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41.
J. Torabinejad R. J. Mueller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,86(2-3):288-294
Summary Four hybrids were obtained between three Australian Elymus taxa and three cereal grains: wheat, rye, and barley. Mean meiotic metaphase-I configurations were 41.14 I, 0.42 rod II, 0.003 ring II, and 0.01 III for E. scabrus var plurinervis x Triticum aestivum (1 hybrid plant), 22.27 I, 2.63 rod II, 0.06 ring II, and 0.12 III for E. scabrus var scabrus x Secale cereale (4 hybrid plants), and 26.65 I, 0.66 rod II, 0.00 ring II, and 0.01 III for E. scabrus var plurinervis x Hordeum vulgare (13 hybrid plants). The I genome of barley also paired very little in a BIII hybrid of apomictic E. rectisetus x H. vulgare (2 hybrid plants). Megasporogenesis in this BIII hybrid was at least facultatively apomeiotic, with the same sort of nuclear elongation, apomeiotic division, and dyad formation seen previously in E. rectisetus itself. All four hybrid combinations were sterile. While spike morphology in the E. scabrus x T. aestivum and E. scabrus x H. vulgare hybrids were intermediate to their parents, E. scabrus x S. cereale and E. rectisetus x H. vulgare looked like their maternal parents. 相似文献
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43.
Taiye Winful Katie McCormack Elsa Mueller Lijuan Chen La Corporación Piñones Se Integra Maricruz Rivera Clemente Jada Benn Torres 《American journal of physical anthropology》2023,182(2):194-209
Objectives
From an anthropological genetic perspective, little is known about the ethnogenesis of African descendants in Puerto Rico. Furthermore, historical interactions between Indigenous Caribbean and African descendant peoples that may be reflected in the ancestry of contemporary populations are understudied. Given this dearth of genetic research and the precedence for Afro-Indigenous interactions documented by historical, archeological, and other lines of evidence, we sought to assess the biogeographic origins of African descendant Puerto Ricans and to query the potential for Indigenous ancestry within this community.Materials and Methods
Saliva samples were collected from 58 self-identified African descendant Puerto Ricans residing in Puerto Rico. We sequenced whole mitochondrial genomes and genotyped Y chromosome haplogroups for each male individual (n = 25). Summary statistics, comparative analyses, and network analysis were used to assess diversity and variation in haplogroup distribution between the sample and comparative populations.Results
As indicated by mitochondrial haplogroups, 66% had African, 5% had European, and 29% had Indigenous American matrilines. Along the Y chromosome, 52% had African, 28% had Western European, 16% had Eurasian, and, notably, 4% had Indigenous American patrilines. Both mitochondrial and Y chromosome haplogroup frequencies were significantly different from several comparative populations.Discussion
Biogeographic origins are consistent with historical accounts of African, Indigenous American, and European ancestry. However, this first report of Indigenous American paternal ancestry in Puerto Rico suggests distinctive features within African descendant communities on the island. Future studies expanding sampling and incorporating higher resolution genetic markers are necessary to more fully understand African descendant history in Puerto Rico. 相似文献44.
Gosselin Luc E.; Megirian David; Rodman Joshua; Mueller Donna; Farkas Gaspar A. 《Journal of applied physiology》1997,83(4):1405
Gosselin, Luc E., David Megirian, Joshua Rodman, DonnaMueller, and Gaspar A. Farkas. Respiratory muscle reserve in ratsduring heavy exercise. J. Appl.Physiol. 83(4): 1405-1409, 1997.The extent towhich the respiratory pump muscles limit maximal aerobic capacity inquadrupeds is not entirely clear. To examine the effect of reducedrespiratory muscle reserve on aerobic capacity, whole bodypeak oxygen consumption(O2 peak) wasmeasured in healthy Sprague-Dawley rats before and after Sham,unilateral, or bilateral hemidiaphragm denervation (Dnv) surgery.O2 peak wasdetermined by using a graded treadmill running test.Hemidiaphragm paralysis was verified after testing byrecording the absence of electromyographic activity duringinspiration. Before surgery, O2 peak averaged 86, 87, and 92 ml · kg1 · min1for the Sham, unilateral, and bilateral Dnv groups, respectively. Twoweeks after surgery, there was no significant change inO2 peak foreither the Sham or unilateral Dnv group. However,O2 peak decreased~19% in the bilateral Dnv group 2 wk after surgery. These findingsstrongly suggest that the pulmonary system in rats is designed suchthat during heavy exercise, the remaining respiratory pump muscles areable to compensate for the loss of one hemidiaphragm, but not of both. 相似文献
45.
