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Clonal growth of chimaeric mouse epidermis
178 THE EFFECT OF NEURONAL CELLS ON KIDNEY DIFFERENTIATION /n v/tro
177 ANOM~T.'T'F'~ CF THE ~ N C E O ~ C ~ D . M.Sara~aBabi6 and A.~vajger. Department of histology and embriology, Faculty of Medicine, University of Zagreb, YU-41000 Zagreb, Yugoslavia.
,~arlo/a,H.~ [kb/om,pO, andHenke-Fah/e,S 0 XDep&-&~ent of Patholo~, Un/vers/tF of Helslnk~ FinleY, ~r~dOMaxPlanckInstitutes,TEb/ngen,FRG The nephrogenlc mesenchyme differentiates into the
Notoohords of 30 human embryos and fetuses ranging in age from 5 th to 20 th week of pregnancy ~ z ~ investigated by light microsoopy. The material was collected from spontareous of arteficial abortions. O3nlole~e reconstructions of all embryos were made by using serial sagital sections. Special attention was payed to the course of the notod%ord in the sacroooccygeal and the intracranial region, especially to its relation to the basisphenoid, basioccipital and pharyngeal epithelium. Reconstruction of the notochordal course in the sacroooccygeal region revealed that the notod%ord leaves the vertebral column backwards and murges with the surrounding tissue. In 45% notochordal alterations sud% as an~Balous positicr~ and branching were found. A delayed development of the notcK~ord was found in cranial spine and coocygeal region. A case of craniorachischisis was investigated and compared w~Lth normal specimens. A possible role of the notodlord on spinal ~ v e lopment and spinal malfcrmaticnes was considered.
epithelium as a result of a morpnogenetio t]ssue interaction. In vivo, the ureter bud induces the tubular differenUation of the mesenchyme. However, m vitro recombination experiments have shown that different tissues of the embryo can be used as inducers when they, are put in close proximity to the nephrogenic mesencnvme. The induction also occurs across a porous f i l t e r . In the present study we shcw that only a few emorvomc tissues act as effectwe inducers in tne transfiIter cultures. The ureter bud does not induce in the transfilter culture conditions, in winch only spinal cord and brain are potent inducers. To analyze which coll type (or types) in the brain possessesthe inducing capacity, neurons or glialcells were selectively lysed in primary cultures of Chicken tectum cells. These cultures were then recombined with nephrogenic mesenchyme. Tubule mouct]on could De mhlbited only by the lysis of neurons. In the transfilter cultures, the growth of neuronal processes through the nephric mesencnyme correlated with the minimal inductiontime of tubules. These studies thus suggest that the neurons are able to induce the differentiationof the nephrogenic mesenchyme.
179
18O
CLONAL GROWTHOF CHIMAERIC MOUSEEPIDERMIS. G.H. Schmidt, B.A.J. Ponder* and M.A. Blount*. Department of Cell Biology, Fraunh-6T6F~Tnstitute, 3000 Hannover 61, F.R.G. and * I n s t i t u t e of Cancer Research, Haddow Laboratories, Sutton, SM2 5PX, U.K.
A PC~31~TALSTUDYOFCEREBELLARVCLUvIE]]4 CHICKS TREATEDWITHJVqTITHYRC)ID~ IN TIE EMBRYONIC PERICO. F.E.ToPresand J. Pulido. Department of Anatomy,SChool of Medicine, University of Granada,Granada, Spain. Changes were observed on different days of postnatal life in cerebellar cortex volume of chicks treated with 4-Propyl-2-Thyouracil in the embryonic period in comparison to control animals. Volumes occupied.by the molecular and granular layers were greater in control animals on postnatal days 7, 13 and 22. By day 68 however, values for these volumes in treated animals had overtaken those of controls, and remained higher in the longer until the end of the experiment. Figures for white matter volume behaved differently, being higher in controls on the first two days they were measured (i.e. on days 7 and 13) and higher in experimental animals on day 22. White matter volume~ioexper~men~l chicks was highest on d~y 68 and remained above that in controls until end of the experiment. The ratio of cortical to subcortical volutes was greated in the control group throughout the experiment. Total cerebella? volume was greater in this group on days 7, 13 and 22 but fell below that of experimental animals on days 68 and 120.
The clonal organisation of chimaeric mouse epidermis was demonstrated by in situ staining of whole-mount preparations uslng monoclonal antibodies directed against H-2k and H-2b antigens. A striking pattern of transverse clonal stripes was observed, extending from approximately mid-dorsal down both flanks. The pattern in the ventral epidermis was markedly d i f f e r e n t ; there were no stripes from the mid-thoracic region to the groin, but a markedly straight mid-ventral clonal boundary was observed. The results suggest that I . growth of the epidermis is strongly directional in the dorso-lateral but not the ventral region and 2. there is a greater degree of c e l l mingling in the dorsal region, following closure of the neural folds, than in the ventral region, following closure of the abdominal wall. The size and geometry of isolated patches at patch boundaries did not conform to that expected i f the basal layer was composedof monoclonal epidermal p r o l i f e r a t i v e units (EPUs). This i n d i cates that each putative EPU is polyclonal. 63S
177 ANOM~T.'T'F'~ CF THE ~ N C E O ~ C ~ D . M.Sara~aBabi6 and A.~vajger. Department of histology and embriology, Faculty of Medicine, University of Zagreb, YU-41000 Zagreb, Yugoslavia.
