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PubMed2002

Regulated appearance of NMDA receptor subunits and channel functions during in vitro neuronal differentiation.

The schedule of NMDA receptor subunit expression and the appearance of functional NMDA-gated ion channels were investigated during the retinoic acid (RA) induced neuronal differentiation of NE-4C, a p53-deficient mouse neuroectodermal progenitor cell line. NR2A, NR2B, and NR2D subunit transcripts were present in both nondifferentiated and neuronally differentiated cultures, while NR2C subunits were expressed only transiently, during the early period of neural differentiation. Several splice variants of NR1 were detected in noninduced progenitors and in RA-induced cells, except the N1 exon containing transcripts that appeared after the fourth day of induction, when neuronal processes were already formed. NR1 and NR2A subunit proteins were detected both in nondifferentiated progenitor cells and in neurons, while the mature form of NR2B subunit protein appeared only at the time of neuronal process elongation. Despite the early presence of NR1 and NR2A subunits, NMDA-evoked responses could be detected in NE-4C neurons only after the sixth day of induction, coinciding in time with the expression of the mature NR2B subunit. The formation of functional NMDA receptors also coincided with the appearance of synapsin I and synaptophysin. The lag period between the production of the subunits and the onset of channel function suggests that subunits capable of channel formation cannot form functional NMDA receptors until a certain stage of neuronal commitment. Thus, the in vitro neurogenesis by NE-4C cells provides a suitable tool to investigate some inherent regulatory processes involved in the initial maturation of NMDA receptor complexes.

Alternative Splicing↗
PubMed2005

A proteomic survey of rat cerebral cortical synaptosomes.

Previous findings from our laboratory and others indicate that two-dimensional gel electrophoresis (2-DE) can be used to study protein expression in defined brain regions, but mainly the proteins which are present in high abundance in glia are readily detected. The current study was undertaken to determine the protein profile in a synaptosomal subcellular fraction isolated from the cerebral cortex of the rat. Both 2-DE and liquid chromatography - tandem mass spectrometry (LC-MS/MS) procedures were used to isolate and identify proteins in the synaptosomal fraction and accordingly >900 proteins were detected using 2-DE; the 167 most intense gel spots were isolated and identified with matrix-assisted laser desorption/ionization - time of flight peptide mass fingerprinting or LC-MS/MS. In addition, over 200 proteins were separated and identified with the LC-MS/MS "shotgun proteomics" technique, some in post-translationally modified form. The following classes of proteins associated with synaptic function were detected: (a) proteins involved in synaptic vesicle trafficking-docking (e.g., SNAP-25, synapsin I and II, synaptotagmin I, II, and V, VAMP-2, syntaxin 1A and 1B, etc.); (b) proteins that function as transporters or receptors (e.g., excitatory amino acid transporters 1 and 2, GABA transporter 1); (c) proteins that are associated with the synaptic plasma membrane (e.g., post-synaptic density-95/synapse-associated protein-90 complex, neuromodulin (GAP-43), voltage-dependent anion-selective channel protein (VDACs), sodium-potassium ATPase subunits, alpha 2 spectrin, septin 7, etc.); and (d) proteins that mediate intracellular signaling cascades that modulate synaptic function (e.g., calmodulin, calcium-calmodulin-dependent protein kinase subunits, etc.). Other identified proteins are associated with mitochondrial or general cytosolic function. Of the two proteins identified as endoplasmic reticular, both interact with the synaptic SNARE complex to regulate vesicle trafficking. Taken together, these results suggest that the integrity of the synaptosomes was maintained during the isolation procedure and that this subcellular fractionation technique enables the enrichment of proteins associated with synaptic function. The results also suggest that this experimental approach can be used to study the differential expression of multiple proteins involved in alterations of synaptic function.

Animals↗
PubMed2006

Analysis of the synaptic vesicle proteome using three gel-based protein separation techniques.

