INTRODUCTION
T h e o r g a n i z a t i o n of v a r i o u s m a c r o m o l e c u l e s in the
eukaryotic
c h r o m o s o m e s is s t i l l an e n g i m a .
T h e r e are two
s c h o o l s of t h o u g h t s on the a r r a n g e m e n t of n u c l e o - h i s t o n e s and
acidic-proteins
in the c h r o m o s o m e s *
It is b e l i e v e d by a
g r o u p of w o r k e r s t h a t e a c h c h r o m o s o m e
c h a i n of D N A e x t e n d i n g
is m a d e up of a s i n g l e
f r o m one end to t h e o t h e r w i t h o u t any
o
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i n t e r r u p t i o n , p o s s i b l y a c c o r d i n g to f o l d e d - f i b e r m o d e l of
Dupraw
(1972) .
A c c o r d i n g to t h e s e w o r k e r s ,
p r o t e i n is n o t i n v o l v e d in m a i n t a i n i n g
the n o n - h i s t o n e
the c h r o m o s o m a l
integrity. The other school believes that non-histone
proteins
constitute a framework,
s c a f f o l d o r a c o r e to w h i c h
the D N A m o l e c u l e s a re a t t a c h e d . Th e p r e s e n t w o r k a d d r e s s e s
i t s e l f to t h i s q u e s t i o n .
A s e a r l y as 1947, M i r s k y and Ri s,
reported
t h a t f r a c t i o n a t i o n of N a C l s o l u t i o n r e s u l t s in the s e p a r a t i o n
of D N A - h i s t o n e c o m p l e x f r o m t h r e a d - l i k e
structures which
are
m a d e u p of r e s i d u a l p r o t e i n s and s o m e R N A . T h e s e t h r e a d - l i k e
C
s t r u c t u r e s r e t a i n the m o r p h o l o g y of t h e c h r o m o s o m e w i t h
distinct constrictions.
This
b a c k b o n e of t h e c h r o m o s o m e
Bril-Peterson
analysis
led t h e m to c o n c l u d e
t h a t the
is m a d e of r e s i d u a l p r o t e i n .
and W e s t e n b r i n i k
(1963)
c o n c l u d e d f r o m an
of b u l l s p e r m t h a t c e r t a i n p r o t e i n s
other than pro­
t a m i n e s ar e a s s o c i a t e d w i t h D N A in the s p e r m and this
p r o t e i n is n o t b a s i c . O n the b a s i s of q u a n t i t a t i v e c y t o c h e m i c a l d e t e r m i n a t i o n of n o n - h i s t o n e p r o t e i n c o m p o n e n t of
2
D N A - p u f f s of R h y n c h o s c j a r a , R u d k i n
non-histone
(1964 )
suggested that a
p r o t e i n m i g h t be c o n s t r u e d as a s t r u c t u r a l one,
n e c e s s a r y fo r o v e r all o r g a n i s a t i o n of c h r o m o s o m a l m a t e r i a l s .
3
S t e f f e n s o n (1963) f r o m a v e r y c r i t i c a l s t u d y of H - t h y m i d i n e
u p t a k e c o n c l u d e d t h a t D N A is l o c a l i s e d
not in th e i n t e r b a n d .
o n l y in the b a n d and
T h e s e o b s e r v a t i o n s r u l e out the
p o s s i b i l i t y t h a t D N A is d i s t r i b u t e d u n i f o r m l y t h r o u g h o u t the
of the b a sic
s t r u c t u r e of the c h r o m o s o m e * L a t e r ,
in
o
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length
196 5 , T r o s k o and W o l f f ,
f r o m a s e r i e s of e n z y m a t i c
o f f i x e d V i c i a faba r o o t ti p s ,
chromosomes
studies
s u g g e s t e d t h a t in m i t o t i c
l i n e a r c o n t i n u i t y is d e p e n d e n t on p r o t e i n .
O n th e basis of e l e c t r o n m i c r o s c o p i c
on i s o l a t e d c h r o m o s o m e s ,
observations
Stubblefield and Wray
(1971)
d e m o n s t r a t e d t h a t t h e m i t o t i c c h r o m o s o m e s c o n s i s t of d i s ­
t i n c t a x i a l an d p e r i p h e r a l c h r o m a t i n c o m p o n e n t s .
