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Normal proliferation rate of galactocerebroside positive oligodendrocytes in brain cell cultures of the hypomyelinated mouse mutant jimpy
Brain Research, 275 (1983) 369-372 Elsevier
369
Normal proliferation rate of galactocerebroside positive oligodendrocytes in brain cell cultures of the hypomyelinated mouse mutant jimpy LIANE BOLOGA, CARL MOLL and NORBERT HERSCHKOWlTZ Department of Pediatrics, Universityof Berne, 3010 Berne (Switzerland) (Accepted May 17th, 1983) Key words: galactocerebroside - - oligodendrocytes- - brain cell culture - - hypomyelination- - jimpy mutant
Proliferation of oligodendrocytes from the jimpy (jp) hypomyelinated mouse mutant was studied in dissociated brain cell cultures. This was done by combining anti-galactocerebroside (GC) immunostaining (for identifying oligodendrocytes) with [3H]thymidine autoradiography (for identifying proliferating cells). Previouslywe showed that the expression of GC in culture by jp oligodendrocytes is not altered by the jp mutation. Present results show that in 7-, 14- and 21-day-oldjp cultures oligodendrocytes proliferate at a rate similar to that of normal GC+ oligodendrocytes. This indicates that, in jp brain cell cultures, oligodendrocytes which are not affected by mutation in their capability to express GC are also unaffected with regard to their proliferation rate. Animal mutants with neurological disorders are widely used as models for studying the mechanisms of normal and abnormal brain development. One example is the mouse mutant jimpy (jp)22. In jp, the phenotypical expression consists of a practical absence of myelin in the central nervous system 29. Morphological studies have shown abnormalities in oligodendroglial development. The number of glioblastic cells is increased, as well as the occurrence of glial cell death in the premyelination stage. In the period of advanced myelination abnormal oligodendrocytes containing lipids are present, while the number of mature oligodendrocytes is decreasedlS,19,20,23,31. Biochemically, the accumulation, during development, of myelin basic protein (MBp)I,8,10,18, galactocerebroside (GC) and sulfatidel2,18 is practically absent. Cholesterol ester hydrolase 11, cerebroside sulfotransferase13,27, 30 and 2',3'-cyclic nucleotide phosphohydrolase activities16,2s are significantly reduced while cerebroside galactosidase6 and cerebroside sulfatase6,7A4,27 show a normal activity. These morphological and biochemical modifications lead to a severe impairment of myelination. Recently, a protracted proliferation of glioblasts in vivo in the whole central nervous system of jp24 and an increased proliferation of oligodendroblasts in the jp spinal cord and optic nerve 32 have been reported. According to these results, it has been suggested that 0006-8993/83/$03.00 © 1983 Elsevier Science Publishers B.V.
these phenomena could be secondary events resulting from the interruption of differentiation and the absence of stabilization of oligodendrocytes which normally occurs at the onset of myelination 24. This protracted proliferation does not lead to an increased number of oligodendrocytes. In these circumstances we considered it of interest to investigate the proliferation rate of jp oligodendrocytes. Since many difficulties exist in the identification of dividing oligodendrocytes9 we used antigenic markers for the cell identification rather than morphological or ultrastructural criteria, as used previously for their precursors24, 32. The identification of oligodendrocytes has been facilitated by their expression of two antigenic markers, galactocerebroside (GC)25 and myelin basic protein (MPB)a3. Developmental studies indicated that G C is an early marker of oligodendrocytes while the additional expression of MBP represents a further step in their differentiation2. Both the GC+MBP - and the more differentiated GC+MBP+ oligodendrocytes are able to proliferate in cultureS. For these reasons we decided to study in culture the proliferation of immunologically identified oligodendrocytes of jp. This study would allow us to answer the question whether the jp mutation affects the proliferation of oligodendrocytes. We used jp+/y animals and made the diagnosis as
