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The fine structure of sow lutein cells.

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The Fine Structure of Sow Lutein Cells
Departments of Anatomy, Pathology, Obstetrics and Gynecology, a7zd the
Eppley Cancer Institute, University of Nebraska College of Medicine, Omaha, Nebraska
The morphological observations described in this reuort are part of a
biochemical study of progesterone intermediates using sow ovary. This tissue is extensively involved in the production of some steroid hormones. Because the lutein cells are
thought to be involved i n the synthesis of progesterone and its intermediates and
because these cells constitute by size and number the greatest portion of the mass of sow
ovary, we confined the morphological investigation to these cells. Sow corpora lutea,
fixed with glutaraldehyde and osmium tetroxide were examined by light and electron
The lutein cells of the sow are large epithelioid cells with oval nuclei and extensive
amounts of cytoplasm. Large masses of highly organized smooth endoplasmic reticulum, many oval mitochondria with tubular cristae, and many lipid droplets are present.
Only a few profiles of rough endoplasmic reticulum are seen in any one section, and
Golgi membranes cannot by distinguished from other smooth membranes. The smooth
endoplasmic reticulum is the major membranous organelle i n these luteal cells. Microsomal preparations from luteal cells must be very rich in fragments of these smooth
membranes. The demonstration of many steroidogenic enzyme systems in microsomal
preparations lends strong support to the supposition that these enzyme systems reside
i n the smooth endoplasmic reticulum.
Christensen ('65) has drawn attention
to the unusual amount and organization
of the smooth endoplasmic reticulum in
the interstitial cells of guinea pig testes.
This report, an adjunct to a biochemical
investigation of the metabolism of progesterone in the sow ovary, deals with
some ultrastructural observations of several sow lutein cells.
Smooth membranes isolated from the
microsomal fraction of sow ovary homogenates by density gradient fractionation
(Fouts, '61) were used in studying some
intermediary products in the metabolism
of progesterone. One of the authors
(B.K.) noting the yield of the smooth
membrane fraction was greater than
expected asked that the purity of the preparation be confirmed by electron microscopy. Subsequent observations of several
pellets confirmed the presence of smooth
membranes with no contaminating ribosomes, mitochondria1 fragments or nuclei.
In addition biochemical checks or purity
were performed. The yield of relatively
clean smooth membranes in greater quantities than was expected prompted this
morphological study on the intact ovary.
We consider the extensive mass of
highly organized smooth membranes, and
ANAT. REC., 161: 77-90.
the associated mass of mitochondria and
lipid are worthy of description. In addition this report contains a description of
a single, highly unusual nucleus that contains an intranuclear membranous system.
The ovaries utilized in this study were
collected under the same conditions as
those used in the biochemical investigation save that tissues from non-pregnant
and pregnant sows were collected separately. At this time only tissues from the
non-pregnant animals have been studied.
The ovaries were removed from slaughtered swine as soon as they reached the
cutting floor at the meat packing plant
(40-50 minutes after death).4 Thin slices
( 5 mm) were placed in cold buffered glutaraldehyde (Millonig's buffer, pH 7.2).
After approximately two hours of fixation
in the glutaraldehyde, the slices were
rinsed in buffer and were then placed in
fresh buffer for an hour. Small blocks of
what grossly were identified as corpora
1 Presented in part before the American Association
of Anatomists at Kansas City, Missouri, April 1967.
2 Supported in part by USPHS grant HD 18-06.
3 USPHS Trainee.
4 Material used in this experiment secured through
the courtesy of Swift and Company, Omaha, Nebraska.
lutea were cut from these slices and were
postfixed in 1% buffered osmium tetroxide
(Millonig’s buffer, pH 7.2) for three
hours. After dehydration in graded alcohols and propylene oxide, the small blocks
of tissue were embedded in Araldite 502.
Thick sections stained with toluidine blue
were examined to ascertain the presence
of granulosa lutein cells in the samples.
Thin sections stained with uranyl acetate
were examined in either the Philips l O O B
or the RCA EMU 3G electron microscope.
Several pieces of the glutaraldehyde fixed
corpus luteum were postfixed with 10%
formalin and embedded i n paraffin. Sections of these blocks were stained with
hematoxylin and eosin.
Sections of the paraffin embedded corpus luteum contain large oval pale stainin diaming cells ranging from 30-50
eter. Theca lutein cells a s described by
Corner (’21) were not seen. Capillaries
are abundant, not collapsed and in close
proximity to each of the lutein cells. The
toluidine blue stained thick sections
showed essentially the same histological
features as the H & E sections.
