Sep 24, 2015 -
487
NOTIZEN
Mit der vorliegenden Untersuchung ist der elektronenmikroskopische Beweis dafür erbracht, daß die Antennalorgane von Polyxenus lagurus endokrine Drüsen sind. Über ihre Funktion kann keine Aussage gemacht werden. Beim Ingangsetzen einer Häutung durch Antennenamputation (SEIFERT 6 ) ist der Grad 6
G . SEIFERT, Z o o l . A n z . 1 7 7 , 2 5 8 [ 1 9 6 6 b ] .
7
G.
SEIFERT
u.
E.
EL-HIFNAWI,
Z.
Zellforsch,
der Exstirpation der Antennendrüsen bisher nicht beachtet worden. Es ist daher völlig offen, ob den Antennendrüsen eine Bedeutung für die Häutung zukommt. Weitere Untersuchungen müssen darüber Aufschluß geben.
8
R . WEINSTEIN, T . ABBISS U. S . BULLIVANT, J. C e l l B i o l . 1 9 ,
74 A
mikroskop.
[1963].
Anatom., im Druck.
T h e Frog's R o d Outer Segment Observed b y the Negative Staining Technique M A N F R E D HAUSER and JÜRGEN
ROSENKRANZ
Lehrstuhl für Zellmorphologie der Ruhr-Universität, Bochum, Germany (Z. Naturforsch. 26 b, 4S7 [1971] ; received Februar 25, 1971; revised March 11, 1971)
Rod outer segments of frogs (Rana esculenta) were isolated by shaking the retina in R i n g e r solution. Before spreading each drop was examined by light microscopy and checked for purity. The outer segments were then either spread on the surface of a phosphotungstic acid solution (1.8 . . . 2.0%) containing 0 . 0 5 . . . 0.1% bovine serum albumin (pH 7.3) or negatively stained as drop preparations; instead of bovine serum albumin a 0.07% glycerol solution was also used. In contrast to micrographs of ultrathin sections (e.g. F E R N Ä N D E Z - M O R Ä N 3 ; N I L S S O N 5 ) and previous negative staining experiments (BLASIE et al. 2 ) which reveal "dense granules", "globular substructures" or "particles ~ 4 0 Ä in diameter" we found fibrillar elements (Fäden) in the outer segments as already postulated before on the basis of freeze-etching experiments
(ROSENKRANZ 6 ) .
In
surface-spread
and
drop preparations we observed fibrils of different structure and diameter as well as partially preserved membranes. In preparations exposed to surface spreading we found predominantly well-spread, smooth fibrils (d a ). Their diameter is 49 Ä < da ^ 58 Ä, see Fig. 1 *. This wide range is due to the fact that several observers in our department made a total of 100 measurements from the same electron micrograph. Some micrographs indicate that each da-fibril might in turn be composed of fibrillar substructures.
In drop preparations two different types of fibrils could regularly be observed; these differ both in structure and — supposedly — in diameter. Micrographs like Fig. 2 depict a number of densely packed and parallel fibrils named db . Their diameter is 4 3 Ä < d b S> 53 Ä (120 measurements, several observers as above). In some places, globular substructures could be recognized indicating these fibrils to be built up of such globular particles. The second type of fibril often seen by us in drop preparations corresponds to the well known picture of spread mitochondria although without the two confining rows of oxisomes. We call them twin fibrils (diameter about 100 Ä) ; they are twisted as in Fig. 3 or parallel as in Figs. 4 and 5. The diameter of the two single fibrils is that of d a . Keeping the difference of the two preparation techniques in mind, this would seem to indicate that the da-fibrils tend to form a very stable twin configuration. Again, each da-fibril seems to be composed of twisted fibrillar subunits, probably two. Fibrils morphologically similar to the db-units have also been demonstrated in lipid suspensions by LUCY et al. 4 and B A N G H A M et al. 1 (negatively stained cholesterol and lecithin). Their findings ("tubular" or "elongated structures") are in good agreement with ours. However, the question remains open to discussion as to whether these myelin-like structures (in the sense of S t o e c k e n i u s ) are formed during preparation by rearrangement, or whether these single layers represent an inherent structural element of the outer segment. The same argument also holds when considering whether membranes are made up of a parallel array of twin fibrils In a subsequent publication
(ROSENKRANZ et al. 7 )
we shall describe our results in more detail, also with respect to negatively stained mitochondrial membranes, whose fine structure may be similar to that of the outer segment membranes.
