scholarly journals Analysis of the small chromosomal Prionium serratum (Cyperid) demonstrates the importance of a reliable method to differentiate between mono- and holocentricity

Author(s):  
M. Baez ◽  
Y.T. Kuo ◽  
Y. Dias ◽  
T. Souza ◽  
A. Boudichevskaia ◽  
...  

AbstractFor a long time, the Cyperid clade (Thurniceae-Juncaceae-Cyperaceae) was considered as a group of species possessing holocentromeres exclusively. The basal phylogenetic position of Prionium serratum L. f. Drège (Thurniceae) within Cyperids makes this species an important specimen to understand the centromere evolution within this clade. Unlike expected, the chromosomal distribution of the centromere-specific histone H3 (CENH3), alpha-tubulin and different centromere associated post-translational histone modifications (H3S10ph, H3S28ph and H2AT120ph) demonstrate a monocentromeric organisation of P. serratum chromosomes. Analysis of the high-copy repeat composition resulted in the identification of a centromere-localised satellite repeat. Hence, monocentricity was the ancestral condition for the Juncaceae-Cyperaceae-Thurniaceae Cyperid clade and holocentricity in this clade has independently arisen at least twice after differentiation of the three families, once in Juncaceae and the other one in Cyperaceae. Methods suitable for the identification of holocentromeres are discussed.

Chromosoma ◽  
2020 ◽  
Vol 129 (3-4) ◽  
pp. 285-297
Author(s):  
M. Baez ◽  
Y. T. Kuo ◽  
Y. Dias ◽  
T. Souza ◽  
A. Boudichevskaia ◽  
...  

AbstractFor a long time, the Cyperid clade (Thurniceae-Juncaceae-Cyperaceae) was considered a group of species possessing holocentromeres exclusively. The basal phylogenetic position of Prionium serratum (Thunb.) Drège (Thurniceae) within Cyperids makes this species an important specimen to understand the centromere evolution within this clade. In contrast to the expectation, the chromosomal distribution of the centromere-specific histone H3 (CENH3), alpha-tubulin and different centromere-associated post-translational histone modifications (H3S10ph, H3S28ph and H2AT120ph) demonstrate a monocentromeric organisation of P. serratum chromosomes. Analysis of the high-copy repeat composition resulted in the identification of two centromere-localised satellite repeats. Hence, monocentricity was the ancestral condition for the Juncaceae-Cyperaceae-Thurniaceae Cyperid clade, and holocentricity in this clade has independently arisen at least twice after differentiation of the three families, once in Juncaceae and the other one in Cyperaceae. In this context, methods suitable for the identification of holocentromeres are discussed.


2019 ◽  
Vol 11 (10) ◽  
pp. 2824-2849 ◽  
Author(s):  
Paweł Mackiewicz ◽  
Adam Dawid Urantówka ◽  
Aleksandra Kroczak ◽  
Dorota Mackiewicz

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.


2021 ◽  
Author(s):  
Satoyo Oya ◽  
Mayumi Takahashi ◽  
Kazuya Takashima ◽  
Tetsuji Kakutani ◽  
Soichi Inagaki

Mono-, di-, and trimethylation of histone H3 lysine 4 (H3K4me1/2/3) are associated with transcription, yet it remains controversial whether H3K4me1/2/3 promote or result from transcription. Our previous characterizations of Arabidopsis H3K4 demethylases suggest roles for H3K4me1 in transcription. However, the control of H3K4me1 remains unexplored in Arabidopsis, in which no methylase for H3K4me1 has been identified. Here, we identified three Arabidopsis methylases that direct H3K4me1. Analyses of their genome-wide localization using ChIP-seq and machine learning revealed that one of the enzymes cooperates with the transcription machinery, while the other two are associated with specific histone modifications and DNA sequences. Importantly, these two types of localization patterns are also found for the other H3K4 methylases in Arabidopsis and mice. These results suggest that H3K4me1/2/3 are established and maintained via interplay with transcription as well as inputs from other chromatin features, presumably enabling elaborate gene control.


2010 ◽  
Vol 19 (1-2) ◽  
pp. 127-147 ◽  
Author(s):  
Krister Hertting

Leading with Pedagogical Tact- a Challenge in Children's Sports in Sweden The purpose of this article is to elucidate and problemize meetings between children and leaders in children's sport. The competitive sport is high valuated in the Swedish society and sport for children is central in the Swedish youth politics. The foundation in Swedish sport, as well as in the other Nordic countries, has for a long time relied on voluntary commitment. Approximately 650 000 people are voluntary engaged as leaders in sport in Sweden and 70% of children between 7 and 14 years compete in sports clubs. There is, however, a tension in the Swedish sport system. The sports for children has double missions - ‘association nurturing’ and ‘competition nurturing’, missions which are not always in harmony. In the daily activity it is the voluntary leaders who have to deal with these missions, which creates a field of tension. In this article I argue for a bridge between these missions by a leadership based on pedagogical tact. The empirical outlook is a narrative based on statements from leaders, children and parents in a study dealing with voluntary leadership within children's football. In the end I argue that focusing on this bridge is a win-win situation, both for children and sports.


