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991.
Kaitlyn M. Campbell Yiding Xu Chintan Patel Jeremy M. Rayl Helena D. Zomer Hari Prasad Osuru Michael Pratt Patcharin Pramoonjago Madeline Timken Lyndzi M. Miller Abigail Ralph Kathryn M. Storey Yiheng Peng Jenny Drnevich Clotilde Lagier-Tourenne Philip C. Wong Huanyu Qiao Prabhakara P. Reddi 《The Journal of biological chemistry》2021,297(5)
Meiotic arrest is a common cause of human male infertility, but the causes of this arrest are poorly understood. Transactive response DNA-binding protein of 43 kDa (TDP-43) is highly expressed in spermatocytes in the preleptotene and pachytene stages of meiosis. TDP-43 is linked to several human neurodegenerative disorders wherein its nuclear clearance accompanied by cytoplasmic aggregates underlies neurodegeneration. Exploring the functional requirement for TDP-43 for spermatogenesis for the first time, we show here that conditional KO (cKO) of the Tardbp gene (encoding TDP-43) in male germ cells of mice leads to reduced testis size, depletion of germ cells, vacuole formation within the seminiferous epithelium, and reduced sperm production. Fertility trials also indicated severe subfertility. Spermatocytes of cKO mice showed failure to complete prophase I of meiosis with arrest at the midpachytene stage. Staining of synaptonemal complex protein 3 and γH2AX, markers of the meiotic synaptonemal complex and DNA damage, respectively, and super illumination microscopy revealed nonhomologous pairing and synapsis defects. Quantitative RT–PCR showed reduction in the expression of genes critical for prophase I of meiosis, including Spo11 (initiator of meiotic double-stranded breaks), Rec8 (meiotic recombination protein), and Rad21L (RAD21-like, cohesin complex component), as well as those involved in the retinoic acid pathway critical for entry into meiosis. RNA-Seq showed 1036 upregulated and 1638 downregulated genes (false discovery rate <0.05) in the Tardbp cKO testis, impacting meiosis pathways. Our work reveals a crucial role for TDP-43 in male meiosis and suggests that some forms of meiotic arrest seen in infertile men may result from the loss of function of TDP-43. 相似文献
992.
Does Auxin Play a Role in the Release of Apical Dominance by Shoot Inversion in Ipomoea nil? 总被引:1,自引:0,他引:1
Prasad T. K.; Li X.; Abdel-Rahman A. M.; Hosokawa Z.; Cloud N. P.; Lamotte C. E.; Cline M. G. 《Annals of botany》1993,71(3):223-229
According to the auxin-inhibition hypothesis of apical dominance,apically produced auxin moves down the stem and inhibits axillarybud outgrowth, either directly or indirectly. This hypothesishas been examined further by monitoring changes in basipetalauxin transport and endogenous auxin concentration in Ipomoeanil caused by shoot inversion, a stimulus that releases apicaldominance. The results indicate that inversion reduces auxintransport in the main stem. In upright shoots of intact plants,a 16-h pretreatment with [3H]IAA 4 cm below the apex resultsin downward movement of label and accumulation in nodes, especiallythe cotyledonary node. Label does not accumulate in the lateralbuds. GC-MS determinations of endogenous free auxin level inthe fourth node, where a lateral bud grows out following inversionof the upper part of the shoot, show no changes at 3 and 8 hafter inversion, the range of times for inversion-induced budrelease, or at 24 h, when bud outgrowth is continuing. However,inversion did cause a just-detectable decrease (approx. 10%)in the IAA level of the shoot's elongation region. Althoughauxin transport in segments of the main stem is partially inhibitedby inversion over a period shorter than the latent time of budrelease, thus providing a means for the expected depletion ofauxin in the fourth node, no depletion could be detected there.These results suggest that either a decrease in IAA level inthe main stem is not causal of bud release or that the decreasedIAA pool responsible for bud release is compartmented and cannotbe measured in whole-tissue extracts.Copyright 1993, 1999 AcademicPress Apical dominance, auxin content, auxin transport, axillary bud release, GC-MS, Ipomoea nil, Pharbitis nil, shoot inversion 相似文献
993.
Shaik Hajira Jillela Santhosh Vijitha Sanjay Janrao Dhoble Borelli Deva Prasad Raju Busireddy Sudhakar Reddy 《Luminescence》2024,39(1):e4612
Red and green rare-earth ion (RE3+) (RE = Eu, Tb):MgLa2V2O9 micro-powder phosphors were produced utilizing a standard solid-state chemical process. The X-ray diffraction examination performed on the phosphors showed that they were crystalline and had a monoclinic structure. The particles grouped together, as shown in the scanning electron microscopy (SEM) images. Powder phosphors were examined using a variety of spectroscopic techniques, including photoluminescence (PL), Fourier-transform infrared, and energy dispersive X-ray spectroscopy. Brilliant red emission at 615 nm (5D0 → 7F2) having an excitation wavelength (λexci) of 396 nm (7F0 → 5L6) and green emission at 545 nm (5D4 → 7F5) having an λexci = 316 nm (5D4 → 7F2) have both been seen in the emission spectra of Tb3+:MgLa2V2O9 nano-phosphors. The emission mechanism that is raised in Eu3+:MgLa2V2O9 and Tb3+:MgLa2V2O9 powder phosphors has been explained in an energy level diagram. 相似文献
994.