Even at relatively low magnifications in
the electron microscope, the smooth endoplasmic reticulum (s.e.r.) is a most outstanding feature of the sow lutein cell (fig.
1). These membranes form extensive
highly organized systems in the cytoplasm
of the lutein cell. The s.e.r. varies in
amount in different portions of the same
cell. There may be only a few isolated
profiles found dispersed among the mitochondria and lipid droplets, or these membranes may form almost solid masses
ranging from 2-25 in diameter. In most
of the lutein cells, the mass of the s.e.r. is
such that the other cytoplasmic organelles
or inclusions are in crowded masses.
The morphological configurations of
these smooth membrane systems vary
greatly. One variety seen frequently consists of layer upon layer of closely packed
undilated cisternae or collapsed tubules.
In section these membranes may be arranged parallel to each other in longitudinal arrays or they may form tightly
swirling whorls very much like a fmgerprint (fig. 1 ) . Another commonly observed variation contains widely dilated
tubules cut either tangentially or in crosssection, stacked layer upon layer and
tightly packed together. This variety of
system closely resembles a honeycomb
(fig. 2 ) .
Most often, however, a combination of
small patches of “honeycomb” are seen
dispersed, embedded in a mass of “fingerprint” membranes (fig. 3 ) . Occasionally,
mitochondria and/or lipid droplets are
found among the masses of s.e.r. (fig. 1).
Were i t not for the unusual mass and
structure of the s.e.r., the mitochondria
would easily be the most striking feature
of the sow lutein cell because of their
great numbers. That portion of the lutein
cell in figure 1 contains an estimated 150
profiles of mitochondria in section. For
the most part, the mitochondria are circular to oval in shape and are from 0.7-1.0
i n diameter. The mitochondria1 cristae
are tubular or tubulo-vesicular in form
(fig. 4). In many sections the poorly defined cristae seem to be vesicular in structure (fig. 5). The cytoplasm of these
lutein cells is very rich in lipid inclusion
droplets, which are often closely associated with the mitochondria.
A few profiles of rough endoplasmic
reticulum (r.e.r.) can be found in most
sections. They are seen most often as
single pairs of membranes studded with
ribosomes and crowded between the
densely packed mitochondria and lipid
droplets (fig. 5). No r.e.r. could be identified among the membranes of the s.e.r.
masses. Occasionally, continuity between
rough and smooth membranes is noted
(fig. 5). Golgi membranes per se are not
distinguishable in the profusion of
smooth membranes. Clusters of unattached ribosomes are seen occasionally
between the other organelles (fig. 5 ) .
Rarely, lysosome-like or crystalloid bodies
are observed.
The nucleus of the sow lutein cell is,
for the most part, not unusual. The nuclear membrane is composed of a n outer
and a n inner lamina continuous with each
other at the nuclear pores. These two
laminae are separate and discrete except
a t the nuclear pores. Deep to the inner
lamina, interposed between it and the
marginated nuclear chromatin, is an electron dense layer of material of constant
thickness (fig. 5 ) . This dense layer is continuously applied to the deep surface of
the inner lamina. It is interrupted only in
the region of the nuclear pore, where the
inner lamina is continuous with the outer
one. The remainder of the nucleus consists of finely dispersed nucleoplasm with
moderate amounts of clumped chromatin.
The single nucleolus is not remarkable.
One section of a highly unique nucleus
contains, among other things, a relatively
large mass of tubules (fig. 6 ) . They are
formed by smooth membranes very similar
to the s.e.r. These tubules occupy almost
half of the nucleus. In addition to the compact mass of tubular membranes located
in the central portion of the nucleus,
there are isolated tubules scattered
throughout the rest of the nucleoplasm.
The mass of tubules lacks the organization
of its cytoplasmic counterpart, the s.e.r.
It shows, rather, a large degree of disorientation. Unlike the cytoplasmic invagination seen in the same section, these
tubular membranes are not isolated by a
nuclear membrane. The electron dense
zone described above is present on the
inner surface of the nuclear membrane
both at the periphery and around the invaginated cytoplasm. It is not identified
surrounding the intranuclear membranous
system. Besides these membranes, this
unusual nucleus also contains several lipid
droplets, a vacuole, a myelin figure, and
a lysosome-like inclusion. Like the intranuclear membranes, these structures are
not segregated from the nucleoplasm. In
addition, there is a cross-section of a finger
of cytoplasm located in this nucleus. However, it is definitely segregated from this
nucleus by, consecutively, the outer and
inner laminae of the nuclear membrane
and the layer of electron dense material.