Synaptic vesicles are key organelles in neurotransmission. Their functions are governed by a unique set of integral and peripherally associated proteins. To obtain a complete protein inventory, we immunoisolated synaptic vesicles from rat brain to high purity and performed a gel-based analysis of the synaptic vesicle proteome. Since the high hydrophobicity of integral membrane proteins hampers their resolution by gel electrophoretic techniques, we applied in parallel three different gel electrophoretic methods for protein separation prior to MS. Synaptic vesicle proteins were subjected to either 1-D SDS-PAGE along with nano-LC ESI-MS/MS or to the 2-D gel electrophoretic techniques benzyldimethyl-n-hexadecylammonium chloride (BAC)/SDS-PAGE, and double SDS (dSDS)-PAGE in combination with MALDI-TOF-MS. We demonstrate that the combination of all three methods provides a comprehensive survey of the proteinaceous inventory of the synaptic vesicle membrane compartment. The identified synaptic vesicle proteins include transporters, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), synapsins, rab and rab-interacting proteins, additional guanine nucleotide triphosphate (GTP) binding proteins, cytoskeletal proteins, and proteins modulating synaptic vesicle exo- and endocytosis. In addition, we identified novel proteins of unknown function. Our results demonstrate that the parallel application of three different gel-based approaches in combination with mass spectrometry permits a comprehensive analysis of the synaptic vesicle proteome that is considerably more complex than previously anticipated.

Animals↗
PubMed1994

Calcium signalling in bovine adrenal chromaffin cells: additive effects of histamine and nicotine.

In a previous report, we described the ability of two secretogogues, histamine and nicotine, to stimulate additive effects on catecholamine (CA) release and synapsin II phosphorylation in bovine adrenal chromaffin cells (BACC) [Firestone and Browning (1992), J. Neurochem., 58:441-447]. We hypothesized that these results were due to the combined effects on cytosolic Ca++ of the two distinct signalling pathways. We therefore examined the intracellular Ca++ signals stimulated by histamine and nicotine, alone and together. In Ca(++)-deficient medium, nicotine-stimulated signals were abolished, whereas histamine-stimulated signals were maintained, demonstrating that nicotine depended entirely on Ca++ influx for its effects. Indeed, the nicotine-stimulated signal could also be prevented using a Ca++ channel blocker, nicardipine. Further, the observation that exposure of BACC to thapsigargin reduced histamine-stimulated Ca++ signals verified that histamine mobilizes Ca++ from intracellular stores. Thus, the two secretogogues mobilize Ca++ from distinct pools. When BACC were stimulated with the two secretogogues together, the resulting Ca++ signal was greater than that from either alone. These data are consistent with a model in which two distinct sources of Ca++ can summate within the cell, producing a greater Ca++ signal and, hence, a greater effect on neurotransmitter release.

Adrenal Glands↗
PubMed1995

Immunochemical localization of calcium/calmodulin-dependent protein kinase I.

Ca2+/calmodulin-dependent protein kinase I (CaM kinase I) was originally identified in rat brain based on its ability to phosphorylate site 1 of synapsin I. Recently a cDNA for the rat brain enzyme has been cloned and the primary structure elucidated [Picciotto et al. (1993), J. Biol. Chem., 268:26512-26521]. The rat cDNA encoded a protein of 374 amino acids with a calculated M(r) of 41,636. Antibodies have now been raised against the recombinant kinase expressed in E. coli as a glutathione-S-transferase fusion protein. Immunoblot analysis of rat cortex lysates revealed two major immunoreactive bands of approximately M(r) 38,000 and 42,000. Minor immunoreactive species of slightly lower M(r) were also detected. Two distinct CaM kinase I activities were partially purified from rat brain and shown to correspond to the two major immunoreactive species. A variety of immunoreactive species of M(r) 35-43,000 were detected in "brain" tissue from cow, zebra finch, goldfish, Xenopus, lamprey, and Drosophila. In rat brain, immunocytochemistry revealed strong staining in cortex, hippocampus, amygdala, hypothalamus, brain stem, and choroid plexus. The labelling was mainly observed in neuropil but clusters of intensely labelled neuronal cell bodies were also detected all along the neuraxis. Neuronal nuclei and glial cells did not appear to be stained. Subcellular fractionation studies confirmed the cytosolic localization of the kinase in the brain. In various rat non-neuronal tissues and in a number of cell lines, immunoreactive species of approximately M(r) 38,000 and approximately 42,000 were detected at lower levels than that detected in brain. The M(r) 38,000 and 42,000 species were also found in different ratios and at different levels in the non-neuronal tissues. These results support a role for CaM kinase I in the regulation of multiple neuronal processes. Furthermore, the widespread cell and tissue distribution suggests that CaM kinase I may function as a ubiquitous multi-functional protein kinase. Finally, the multiple immunoreactive species may represent isoforms of CaM kinase I.