Kishore Kumar Aitha Dantala Dinakar K. V. R. Murthy A. S. Sai Prasad Divi Haranath 《Luminescence》2024,39(1):e4623
Direct white light emitting phosphors play a significant role in the display industry due to their ability to improve the quality, efficiency, and versatility of lighting sources used in most of the displays. The currently investigated phosphor SrZr2CaLa2O8:Eu3+ was prepared by a conventional solid-state reaction method. It has been observed that the stoichiometric ratio of all precursors plays an important role in determining the characteristics of the final phosphor. From X-ray diffraction (XRD) analysis, the phosphor was observed to have a hexagonal phase and a crystal size of ~28 nm. Scanning electron microscopy (SEM) observations revealed a cluster of rod-like structures with an average diameter of ~0.2 μm. The excitation peak maximum observed at 280 nm is due to charge transfer between Eu3+-O2− ions. The energy transitions 7F0 → 5L6 and 7F0 → 5D2 are responsible for the appearance of other excitation peaks at ultraviolet (UV) (395 nm), blue (~467 nm), green (~540 nm), orange (~590 nm), and red (~627 nm) attributed to 5D0 → 7FJ (J = 0–4) transitions of europium ion (Eu3+). The Commercial International de I'Eclairage (CIE) chromaticity coordinates were estimated to be (0.37, 0.0.33) and (0.67, 0.33) for the emissions corresponding to 395 and 590 nm, respectively. The characteristic emissions of Eu3+ ions allow this novel phosphor to be used to generate direct white light in light-emitting diodes (LEDs), which is otherwise difficult to achieve in single-component systems. 相似文献
995.
996.
Sunil A. Patil Venkata Prasad Surakasi Sandeep Koul Shrikant Ijmulwar Amar Vivek Y.S. Shouche B.P. Kapadnis 《Bioresource technology》2009,100(21):5132-5139
Feasibility of using chocolate industry wastewater as a substrate for electricity generation using activated sludge as a source of microorganisms was investigated in two-chambered microbial fuel cell. The maximum current generated with membrane and salt bridge MFCs was 3.02 and 2.3 A/m2, respectively, at 100 Ω external resistance, whereas the maximum current generated in glucose powered MFC was 3.1 A/m2. The use of chocolate industry wastewater in cathode chamber was promising with 4.1 mA current output. Significant reduction in COD, BOD, total solids and total dissolved solids of wastewater by 75%, 65%, 68%, 50%, respectively, indicated effective wastewater treatment in batch experiments. The 16S rDNA analysis of anode biofilm and suspended cells revealed predominance of β-Proteobacteria clones with 50.6% followed by unclassified bacteria (9.9%), α-Proteobacteria (9.1%), other Proteobacteria (9%), Planctomycetes (5.8%), Firmicutes (4.9%), Nitrospora (3.3%), Spirochaetes (3.3%), Bacteroides (2.4%) and γ-Proteobacteria (0.8%). Diverse bacterial groups represented as members of the anode chamber community. 相似文献
997.
Jatin Kakkar Kamal Kumar Chaudhary Chekkara Venkata Satya Siva Prasad 《Bioinformation》2013,9(15):777-781
The HIV-1 Nef protein has the ability to down regulate important molecules at the immune synapse. These include class I and class
II (Human Leukocyte Antigen) HLA on the Antigen Presenting Cells (APC). The receptors in these molecules consist of SH-3
domain and their interaction with the HIV-1 Nef is critical. Therefore, it is important to inhibit this HIV-Nef and human SH3
domain interaction. Thus, we used a combinatorial library to screen for molecules to inhibit this interaction. The exercise identified
a group of top ranking compounds for further consideration. 相似文献
998.
999.
Cynthia S. Ricard Janelle M. Jakubowski John W. Verbsky M. Alejandro Barbieri William M. Lewis G. Esteban Fernandez Marion Vogel Christina Tsou Vinoy Prasad Philip D. Stahl Gabriel Waksman Clarissa M. Cheney 《Genesis (New York, N.Y. : 2000)》2001,31(1):17-29
Summary: Rab GTPases are essential for vesicular transport. Rab GDP dissociation inhibitor (GDI) binds to GDP‐bound rabs, removes rabs from acceptor membranes and delivers rabs to donor membranes. We isolated lethal GDI mutations in Drosophila and analyzed their developmental phenotypes. To learn how these mutations affect GDI structure, the crystal structure of Drosophila GDI was determined by molecular replacement to a resolution of 3.0 Å. Two hypomorphic, missense mutations are located in domain II of GDI at highly conserved positions, but not in previously identified sequence conserved regions. The mutant GDIs were tested for ability to extract rabs from membranes and showed wild‐type levels of rab membrane extraction. The two missense alleles showed intragenic complementation, indicating that domain II of GDI may have two separable functions. This study indicates that GDI function is essential for development of a complex, multicellular organism and that puparium formation and pole cell formation are especially dependent on GDI function. genesis 31:17–29, 2001. © 2001 Wiley‐Liss, Inc. 相似文献
1000.
Essential oils isolated from leaves (LO), bast (BO), heartwood (HO), and ethereal extract of resin (EER) of Shorea robusta were bioassayed with electroantennograph (EAG) and wind tunnel to study the behavioral response of male and female beetles, Hoplocerambyx spinicornis Newm., the most injurious heartwood borer of the tree. LO, BO, HO, and EER were shown to exhibit the electrophysiological activity in the female beetle, while LO and BO in the male beetle. In wind-tunnel studies, only BO elicited the attractant activity to both the sexes. A possible correlation of the constituents of the BO identified by GC/MS with the bioactivity is also presented. 相似文献