The absence of grossly visible placentation in the uterus and the histological details suggest that the corpora lutea used in
this study were between 7 and 15 days old
and from a non-pregnant sow (Corner,
'21). The lack of any other physiological
data is regrettable. More than 5,000 swine
are slaughtered daily in the local packing
houses and the task of tracking down any
information on the animals used either in
the biochemical study or in this morphological study was too formidable to contemplate.
Because of the adverse conditions under
which the tissues for both studies were
collected there was originally only the intention of looking at the ultrastructure of
the tissue that yielded such large quantities of smooth membranes. However, the
high degree of organization of the smooth
endoplasmic reticulum in such large
masses prompted this report despite these
Descriptions of notable quantities of
smooth endoplasmic reticulum in cells involved in steroid metabolism are not rare.
They have been reported in the interstitial
cells of the testis of the guinea pig (Christensen, '65), the mouse (Christensen and
Fawcett, '66), the opossum (Christensen
and Fawcett, '61), in the ovaries of the
mouse (Yamada and Ishikawa, '60), rat,
mink, and armadillo (Enders, '62), and in
the fetal adrenal of the armadillo (Enders,
Schlafke and Warren, '66) and the human
(Ross, Pappas, Lanman and Lind, '58).
Now the lutein cell of sow ovary has been
added to this Iist (Bjersing, '67; Goodman, Latta, Wilson and Kadis, '67). Even
the extensive degree of organization found
in the s.e.r. of the sow lutein cell has to
a smaller extent been described before.
The "whorl" of smooth membranes was
seen in the interstitial cell of the mouse by
Carr and Carr ('62), and again in the
interstitial cell of the guinea pig by Christensen ('65). Enders, Schlafke and Warren ('66) described s.e.r. with a honeycomb pattern in their article on the fetal
adrenal of the armadillo. They considered
the widespread dilation of the smooth
membrane tubules to be a result of degenerative changes in those cells. The
elaboration of membranes and the arranging of these membranes into highly organized systems requires a great deal of
energy. The manufacturing of the necessary enzyme systems and substrates and
the production of the energy needed to produce the membranes must be characteristics of an actively vital cell rather than a
degenerating cell. We feel the high degree
of organization seen in the s.e.r. of the
sow lutein cell is therefore more probably
an indication of high metabolic activity
than of degeneration (Bjersing, ’67). The
presence of many mitochondria in these
cells would tend to support the hypothesis
of high metabolic activity.
The literature on the biochemical activities of various fractions of homogenized
cells is quite extensive (DeDuve, Wattiaux
and Baudhuin, ’62). One fraction, the
microsomal, is of interest to us here. Exactly which cellular organelles and inclusions are present in this fraction depend
a great deal on the density gradient media
and methods utilized to effect the separation (Schneider, ’59). Usually, the microsomes include all the particulate matter
that remains unsedimented after being
spun at 10,000XG and that is found in
the residue after spinning at 100,000XG.
Among the morphological entities that
may be present in this fraction are the
s.e.r., the r.e,r. with attached ribosomes,
the Golgi membranes and possibly fragments of ruptured plasma membranes or
ruptured mitochondria. Lysosomes are
sometimes isolated in this fraction.
The cellular production of steroid hormones by the ovary, testis, or adrenal
gland involves many enzymes located in
the microsomal fraction, (Ball and Kadis,
’65; Kadis, ’66; Koritz, ’64; Lynn and
Brown, ’58; Shikita and Tamaoki, ’65;
Harding, Wilson, Wong and Nelson, ’65;
and Chamberlain, Jagarinec and Ofner,
’65). In addition the placenta and liver
contain some of the same enzymes in their
microsomal fractions (Ryan, ’59; Jellinck,
Lazier, and Copp, ’65; Bucher and McGarrahan, ’56; and Wilcox and Engel, ’65).
In general, any steroid endocrine organ is
capable of producing any of the steroid
hormones or their intermediaries. Although one type of hormone usually predominates, androgen, etc., the other
metabolites may be present in amounts
too small to measure without great difficulty. These tissues seem to follow the
same biosynthetic pathway from acetate
to cholesterol and pregnenolone and seem
to have similar enzymes with similar subcellular locations (Ryan and Smith, ’65;
Dorfman and Ungar, ’65).