370 previously described3. Cultures were made by plating mechanically dissociated brain cells of 3-day-old jp or normal mice at a density of 3 x 105 cells/cm 2 in plastic petri dishes containing glass coverslips. They were maintained in Minimum Essential Medium Eagle Dulbecco modified containing 10% fetal calf serum at 37 °C in a 5% CO2, 80% humid atmosphere. The 3-day-old jp were recognized due to the Tabby markerl7. 34 carried by the normal littermates. The diagnosis was confirmed histologically by examination of spinal cord sections ~9. Oligodendrocytes were identified with anti-GC and anti-MBP sera 2 in the indirect immunoperoxidase technique21. Proliferating cells were identified by [3H]thymidine autoradiography 26. For the identification of proliferating oligodendrocytes we combined the immunoperoxidase with the autoradiography as previously described 5. Briefly, 7, 14 and 21-day-old cultures were incubated for 12 h with 0.2/tCi/ml [3H]thymidine (Amersham; spec. act. 25 Ci/mmol), then fixed and stained. After immunostaining the cultures were rinsed in distilled water, air dried, mounted on slides and dipped in 1:2 diluted Ilford K 2 emulsion at 42 °C. After a 2 week's exposure at 4 °C they were developed with Kodak D19 solution, covered with a second coverslip and examined in a Leitz orthoplan microscope equipped with incident and transmitted light. Results showed that jp G C ÷ oligodendrocytes are able to proliferate in culture (Fig. 1) and that their appearance is similar to that of GC ÷ proliferating oli-
Fig. 1. Combined [3H]thymidine autoradiography with immunoperoxidase staining with rabbit anti-GC serum of a jimpy mouse brain cell culture, 14 days in vitro. One cell, both GC and 3H-Thymidine positive is seen. The silver grains appear bright in epiilumination. Bar represents 4 #m.
TABLE I Proliferative activity of GC ÷ oligodendrocytes of normal and lp mice in culture
Results are expressed as a percentage of both (3C and [3H]thymidine positive cells per total number of GC positive cells. Each number represents the mean value + standard deviation of 12 estimates from 3 different cultures.
Normal mouse jp mouse
Culture age
14 days
21 days
20.9 + 3.3 20.8 + 3.5
11.1 + 1.6 11.6 + 2.4
11.1 + 1.2 10.5 + 3.6
godendrocytes from normal cultures. The proliferation rate of GC ÷ oligodendrocytes was very similar in jp and normal cultures and it followed the same developmental pattern (Table I). Usually, the few G C + M B P ÷ cells present in jp culture did not incorporate [3H]thymidine; exceptionally one cell both MBP ÷ and [3H]thymidine positive was once seen, indicating that jp G C ÷ M B P + cells keep the capability to proliferate but probably because of their reduced number this is difficult to observe. In contrast, in normal cultures the [3H]thymidine incorporation rate in MPB ÷ cells was about 3%. By studying jp brain cells in dissociated cell culture we have previously shown that G C + M B P -- cells have a normal appearance and their number is identical to that found in normal cultures of the same age3. In culture, the jp defect was expressed only at the level of G C ÷ M B P ÷ oligodendrocytes whose number was reduced to 5 % of the normal 4. We show now that the proliferation pattern of G C + M B P -- oligodendrocytes is similar in 7-, 14- and 21-day-old cell cultures of jp and normal mice dissociated brain. Our present results showing a normal proliferation rate of oligodendrocytes in jp brain cell cultures are not in conflict with the data of Privat et al. 24 and Skoff32 as their findings relate to oligodendroblasts while ours relate to oligodendrocytes. Furtherrnore, their studies were done in vivo and not in culture and also the animals used were jp Ta/y and not as in our s t u d y j p + / y . It is still interesting to speculate that in jp an increased proliferation of oligodendroblasts is followed by a normal proliferation rate of G C + M B P - oligodendrocytes which is followed by a defective further differentiation from G C + M B P - oligodendrocytes to G C + M B P + oligodendrocytes.