,~arlo/a,H.~ [kb/om,pO, andHenke-Fah/e,S 0 XDep&-&~ent of Patholo~, Un/vers/tF of Helslnk~ FinleY, ~r~dOMaxPlanckInstitutes,TEb/ngen,FRG The nephrogenlc mesenchyme differentiates into the
Notoohords of 30 human embryos and fetuses ranging in age from 5 th to 20 th week of pregnancy ~ z ~ investigated by light microsoopy. The material was collected from spontareous of arteficial abortions. O3nlole~e reconstructions of all embryos were made by using serial sagital sections. Special attention was payed to the course of the notod%ord in the sacroooccygeal and the intracranial region, especially to its relation to the basisphenoid, basioccipital and pharyngeal epithelium. Reconstruction of the notochordal course in the sacroooccygeal region revealed that the notod%ord leaves the vertebral column backwards and murges with the surrounding tissue. In 45% notochordal alterations sud% as an~Balous positicr~ and branching were found. A delayed development of the notcK~ord was found in cranial spine and coocygeal region. A case of craniorachischisis was investigated and compared w~Lth normal specimens. A possible role of the notodlord on spinal ~ v e lopment and spinal malfcrmaticnes was considered.
epithelium as a result of a morpnogenetio t]ssue interaction. In vivo, the ureter bud induces the tubular differenUation of the mesenchyme. However, m vitro recombination experiments have shown that different tissues of the embryo can be used as inducers when they, are put in close proximity to the nephrogenic mesencnvme. The induction also occurs across a porous f i l t e r . In the present study we shcw that only a few emorvomc tissues act as effectwe inducers in tne transfiIter cultures. The ureter bud does not induce in the transfilter culture conditions, in winch only spinal cord and brain are potent inducers. To analyze which coll type (or types) in the brain possessesthe inducing capacity, neurons or glialcells were selectively lysed in primary cultures of Chicken tectum cells. These cultures were then recombined with nephrogenic mesenchyme. Tubule mouct]on could De mhlbited only by the lysis of neurons. In the transfilter cultures, the growth of neuronal processes through the nephric mesencnyme correlated with the minimal inductiontime of tubules. These studies thus suggest that the neurons are able to induce the differentiationof the nephrogenic mesenchyme.
179
18O
CLONAL GROWTHOF CHIMAERIC MOUSEEPIDERMIS. G.H. Schmidt, B.A.J. Ponder* and M.A. Blount*. Department of Cell Biology, Fraunh-6T6F~Tnstitute, 3000 Hannover 61, F.R.G. and * I n s t i t u t e of Cancer Research, Haddow Laboratories, Sutton, SM2 5PX, U.K.
A PC~31~TALSTUDYOFCEREBELLARVCLUvIE]]4 CHICKS TREATEDWITHJVqTITHYRC)ID~ IN TIE EMBRYONIC PERICO. F.E.ToPresand J. Pulido. Department of Anatomy,SChool of Medicine, University of Granada,Granada, Spain. Changes were observed on different days of postnatal life in cerebellar cortex volume of chicks treated with 4-Propyl-2-Thyouracil in the embryonic period in comparison to control animals. Volumes occupied.by the molecular and granular layers were greater in control animals on postnatal days 7, 13 and 22. By day 68 however, values for these volumes in treated animals had overtaken those of controls, and remained higher in the longer until the end of the experiment. Figures for white matter volume behaved differently, being higher in controls on the first two days they were measured (i.e. on days 7 and 13) and higher in experimental animals on day 22. White matter volume~ioexper~men~l chicks was highest on d~y 68 and remained above that in controls until end of the experiment. The ratio of cortical to subcortical volutes was greated in the control group throughout the experiment. Total cerebella? volume was greater in this group on days 7, 13 and 22 but fell below that of experimental animals on days 68 and 120.
The clonal organisation of chimaeric mouse epidermis was demonstrated by in situ staining of whole-mount preparations uslng monoclonal antibodies directed against H-2k and H-2b antigens. A striking pattern of transverse clonal stripes was observed, extending from approximately mid-dorsal down both flanks. The pattern in the ventral epidermis was markedly d i f f e r e n t ; there were no stripes from the mid-thoracic region to the groin, but a markedly straight mid-ventral clonal boundary was observed. The results suggest that I . growth of the epidermis is strongly directional in the dorso-lateral but not the ventral region and 2. there is a greater degree of c e l l mingling in the dorsal region, following closure of the neural folds, than in the ventral region, following closure of the abdominal wall. The size and geometry of isolated patches at patch boundaries did not conform to that expected i f the basal layer was composedof monoclonal epidermal p r o l i f e r a t i v e units (EPUs). This i n d i cates that each putative EPU is polyclonal. 63S