The lutein cell of the sow offers additional proof that the microsomes involved
in steroidogenesis are derived from the
smooth membranes. The extensive preponderance of the s.e.r. over identifiable
Golgi membranes or the r.e.r. is obvious.
The microsomal fraction of this tissue,
rich in stereoidogenic enzymes (Ball and
Kadis, ’65; Kadis, ’66), must be composed
of vesicles and fragments derived mainly
from the s.e.r. However, we cannot ignore
the fact that these microsomes were isolated from homogenates of the entire ovary
and not of corpora lutea alone, and therefore, cannot state with absolute certainty
that the smooth membranes of the lutein
cells are definitely the organelles which
contain the steroidogenic enzymes identified in the microsomal studies on sow
Mitochondria1 enzymes play an important role in steroid metabolism also
(Toren, Menon, Forchielli and Dorfman,
’64), and in addition are involved in furnishing the energy requirements of these
highly active tissues. It is obvious that
mitochondria are very abundant in these
sow lutein cells. The tubular morphology
of the mitochondria1 cristae is consistent
with that seen in other steroid endocrine
tissues. The mitochondria are rather uniform in both size and shape. There are
none of the large mitochondria noted in
rat adrenal cortex (Belt and Pease, ’56).
Nor were any cup-shaped mitochondria
observed as has been reported in the rat
testis (Christensen and Chapman, ’59;
Enders, ’62; Enders and Lyons, ’64).
The electron dense layer of material on
the deep surface of the nuclear membrane
has been described (Patrizi and Poger,
’67; Fawcett, ’66). It is seen in tissues
that have been fixed in glutaraldehyde and
postfixed in osmium. Patrizi and Poger
(’67) have proposed the name “nuclear
limiting zone” or “Zonula Nucleum
Limitans” for this structure.
With the exception of the one isolated
observation noted above, the large, oval
nuclei of the lutein cell appear quite normal. The presence of some form of intranuclear membrane has been reported in
both mammalian and non-mammalian tissues. Kessel (’66) has described “intranuclear annulate lamellae” in the oocytes
of several species of tunicates. Annular
membranes have been reported within the
nuclei of human endometrial gland cells,
(Dubrauszky and Pohlmann, '61 ; Clyman
'63). The nuclei of indifferent cells in the
immature calf testis contain similar intranuclear membranes (Nicander, AbdelRaouf and Crabo, '61). Bucciarelli ('66)
has described Golgi-like intranuclear membranes in virus-infected tissues of an intracranial chicken sarcoma. Mori and
Onoe ('67) have described intranuclear
inclusions in neoplastic human renal cells.
In comparing the intranuclear membranes observed in a single luteal cell with
those described in the literature, some
differences in the extent and type of membranes present are noted. In the nuclei of
the human endometrial gland cells these
membranes are described as canalicular
and are associated with the nucleolus. In
calf testis they are described as vacuoles in
the nucleolus. Those found in tunicate
oocytes are almost identical in structure
to its nuclear membrane. Closest in morphology to the membranes we have described are the Golgi-like vesicles and
tubules seen in a Rous sarcoma cell
nucleus and the intranuclear inclusions in
the renal neoplasm. In the reports known
to us the intranuclear membranes are not
as numerous or as massive as those described in this paper.
While we have no explanation for this
phenomenon, it is worth noting that there
is a common factor shared by many of the
cells in which intranuclear membranes
have been described. Most of the cells involved are those which undergo repeated
mitoses. One of two processes may explain the formation of intranuclear inclusions. A portion of invaginating cytoplasm may have been pinched off in the
reconstruction of the nucleus with subsequent loss of membranous continuity with
the remainder of the cytoplasm and deterioration of its encircling membrane.
Alternately, in the process of mitosis some
of the cytoplasmic subunits may have
been caught inside the regenerating nuclear membrane. The lipid droplets and
the membrane bound inclusion body seen
in the sow lutein cell described above, lend
support to either explanation.
Ball, H., and B. Kadis 1965 Steroid hydroxylation. 11. Intracellular location of 17 alpha hydroxylase and its substrate specificity i n sow
ovary. Arch. Biochem., 110: 427431.
