scholarly journals Central-pair microtubular complex of Chlamydomonas flagella: polypeptide composition as revealed by analysis of mutants.

1981 ◽  
Vol 91 (1) ◽  
pp. 69-76 ◽  
Author(s):  
G M Adams ◽  
B Huang ◽  
G Piperno ◽  
D J Luck
Keyword(s):  
Minor Component ◽  
Cellular Growth ◽  
Two Dimensional ◽  
Wild Type ◽  
Beta Tubulin ◽  
Central Pair ◽  
Electrophoresis System ◽  
A Minor ◽  
Dimensional Electrophoresis

Four mutants of Chlamydomonas reinhardtii representing independent gene loci have been shown to lack totally (pf-18, pf-19, and pf-15) or nearly totally (pf-20) the central microtubular pair complex in isolated axonemal preparations. Analysis of 35S-labeled axonemal proteins, using two methods of electrophoresis, reveals that all four mutants lack or are markedly deficient in 18 polypeptides, ranging in molecular weight from 360,000 to 20,000, that are regularly present in wild-type axonemes. Analyses of axonemal proteins labeled by cellular growth on 32P-labeled medium indicates that a subset of 8 of the 18 polypeptides are phosphorylated. Mutant and wild-type axonemes and flagella have been analyzed for their content of tubulin subunits using a high resolution two-dimensional electrophoresis system combined with agarose gel overlays containing either anti-alpha or anti-beta tubulin sera prepared from Chlamydomonas tubulins. The immunoprecipitates identify two major alpha tubulins, a major beta tubulin, and a minor component which is also precipitated by the anti-beta serum. None of these tubulins shows a specific defect in mutant axonemes, nor do the tubulin polypeptides show altered two-dimensional map positions in the mutant flagella. The 18 polypeptides provide a useful signature for identifying other mutants affecting the central-pair microtubular complex. Such mutants could be useful in defining the structural or functional role of these polypeptides in the central microtubules. Efforts to obtain additional central-pair mutants based on the motility phenotype of the four mutants analyzed here have yielded mutants which are allelic to three of the four mutants.

The Emergence of Bone Technologies at the End of the Pleistocene in Southeast Asia: Regional and Evolutionary Implications

2012 ◽  
Vol 22 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Ryan J. Rabett ◽  
Philip J. Piper
Keyword(s):  
Early Modern ◽  
Large Scale ◽  
Minor Component ◽  
Modern Human ◽  
Small Element ◽  
Adaptive Process ◽  
Long Time ◽  
One Step ◽  
A Minor

For many decades Palaeolithic research viewed the development of early modern human behaviour as largely one of progress down a path towards the ‘modernity’ of the present. The European Palaeolithic sequence — the most extensively studied — was for a long time the yard-stick against which records from other regions were judged. Recent work undertaken in Africa and increasingly Asia, however, now suggests that the European evidence may tell a story that is more parochial and less universal than previously thought. While tracking developments at the large scale (the grand narrative) remains important, there is growing appreciation that to achieve a comprehensive understanding of human behavioural evolution requires an archaeologically regional perspective to balance this.One of the apparent markers of human modernity that has been sought in the global Palaeolithic record, prompted by finds in the European sequence, is innovation in bonebased technologies. As one step in the process of re-evaluating and contextualizing such innovations, in this article we explore the role of prehistoric bone technologies within the Southeast Asian sequence, where they have at least comparable antiquity to Europe and other parts of Asia. We observe a shift in the technological usage of bone — from a minor component to a medium of choice — during the second half of the Last Termination and into the Holocene. We suggest that this is consistent with it becoming a focus of the kinds of inventive behaviour demanded of foraging communities as they adapted to the far-reaching environmental and demographic changes that were reshaping this region at that time. This record represents one small element of a much wider, much longerterm adaptive process, which we would argue is not confined to the earliest instances of a particular technology or behaviour, but which forms part of an on-going story of our behavioural evolution.

The role of the flagellar transition region: inferences from the analysis of a Chlamydomonas mutant with defective transition region structures

1991 ◽  
Vol 99 (4) ◽  
pp. 731-740
Author(s):  
JONATHAN W. JARVIK ◽  
JOSEPH P. SUHAN
Keyword(s):  
Transition Region ◽  
Basal Body ◽  
Wild Type ◽  
Central Pair ◽  
Normal Transition ◽  
Thin Section Electron Microscopy ◽  
Concomitant Reduction ◽  
Section Electron ◽  
Type Variable

Thin-section electron microscopy of the Chlamydomonas reinhardtii mutant vfl-2 revealed striking defects in the transition region between basal body and flagellum. In place of the highly organized transition cylinders and stellate fibers characteristic of wild type, variable quantities of poorly organized electron-dense material were present. In many cases the transition region was penetrated by central pair microtubules that passed from the axoneme into the basal body. On the basis of these observations we propose that an important function of the structures present in the normal transition region is to physically exclude the central pair microtubules from the basal body. The transition region is the site of flagellar autotomy – the process by which doublet microtubules are severed and flagella are released from the cell. It has been claimed that autotomy is caused by contraction of the centrin-containing stellate fibers, resulting in the mechanical severing of the doublet microtubules and a concomitant reduction of the diameter of the axoneme adjacent to the abscission point. Our observations do not support this claim in that vfl-2 cells, which lack organized stellate fibers, display effective autotomy unaccompanied by detectable narrowing of the axoneme.