371 This study was supported by G r a n t 3.717.80 from the
in Mental Retardation. W e t h a n k Mrs. C. Kunz and
Swiss National Research F o u n d a t i o n , a grant from the Swiss Multiple Sclerosis Society and a grant from the Swiss F o u n d a t i o n of E n c o u r a g e m e n t of Research
A. Z'graggen for technical assistance and Miss H. Jenny for typing.
1 Barbarese, E., Carson, J. H. and Braun, P. E., Subcellular distribution and structural polymorphism of myelin basic protein in normal and jimpy mouse brain, J. Neurochem., 32 (1979) 1437-1446. 2 Bologa-Sandru, L., Siegrist, H. P., Z'graggen, A., Hofmann, K., Wiesmann, U., Dahl, D. and Herschkowitz, N., Expression of antigenic markers during the development of oligodendrocytes in mouse brain cell cultures, Brain Research, 210 (1981) 217-229. 3 Bologa-Sandru, L., Zalc, B., Herschkowitz, N. and Baumann, N., Oligodendrocytes of jimpy mice express galactosylceramide: an immunofluorescence study on brain sections and dissociated brain cell cultures, Brain Research, 225 (1981) 425-430. 4 Bologa-Sandru, L., Siegrist, H. P., Z'graggen, A., Wiesmann, U. and Herschkowitz, N., Abnormal oligodendrocytes differentiation in a mouse mutant with defect in myelination. In F. Cockburn and R. Gitzelmann (Eds.), Inborn Errors of Metabolic in Humans (Proceedings of the 1980 Interlaken Symposium), MTP Press, Lancaster, 1982, pp. 201-208. 5 Bologa, L., Z'graggen, A., Rossi, E. and Herschkowitz, N., Differentiation and proliferation: two possible mechanisms for the regeneration of oligodendrocytes in culture, J. neurol. Sci., 57 (1982) 419-434. 6 Bowen, D. M. and Radin, N. S., Hydrolase activities in brain of neurological mutants: cerebroside galactosidase, nitrophenyl galactosidase hydrolase, nitrophenyl glucoside hydrolase and sulphatase, J. Neurochem., 16 (1979) 457-460. 7 Burkart, T., Wiesmann, U. N. and Herschkowitz, N., Arylsulfatase A in developing normal and jimpy mice, Neuroscience, 2 (1977) 175-180. 8 Campagnoni, A. T. and Roberts, J. L., Isolation of myelin basic proteins from jimpy mice, Brain Research, 115 (1976) 352-356. 9 Cavanagh, J. B., The proliferation of astrocytes around a needle wound in the rat brain, J. Anat., 106 (1979) 471-487. 10 Delassalle, A., Zalc, B., Lachapelle, F., Raoul, M., Collier, P. and Jacque, C., Regional distribution of myelin basic protein in the central nervous system of quaking, jimpy and normal mice, during development and aging, J. Neurosci. Res., 6 (1981) 303-313. 11 Eto, Y. and Suzuki, K., Cholesterol ester metabolism in rat brain, J. biol. Chem., 248 (1973) 1986-1991. 12 Galli, C. and Re Cecconi Galli, D., Cerebroside sulphatide deficiency in the brain of 'Jimpy mice', a mutant strain of mice exhibiting neurological symptoms, Nature (Lond.), 220 (1968) 165-166. 13 Herschkowitz, N., Vassella, F. and Bischoff, A., Myelin differences in the central and peripheral nervous system in the 'Jimpy' mouse, J. Neurochem., 18 (1971) 1361-1363. 14 Hogan, E. L., Joseph, K. C. and Schmidt, G., Composition of cerebral lipids in murine sudanophilic leucodistrophy: the Jimpy mutant, J. Neurochem., 17 (1970) 75-83.