P a u l s o n an d L a e m m l i
(1977)
showed that w h e n m e t a p h a s e
c h r o m o s o m e s w e r e s t r i p p e d of h i s t o n e s
spreading,
C
showed
and exami ne d by surface
a residual axial structure wa s found
l o o p s of D N A w e r e a t t a c h e d .
Similarly
to w h i c h
the
A d o l p h et a l . ( 1 9 7 7 a, 1 9 7 7 b)
if t h e c h r o m o s o m a l D N A w a s e x t e n s i v e l y d i g e s t e d w i t h
nuclease before removal of histone,
i s o l a t e th e r e s i d u a l
scaffold
’
’
scaffold"
it w a s p o s s i b l e t o
in a s t a b l e
i s o l a t e d in t h i s w a y p r e s e r v e d
f o r m and
the c h a r a c t e r i s t i c
paired chromatid morphology. Marsden and Laemmli
o b s e r v e d th e t h i n s e c t i o n o f s w o l l e n m e t a p h a s e
u n d e r e l e c t r o n m i c r o s c o p e and r e c o r d e d
the
(1979)
chromosomes
t h a t l o o p s of
3
chromatin
fibres radiate
r e g i o n of the c h r o m a t i d .
meiotic
f r o m the
less d i s p e r s e d c e n t r e
R a t t n e r et a_l.
(1980)
s t u d i e d the
p r o p h a s e n u c l e i , w h i c h w e r e s p r a y e d on e l e c t r o n
microscopic
gr id. In v e r y e a r l y s t a g e s
c h r o m a t i n is r e l e a s e d in l i n e a r a r r a y s
chromatin material.
d i s t r i b u t e d a l on g
At pachytene,
of p r o p h a s e the
t y p i c a l fo r i n t e r p h a s e
the l o o p s are e v e n l y
the l e n g t h of the c h r o m o s o m e s and g i v e a
E a r n s h a w and L a e m m l i
(1983)
isolated
o
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brush-like appearance.
residual protein scaffold
on e l e c t r o n m i c r o s c o p i c g r i d
n u c l e a s e d i g e s t e d c h r o m o s o m e s . T h e s c a f f o l d is f i b r o u s
nature,
b u t re t a i n s
from
in
the s h a p e of c h r o m o s o m e s and a p p e a r s to
be d e r i v e d f r o m the k i n e t o c h o r e and th e c h r o m a t i d a x i s *
T h e s e f i n d i n g s i n d i c a t e t h a t t he D N A l o o p s are h e l d c l o s e d
at the c h r o m a t i d a x i s by n o n - h i s t o n e
"scaffolding"
proteins.
In e s s e n c e the q u e s t i o n of m a c r o m o l e c u l a r o r g a n i z a ­
t i o n of
the c h r o m o s o m e s b o i l s d o w n to t h e e x i s t e n c e o f a
p r o t e i n a c e o u s c o r e a n d its p o s s i b l e r o l e
C
chromosomal
in m a i n t a i n i n g the
integrity.
T h e p r e s e n t w o r k d e a l s w i t h the e f f e c t of t h r e e
a n t i b i o t i c s w h i c h d i r e c t l y or i n d i r e c t l y a f f e c t the p r o t e i n
synthesis.
The rationale
is t h a t if a d m i n i s t e r e d at a p r o p e r
c o n c e n t r a t i o n at p r o p e r t i m e ,
the p r o t e i n a c e o u s c o r e w i l l be
a f f e c t e d b y the a n t i b i o t i c and the e f f e c t w i l l be d e t e c t a b l e
at the l e v e l of l i g h t m i c r o s c o p y . T h r e e w e l l k n o w n a n t i b i o ­
tic s ,
cycloheximide
(CH),
puromycin
(PM ),
and r i f a m y c i n
(RM)
4
w e r e u s e d in the p r e s e n t i n v e s t i g a t i o n t o see the ir e f f e c t
on c h r o m o s o m e
structure.
T h e a n t i b i o t i c C H i n h i b i t s p r o t e i n s y n t h e s i s in a
w i d e r a n g e of e u k a r y o t i c c e l l s ,
fungi, T e t r a h y m e n a , m a m m a l i a n
c e l l s a nd t u m o u r c e l l s i n c u l t u r e
S i e g e l ,1967)•
(K e r r i d g e ,1958, S i s l e r and
It is k n o w n t h a t CH i n h i b i t s t r a n s l o c a t i o n of
o
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p e p t i d y l - t R N A f r o m the r i b o s o m a l A s i t e to the P s i t e
( F e l i c e t t i and L i p m a n n 1 9 68 , M o n r o et _al. 1 968, C u l p e t . a l .
