Transposable element mobilization in interspecific yeast hybrids

Barbara McClintock first hypothesized that interspecific hybridization could provide a “genomic shock” that leads to the mobilization of transposable elements. This hypothesis is based on the idea that regulation of transposable element movement is potentially disrupted in hybrids. However, the handful of studies testing this hypothesis have yielded mixed results. Here, we set out to identify if hybridization can increase transposition rate and facilitate colonization of transposable elements in Saccharomyces cerevisiae x Saccharomyces uvarum interspecific yeast hybrids. S. cerevisiae have a small number of active long terminal repeat (LTR) retrotransposons (Ty elements), while their distant relative S. uvarum have lost the Ty elements active in S. cerevisiae. While the regulation system of Ty elements is known in S. cerevisiae, it is unclear how Ty elements are regulated in other Saccharomyces species, and what mechanisms contributed to the loss of most classes of Ty elements in S. uvarum. Therefore, we first assessed whether transposable elements could insert in the S. uvarum sub-genome of a S. cerevisiae x S. uvarum hybrid. We induced transposition to occur in these hybrids and developed a sequencing technique to show that Ty elements insert readily and non-randomly in the S. uvarum genome. We then used an in vivo reporter construct to directly measure transposition rate in hybrids, demonstrating that hybridization itself does not alter rate of mobilization. However, we surprisingly show that species-specific mitochondrial inheritance can change transposition rate by an order of magnitude. Overall, our results provide evidence that hybridization can potentially facilitate the introduction of transposable elements across species boundaries and alter transposition via mitochondrial transmission, but that this does not lead to unrestrained proliferation of transposable elements suggested by the genomic shock theory.

The 4-Element Movement System Model to Guide Physical Therapist Education, Practice, and Movement-Related Research

The movement system has been adopted as the key identity for the physical therapy profession and recognition of physical therapists’ primary expertise as managing movement dysfunction is an important achievement. However, existing movement system models seem inadequate for guiding education, practice, or research. Lack of a clear, broadly applicable model may hamper progress in physical therapists actually adopting this identity. We propose a model composed of 4 primary elements essential to all movement: motion, force, energy, and control. Although these elements overlap and interact, they can each be examined and tested with some degree of specificity. The proposed 4-element model incorporates specific guidance for visual, qualitative assessment of movement during functional tasks that can be used to develop hypotheses about movement dysfunction and serve as a precursor to more quantitative tests and measures. Human movement always occurs within an environmental context and is affected by personal factors, and these concepts are represented within the model. The proposed scheme is consistent with other widely used models within the profession such as the International Classification of Functioning, Disability and Health and the Patient Management Model. We demonstrate with multiple examples how the model can be applied to a broad spectrum of patients across the lifespan with musculoskeletal, neurologic, and cardiopulmonary disorders.

Real-Time Element Movement in a Plant

We developed an imaging method utilizing the available RIs. We developed two types of real-time RI imaging systems (RRIS), one for macroscopic imaging and the other for microscopic imaging. The principle of visualization was the same, converting the radiation to light by a Cs(Tl)I scintillator deposited on a fiber optic plate (FOS). Many nuclides were employed, including 14C, 18F, 22Na, 28Mg, 32P 33P, 35S, 42K, 45Ca, 48V, 54Mn, 55Fe, 59Fe, 65Zn, 86Rb, 109Cd, and 137Cs.Since radiation can penetrate the soil as well as water, the difference between soil culture and water culture was visualized. 137Cs was hardly absorbed by rice roots growing in soil, whereas water culture showed high absorption, which could provide some reassurance after the Fukushima Nuclear Accident and could indicate an important role of soil in firmly adsorbing the radioactive cesium.28Mg and 42K, whose production methods were presented, were applied for RRIS to visualize the absorption image from the roots. In addition to 28Mg and 42K, many nuclides were applied to image absorption in the roots. Each element showed a specific absorption speed and accumulation pattern. The image analysis of the absorption of Mg is presented as an example. Through successive images of the element absorption, phloem flow in the aboveground part of the plant was analyzed. The element absorption was visualized not only in the roots but also in the leaves, a basic study of foliar fertilization.In the case of the microscopic imaging system, a fluorescence microscope was modified to acquire three images at the same time: a light image, fluorescent image, and radiation image. Although the resolution of the image was estimated to be approximately 50 μm, superposition showed the expression site of the transporter gene and the actual 32P-phosphate absorption site to be the same in Arabidopsis roots.