15 Kraus-Ruppert, R., Herschkowitz, N. and Ftirst, H., Morphological studies on neuroglial cells in the corpus callosum of the jimpy mouse, J. Neuropath. exp. Neurol., 32 (1973) 197-203. 16 Kurihara, Z. T., Nussbaum, J. L. and Mandel, P., 2',3'-cyclic nucleotide 3'-phosphohydrolase in brains of mutant mice with deficient myelination, J. Neurochem., 17 (1970) 993-997. 17 Lachapelle, F., Zalc, B., Banmann, N. and Guenet, J. L., In N. Baumann (Ed.),Neurological Mutations Affecting Myelination (INSERM Symposium No. 14),Elsevier~North Holland Biomedical Press, Amsterdam, 1980, pp. 23-25. 18 Matthieu, J. M., Widmer, S. and Herschkowitz, N., Jimpy, an anomaly of myelin maturation; biochemical studies of myelination phases, Brain Research, 55 (1973) 403-412. 19 Meier, C., Herschkowitz, N. and Bischoff, A., Morphological and biochemical observations in the jimpy spinal cord, Acta neuropath., 27 (1974) 349-362. 20 Meier, C. and Bischoff, A., Oligodendroglial cell development in jimpy mice and controls. An electron microscopic study in the optic nerve, J. neurol. Sci., 26 (1975) 517-528. 21 Nakane, P. K. and Pierce, G. B. Jr., Enzyme labeled antibodies for the light and electron microscopic localization of tissue antigens, J. Cell Biol., 33 (1967) 307-318. 22 Phillips, R. J. S., Jimpy, a new totally sex-linked gene in the house mouse, Z. Vererbungslehre, 86 (1954) 322-326. 23 Privat, A., Robain, O. and Mandel, P., Aspects ultrastructuraux du corps calleux chez la souris jimpy, Acta neuropath., 21 (1972) 282-295. 24 Privat, A., Valat, J., Lachapelle, F., Baumann, N. and Fulcrand, J., Radioautographic evidence for the protracted proliferation of glial cells in the central nervous system of jimpy mice, Develop. Brain Res., 2 (1982) 411-416. 25 Raft, M. C., Mirsky, R., Fields, K. L., Lisak, R. P., Dorfman, S. H., Silberberg, D. H., Gregson, N. A., Leibowitz, S. and Kennedy, M. C., Galactocerebroside is a specific cell surface antigenic marker for oligodendrocytes in culture, Nature (Lond.), 274 (1978) 813-816. 26 Rogers, A. W., Techniques of Autoradiography, Elsevier, Amsterdam, 1979. 27 Sarli~ve, L. L., Neskovic, N. M. and Mandel, P., PAPScerebroside sulfotransferase activity in brain and kidney of neurological mutants, FEBS Lett., 19 (1971) 91-95. 28 Sarli~ve, L. L., Farooqui, A. A., Rebel, G. and Mandel, P., Arylsulfatase A and 2',Y-cyclic nucleotide 3'-phosphohydrolase activities in the brains of myelin deficient mutant mice, Neuroscience, 1 (1976) 519-522. 29 Sidman, R. L., Dickie, M. M. and Appel, St. H., Mutant mice (quaking and jimpy) with deficient myelination in the central nervous system, Science, 144 (1964) 309-311. 30 Siegrist, H. P., Burkart, T., Steck, A. P., Wiesmann, U. and Herschkowitz, N. N., Influence of lipids on the activity of cerebroside-sulfotransferase in mouse brain: a comparative study of jimpy and normal mouse brains, J. Neurochem., 27 (1967) 599-604.
372 31 Skoff, R. P., Myelin deficit in the Jimpy mouse may be due to cellular abnormalities in astroglia, Nature (Lond.), 264 (1976) 560-562. 32 Skoff, R. P., Increased proliferation of oligodendrocytes in the hypomyelinated mouse mutant Jimpy, Brain Research, 248 (1982) 19-31. 33 Sternberger, N. H., Itoyama, Y.. Kies, M. W. and
Webster, H. deF., Immunocytochemical method to identify basic protein in myelin forming oligodendrocytes of new born rat C.N.S., J. Neurocytol., 7 (1978) 251-263. 34 Wolf, M. K. and Holden, A. B., Tissue culture analysis of the inherited defect of central nervous system myelination in jimpy mice, J. Neuropath. exp. Neurol.. 28 (1969) 195-213.
