.


Science ◽  
2021 ◽  
Vol 373 (6551) ◽  
pp. 226-231 ◽  
Author(s):  
Yasuka Toda ◽  
Meng-Ching Ko ◽  
Qiaoyi Liang ◽  
Eliot T. Miller ◽  
Alejandro Rico-Guevara ◽  
...  

Early events in the evolutionary history of a clade can shape the sensory systems of descendant lineages. Although the avian ancestor may not have had a sweet receptor, the widespread incidence of nectar-feeding birds suggests multiple acquisitions of sugar detection. In this study, we identify a single early sensory shift of the umami receptor (the T1R1-T1R3 heterodimer) that conferred sweet-sensing abilities in songbirds, a large evolutionary radiation containing nearly half of all living birds. We demonstrate sugar responses across species with diverse diets, uncover critical sites underlying carbohydrate detection, and identify the molecular basis of sensory convergence between songbirds and nectar-specialist hummingbirds. This early shift shaped the sensory biology of an entire radiation, emphasizing the role of contingency and providing an example of the genetic basis of convergence in avian evolution.


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