Animals↗
PubMed1998

Nuclear glycogen and glycogen synthase kinase 3.

Glycogen is the principal storage form of glucose in animal cells. It accumulates in electron-dense cytoplasmic granules and is synthesized by glycogen synthase (GS), the rate-limiting enzyme of glycogen deposition. Glycogen synthase kinase-3 (GSK-3) is a protein kinase that phosphorylates GS. Two nearly identical forms of GSK-3 exist: GSK-3 alpha and GSK-3 beta. Both are constitutively active in resting cells and their activity can be modulated by hormones and growth factors. GSK-3 is implicated in the regulation of many physiological responses in mammalian cells by phosphorylating substrates including neuronal cell adhesion molecule, neurofilaments, synapsin I, and tau. Recent observations point to functions for glycogen and glycogen metabolism in the nucleus. GSK-3 phosphorylates several transcription factors, and we have recently shown that it modifies the major nuclear pore protein p62. It also regulates PK1, a protein kinase required for maintaining the interphase state and for DNA replication in cycling Xenopus egg extracts. Recently, glycogen was shown to be required for nuclear reformation in vitro using ovulated Xenopus laevis egg lysates. Because neither glycogen nor GSK-3 has been localized to the nuclear envelope or intranuclear sites, glycogen and GSK-3 activites were measured in rat liver nuclei and nuclear reformation extracts. Significant quantities of glycogen-like material co-purified with the rat-liver nuclear envelope. GSK-3 is also highly enriched in the glycogen pellet of egg extracts of Xenopus that is required for nuclear assembly in vitro. Based on the finding that enzymes of glycogen metabolism copurify with glycogen, we propose that glycogen may serve a structural role as a scaffold for nuclear assembly and sequestration of critical kinases and phosphatases in the nucleus.

Animals↗
PubMed1997

Collateral sprouting of central noradrenergic neurons during aging: histochemical and neurochemical studies in intraocular triple transplants.

The sprouting capacity of aged noradrenergic neurons of the brain-stem nucleus locus coeruleus (LC) was examined using intraocular transplants of fetal tissues. Fetal hippocampal tissue (E18) and LC tissue (E15) were transplanted together as a double transplant into the anterior chamber of the eye of young adult Fischer 344 rats. The double transplants were allowed to mature for 14-18 months, after which an additional fetal hippocampal transplant was placed next to the LC graft. The triple transplants were monitored for overall growth and vascularization for an additional 2-6 months. Immunohistochemical examinations showed that both young (2-6 months old) and aged (16-24 months old) hippocampal cografts contained a plexus of thin varicose tyrosine hydroxylase (TH)-immunoreactive fibers extending throughout the grafted hippocampal tissues. However, the aged hippocampal grafts contained a denser uniform plexus of TH-positive fibers compared to the young transplants. Immunohistochemistry with synapsin antibodies demonstrated that both the young and the aged hippocampal transplants contained much higher densities of synaptic elements than the LC grafts. In vivo electrochemical measurements of potassium-evoked overflow of norepinephrine (NE) in the grafts showed that similar amounts of NE overflow were detected in both the young and the aged hippocampal grafts. HPLC-EC measurements of NE levels in the grafts revealed that there were similar amounts of NE in the young and the aged grafts, and the grafts did not contain serotonin or dopamine. In summary, the findings of the present study show that aged LC neurons are capable of undergoing collateral sprouting producing a functional NE neuronal system when introduced to an appropriate young target.

Animals↗
PubMed2003

Transcription factor REST dependent proteins are comparable between Down syndrome and control brains: challenging a hypothesis.

Impairment of the RE-1-silencing transcription factor (REST) and REST-dependent genes in Down Syndrome (DS) neuronal progenitor cells and neurospheres has been published recently. As dysregulation of this system has been shown at the RNA level and considering the long and unpredictable way from RNA to proteins, and as it is the proteins that do the function in brain, we decided to test this hypothesis at the protein level. Cortex of brains of patients with Down Syndrome at the early second trimester were used. REST-dependent structures as synapsin I, brain derived neurotrophic factor BDNF and neuronal growth-associated protein SCG10 were determined at the protein level using immunoblotting. Proteins were comparably expressed in fetal Down syndrome and control brains. Even when normalized versus housekeeping genes (glyceraldehyde-6-phosphate-dehydrogenease) and a marker for neuronal density (neuron-specific enolase) DS results were resembling controls. Therefore, we cannot confirm the REST-hypothesis by our studies in the 18/19th week of gestation at the protein level in brain and taking into account that the hypothesis was based upon studies in progenitor cells.

