Characterization of wheat Bell1-type homeobox genes in floral organs of alloplasmic lines with Aegilops crassa cytoplasm

<p>Abstract</p> <p>Background</p> <p>Alloplasmic wheat lines with <it>Aegilops crassa </it>cytoplasm often show homeotic conversion of stamens into pistils under long-day conditions. In the pistillody-exhibiting florets, an ectopic ovule is formed within the transformed stamens, and female sterility is also observed because of abnormal integument development.</p> <p>Results</p> <p>In this study, four wheat <it>Bell1</it>-like homeobox (<it>BLH</it>) genes were isolated and named <it>WBLH1 </it>to <it>WBLH4</it>. <it>WBLH1</it>/<it>WBLH3</it>/<it>WBLH4 </it>expression was observed in the basal boundary region of the ovary in both normal pistils and transformed stamens. <it>WBLH2 </it>was also strongly expressed in integuments not only of normal ovules in pistils but also of the ectopic ovules in transformed stamens, and the <it>WBLH2 </it>expression pattern in the sterile pistils seemed to be identical to that in normal ovules of fertile pistils. In addition, WBLH1 and WBLH3 showed interactions with the three wheat KNOX proteins through the BEL domain. WBLH2, however, formed a complex with wheat KNOTTED1 and ROUGH SHEATH1 orthologs through SKY and BEL domains, but not with a wheat LIGULELESS4 ortholog.</p> <p>Conclusions</p> <p>Expression of the four <it>WBLH </it>genes is evident in reproductive organs including pistils and transformed stamens and is independent from female sterility in alloplasmic wheat lines with <it>Ae. crassa </it>cytoplasm. KNOX-BLH interaction was conserved among various plant species, indicating the significance of KNOX-BLH complex formation in wheat developmental processes. The functional features of <it>WBLH2 </it>are likely to be distinct from other <it>BLH </it>gene functions in wheat development.</p

Wnt Signals Can Function as Positional Cues in Establishing Cell Polarity

Wnt signaling plays important roles in cell polarization in diverse organisms, and loss of cell polarity is an early event in tumorigenesis caused by mutations in Wnt pathway genes. Despite this, the precise roles of Wnt proteins in cell polarization have remained elusive. In no organism has it been shown that the asymmetric position of a Wnt signal is essential to establishing a cell’s polarity. Attempts to test this by ubiquitous expression of Wnt genes have suggested that Wnt signals might act only as permissive factors in cell polarization. Here we find, using cell manipulations and ectopic gene expression in C. elegans, that the position from which Wnt signals are presented can determine the polarity of both embryonic and postembryonic cells. Furthermore, the position from which a Wnt signal is presented can determine the polarity of Frizzled receptor localization, suggesting that the polarizing effect of Wnt is likely to be direct. These results demonstrate that Wnt proteins can function as positional cues in establishing cell polarity

Proton beam therapy for bone sarcomas of the skull base and spine: A retrospective nationwide multicenter study in Japan

We conducted a retrospective, nationwide multicenter study to evaluate the clinical outcomes of proton beam therapy for bone sarcomas of the skull base and spine in Japan. Eligibility criteria included: (i) histologically proven bone sarcomas of the skull base or spine; (ii) no metastases; (iii) ≥20 years of age; and (iv) no prior treatment with radiotherapy. Of the 103 patients treated between January 2004 and January 2012, we retrospectively analyzed data from 96 patients who were followed-up for >6 months or had died within 6 months. Seventy-two patients (75.0%) had chordoma, 20 patients (20.8%) had chondrosarcoma, and four patients (7.2%) had osteosarcoma. The most frequent tumor locations included the skull base in 68 patients (70.8%) and the sacral spine in 13 patients (13.5%). Patients received a median total dose of 70.0 Gy (relative biological effectiveness). The median follow-up was 52.6 (range, 6.3–131.9) months. The 5-year overall survival, progression-free survival, and local control rates were 75.3%, 49.6%, and 71.1%, respectively. Performance status was a significant factor for overall survival and progression-free survival, whilst sex was a significant factor for local control. Acute Grade 3 and late toxicities of ≥Grade 3 were observed in nine patients (9.4%) each (late Grade 4 toxicities [n = 3 patients; 3.1%]). No treatment-related deaths occurred. Proton beam therapy is safe and effective for the treatment of bone sarcomas of the skull base and spine in Japan. However, larger prospective studies with a longer follow-up are warranted

Two Wnts Instruct Topographic Synaptic Innervation in C. elegans

Gradients of topographic cues play essential roles in the organization of sensory systems by guiding axonal growth cones. Little is known about whether there are additional mechanisms for precise topographic mapping of synaptic connections. Whereas the C. elegans DA8 and DA9 neurons have similar axonal trajectories, their synapses are positioned in distinct but adjacent domains in the anterior-posterior axis. We found that two Wnts, LIN-44 and EGL-20, are responsible for this spatial organization of synapses. Both Wnts form putative posterior-high, anterior-low gradients. The posteriorly expressed LIN-44 inhibits synapse formation in both DA9 and DA8, and creates a synapse-free domain on both axons via LIN-17 /Frizzled. EGL-20, a more anteriorly expressed Wnt, inhibits synapse formation through MIG-1/Frizzled, which is expressed in DA8 but not in DA9. The Wnt-Frizzled specificity and selective Frizzled expression dictate the stereotyped, topographic positioning of synapses between these two neurons

Targeting endogenous proteins for spatial and temporal knockdown using auxin-inducible degron in Caenorhabditis elegans

Summary: The auxin-inducible degron (AID) provides reversible, spatiotemporal control for the knockdown of target proteins. Here, we present a protocol for AID-mediated protein knockdown in Caenorhabditis elegans. We describe steps for generating the knock-in mutants using two CRISPR-Cas9 genome editing techniques and preparing the auxin-containing nematode growth media (NGM) plates. We also detail AID-mediated spatiotemporal protein knockdown.For complete details on the use and execution of this protocol, please refer to Kurashina et al. (2021).1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

Adaptive output regulation based on internal model principle for systems, with uncertain disturbances and reference signals

An output regulation problem under the existence of disturbances is one of the main objectives to design the control system for mechanical systems, and the strategy based on the internal model principle (IMP) is one of the attractive ways to suppress the disturbances. In this paper, we propose an almost strictly positive real (ASPR) based adaptive output feedback control with adaptive internal model for output regulation for systems with uncertain disturbances and reference signals. The stability of the obtained adaptive control system is analysed, and the effectiveness of the proposed method is confirmed through numerical simulations

Synaptogenesis: unmasking molecular mechanisms using Caenorhabditis elegans.

The nematode Caenorhabditis elegans is a research model organism particularly suited to the mechanistic understanding of synapse genesis in the nervous system. Armed with powerful genetics, knowledge of complete connectomics, and modern genomics, studies using C. elegans have unveiled multiple key regulators in the formation of a functional synapse. Importantly, many signaling networks display remarkable conservation throughout animals, underscoring the contributions of C. elegans research to advance the understanding of our brain. In this chapter, we will review up-to-date information of the contribution of C. elegans to the understanding of chemical synapses, from structure to molecules and to synaptic remodeling