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Development of the receptor cells of the olfactory and vomeronasal organs in man
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TERMINAL CELL DIFFERENTIATION AND THE REGULATION OF DNA SYNTHESIS IN HETEROKARYONS. I • A. Prudovsk~j Ye. Y. V e g o r OVER, R, Gum~-~~u--k~-~E__i.-I~,l~;~_n_--~-I~_ J ..... PFJV~. . %riI • hn-i I -~--1~n-u~E~ ~ u t e -OTT~o~I-iE~-I~ar B~-gy~-~ Academy oT S c i e n c e s . Moscow, 117334.
D E V E L O F ~ E N T OF T H E R E C E P T O R C E L L S OF T H E O L F A C T O R Y A N D V O ~ E R O N A 3 A L O R G A N S IN MAN. G.A.Pyatkina. S e c h e n o v I n s t i t u t e of E v o l u t i o n a r y Physiology and Biochemistry,Academy of S c i e n c e s U S S R , L e n i n g r a d , USSR.
H e t e r o k a r y o n s between n o n - d i v i ding terminally differentiated cells (mouse p e r i t o n e a l macrophages, hen e r y t r o c y t e s ) and v a r i o u s a c t i v e l y proliferating c u l t u r e c e l l s (.3T3,C3H lOT 1 / 2 , m o u s e , r a t and human embryo fibroblasts, r a t c h o n d r o c y t e s ) were o b t a i n e d by PEG- o r e l e c t r o s h o c k induced f u s i o n . The macrophages and hen e r y t h r o c y t e s were shown n o t t o i n h i b i t t h e e n t r y of a c t i v e n u c l e i of e s t a b l i s h e d c e l l l i n e s i n DNA r e p l i c a t i o n . Similar r e s u l t s were o b t a i n e d on t h e h e t e r o k a r y o n s o f macrophagem and t h e i r proliferating bone m a r r o w - d e r i v e d p r e c u r s o r s ( p r e m a c r o p h a g e s ) . Theme d a t a s u g g e s t t h e abscence i n macrophages o~ i n t r a c e l l u l a r negative r e g u l a t o r s o f DNA s y n t h e s i s . The r e a c t i v a t i o n o f DNA s y n t h e s i s i n macrophage n u c l e i i n h e t e r o k a r y o n s t o o k @lace o n l y a f t e r f u s i o n w i t h t h e i m m o r t a l i z e d c e l l s .3T.3 and C3H lOT I / 2 . T h e f u s i o n o f m a c r o p h a gem and S y r i a n h a m s t e r c e l l s t r a n s f o r m e d w i t h a t s - m u t a n t o f SV40 v i r u s have shown t h a t t h e r e a c t i v a t i o n o f DNA s y n t h e s i s depends on t h e e x p r e s s i o n of the i m m o r t a l i z i n g onc o g e n e , i . e . t h e gene c o d i n g t h e v i r a l T-antigen.
D e v e l o p m e n t of the o l f a c t o r y a n d v o m e r o n a s a l s e n s o r y e p i t h e l i a in 7 to 11 w e e k o l d h u m a n f e t u s e s w e r e s t u d i e d by e l e c t r o n m i c r o s c o p y . B o t h epithelia divergently derived from the olfactory placode and had comm o n s t e m c e l l s that g e n e r a t e d b o t h receptor and supporting cells. Diff e r e n t i a t i m n of the o l f a c t o r y epi~h~ thelium progressed with age,whereas v o m e r o n a s a l e p i t h e l i u m w a s k n o w n to be r e d u c e d at 5 t h m o n t h of t h e g e s t a t i o n . In o l f a c t o r y c e l l s , b a s a l b o d i e s p r o d u c e d by c e n t r i o l e s g a v e o r i g i n to o l f a c t o r y f l a g e l l a w h i l e , in v o m e r o n a s a l r e c e p t o r c e l l s , the d e v e l o p m e n t of b a s a l b o d i e s w a s b l o c e d a n d o n l y m i c r o v i l l i , not flagella, developed. The completely differentiated flagellar olfactory cells which possessed almost the s a m e c y t o l o g i c a l f e a t u r e s as t h o s e in a d u l t s , w e r e f o u n d by the 11th week. Z~
EN~RIMENTAL TREATMENTS WHICHREDUCETHE NUMBEROF PRIMORDIAL GERM CELLS IN X. La61tIS HAVE SIMILAR EFFECTS ON THE GE~ PLASM. R~I~.~.....I~...~._K.E,~ Dixgn Flinders University of South Australia, Bedford Park, 5042, Australia. UV-irradiation of the vegetal pole of X. laevis eggs or rotation to an off-axisposition or delayed fertilisation all decrease to various degrees the number of primordial germ cells (pgcs) which eventually enter the genital ridges. We have investigatedWhether these treatmentshavea co~m~q effect on germplasm, the cytoplasmicdeterminant of pgcs, which consists of two majorcomponents: numerous mitochondria and aggregatesof germinal granules. All treatmentsresulted in an increase in relative to controls and a decrease in the numerical density of mitochondria in the germ plasm suggesting that aggregation of germ plsm was impaired. A quantitativeanalysis showed that the severity of these effects correlated with the reduction in number of pgcs. In all treated embryos the aggregates of germinal granules were less compact and less hQmogen~ than in controls. We conclude that all treatments affect the cyto6keletonand in turn aggregation is impaired resulting in ultrestructurally abnormal aggregates of germinal granules. We suggest the structural abnormalities are reflected in disruption of the determinativeaction of germplasm, and hencefewer pgcs enter the genital ridges.