Demonstration of the Role of Prostate-Specific Antigen in Semen Liquefaction by Two-Dimensional Electrophoresis

1989 ◽  
Vol 10 (6) ◽  
pp. 432-438 ◽  
Author(s):  
CHUNG LEE ◽  
MARTIN KEEFER ◽  
ZHONG WEN ZHAO ◽  
ROGER KROES ◽  
LORI BERG ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Dimensional Electrophoresis

Role of ATP-sensitive K+ channels in CGRP-induced dilatation of basilar artery in vivo

1993 ◽  
Vol 265 (2) ◽  
pp. H581-H585 ◽  
Author(s):  
T. Kitazono ◽  
D. D. Heistad ◽  
F. M. Faraci
Keyword(s):  
Basilar Artery ◽  
Minor Component ◽  
K Channels ◽  
Cranial Window ◽  
Calcitonin Gene ◽  
A Minor ◽  
Oxide Synthase ◽  
Camp Levels

Stimulation of adenylate cyclase appears to activate ATP-sensitive K+ channels in the basilar artery. We tested the hypothesis that calcitonin gene-related peptide (CGRP), which increases intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels, activates ATP-sensitive K+ channels and thereby causes vasodilatation. Using a cranial window in anesthetized rats, we examined responses of the basilar artery to CGRP in vivo. We also examined responses of the artery to another vasoactive peptide, vasoactive intestinal peptide (VIP). Topical application of CGRP (10(-11) to 10(-8) M) increased diameter of the basilar artery. Responses of the basilar artery to CGRP were almost abolished by a CGRP1 receptor antagonist, CGRP-(8-37). Vasodilatation in response to VIP was much smaller than that produced by CGRP. Dilator responses of the basilar artery to 10(-9) and 10(-8) M CGRP were inhibited by glibenclamide (10(-6) M), a selective inhibitor of ATP-sensitive K+ channels, by 69 +/- 19 and 41 +/- 9%, respectively. NG-nitro-L-arginine methyl ester (10(-5) M), an inhibitor of nitric oxide synthase, did not attenuate dilator response to 10(-8) M CGRP but inhibited responses to 10(-9) M CGRP by 34 +/- 12%. Indomethacin did not alter dilator responses to CGRP. These findings suggest that a minor component of CGRP-induced dilatation of the basilar artery is mediated by endothelium-derived relaxing factor. Vasodilatation in response to CGRP appears to be mediated primarily by direct activation of CGRP1 receptors on vascular muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of Escherichia coli ribosomal proteins by an alternative two-dimensional electrophoresis system

1988 ◽  
Vol 173 (2) ◽  
pp. 241-245 ◽  
Author(s):  
Dipak B. Datta ◽  
Li-Ming Changchien ◽  
Concepcion R. Nierras ◽  
William A. Strycharz ◽  
Gary R. Craven
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Electrophoresis System ◽  
Dimensional Electrophoresis

Biochemical studies on haemoglobin variants of the irus macaque

1966 ◽  
Vol 165 (999) ◽  
pp. 224-244 ◽  
Keyword(s):  
Minor Component ◽  
Starch Gel Electrophoresis ◽  
Red Cell ◽  
Alkaline Ph ◽  
Peptide Analysis ◽  
Simian Malaria ◽  
Starch Gel ◽  
A Minor ◽  
Recombination Experiments

Haemolysates from 202 M . irus , imported mainly from Thailand and Vietnam, were examined by starch-gel electrophoresis. In addition to the normal haemoglobin, Hb-A mi , two major haemoglobin variants designated as Hb-P mi and Hb-Q mi and two minor components were found. Hb-P mi , which occurred in 12% of the sample, forms molecular aggregates, especially when released from the red cell. Peptide analysis showed that it differs from Hb-A mi in the absence of peptides α .TP III and α -Tp IV. Sera from animals with this haemoglobin in their red cells show two haeme-positive bands in addition to the usual single haptoglobin band; this pattern can be produced in the sera of some animals which do not possess it, by addition of Hb-P mi . Hb-Q mi , which occurred in 24% of the animals, migrates anodally to Hb-A mi at alkaline pH and does not form aggregates. It is found in two ranges of concentration when present with Hb-A mi . It was shown by recombination experiments to have normal β Ami -chains. The sample was polymorphic for a minor component which was shown to have normal β Ami chains. Some animals have two major haemoglobins and also this minor component and therefore possesses three different non- β -chains. It is suggested that the minor component is the product of a mutated duplicate of the α -locus. The population genetics of these variant haemoglobins and the possible selective role of simian malaria are discussed.

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