Brain↗
PubMed1993

X chromosome linkage studies in familial Rett syndrome.

Four families, each with two individuals affected by Rett Syndrome (RS), were analysed using restriction fragment length polymorphisms and microsatellite markers from the X chromosome. In two of the families, X-linked dominant inheritance of the RS defect from a germinally mosaic mother could be assumed. Therefore, maternal X chromosome markers showing discordant inheritance were used to exclude regions of the X chromosome as locations of the RS gene. Much of the short arm could be excluded, including regions containing three candidate genes, OTC, synapsin 1 and synaptophysin. Although most of the long arm was inherited in common it was possible to exclude a centromeric region. Inheritance of X chromosome markers is also presented for two families with affected aunt-niece pairs, one of which has not been previously studied at the DNA level.

Chromosome Mapping↗
PubMed1989

Regional localization of the TIMP gene on the human X chromosome. Extension of a conserved synteny and linkage group on proximal Xp.

The gene encoding a tissue inhibitor of metallo-proteinases, TIMP, has previously been shown to be X-linked in both the human and mouse genomes. We have used a series of somatic cell hybrids segregating translocation and deletion X chromosomes to map the TIMP gene on the human X chromosome. In combination with previous data, the gene can be assigned to Xp11.23----Xp11.4. Genetic linkage analyses demonstrate that TIMP is linked to the more distal ornithine transcarbamylase (OTC) locus at a distance of about 22 centimorgans. The data are consistent with the conclusion that TIMP maps to a conserved synteny and linkage group on the proximal short arm of the human X chromosome and on the pericentric region of the mouse X chromosome, including loci for synapsin-1, a member of the raf oncogene family, OTC, and TIMP.

Animals↗
PubMed1994

Fast and slow axonal transport-different methodological approaches give complementary information: contributions of the stop-flow/crush approach.

This 'minireview' describes experiments in short term crush operated rat nerves, to study endogenous substances in anterograde and retrograde fast axonal transport. Immunofluorescence was used to recognize transported antigens, and cytofluorimetric scanning was employed to quantitate different antigens which had accumulated proximal and distal to the crushes. Vesicle membrane components p38 (synaptophysin) and SV2 accumulated on both sides of a crush. This was expected from a number of studies from different laboratories. Surface associated molecules, however, like synapsins and rab3a, have been studied by other groups with biochemical methods, and suggested to be transported with slow transport. The crush method, however, revealed that a considerable fraction of these two substances are transported with the fast transport system, and, thus, associated with fast transported organelles in the living neuron. Evidently, more than one technique is required to give a more complete picture of intraneuronal transport related events.

Animals↗
PubMed1989

Purification and characterization of a Mn2+/phospholipid-dependent protein phosphatase from pig brain membranes.

A Mn2+/phospholipid-dependent protein phosphatase has been identified and characterized from brain membranes. The phosphatase contains three subunits with molecular weights of 64,000, 54,000, and 35,000 in a 1:1:1 molar ratio. On gel filtration, the enzyme has an apparent molecular weight of approximately 180,000. The phosphatase was active on many substrates, including p-nitrophenyl phosphate, phosphotyrosine, phosphothreonine, phosphorylase a, myelin basic protein, histones, type 1 phosphatase inhibitor-2, microtubule tau protein, and synapsin I. To dephosphorylate phosphoproteins, the phosphatase was dependent on such acidic phospholipids as phosphatidylinositol and phosphatidylserine but not on neutral phospholipids such as phosphatidylcholine and phosphatidylethanolamine. The phospholipid-mediated activation of the phosphatase was time and dose dependent and could be reversed by Triton X-100 or gel filtration. Kinetic study further indicates that phospholipid was able to increase the Vmax of the phosphatase but had no effect on the Km value for substrates, suggesting a direct interaction of phospholipids with the phosphatase. Conversely, in order to dephosphorylate phosphoamino acids such as phosphotyrosine and phosphothreonine, this phosphatase was entirely dependent on Mn2+. Phospholipids had no effect on the dephosphorylation of phosphoamino acids, whereas Mn2+ had no effect on the dephosphorylation of phosphoproteins. It is concluded that this Mn2+/phospholipid-dependent membrane phosphatase has two distinct activation mechanisms. The enzyme requires Mn2+ to dephosphorylate micromolecules, whereas acidic phospholipids are needed to dephosphorylate macromolecules. This suggests that Mn2+ and phospholipids may play a role in regulating the substrate specificity of this multisubstrate membrane phosphatase.