PROPERTIES OF CULTURED INCISOR AND MOLAR TOOTH GERM COMPONENTS. A.J. Reynolds, R.F. Oliver and C.A.B. Jahoda, Department of Biological Sciences, University of Dundee, Dundee DDI 4HN, Scotland. Cell culture has been used to investigate the growth properties of the epithelial and dermal components of developing rat molar and incisor tooth germs. Tooth germs were dissected from rats between 12 days gestation and 3 days of age. Dermal/epithelial components were separated by mechanical manipulation or enzymatic digestion. Absence of contamination was verified by means of scanning electron microscopy and histologically. Clean incisor dermal papillae explant cultures showed greater cell outgrowth and proliferation than molar equivalents from the same developmental stage. Moreover, cells from sections along the length of incisor papillae revealed site derived variations in proliferative activity, which were accentuated as development proceeded. When epithelial cells from incisor germs were isolated and cultured in association with dermal cells they closely resembled analagous whisker follicle equivalents and formed organotypic structures. These observations provide the basis for further recombination work. 915
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TERMINAL CELL DIFFERENTIATION AND THE REGULATION OF DNA SYNTHESIS IN HETEROKARYONS. I • A. Prudovsk~j Ye. Y. V e g o r OVER, R, Gum~-~~u--k~-~E__i.-I~,l~;~_n_--~-I~_ J ..... PFJV~. . %riI • hn-i I -~--1~n-u~E~ ~ u t e -OTT~o~I-iE~-I~ar B~-gy~-~ Academy oT S c i e n c e s . Moscow, 117334.
D E V E L O F ~ E N T OF T H E R E C E P T O R C E L L S OF T H E O L F A C T O R Y A N D V O ~ E R O N A 3 A L O R G A N S IN MAN. G.A.Pyatkina. S e c h e n o v I n s t i t u t e of E v o l u t i o n a r y Physiology and Biochemistry,Academy of S c i e n c e s U S S R , L e n i n g r a d , USSR.
H e t e r o k a r y o n s between n o n - d i v i ding terminally differentiated cells (mouse p e r i t o n e a l macrophages, hen e r y t r o c y t e s ) and v a r i o u s a c t i v e l y proliferating c u l t u r e c e l l s (.3T3,C3H lOT 1 / 2 , m o u s e , r a t and human embryo fibroblasts, r a t c h o n d r o c y t e s ) were o b t a i n e d by PEG- o r e l e c t r o s h o c k induced f u s i o n . The macrophages and hen e r y t h r o c y t e s were shown n o t t o i n h i b i t t h e e n t r y of a c t i v e n u c l e i of e s t a b l i s h e d c e l l l i n e s i n DNA r e p l i c a t i o n . Similar r e s u l t s were o b t a i n e d on t h e h e t e r o k a r y o n s o f macrophagem and t h e i r proliferating bone m a r r o w - d e r i v e d p r e c u r s o r s ( p r e m a c r o p h a g e s ) . Theme d a t a s u g g e s t t h e abscence i n macrophages o~ i n t r a c e l l u l a r negative r e g u l a t o r s o f DNA s y n t h e s i s . The r e a c t i v a t i o n o f DNA s y n t h e s i s i n macrophage n u c l e i i n h e t e r o k a r y o n s t o o k @lace o n l y a f t e r f u s i o n w i t h t h e i m m o r t a l i z e d c e l l s .3T.3 and C3H lOT I / 2 . T h e f u s i o n o f m a c r o p h a gem and S y r i a n h a m s t e r c e l l s t r a n s f o r m e d w i t h a t s - m u t a n t o f SV40 v i r u s have shown t h a t t h e r e a c t i v a t i o n o f DNA s y n t h e s i s depends on t h e e x p r e s s i o n of the i m m o r t a l i z i n g onc o g e n e , i . e . t h e gene c o d i n g t h e v i r a l T-antigen.