Transposable element mobilization in interspecific yeast hybrids

Barbara McClintock first hypothesized that interspecific hybridization could provide a “genomic shock” that leads to the mobilization of transposable elements. This hypothesis is based on the idea that regulation of transposable element movement is potentially disrupted in hybrids. However, the handful of studies testing this hypothesis have yielded mixed results. Here, we set out to identify if hybridization can increase transposition rate and facilitate colonization of transposable elements in Saccharomyces cerevisiae x Saccharomyces uvarum interspecific yeast hybrids. S. cerevisiae have a small number of active long terminal repeat (LTR) retrotransposons (Ty elements), while their distant relative S. uvarum have lost the Ty elements active in S. cerevisiae. While the regulation system of Ty elements is known in S. cerevisiae, it is unclear how Ty elements are regulated in other Saccharomyces species, and what mechanisms contributed to the loss of most classes of Ty elements in S. uvarum. Therefore, we first assessed whether transposable elements could insert in the S. uvarum sub-genome of a S. cerevisiae x S. uvarum hybrid. We induced transposition to occur in these hybrids and developed a sequencing technique to show that Ty elements insert readily and non-randomly in the S. uvarum genome. We then used an in vivo reporter construct to directly measure transposition rate in hybrids, demonstrating that hybridization itself does not alter rate of mobilization. However, we surprisingly show that species-specific mitochondrial inheritance can change transposition rate by an order of magnitude. Overall, our results provide evidence that hybridization can facilitate the introduction of transposable elements across species boundaries and alter transposition via mitochondrial transmission, but that this does not lead to unrestrained proliferation of transposable elements suggested by the genomic shock theory.

Synaptonemal Complex-Deficient Drosophila melanogaster Females Exhibit Rare DSB Repair Events, Recurrent Copy-Number Variation, and an Increased Rate of de Novo Transposable Element Movement

Genetic stability depends on the maintenance of a variety of chromosome structures and the precise repair of DNA breaks. During meiosis, programmed double-strand breaks (DSBs) made in prophase I are normally repaired as gene conversions or crossovers. DSBs can also be made by other mechanisms, such as the movement of transposable elements (TEs), which must also be resolved. Incorrect repair of these DNA lesions can lead to mutations, copy-number changes, translocations, and/or aneuploid gametes. In Drosophila melanogaster, as in most organisms, meiotic DSB repair occurs in the presence of a rapidly evolving multiprotein structure called the synaptonemal complex (SC). Here, whole-genome sequencing is used to investigate the fate of meiotic DSBs in D. melanogaster mutant females lacking functional SC, to assay for de novo CNV formation, and to examine the role of the SC in transposable element movement in flies. The data indicate that, in the absence of SC, copy-number variation still occurs and meiotic DSB repair by gene conversion occurs infrequently. Remarkably, an 856-kilobase de novo CNV was observed in two unrelated individuals of different genetic backgrounds and was identical to a CNV recovered in a previous wild-type study, suggesting that recurrent formation of large CNVs occurs in Drosophila. In addition, the rate of novel TE insertion was markedly higher than wild type in one of two SC mutants tested, suggesting that SC proteins may contribute to the regulation of TE movement and insertion in the genome. Overall, this study provides novel insight into the role that the SC plays in genome stability and provides clues as to why the sequence, but not structure, of SC proteins is rapidly evolving.

Synaptonemal complex-deficient Drosophila melanogaster females exhibit rare DSB repair events, recurrent copy number variation, and an increased rate of de novo transposable element movement

ABSTRACTGenetic stability depends on the maintenance of a variety of chromosome structures and the precise repair of DNA breaks. During meiosis, programmed double-strand breaks (DSBs) made in prophase I are normally repaired as gene conversions or crossovers. Additionally, DSBs are made by the movement of transposable elements (TEs), which must also be resolved. Incorrect repair of these DNA lesions can lead to mutations, copy number variations, translocations, and/or aneuploid gametes. In Drosophila melanogaster, as in most organisms, meiotic DSB repair occurs in the presence of a rapidly evolving multiprotein structure called the synaptonemal complex (SC). Here, whole-genome sequencing is used to investigate the fate of meiotic DSBs in D. melanogaster mutant females lacking functional SC, to assay for de novo CNV formation, and to examine the role of the SC in transposable element movement in flies. The data indicate that, in the absence of SC, copy number variation still occurs but meiotic DSB repair by gene conversion may occur only rarely. Remarkably, an 856-kilobase de novo CNV was observed in two unrelated individuals of different genetic backgrounds and was identical to a CNV recovered in a previous wild-type study, suggesting that recurrent formation of large CNVs occurs in Drosophila. In addition, the rate of novel TE insertion was markedly higher than wild type in one of two SC mutants tested, suggesting that SC proteins may contribute to the regulation of TE movement and insertion in the genome. Overall, this study provides novel insight into the role that the SC plays in genome stability and provides clues as to why SC proteins are among the most rapidly evolving in any organism.