2014 ◽  
pp. 691-697
Author(s):  
Suleiman José Hassuani

The sugarcane industry for a long time has focused only on the cane juice, its extraction and conversion to sugar. Bagasse was considered a residue and burnt inefficiently to generate steam and power. In the last decades, bagasse gradually started to be converted into energy in a more efficient way, supplying all the sugar industry energy needs (power, and steam) and, in some cases, significant excess electricity has been exported to the grid, becoming another important source of revenue. This motivated several studies of more advanced energy generation systems to boost energy exports. In more recent years, technologies called 2nd and 3rd generation have taken over the scene with many options, promising to convert biomass into more valuable products such as biofuels, chemicals, fertilisers, pellets, etc. Unfilled expectations and opportunities are rising. On the other hand, these technologies are competing for the same biomass, and this has to be considered. The industry has started to question ‘which way to go’, strategy and investment wise. The present study provides a broad scenario for the biomass availability, and its employment, with a close view to the main processes and products that might have an important role in the future of the biomass in the sugarcane industry.


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Kenta Higuchi ◽  
Takashi Komatsu ◽  
Norio Konno ◽  
Hisashi Morioka ◽  
Etsuo Segawa

We consider the discrete-time quantum walk whose local dynamics is denoted by a common unitary matrix C at the perturbed region {0,1,⋯,M−1} and free at the other positions. We obtain the stationary state with a bounded initial state. The initial state is set so that the perturbed region receives the inflow ωn at time n(|ω|=1). From this expression, we compute the scattering on the surface of −1 and M and also compute the quantity how quantum walker accumulates in the perturbed region; namely, the energy of the quantum walk, in the long time limit. The frequency of the initial state of the influence to the energy is symmetric on the unit circle in the complex plain. We find a discontinuity of the energy with respect to the frequency of the inflow.


Author(s):  
Hyen Woo Lee ◽  
Sung ok Hong ◽  
Heeyeon Bae ◽  
Youngjin Shin ◽  
Yu-jin Jee

Abstract Background The pedicled buccal fat pad has been used for a long time to reconstruct oral defects due to its ease of flap formation and few complications. Many cases related to reconstruction of defects in the maxilla, such as closing the oroantral fistula, have been reported, but cases related to the reconstruction of defects in the mandible are limited. Under adequate anterior traction, pedicled buccal fat pad can be a reliable and effective method for reconstruction of surgical defects in the posterior mandible. Case presentation This study describes two cases of reconstruction of surgical oral defects in the posterior mandible, all of which were covered by a pedicled buccal fat pad. The size of the flap was sufficient to perfectly close the defect without any tension. Photographic and radiologic imaging showed successful closure of the defects and no problems were noted in the treated area. Conclusion In conclusion, the pedicled buccal fat pad graft is a convenient and reliable method for the reconstruction of surgical defects on the posterior mandible.


2012 ◽  
Vol 442 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Gráinne Barkess ◽  
Yuri Postnikov ◽  
Chrisanne D. Campos ◽  
Shivam Mishra ◽  
Gokula Mohan ◽  
...  

HMGNs are nucleosome-binding proteins that alter the pattern of histone modifications and modulate the binding of linker histones to chromatin. The HMGN3 family member exists as two splice forms, HMGN3a which is full-length and HMGN3b which lacks the C-terminal RD (regulatory domain). In the present study, we have used the Glyt1 (glycine transporter 1) gene as a model system to investigate where HMGN proteins are bound across the locus in vivo, and to study how the two HMGN3 splice variants affect histone modifications and gene expression. We demonstrate that HMGN1, HMGN2, HMGN3a and HMGN3b are bound across the Glyt1 gene locus and surrounding regions, and are not enriched more highly at the promoter or putative enhancer. We conclude that the peaks of H3K4me3 (trimethylated Lys4 of histone H3) and H3K9ac (acetylated Lys9 of histone H3) at the active Glyt1a promoter do not play a major role in recruiting HMGN proteins. HMGN3a/b binding leads to increased H3K14 (Lys14 of histone H3) acetylation and stimulates Glyt1a expression, but does not alter the levels of H3K4me3 or H3K9ac enrichment. Acetylation assays show that HMGN3a stimulates the ability of PCAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] to acetylate nucleosomal H3 in vitro, whereas HMGN3b does not. We propose a model where HMGN3a/b-stimulated H3K14 acetylation across the bodies of large genes such as Glyt1 can lead to more efficient transcription elongation and increased mRNA production.


Zootaxa ◽  
2021 ◽  
Vol 4958 (1) ◽  
pp. 489-502
Author(s):  
FILIPE MICHELS BIANCHI

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided. 


2021 ◽  
Author(s):  
Ksenia Juravel ◽  
Luis Porras ◽  
Sebastian Hoehna ◽  
Davide Pisani ◽  
Gert Wörheide

An accurate phylogeny of animals is needed to clarify their evolution, ecology, and impact on shaping the biosphere. Although multi-gene alignments of up to several hundred thousand amino acids are nowadays routinely used to test hypotheses of animal relationships, some nodes towards the root of the animal phylogeny are proving hard to resolve. While the relationships of the non-bilaterian lineages, primarily sponges (Porifera) and comb jellies (Ctenophora), have received much attention since more than a decade, controversies about the phylogenetic position of the worm-like bilaterian lineage Xenacoelomorpha and the monophyly of the "Superphylum" Deuterostomia have more recently emerged. Here we independently analyse novel genome gene content and morphological datasets to assess patterns of phylogenetic congruence with previous amino-acid derived phylogenetic hypotheses. Using statistical hypothesis testing, we show that both our datasets very strongly support sponges as the sister group of all the other animals, Xenoacoelomorpha as the sister group of the other Bilateria, and largely support monophyletic Deuterostomia. Based on these results, we conclude that the last common animal ancestor may have been a simple, filter-feeding organism without a nervous system and muscles, while the last common ancestor of Bilateria might have been a small, acoelomate-like worm without a through gut.


Sign in / Sign up

Export Citation Format

Share Document