369
Normal proliferation rate of galactocerebroside positive oligodendrocytes in brain cell cultures of the hypomyelinated mouse mutant jimpy LIANE BOLOGA, CARL MOLL and NORBERT HERSCHKOWlTZ Department of Pediatrics, Universityof Berne, 3010 Berne (Switzerland) (Accepted May 17th, 1983) Key words: galactocerebroside - - oligodendrocytes- - brain cell culture - - hypomyelination- - jimpy mutant
Proliferation of oligodendrocytes from the jimpy (jp) hypomyelinated mouse mutant was studied in dissociated brain cell cultures. This was done by combining anti-galactocerebroside (GC) immunostaining (for identifying oligodendrocytes) with [3H]thymidine autoradiography (for identifying proliferating cells). Previouslywe showed that the expression of GC in culture by jp oligodendrocytes is not altered by the jp mutation. Present results show that in 7-, 14- and 21-day-oldjp cultures oligodendrocytes proliferate at a rate similar to that of normal GC+ oligodendrocytes. This indicates that, in jp brain cell cultures, oligodendrocytes which are not affected by mutation in their capability to express GC are also unaffected with regard to their proliferation rate. Animal mutants with neurological disorders are widely used as models for studying the mechanisms of normal and abnormal brain development. One example is the mouse mutant jimpy (jp)22. In jp, the phenotypical expression consists of a practical absence of myelin in the central nervous system 29. Morphological studies have shown abnormalities in oligodendroglial development. The number of glioblastic cells is increased, as well as the occurrence of glial cell death in the premyelination stage. In the period of advanced myelination abnormal oligodendrocytes containing lipids are present, while the number of mature oligodendrocytes is decreasedlS,19,20,23,31. Biochemically, the accumulation, during development, of myelin basic protein (MBp)I,8,10,18, galactocerebroside (GC) and sulfatidel2,18 is practically absent. Cholesterol ester hydrolase 11, cerebroside sulfotransferase13,27, 30 and 2',3'-cyclic nucleotide phosphohydrolase activities16,2s are significantly reduced while cerebroside galactosidase6 and cerebroside sulfatase6,7A4,27 show a normal activity. These morphological and biochemical modifications lead to a severe impairment of myelination. Recently, a protracted proliferation of glioblasts in vivo in the whole central nervous system of jp24 and an increased proliferation of oligodendroblasts in the jp spinal cord and optic nerve 32 have been reported. According to these results, it has been suggested that 0006-8993/83/$03.00 © 1983 Elsevier Science Publishers B.V.
these phenomena could be secondary events resulting from the interruption of differentiation and the absence of stabilization of oligodendrocytes which normally occurs at the onset of myelination 24. This protracted proliferation does not lead to an increased number of oligodendrocytes. In these circumstances we considered it of interest to investigate the proliferation rate of jp oligodendrocytes. Since many difficulties exist in the identification of dividing oligodendrocytes9 we used antigenic markers for the cell identification rather than morphological or ultrastructural criteria, as used previously for their precursors24, 32. The identification of oligodendrocytes has been facilitated by their expression of two antigenic markers, galactocerebroside (GC)25 and myelin basic protein (MPB)a3. Developmental studies indicated that G C is an early marker of oligodendrocytes while the additional expression of MBP represents a further step in their differentiation2. Both the GC+MBP - and the more differentiated GC+MBP+ oligodendrocytes are able to proliferate in cultureS. For these reasons we decided to study in culture the proliferation of immunologically identified oligodendrocytes of jp. This study would allow us to answer the question whether the jp mutation affects the proliferation of oligodendrocytes. We used jp+/y animals and made the diagnosis as