Animals↗
PubMed1998

Characterization of calcium/calmodulin-dependent protein kinase II activity in the nervous system of the lobster, Panulirus interruptus.

Nervous system tissue from Panulirus interruptus has an enzyme activity that behaves like calcium/calmodulin-dependent protein kinase II (CaM KII) This activity phosphorylates known targets of CaM KII, such as synapsin I and autocamtide 3. It is inhibited by a CaM KII-specific autoinhibitory domain peptide. In addition, this lobster brain activity displays calcium-independent activity after autophosphorylation, another characteristic of CaM KII. A cDNA from the lobster nervous system was amplified using polymerase chain reaction. The fragment was cloned and found to be structurally similar to CaM KII. Serum from rabbits immunized with a fusion protein containing part of this sequence immunoprecipitated a CaM KII enzyme activity and a family of phosphoproteins of the appropriate size for CaM KII subunits. Lobster CaM KII activity is found in the brain and stomatogastric nervous system including the commissural ganglia, commissures, stomatogastric ganglion and stomatogastric nerve. Immunoblot analysis of these same regions also identifies bands at an apparent molecular weight characteristic of CaM KII.

Amino Acid Sequence↗
PubMed2001

Differential expression between synaptic vesicle proteins and presynaptic plasma membrane proteins in the anterior horn of amyotrophic lateral sclerosis.

This study concerns the immunohistochemical investigation of synaptic proteins in the anterior horn of amyotrophic lateral sclerosis (ALS). Antibodies against synapsin 1 and synaptophysin (i.e. synaptic vesicle proteins), and those against syntaxin and the synaptosomal-associated, 25 kDa protein, SNAP25 (i.e. presynaptic plasma membrane proteins) were used for immunostaining, respectively. Lumbar spinal cords from five ALS and eight control patients were examined. In the controls, all four synaptic proteins exhibited fine granular immunoreactivities, distributed throughout the spinal gray matter almost uniformly. In contrast, in all five ALS patients, two of the synaptic vesicle proteins examined decreased in the anterior horn neuropil diffusely, while in the same lumbar segments of these cases the immunoreactivities of the two presynaptic plasma membrane proteins showed no apparent decrease, or were only mildly diminished in the same gray matter area. These results indicate that, during the presynaptic terminal degeneration in the anterior horn of ALS, synaptic vesicle involvement may precede that of the presynaptic plasma membrane.

Adult↗
PubMed2002

Development of the nervous system in the "head" of Limulus polyphemus (Chelicerata: Xiphosura): morphological evidence for a correspondence between the segments of the chelicerae and of the (first) antennae of Mandibulata.

We investigated brain development in the horseshoe crab Limulus polyphemus and several other arthropods via immunocytochemical methods, i.e. antibody stainings against acetylated alpha-tubulin and synapsin. According to the traditional view, the first appendage-bearing segment in chelicerates (the chelicerae) is not homologous to the first appendage-bearing segment of mandibulates (first antenna, deutocerebrum) but to the segment of the second antenna (tritocerebrum) or the intercalary segment in hexapods and myriapods. Accordingly, the segment of the deutocerebrum in chelicerates would be completely reduced. The main arguments for this view are: (1) the postoral origin of the cheliceral ganglion, (2) a poststomodaeal commissure, and (3) a connection of the cheliceral ganglion to the stomatogastric system. Our data show that these arguments are not convincing. During the development of horseshoe crabs there is no evidence for a former additional segment in front of the chelicerae. Instead, comparison of the brain structure (neuropil ring) between chelicerates, crustaceans and insects shows remarkable similarities. Furthermore, the cheliceral commissure in horseshoe crabs runs mainly praestomodaeal, which would be unique for a tritocerebral commissure. An unbiased view of the developing nervous system in the "head" of chelicerates, crustaceans and insects leads to a homologisation of the cheliceral segment and that of the (first) antenna (= deutocerebrum) of mandibulates that is also congruous to the interpretation of the Hox gene expression patterns. Thus, our data provide morphological evidence for the existence of a chelicerate deutocerebrum.