1969),
t h r o u g h i n h i b i t i o n of the t r a n s f e r f a c t o r II m e d i a t e d
t r a n s l o c a t i o n of p e p t i d y l - t R N A ( M c k e e h a n and H a r d e s t y ,
1 969, B a l i g a e t jal, 1 9 7 0 ) . O l e i n i c k
the d r u g i n h i b i t s i n i t i a t i o n ,
(1977)
suggested that
e l o n g a t i o n an d t e r m i n a t i o n
and t h a t i n i t i a t i o n is t h e m o s t s e n s i t i v e p h a s e .
T h e m e c h a n i s m of p u r o m y c i n a c t i o n w a s e s t a b l i s h e d
by Y a r m o l i n s k y and H a b a
a n a l o g of 3'
and H a b a ,
( 1 9 5 9 ) , and K a j i
(19 7 3 ) .
terminal end of amino a c y l - t RNA
195 9)
and
It is an
(Yarmolinsky
i n t e r a c t s w i t h a c c e p t o r site of the
C
r i b o s o m a l p e p t i d y l t r a n s f e r a s e c e n t r e on th e l a r g e r s u b u n i t s
(50s or 6 0 s ) . The p r o d u c t o f the p u r o m y c i n r e a c t i o n
(Peptidyl-puromycin)
is u n a b l e to take p a r t in th e n e x t s t e p
of p r o t e i n s y n t h e s i s .
R i f a m y c i n has the u n i q u e p r o p e r t y of i n h i b i t i n g R N A
polymerase.
I t s p e c i f i c a l l y b i n d s t o t h e e n z y m e and n o t to
the D N A t e m p l a t e , a n d p r e v e n t s i n i t i a t i o n
1968).
(Wehrli et a l .
R i famycin forms a stable complex w i t h
£ -subunit
of
5
the e n z y m e
( Z i l l i g ej; a_l. 1 970) t h e r e b y b l o c k i n g R N A - c h a i n
initiation
( S i p p e l and H a r t m a n n ,
Thus,
affect
1968 ,
L i l l et a^l. 19 70).
it m a y be e x p e c t e d t h a t all the t h r e e a n t i b i o t i c s w i l l
the p r o t e i n in g r a s s h o p p e r s y s t e m .
In o r d e r to a s c e r t a i n the s u i t a b i l i t y of d r u g it is
d e s i r a b l e to c h e c k its e f f e c t at the c e l l u l a r lev e l w i t h the
light microscopy.
T h u s p r i m a r y iri s i t u e f f e c t m a y be
o
IIT py
r
Kh ig
h
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ag
pu
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aid of
d e t e r m i n e d t h r o u g h s e m i - q u a n t i t a t i v e a s s e s s m e n t of p r o t e i n
s t a i n a b i l i t y . Moreover,
the protein
the s t a L e of D N A c o u l d be a s s e s s e d
s t a i n a b i l i t y as w e l l as
through both light
m i c r o s c o p y and fluorescence microscopy.
that cytochemical
I t is w e l l - d o c u m e n t e d
r e a c t i o n s c a n be m a d e a b s o l u t e l y s p e c i f i c
for strict chemical evaluation*
In o r d e r to a s c e r t a i n t h a t CH ,
p r o t e i n c o n t e n t of the n u c l e i ,
PM,
R M affect the
a s e r i e s o f e x p e r i m e n t s on
s t a i n i n g r e a c t i o n f o r t o ta l
protein, h i s t o n e - p r o t e i n , n o n ­
h i s t o n e p r o t e i n was carried
out by t h r e e e s t a b l i s h e d
C
m e t h o d s viz. m e r c u r y - b r o m o p h e n o l blue,
staining
alkaline-fast green,
and a c i d - f a s t green r e s p e c t i v e l y 0
The m e r c u r y - b r o m o p h e n o l blue s t aining method w a s
i n t r o d u c e d by D u r r u m
(1950 )
o n f i l t e r p a p e r s po ts .
p r o t e i n by Mazia,
fo r t he d e m o n s t r a t i o n of p r o t e i n
It w a s a d o p t e d as a g e n e r a l
Brew e r and Alfert
stated that preparations
first
s t a i n for
(1953). These authors
s t a i n e d by t h e i r p r o c e d u r e f o l l o w e d
t h e B e e r - L a m b e r t s l a w s an d t h a t t h e a m o u n t of d y e b o u n d w a s
6
proportioned
to the a m o u n t of p r o t e i n
The method was employed by Bonhag
o v e r a w i d e range.