370 previously described3. Cultures were made by plating mechanically dissociated brain cells of 3-day-old jp or normal mice at a density of 3 x 105 cells/cm 2 in plastic petri dishes containing glass coverslips. They were maintained in Minimum Essential Medium Eagle Dulbecco modified containing 10% fetal calf serum at 37 °C in a 5% CO2, 80% humid atmosphere. The 3-day-old jp were recognized due to the Tabby markerl7. 34 carried by the normal littermates. The diagnosis was confirmed histologically by examination of spinal cord sections ~9. Oligodendrocytes were identified with anti-GC and anti-MBP sera 2 in the indirect immunoperoxidase technique21. Proliferating cells were identified by [3H]thymidine autoradiography 26. For the identification of proliferating oligodendrocytes we combined the immunoperoxidase with the autoradiography as previously described 5. Briefly, 7, 14 and 21-day-old cultures were incubated for 12 h with 0.2/tCi/ml [3H]thymidine (Amersham; spec. act. 25 Ci/mmol), then fixed and stained. After immunostaining the cultures were rinsed in distilled water, air dried, mounted on slides and dipped in 1:2 diluted Ilford K 2 emulsion at 42 °C. After a 2 week's exposure at 4 °C they were developed with Kodak D19 solution, covered with a second coverslip and examined in a Leitz orthoplan microscope equipped with incident and transmitted light. Results showed that jp G C ÷ oligodendrocytes are able to proliferate in culture (Fig. 1) and that their appearance is similar to that of GC ÷ proliferating oli-
Fig. 1. Combined [3H]thymidine autoradiography with immunoperoxidase staining with rabbit anti-GC serum of a jimpy mouse brain cell culture, 14 days in vitro. One cell, both GC and 3H-Thymidine positive is seen. The silver grains appear bright in epiilumination. Bar represents 4 #m.
TABLE I Proliferative activity of GC ÷ oligodendrocytes of normal and lp mice in culture
Results are expressed as a percentage of both (3C and [3H]thymidine positive cells per total number of GC positive cells. Each number represents the mean value + standard deviation of 12 estimates from 3 different cultures.
Normal mouse jp mouse
Culture age
14 days
21 days
20.9 + 3.3 20.8 + 3.5
11.1 + 1.6 11.6 + 2.4
11.1 + 1.2 10.5 + 3.6
godendrocytes from normal cultures. The proliferation rate of GC ÷ oligodendrocytes was very similar in jp and normal cultures and it followed the same developmental pattern (Table I). Usually, the few G C + M B P ÷ cells present in jp culture did not incorporate [3H]thymidine; exceptionally one cell both MBP ÷ and [3H]thymidine positive was once seen, indicating that jp G C ÷ M B P + cells keep the capability to proliferate but probably because of their reduced number this is difficult to observe. In contrast, in normal cultures the [3H]thymidine incorporation rate in MPB ÷ cells was about 3%. By studying jp brain cells in dissociated cell culture we have previously shown that G C + M B P -- cells have a normal appearance and their number is identical to that found in normal cultures of the same age3. In culture, the jp defect was expressed only at the level of G C ÷ M B P ÷ oligodendrocytes whose number was reduced to 5 % of the normal 4. We show now that the proliferation pattern of G C + M B P -- oligodendrocytes is similar in 7-, 14- and 21-day-old cell cultures of jp and normal mice dissociated brain. Our present results showing a normal proliferation rate of oligodendrocytes in jp brain cell cultures are not in conflict with the data of Privat et al. 24 and Skoff32 as their findings relate to oligodendroblasts while ours relate to oligodendrocytes. Furtherrnore, their studies were done in vivo and not in culture and also the animals used were jp Ta/y and not as in our s t u d y j p + / y . It is still interesting to speculate that in jp an increased proliferation of oligodendroblasts is followed by a normal proliferation rate of G C + M B P - oligodendrocytes which is followed by a defective further differentiation from G C + M B P - oligodendrocytes to G C + M B P + oligodendrocytes.