D e v e l o p m e n t of the o l f a c t o r y a n d v o m e r o n a s a l s e n s o r y e p i t h e l i a in 7 to 11 w e e k o l d h u m a n f e t u s e s w e r e s t u d i e d by e l e c t r o n m i c r o s c o p y . B o t h epithelia divergently derived from the olfactory placode and had comm o n s t e m c e l l s that g e n e r a t e d b o t h receptor and supporting cells. Diff e r e n t i a t i m n of the o l f a c t o r y epi~h~ thelium progressed with age,whereas v o m e r o n a s a l e p i t h e l i u m w a s k n o w n to be r e d u c e d at 5 t h m o n t h of t h e g e s t a t i o n . In o l f a c t o r y c e l l s , b a s a l b o d i e s p r o d u c e d by c e n t r i o l e s g a v e o r i g i n to o l f a c t o r y f l a g e l l a w h i l e , in v o m e r o n a s a l r e c e p t o r c e l l s , the d e v e l o p m e n t of b a s a l b o d i e s w a s b l o c e d a n d o n l y m i c r o v i l l i , not flagella, developed. The completely differentiated flagellar olfactory cells which possessed almost the s a m e c y t o l o g i c a l f e a t u r e s as t h o s e in a d u l t s , w e r e f o u n d by the 11th week. Z~
EN~RIMENTAL TREATMENTS WHICHREDUCETHE NUMBEROF PRIMORDIAL GERM CELLS IN X. La61tIS HAVE SIMILAR EFFECTS ON THE GE~ PLASM. R~I~.~.....I~...~._K.E,~ Dixgn Flinders University of South Australia, Bedford Park, 5042, Australia. UV-irradiation of the vegetal pole of X. laevis eggs or rotation to an off-axisposition or delayed fertilisation all decrease to various degrees the number of primordial germ cells (pgcs) which eventually enter the genital ridges. We have investigatedWhether these treatmentshavea co~m~q effect on germplasm, the cytoplasmicdeterminant of pgcs, which consists of two majorcomponents: numerous mitochondria and aggregatesof germinal granules. All treatmentsresulted in an increase in relative to controls and a decrease in the numerical density of mitochondria in the germ plasm suggesting that aggregation of germ plsm was impaired. A quantitativeanalysis showed that the severity of these effects correlated with the reduction in number of pgcs. In all treated embryos the aggregates of germinal granules were less compact and less hQmogen~ than in controls. We conclude that all treatments affect the cyto6keletonand in turn aggregation is impaired resulting in ultrestructurally abnormal aggregates of germinal granules. We suggest the structural abnormalities are reflected in disruption of the determinativeaction of germplasm, and hencefewer pgcs enter the genital ridges.
PROPERTIES OF CULTURED INCISOR AND MOLAR TOOTH GERM COMPONENTS. A.J. Reynolds, R.F. Oliver and C.A.B. Jahoda, Department of Biological Sciences, University of Dundee, Dundee DDI 4HN, Scotland. Cell culture has been used to investigate the growth properties of the epithelial and dermal components of developing rat molar and incisor tooth germs. Tooth germs were dissected from rats between 12 days gestation and 3 days of age. Dermal/epithelial components were separated by mechanical manipulation or enzymatic digestion. Absence of contamination was verified by means of scanning electron microscopy and histologically. Clean incisor dermal papillae explant cultures showed greater cell outgrowth and proliferation than molar equivalents from the same developmental stage. Moreover, cells from sections along the length of incisor papillae revealed site derived variations in proliferative activity, which were accentuated as development proceeded. When epithelial cells from incisor germs were isolated and cultured in association with dermal cells they closely resembled analagous whisker follicle equivalents and formed organotypic structures. These observations provide the basis for further recombination work. 915