Silencing of a metaphase I-specific gene results in a phenotype similar to that of the Pairing homeologous 1 (Ph1) gene mutations

Although studied extensively since 1958, the molecular mode of action of the Pairing homeologous 1 (Ph1) gene is still unknown. In polyploid wheat, the diploid-like chromosome pairing is principally controlled by the Ph1 gene via preventing homeologous chromosome pairing (HECP). Here, we report a candidate Ph1 gene (C-Ph1) present in the Ph1 locus, transient as well as stable silencing of which resulted in a phenotype characteristic of the Ph1 gene mutants, including HECP, multivalent formation, and disrupted chromosome alignment on the metaphase I (MI) plate. Despite a highly conserved DNA sequence, the C-Ph1 gene homeologues showed a dramatically different structure and expression pattern, with only the 5B copy showing MI-specific expression, further supporting our claim for the Ph1 gene. In agreement with the previous reports about the Ph1 gene, the predicted protein of the 5A copy of the C-Ph1 gene is truncated, and thus perhaps less effective. The 5D copy is expressed around the onset of meiosis; thus, it may function during the earlier stages of chromosome pairing. Along with alternate splicing, the predicted protein of the 5B copy is different from the protein of the other two copies because of an insertion. These structural and expression differences among the homeologues concurred with the previous observations about Ph1 gene function. Stable RNAi silencing of the wheat gene in Arabidopsis showed multivalents and centromere clustering during meiosis I.The Pairing homeologous 1 (Ph1) gene was discovered in 1958 based on the observation that plants lacking wheat chromosome 5B exhibit homeologous pairing (1, 2). Lack of the gene results in multivalents during metaphase I (MI) of meiosis, resulting in partial sterility. Conversely, six doses of the gene in the triisosomic line of chromosome 5BL resulted in interlocking of the bivalents and reduced chiasmata frequency even among homologs, along with rare multivalents (3). Several other genes promoting or suppressing homeologous chromosome pairing (HECP) have also been reported (4, 5), although their effect is difficult to measure in the presence of the Ph1 gene (6). Ph1-like genes were also reported in other sexually propagating polyploids, including Avena sativa, Festuca arundinacea, Brassica napus, Gossypium hirsutum, and Gossypium barbadense, as well as in some diploids, including Lolium perenne, Lolium multiflorum, and Lolium rigidum (7–11).Ph1 gene mutants in tetraploid (ph1c) (12, 13) and hexaploid (ph1b) (14) wheat were shown to be interstitial deletions involving an ∼0.84-μm region and an ∼1.05-μm region around the gene, respectively (15, 16) (SI Appendix, Fig. S1). Physical mapping localized the gene to an ∼2.5-Mb chromosomal region referred to as “Ph1 gene region,” bracketed by the distal breakpoint of ph1c deletion on the distal end and the breakpoint of deletion line 5BL-1 on the proximal end (16) (SI Appendix, Fig. S1). Various marker enrichment efforts identified nine markers for the region (17). Detailed microsynteny analyses and comparative mapping identified a 450-kb region of rice chromosome 9 (17). The corresponding rice region contained 91 genes. The major objective of the present study is to identify the gene(s) responsible for the Ph1 gene-like function using the available mapping information.     

High nodal FDG uptake increases risk of distant metastasis in patients with oropharyngeal squamous cell carcinoma

European Journal of Nuclear Medicine and Molecular Imaging - The purpose of this study was to investigate if FDG uptake metrics in primary tumor and lymph node metastases in patients with...     

Increasing use of anticoagulants in Germany and its impact on hospitalization rates for genitourinary bleeding

Journal of Thrombosis and Thrombolysis - The aim of the study was to compare nationwide time trends of prescribed oral anticoagulants (OAC) with the time trend of genitourinary bleedings (GUB) in...     

Reamed intramedullary exchange nailing: treatment of choice of aseptic femoral shaft nonunion

Background

There has been much controversy over specific tests for diagnosis of supraspinatus tendon tear. The aim of this study was to evaluate the metabolic activity of the deltoid and rotator cuff muscles while maintaining the full-can and empty-can testing positions using 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT).