Studying of movement kinematics of dynamically active sieve

The article presents the movement kinematics of the modular bar element of a dynamically active polymer sieve of a vibrating screen. On the basis of analytical methods, the mathematical model was obtained, which makes it possible to determine the law and trajectory of the modular bar element movement depending on its geometric characteristics, physico-mechanical properties of the polymer material, the regime and technological parameters of the vibrating screen. The results of this research show that in the working frequency range of the vibrating screen grate, modular bar element of the dynamically active sieve moves along the trajectories, the envelope of which is represented by Cassini’s ovals, which along with the generation of the amplitude component in the horizontal and vertical directions allows one to obtain the selfcleaning effect of the sowing surface.

Design parameters of the rotor of a tilling and separating machine

The subject of the research is the operation process of the rotor of a tilling and separating machine which changes the structure and solidity of the cultivated soil layer according to the agricultural requirements. The author considers the design of the blade of the rotor of a tilling and separating machine. The research object is the blade of the rotor whose form allows it to rotate with a minimum expenditure of energy. The topicality of the research is determined by the fact that the theoretically justified design of the blade of the rotor of a tilling and separating machine will help improve the methods of secondary tillage aimed at the improvement of its agrotechnical characteristics with a minimum expenditure of energy. To define the value of a relative speed of a soil element movement along the blade, the author derives an equation using the method described in P.M. Vasilenko’s theory of soil particles movement along rough surfaces, but the author considers soil particles movement along the blade. The article is based on theoretical research using mechanical and mathematical modeling of working tools interaction with soil. The initial data was collected via the analysis of literary sources. The author substantiates the design of the blade of the rotor of a tilling and separating machine which guarantees its rotation with a minimum expenditure of energy owing to the lesser dispersion of soil particles and the prevention of their building-up on the separating grill. The research results can be used by constructors and specialists developing tillage tools.

Mondrian's "transdance": Transposition of music and dance movements into painting

The syntagm, Mondrian's "transdance" is a term with which the author wanted to symbolically indicate the main research interest presented in this paper, that is, the examination of how the basic stance, steps and movements in the Foxtrot and, implicitly, the main elements of jazz, i.e. melody, rhythm, harmony, are transposed into the particular visual compositions - Fox Trot A (1930) and Fox Trot B (1929). All of these particular art forms (dance, painting, and music), though very different in the aesthetical and poetical respect, are nevertheless connected with one essential element - movement, as a measure of both time and space. In this consideration of painting as a temporal, and not only a spatial object, the visual art discourse is influenced by the vocabulary of the art of music and of dance. Thus, this paper should be understood as the author's intimate observation of time-space transpositions (at the wider level), as well as the author's discussion about the latent (interdisciplinary) 'dialogue' which the painter, Piet Mondrian, aka "The Dancing Madonna", conducted with dance and music (in the strictest sense). This premise is explored from several aspects, but none of them deviates from the main methodological course, determined by the "interdisciplinary model of musicological competence" (Veselinović-Hofman).

Complex complement constructions in Early Modern English

The paper deals with the main peculiarities of syntactic compatability within matrix volitional verbs finite complements of complex constructions in the framework of generative syntax within the Minimalist Program of N. Chomsky using the leading transformational rules such as projection principle, a-movement. The article outlines the ways of that/wh-correlatives origin inside subordinate relationship in the head-specifier location in [Spec, CP] of the functional projection CP. We postulate generation and contact location of embedded finite clauses directly after principal clauses by way of that/wh-element movement up left where its landing site occurs to be the clausal complement specifier [Spec, CP] occupying the head place of the functional projection CP which c-commands over the whole complement and its internal constituents in the node of a complementizer phrase. The article provides special fundamental arguments for proving that CP forms an independent complementizer phrase for expanding of the the matrix verb VP lexical projection function. The paper considers main grammatical categories and syntactic functions of subordinate finite clauses embedded in constructions of higher level as indirect statements, directives or questions in the function of a direct object and a complement. Special attention is focused on defining finite sentencial complements types as declarative and interrogative ones depending on the semantics of the principal verbs of willing. Namely, we distinguish subordinate type clauses as: 1) a declarative type that actualizes indirect statements (hope, intend, resolve, persuade, promise, warn) and indirect directives (ask, beg, charge, appoint, require, command, instruct, order) of volitional predicates; 2) an interrogative type that realizes indirect questions of ask, advise, choose, promise, instruct predicates. The choice of a complementizer also influences on the grammatical category of an embedded sentencial complement. Hereby, conjunction that preferably introduces a declarative type whereas wh-correlative points to the interrogative categorial function of a finite content clause.