371 This study was supported by G r a n t 3.717.80 from the
in Mental Retardation. W e t h a n k Mrs. C. Kunz and
Swiss National Research F o u n d a t i o n , a grant from the Swiss Multiple Sclerosis Society and a grant from the Swiss F o u n d a t i o n of E n c o u r a g e m e n t of Research
A. Z'graggen for technical assistance and Miss H. Jenny for typing.
1 Barbarese, E., Carson, J. H. and Braun, P. E., Subcellular distribution and structural polymorphism of myelin basic protein in normal and jimpy mouse brain, J. Neurochem., 32 (1979) 1437-1446. 2 Bologa-Sandru, L., Siegrist, H. P., Z'graggen, A., Hofmann, K., Wiesmann, U., Dahl, D. and Herschkowitz, N., Expression of antigenic markers during the development of oligodendrocytes in mouse brain cell cultures, Brain Research, 210 (1981) 217-229. 3 Bologa-Sandru, L., Zalc, B., Herschkowitz, N. and Baumann, N., Oligodendrocytes of jimpy mice express galactosylceramide: an immunofluorescence study on brain sections and dissociated brain cell cultures, Brain Research, 225 (1981) 425-430. 4 Bologa-Sandru, L., Siegrist, H. P., Z'graggen, A., Wiesmann, U. and Herschkowitz, N., Abnormal oligodendrocytes differentiation in a mouse mutant with defect in myelination. In F. Cockburn and R. Gitzelmann (Eds.), Inborn Errors of Metabolic in Humans (Proceedings of the 1980 Interlaken Symposium), MTP Press, Lancaster, 1982, pp. 201-208. 5 Bologa, L., Z'graggen, A., Rossi, E. and Herschkowitz, N., Differentiation and proliferation: two possible mechanisms for the regeneration of oligodendrocytes in culture, J. neurol. Sci., 57 (1982) 419-434. 6 Bowen, D. M. and Radin, N. S., Hydrolase activities in brain of neurological mutants: cerebroside galactosidase, nitrophenyl galactosidase hydrolase, nitrophenyl glucoside hydrolase and sulphatase, J. Neurochem., 16 (1979) 457-460. 7 Burkart, T., Wiesmann, U. N. and Herschkowitz, N., Arylsulfatase A in developing normal and jimpy mice, Neuroscience, 2 (1977) 175-180. 8 Campagnoni, A. T. and Roberts, J. L., Isolation of myelin basic proteins from jimpy mice, Brain Research, 115 (1976) 352-356. 9 Cavanagh, J. B., The proliferation of astrocytes around a needle wound in the rat brain, J. Anat., 106 (1979) 471-487. 10 Delassalle, A., Zalc, B., Lachapelle, F., Raoul, M., Collier, P. and Jacque, C., Regional distribution of myelin basic protein in the central nervous system of quaking, jimpy and normal mice, during development and aging, J. Neurosci. Res., 6 (1981) 303-313. 11 Eto, Y. and Suzuki, K., Cholesterol ester metabolism in rat brain, J. biol. Chem., 248 (1973) 1986-1991. 12 Galli, C. and Re Cecconi Galli, D., Cerebroside sulphatide deficiency in the brain of 'Jimpy mice', a mutant strain of mice exhibiting neurological symptoms, Nature (Lond.), 220 (1968) 165-166. 13 Herschkowitz, N., Vassella, F. and Bischoff, A., Myelin differences in the central and peripheral nervous system in the 'Jimpy' mouse, J. Neurochem., 18 (1971) 1361-1363. 14 Hogan, E. L., Joseph, K. C. and Schmidt, G., Composition of cerebral lipids in murine sudanophilic leucodistrophy: the Jimpy mutant, J. Neurochem., 17 (1970) 75-83.