Belt, W. D., and D. C. Pease 1965 Mitochondria1
structure i n sites of steroid secretions. J. Biophys. Biochem. Cytol., 2 (Suppl.): 369-374.
Bjersing, Lars 1967 On the ultrastructure of
granulosa lutein cells in porcine corpus luteum. Z . Zellforsch, 82: 187-211.
Bucciarelli, E. 1966 Intranuclear cisternae resembling structures of the Golgi complex. J.
Cell Biol., 30: 664-665.
Bucher, N. L., and K. McGarrahan 1956 The
biosynthesis of cholesterol from acetate I-&&by
cellular fractions of rat liver. J. Biol. Chem.,
222: 1-15.
Carr, I., and J. Carr 1962 Membranous whorls
i n the testicular interstitial cell. Anat. Rec., 244:
Chamberlain, J., N. Jagarinec and P. Ofner 1965
Catabolism of c-19 steroids by subcellular fractions of mammalian and avian tissues. Steroids,
Suppl., 11, 1-12.
Christensen, A. K. 1965 The fine structure of
testicular interstitial cells in guinea pigs. J.
Cell Biol., 26: 911-935.
Christensen, A. K., and G . B. Chapman 1959
Cup-shaped mitochondria in interstitial cells of
albino rat testis. Exp. Cell Res., 18: 576-579.
Christensen, A. K., and D. W. Fawcett 1961 The
normal fine structure of opossum testicular interstitial cells. J. Biophys. Biochem. Cytol., 9:
1966 The fine structure of testicular
interstitial cells i n mice. Am. J. Anat., 218:
Clyman, M. J. 1963 A new structure observed
in the nucleolus of the human endometrial epithelial cells. Amer. J. Obstet. and Gynec., 86:
Corner, G. W. 1921 Cyclic changes in the ovaries and uterus of the sow and their relation to
the mechanism of implantation. Contr. Embryol. Carnex Instn., 13: 117-146.
DeDuve, C., R. Wattiaux and P. Baudhuin 1962
Distribution of enzymes between subcellular
fractions i n animal tissues. Advances Enzym.,
24: 291-358.
Dorfman, R. I., and F. Ungar 1965 Metabolism
of Steroid Hormones. Academic Press, New
York. Chap. 11, 23.
Dubrauszky, V . , and G. Pohlmann 1961 Die
ultrastruktur des korpus endometriums wahrend
des cyclus. Arch. Gynaek., 196: 180-199.
Enders, A. C. 1962 Observations on the fine
structure of lutein cells. J. Cell Biol., 12: 101113.
Enders, A. C., and W. R. Lyons 1964 Observations on the fine structure of lutein cells. 11. The
effects of hypophysectomy and mammotrophic
hormone i n the rat. J. Cell Biol., 22: 127-141.
Enders, A. C., S . Schlafke and R. Warren 1966
Cytology of the fetal zone of the adrenal gland
of the armadillo. Anat. Rec., 254: 807-822.
Fawcett, D. 1966 An Atlas of Fine Structure:
The Cell. W. B. Saunders Company, Philadelphia, Pennsylvania, pp. 4 0 4 2 .
Fouts, J. R. 1961 The metabolism of drugs by
subfractions of hepatic microsomes. Biochem.
Biophys. Res. Comm., 6: 373-378.
Goodman, P., J. S. Latta, R. B. Wilson and B. Kadis
1967 Massive smooth endoplasmic reticulum
i n porcine granulosa lutein cells. Anat. Rec.,
157: 249-250.
Harding, B. W., L. D. Wilson, S. H. Wong and D.
G. Nelson 1965 Electron carriers of the rat
adrenal and the 11-beta-hydroxylating system.
Steroids, Suppl. 11, 51-77.
Jellinck, P. H., C. Lazier and M. L. Copp 1965
Nature of the water-soluble estrogen metabolites
formed by rat liver in nitro. Canad. J. Biochem.,
43: 1774-1776.
Kadis, B. 1966 Steroid hydroxylations V. Intracellular location of 16 alpha-hydroxylase and its
substrate specificity in sow ovary. Biochemistry,
5: 3604-3608.
Kessel, R. G. 1966 Ultrastructure and relationships of ooplasmic components in tunicates.
Acta Embryol. Morph. Exp., 9: 1-24.
Koritz, S. B. 1964 The conversion of pregnenolone to progesterone by small particles from
rat adrenal. Biochemistry, 3: 1098-1102.