Animals↗
PubMed1998

A single human cell expresses all messenger ribonucleic acids: the arrow of time in a cell.

Expression of 25 mRNAs in a single human lymphocyte was investigated using the reverse transcription nested polymerase chain reaction (RT nested PCR) method. Proteins corresponding to the mRNA investigated were mucin antigen, melanoma antigen, pregnancy-specific beta-1 glycoprotein 4, phenylethanolamine-N-methyl-transferase, beta B3-crystallin, homeobox 4A, interleukin 2, cluster of differentiation 8, progesterone receptor, parathyroid hormone, gastrin, cholecystokinin/pancreozymin, glucagon, insulin, enkephalin, thyroid stimulating hormone, adrenocorticotropic hormone, synapsin I, immunoglobulin (Ig)M, IgD, IgG1, IgG3, IgE, IgA, and T cell receptor alpha. All mRNAs were detected in single lymphocytes of two individuals, without exception. In addition, transcripts of IgM, IgD, IgG1, IgG3, IgE, IgA, and the T cell receptor a gene were detected in single sperms. The results strongly suggest the possibility that all mRNAs may be expressed in a single human cell, of both somatic and germ lineage. Thus, cells can consume energy in vain to produce functionally meaningless gene transcripts. However, this basal or illegitimate transcription may be essential for the birth of living matter: the arrow of time in a cell. Moreover, the phenomenon implies the potential of using lymphocytes in place of inaccessible tissue for the diagnosis of genetic diseases.

DNA Primers↗
PubMed2002

Evidence for involvement of protein kinases in the regulation of serotonin synthesis and turnover in the mouse brain in vivo.

Inhibition of cAMP-dependent protein kinase (PKA) with N-[2-methylamino)ethyl]-5-isoquinolinesulfonamide (H-8) almost completely antagonized the increase in 5-HTP accumulation and 5-HIAA/5-HT ratio in hypothalamus induced by NAS-181, a 5-HT(1B) receptor antagonist, but had no effect when the mice were treated with NAS-181 together with WAY-100,635, a selective 5-HT(1A) receptor antagonist. Inhibition of Ca(2+)-calmodulin-dependent protein kinase (CaM kinase II) with the calmodulin antagonist N-(4-aminobutyl)-5-chloro-2-naphtalenesulfonamide (W-13) did not antagonise the effect of NAS-181 alone, but counteracted that evoked by the combined treatment with NAS-181 and WAY-100,635. The results indicate that activation of tryptophan hydroxylase by reducing the tone from terminal 5-HT(1B) receptors involves PKA whereas the depolarisation-induced activation of tryptophan hydroxylase involves CaM kinase II. The increase in the 5-HIAA/5-HT ratio may under the experimental conditions used suggest CaM kinase II-induced phosphorylation of synapsin I resulting in increased 5-HT release.

Animals↗
PubMed2003

Human endogenous retroviruses with transcriptional potential in the brain.

Genetic studies of neuropsychiatric disorders have often produced conflicting results, which might partly result from the involvement of epigenetic modifications. We intended to explore the possible implication of DNA methylation and human endogenous retroviruses (HERVs) in neuropsychiatric disorders. In the present study, we identified two HERV loci that are expected to retain the transcriptional activity in the brain. One was located on chromosome 1q21-q22 and the other on 22q12. Interestingly, these regions were overlapped with or included in those of schizophrenia-susceptible loci, SCZD9 and SCZD4, respectively. Particularly, the HERV on 22q12 was located in the opposite direction 4 kb downstream of the Synapsin III gene. These HERV loci could afford clear targets for methylation and expression analyses in postmortem brains of patients with psychiatric disorders such as schizophrenia. In addition, we confirmed our previous finding that only a few of particular HERV-K loci were activated among a number of highly homologous loci in teratocarcinoma cell lines. These activated loci included ones common to all teratocarcinoma cell lines analyzed and depending on their male or female origin.

Brain↗