15 Kraus-Ruppert, R., Herschkowitz, N. and Ftirst, H., Morphological studies on neuroglial cells in the corpus callosum of the jimpy mouse, J. Neuropath. exp. Neurol., 32 (1973) 197-203. 16 Kurihara, Z. T., Nussbaum, J. L. and Mandel, P., 2',3'-cyclic nucleotide 3'-phosphohydrolase in brains of mutant mice with deficient myelination, J. Neurochem., 17 (1970) 993-997. 17 Lachapelle, F., Zalc, B., Banmann, N. and Guenet, J. L., In N. Baumann (Ed.),Neurological Mutations Affecting Myelination (INSERM Symposium No. 14),Elsevier~North Holland Biomedical Press, Amsterdam, 1980, pp. 23-25. 18 Matthieu, J. M., Widmer, S. and Herschkowitz, N., Jimpy, an anomaly of myelin maturation; biochemical studies of myelination phases, Brain Research, 55 (1973) 403-412. 19 Meier, C., Herschkowitz, N. and Bischoff, A., Morphological and biochemical observations in the jimpy spinal cord, Acta neuropath., 27 (1974) 349-362. 20 Meier, C. and Bischoff, A., Oligodendroglial cell development in jimpy mice and controls. An electron microscopic study in the optic nerve, J. neurol. Sci., 26 (1975) 517-528. 21 Nakane, P. K. and Pierce, G. B. Jr., Enzyme labeled antibodies for the light and electron microscopic localization of tissue antigens, J. Cell Biol., 33 (1967) 307-318. 22 Phillips, R. J. S., Jimpy, a new totally sex-linked gene in the house mouse, Z. Vererbungslehre, 86 (1954) 322-326. 23 Privat, A., Robain, O. and Mandel, P., Aspects ultrastructuraux du corps calleux chez la souris jimpy, Acta neuropath., 21 (1972) 282-295. 24 Privat, A., Valat, J., Lachapelle, F., Baumann, N. and Fulcrand, J., Radioautographic evidence for the protracted proliferation of glial cells in the central nervous system of jimpy mice, Develop. Brain Res., 2 (1982) 411-416. 25 Raft, M. C., Mirsky, R., Fields, K. L., Lisak, R. P., Dorfman, S. H., Silberberg, D. H., Gregson, N. A., Leibowitz, S. and Kennedy, M. C., Galactocerebroside is a specific cell surface antigenic marker for oligodendrocytes in culture, Nature (Lond.), 274 (1978) 813-816. 26 Rogers, A. W., Techniques of Autoradiography, Elsevier, Amsterdam, 1979. 27 Sarli~ve, L. L., Neskovic, N. M. and Mandel, P., PAPScerebroside sulfotransferase activity in brain and kidney of neurological mutants, FEBS Lett., 19 (1971) 91-95. 28 Sarli~ve, L. L., Farooqui, A. A., Rebel, G. and Mandel, P., Arylsulfatase A and 2',Y-cyclic nucleotide 3'-phosphohydrolase activities in the brains of myelin deficient mutant mice, Neuroscience, 1 (1976) 519-522. 29 Sidman, R. L., Dickie, M. M. and Appel, St. H., Mutant mice (quaking and jimpy) with deficient myelination in the central nervous system, Science, 144 (1964) 309-311. 30 Siegrist, H. P., Burkart, T., Steck, A. P., Wiesmann, U. and Herschkowitz, N. N., Influence of lipids on the activity of cerebroside-sulfotransferase in mouse brain: a comparative study of jimpy and normal mouse brains, J. Neurochem., 27 (1967) 599-604.
372 31 Skoff, R. P., Myelin deficit in the Jimpy mouse may be due to cellular abnormalities in astroglia, Nature (Lond.), 264 (1976) 560-562. 32 Skoff, R. P., Increased proliferation of oligodendrocytes in the hypomyelinated mouse mutant Jimpy, Brain Research, 248 (1982) 19-31. 33 Sternberger, N. H., Itoyama, Y.. Kies, M. W. and
Webster, H. deF., Immunocytochemical method to identify basic protein in myelin forming oligodendrocytes of new born rat C.N.S., J. Neurocytol., 7 (1978) 251-263. 34 Wolf, M. K. and Holden, A. B., Tissue culture analysis of the inherited defect of central nervous system myelination in jimpy mice, J. Neuropath. exp. Neurol.. 28 (1969) 195-213.