Reprints request to Dr. M . HAUSER, Ruhr-Univ. Bochum, Lehrstuhl f. Zellmorphologie, D-4630 Bochum, Postfach 2148.
3
H. FERNÄNDEZ-MORÄN, Circulation 26, 1039 [ 1 9 6 2 ] .
4
J. A . L U C Y a n d A . M . GLAUERT, J. m o l e c u l a r B i o l . 8 , 7 2 7
1
A . D . BANGHAM and R . W .
8,
5
660 [1964].
6
[1964]. S. E. G. NILSSON, J. Ultrastructure Res. 12, 207 [ 1 9 6 5 ] . J. ROSENKRANZ, Z. Zellforsch. I l l , 228 [ 1 9 7 0 ] .
2
J. K . BLASIE, C . R . WORTHINGTON, a n d M . M . DEWEY, J.
7
HÖRNE, J. m o l e c u l a r B i o l .
molecular Biol. 39, 407 [ 1 9 6 9 ] . * Figs. 1 — 5 see pag. 486 b.
J. ROSENKRANZ, M . HAUSER, a n d A . RUTHMANN, in prepa-
ration.
Unauthenticated Download Date | 9/24/15 11:23 PM
488
NOTIZEN
Flash Photolysis of Rhodopsin
I. Measurements on Bovine R o d Outer Segments G Ü N T E R V. SENGBUSCH * a n d H E N N I G STIEVE
**
Institut für Zoologie der Rheinisch-Westfälischen Technischen Hochschule Aachen (Z. Naturforsch. 26 b, 4 8 8 - ^ 8 9 [1971] ; received March 6, 1971)
Reactions of the bovine visual pigment rhodopsin up to the formation of metarhodopsin II were measured kinetically by means of flash light photolysis 1 _ 3 . Rod outer segments as well as fragments of rod outer segments sedimenting between 4000 g and 30 000 g were used as test material. The fragments were produced according to the following method: Isolated rod outer segments3 were treated with buffered (pH 7) 0,5% digitonin solution for 30 min. and then centrifuged at 4000 g. The supernatant was separated from the precipitate and then centrifuged at 30 000 g. The resulting precipitate consisted of fragments of rod outer segments sedimenting between 4000 g and 30 000 g ***.
rhodopsin solution whereas rods frozen and stored at —15 °C yield more rhodopsin solution and less fragments. The reactions occurring after a flash were characterized by difference absorption spectra and activation energies 3 . Fig. 1 shows three difference absorption spectra measured on suspensions of rod outer segments. The same spectra also occur in fragments of rod outer segments treated with digitonin. These difference absorption spectra correspond with extinction spectra having the following extinction maxima: I: Imax = (498 ± 4 ) nm, II: Xmax = (485 ± 4) nm, III: Imax = (386 it 6) nm. The reactions associated with these difference spectra are most probably rhodopsin —lumirhodopsin, lumirhodopsin—metarhodopsin I, and metarhodopsin I — metarhodopsin II 4 ~ 9 .
The amount of fragments obtained from a certain quantity of rods after digitonin treatment varies with the temperature at which the rods were previously frozen and stored. Rods frozen and stored at —195 °C in liquid nitrogen yield more fragments and less i 0
i 10
i 20
i 30
i 40
i 50
i i 60 70 t [msec]
I 100
a1
Fig. 2. Time course of the absorption changes at 4 3 4 nm measured on rod suspensions. Suspension medium: modified R i n g e r's solution; temperature 0 ° C ; flash at < = 0.
C o. o
.
4 5
6 7
G. v. SENGBUSCH, Thesis, Technische Hochschule Aachen, Germany, 1970. R. A . CONE, Exp. Eye Res. 8, 246 [ 1 9 6 9 ] . R. A . CONE, Processing of Optical Data by Organisms and by Machines, p. 187, Academic Press, 1969. W . A. HAGINS, Nature [London] 177, 989 [ 1 9 5 6 ] . E. W .
ABRAHAMSON a n d S . E . OSTROY, P r o g r e s s in B i o -
physics and Molecular Biology, p. 181, Pergamon Press 17. 1967. V.
J.
WULFF,
H.
LINSCHITZ,
and
E.
W.
ABRAHAMSON.
Ann. N. Y . Acad. Sei. 74, 281 [1958], 9
R.
G.
MATTHEWS,
R.
HUBBARD,
P.
WALD, J. gen. Physiol. 47, 215 [ 1 9 6 3 ] .
Unauthenticated Download Date | 9/24/15 11:23 PM
K.
BROWN,
and
G.