Keith L. Constantine Mark S. Friedrichs David Detlefsen Maki Nishio Mitsuaki Tsunakawa Tamotsu Furumai Hiroaki Ohkuma Toshikazu Oki Susan Hill Robert E. Bruccoleri Pin-Fang Lin Luciano Mueller 《Journal of biomolecular NMR》1995,5(3):271-286
Summary The 21-amino acid peptides siamycin II (BMY-29303) and siamycin I (BMY-29304), derived from Streptomyces strains AA3891 and AA6532, respectively, have been found to inhibit HIV-1 fusion and viral replication in cell culture. The primary sequence of siamycin II is CLGIGSCNDFAGCGYAIVCFW. Siamycin I differs by only one amino acid; it has a valine residue at position 4. In both peptides, disulfide bonds link Cys1 with Cys13 and Cys7 with Cys19, and the side chain of Asp9 forms an amide bond with the N-terminus. Siamycin II, when dissolved in a 50:50 mixture of DMSO and H2O, yields NOESY spectra with exceptional numbers of cross peaks for a peptide of this size. We have used 335 NOE distance constraints and 13 dihedral angle constraints to generate an ensemble of 30 siamycin II structures; these have average backbone atom and all heavy atom rmsd values to the mean coordinates of 0.24 and 0.52 Å, respectively. The peptide displays an unusual wedge-shaped structure, with one face being predominantly hydrophobic and the other being predominantly hydrophilic. Chemical shift and NOE data show that the siamycin I structure is essentially identical to siamycin II. These peptides may act by preventing oligomerization of the HIV transmembrane glycoprotein gp41, or by interfering with interactions between gp41 and the envelope glycoprotein gp120, the cell membrane or membrane-bound proteins [Frèchet, D. et al. (1994) Biochemistry, 33, 42–50]. The amphipathic nature of siamycin II and siamycin I suggests that a polar (or apolar) site on the target protein may be masked by the apolar (or polar) face of the peptide upon peptide/protein complexation.Abbreviations ABNR
adopted basis Newton Raphson
- AIDS
acquired immunodeficiency syndrome
- CW
continuous wave
- DMSO
dimethylsulfoxide
- DQF-COSY
two-dimensional double-quantum-filtered correlation spectroscopy
- HIV
human immunodeficiency virus
- HSQC
heteronuclear single-quantum coherence
- NOE
nuclear Overhauser enhancement
- NOESY
two-dimensional nuclear Overhauser enhancement spectroscopy
- ppm
parts per million
- P.E.-COSY
two-dimensional primitive exclusive correlation spectroscopy
- REDAC
redundant dihedral angle constraint
- rf
radio frequency
- rmsd
root-mean-square difference
- SIV
simian immunodeficiency virus
- sw
spectral width
- m
mixing time
- TOCSY
two-dimensional total correlation spectroscopy
- TSP
trimethylsilyl-2,2,3,3-2H4-propionate
- 2D
two-dimensional 相似文献
46.
W. J. Metzler B. T. Farmer nd K. L. Constantine M. S. Friedrichs T. Lavoie L. Mueller 《Protein science : a publication of the Protein Society》1995,4(3):450-459
Profilin is a ubiquitous eukaryotic protein that binds to both cytosolic actin and the phospholipid phosphatidylinositol-4,5-bisphosphate. These dual competitive binding capabilities of profilin suggest that profilin serves as a link between the phosphatidyl inositol cycle and actin polymerization, and thus profilin may be an essential component in the signaling pathway leading to cytoskeletal rearrangement. The refined three-dimensional solution structure of human profilin I has been determined using multidimensional heteronuclear NMR spectroscopy. Twenty structures were selected to represent the solution conformational ensemble. This ensemble of structures has root-mean-square distance deviations from the mean structure of 0.58 A for the backbone atoms and 0.98 A for all non-hydrogen atoms. Comparison of the solution structure of human profilin to the crystal structure of bovine profilin reveals that, although profilin adopts essentially identical conformations in both states, the solution structure is more compact than the crystal structure. Interestingly, the regions that show the most structural diversity are located at or near the actin-binding site of profilin. We suggest that structural differences are reflective of dynamical properties of profilin that facilitate favorable interactions with actin. The global folding pattern of human profilin also closely resembles that of Acanthamoeba profilin I, reflective of the 22% sequence identity and approximately 45% sequence similarity between these two proteins. 相似文献
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49.
Movements and associations of ribosomal subunits in a secretory cell during growth inhibition by starvation 下载免费PDF全文
In Chironomus tentans salivary gland cells, the cytoplasm can be dissected into concentric zones situated at increasing distances from the nuclear envelope. After RNA labeling, the newly made ribosomal subunits are found in the cytoplasm mainly in the neighborhood of the nucleus with a gradient of increasing abundance towards the periphery of the cell. The gradient for the small subunit lasts for a few hours and disappears entirely after treatment with puromycin. The large subunit also forms a gradient but one which is only partially abolished by puromycin. The residual gradient which which is resistant to the addition of the drug is probably due to the binding of some large ribosomal units to the membranes of the endoplasmic reticulum (J.-E. Edstrom and u. Lonn. 1976. J. Cell Biol. 70:562-572, and U. Lonn and J.-E. Edstrom. 1976. J. Cell. Biol. 70:573-580). If growth is inhibited by starvation, only the puromycin-sensitive type gradient is observed for the large subunit, suggesting that the attachment of these newly made subunits to the endoplasmic reticulum membranes will not occur. If, on the other hand, the drug-resistant gradient is allowed to form in feeding animals, it is conserved during a subsequent starvation for longer periods than in control feeding animals. This observation provides a further support for an effect of starvation on the normal turnover of the large subunits associated with the endoplasmic reticulum. These results also indicate a considerable structural stability in the cytoplasm of these cells worth little or no gross redistribution of cytoplasmic structures over a period of at least 6 days. 相似文献
50.
A new flow cytometer with a very small observation volume has been developed to detect individual viruses with good resolution, and has been used to discriminate between two types of viral particles based on differences in their light scattering. Measurements of light scattering and fluorescence made with such an instrument can provide a basis for quantitative analysis and sorting of viruses and other particles in the micron and submicron size range. 相似文献