Methods

Ten healthy volunteers without shoulder pain or diabetes mellitus participated in this study. Following FDG injection, both arms were maintained in either the empty-can or full-can position for 10 min. PET/CT was performed 40 min after injection. Maximum standardized uptake values (SUVs) were measured in the deltoid and rotator cuff muscles on axial PET images.

Results

The middle deltoid exhibited the most significant increase in muscle activity at both testing positions. Additionally, a significant increase in muscle activity was observed in the middle deltoid compared with the supraspinatus (P < 0.05) in the empty-can testing position. SUVs of the middle deltoid, supraspinatus, and subscapularis showed a significant increase in the empty-can testing position compared with the full-can testing position (P < 0.05).

Conclusions

Significantly increased activity of the supraspinatus in conjunction with the middle deltoid and subscapularis after empty-can testing may result in decreased specificity of the empty-can test in detecting isolated supraspinatus activity. The full-can test, however, may be used to test the function of the supraspinatus with the least amount of surrounding middle deltoid and subscapularis activity.

     

Oestradiol‐Induced Synapse Formation in the Female Hippocampus: Roles of Oestrogen Receptor Subtypes

During the oestrus cycle, varying spine synapse density correlates positively with varying local synthesis of oestradiol in the hippocampus. In this context, the roles of the oestrogen receptor (ER) subtypes ERα and β are not fully understood. In the present study, we used neonatal hippocampal slice cultures from female rats because these cultures synthesise oestradiol and express both receptor subtypes, and inhibition of oestradiol synthesis in these cultures results in spine synapse loss. Using electron microscopy, we tested the effects on spine synapse density in response to agonists of both ERα and ERβ. Application of agonists to the cultures had no effect. After inhibition of oestradiol synthesis, however, agonists of ERα induced spine synapse formation, whereas ERβ agonists led to a reduction in spine synapse density in the CA1 region of these cultures. Consistently, up‐regulation of ERβ in the hippocampus of adult female aromatase‐deficient mice is paralleled by hippocampus‐specific spine synapse loss in this mutant. Finally, we found an increase in spine synapses in the adult female ERβ knockout mouse, but no effect in the adult female ERα knockout mouse. Our data suggest antagonistic roles of ERβ and ERα in spine synapse formation in the female hippocampus, which may contribute to oestrus cyclicity of spine synapse density in the hippocampus.     

Expertise modulates local regional homogeneity of spontaneous brain activity in the resting brain: An fMRI study using the model of skilled acupuncturists

Studies on training/expertise‐related effects on human brain in context of neuroplasticity have revealed that plastic changes modulate not only task activations but also patterns and strength of internetworks and intranetworks functional connectivity in the resting state. Much has known about plastic changes in resting state on global level; however, how training/expertise‐related effect affects patterns of local spontaneous activity in resting brain remains elusive. We investigated the homogeneity of local blood oxygen level‐dependent fluctuations in the resting state using a regional homogeneity (ReHo) analysis among 16 acupuncturists and 16 matched nonacupuncturists (NA). To prove acupuncturists' expertise, we used a series of psychophysical tests. Our results demonstrated that, acupuncturists significantly outperformed NA in tactile‐motor and emotional regulation domain and the acupuncturist group showed increased coherence in local BOLD signal fluctuations in the left primary motor cortex (MI), the left primary somatosensory cortex (SI) and the left ventral medial prefrontal cortex/orbitofrontal cortex (VMPFC/OFC). Regression analysis displayed that, in the acupuncturists group, ReHo of VMPFC/OFC could predict behavioral outcomes, evidenced by negative correlation between unpleasantness ratings and ReHo of VMPFC/OFC and ReHo of SI and MI positively correlated with the duration of acupuncture practice. We suggest that expertise could modulate patterns of local resting state activity by increasing regional clustering strength, which is likely to contribute to advanced local information processing efficiency. Our study completes the understanding of neuroplasticity changes by adding the evidence of local resting state activity alterations, which is helpful for elucidating in what manner training effect extends beyond resting state. Hum Brain Mapp 35:1074–1084, 2014. © 2013 Wiley Periodicals, Inc.