Lynn, W. S., Jr., and R. H. Brown 1958 The
conversion of progesterone to androgens by
testes. J. Biol. Chem., 232: 1015-1029.
Mori, M., and Tamenori Onoe 1967 A n electron
microscopic study on the formation of intranuclear inclusions. J. J. Electron Microscopy,
16: 137-142.
Nicander, L., M. Abdel-Raouf and B. Crabo 1961
On the ultrastructure of the seminiferous tubules in bull calves. Acta Morph. Neerl. Scand.,
4: 127-135.
Patrizi, G., and M. Poger 1967 The ultrastructure of the nuclear periphery. J. Ultrastruct.
Res., 17: 127-136.
Ross, M. H., G . D. Pappas, J. T. Lanman and J.
Lind 1958 Electron microscope observations
on the endoplasmic reticulum in the human
fetal adrenal. J. Biophys. Biochem. Cytol., 4:
Ryan, K. J. 1959 Biological aromatization of
steroids. J. Biol. Chem., 234: 268-272.
Ryan, K. J., and 0. W. Smith 1965 Biogenesis
of steroid hormones i n the human ovary. Recent
Prog. Hormone Res., 21: 367-402.
Schneider, W. C. 1959 Manometric Techniques.
Ed. by W. W . Umbreit, R. H. Burris and J. P.
Stauffer, Burgess Publ. Co., Minneapolis. Chap.
Shikita, M., and B. Tamaoki 1965 Testosterone
formation by subcellular particles of rat testes.
Endocrinology, 76: 563-569.
Toren, D., K. M. J. Menon, E. Forchielli and R. I.
Dorfman 1964 112 nitro enzymatic cleavage of
the cholesterol side chain in rat testis preparations. Steroids, 3: 381-390.
Wilcox, R. B., and L. L. Engel 1965 The aromatization of 10-methyl and 10-hydroxymethyl
steroids by human placental microsomes. Steroids, Suppl. 11, 249-255.
Yamada, E., and T. M. Ishikawa 1960 The fine
structure of the corpus luteum in the mouse
ovary as revealed by electron microscopy.
Kyushu J. Med. Sci., 11: 235-259.
cytoplasmic invagination
intranuclear membrane system
inner nuclear lamina
myelin figure
nP >
nuclear pore
outer nuclear lamina
plasma membrane
red bood cell
rough endoplasmic reticulum
smooth endoplasmic reticulum
zonula nucleum limitans (electron
dense zone)
This photomicrograph of sow corpus luteum includes portions of several
lutein cells and a capillary. Note the size and extent of the smooth
membranes (ser), and the numbers of mitochondria and lipid droplets.
The smooth membranes seen here are excellent examples of the “fingerprint whorls” described in the text. Note also the mitochondria and
lipid droplets trapped with the mass of s.e.r. at the upper right corner.
x 5,600.
Paul Goodman, John S. Latta, Richard B. Wilson and Barney Kadis
This is an example of the “honeycomb” type smooth membrane system.
x 21,000.
This combination of “honeycomb” and “fingerprint” system is the most
frequently observed type of smooth membrane system. Note the continuity between the flattened cisternae and dilated tubules (arrow).
Paul Goodman, John S. Latta, Richard B. Wilson and Barney Kadis
These mitochondria demonstrate the tubular or tubulo-vesicular cristae
of steroidogenic tissues (arrows). Note the many profiles of rough membranes (rer).
This is a small portion of the nucleus and adjacent cytoplasm of a sow
lutein cell. The nuclear membrane is composed of outer and inner
laminae (onl, inl) and a n inner electron dense zone, the zonula nucleum
limitans (znl), which are all fused at the nuclear pore ( n p ) . The rough
endoplasmic reticulum (rer ) is continuous with the smooth endoplasmic
reticulum ( * ) .
Paul Goodman, John S. Latta, Richard B. Wilson and Barney Kadis
Paul Goodman, John S. Latta, Richard B. Wilson and Barney Kadis
This sow lutein cell nucleus contains an extensive intranuclear smooth
membrane system (ims). In addition this nucleus has a nucleolus (nl),
a cytoplasmic invagination (ci), a membrane-bound body that contains
a myelin figure ( m f ) and a lysosome-like structure (ly), some scattered
smooth membranes (unlabeled arrows), a vacuole ( v ) and several
lipid droplets (1). The nuclear membrane exhibits the same threelayered structure as the normal nucleus in figure 5. x 10,600.
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