(1955 )
for i n v e s t i g a t i n g
the c o m p o s i t i o n of the o v a r y of the m i l k w e e d bug. A l f e r t
and G e s c h w i n d
(1953) d e m o n s t r a t e d b a s i c
w h i c h s t a i n w i t h fast g r e e n at pH 8.0,
nucleic acids.
proteins
in n u c l e i
a f t e r r e m o v a l of
By the use of m o d e l s y s t e m s ,
they obtained
e v i d e n c e t h a t t h e s e p r o t e i n s are h i s t o n e s anci p r o t a m i n e s .
(Alfert 1956),
h i s t o n e s a r e the
o
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Kh ig
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ag
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In f o r m a l i n - f i x e d t i s s u e s
only p r o t e i n s w h i c h c o u l d
green.
be s t a i n e d w i t h a l k a l i n e - f a s t
A gain histones are high
they h a v e i s o e l e c t r i c
than o t h e r p r o t e i n s .
in b a s i c
a m i n o acids,
p o i n t s w h i c h are m u c h m o r e
At the is oe lectric
point,
acid
dy e
b i n d i n g by p r o t e i n s is m i n i m a l . T h e g e n e r a l c h a r a c t e r i s t i c
of p r o t e i n s
f o u n d in t i s s u e s
are such t h a t , w h e n the
t i s s u e s ar e p l a c e d a t pH 8.0, m o s t of the p r o t e i n s are
a b o v e or n e a r t h e i r i s o e l e c t r i c p o i n t .
A t p H 8.0 ,
histones
are s t i l l b e l o w t h e i r i s o e l e c t r i c p o i n t . T h i s m e a n s t h at ,
by p l a c i n g
in an a c i d dye ,
the o n l y p r o t e i n s h a v i n g g r o u p s
C
green,
t i s s u e s at p H 8. 0,
the dy e ar e the h i s t o n e s .
s u c h as f a s t
available
The colour d e v e l o p e d
to b i n d
appears
p r o p o r t i o n a l to the a m o u n t of h i s t o n e p r e s e n t a n d c a n be
measured microspectrophotometrically
r e s i d u a l or n o n - h i s t o n e p r o t e i n s
(Jensen 1962). The
remaining
in the n u c l e i
a f t e r e x t r a c t i o n of n u c l e o h i s t o n e has b e e n c a l l e d
c h r o m o s i n b y M i r s k y and P o l l i s t e r
McMaster-Kaye
(1946).
(1966) u s e d d i l u t e H C 1 f o r
K a y e and
several hours
for
7
r e m o v a l of histories,
after hot TCA treatment,
and then
s t a i n e d n o n - h i s t o n e p r o t e i n w i t h a c i d - f a s t g r e e n at pH 4.6,
w h i c h t h e y s u g g e s t e d w i l l be s p e c i f i c
for non-histone
protein*
In a d d i t i o n to the a b o v e m e n t i o n e d
st a i n s ,
three different
protein
acridine orange
(EB), and m e r c u r o c h r o m e
(MC) w e r e
o
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Kh ig
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ag
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(AO), e t h i d i u m b r o m i d e
fluoroc h r o m e s viz.
specific
u s e d to s t a i n
the t r e a t e d an d c o n t r o l c e l l s . A n y d i f f e r e n c e
in f l u o r e s c e n c e p a t t e r n and i n t e n s i t y m a y r e f l e c t a c h a n g e
in the n u c l e o p r o t e i n m o i e t y of
the t r e a t e d c e l l .
The d y e A O e x h i b i t s l a r g e c h a n g e s in its e m i s s i o n
properties when interacting with nucleic acids with different
d e g r e e of s t r a n d e d n e s s .
A O staining has been used
for
d i f f e r e n t i a t i o n of native d o u b l e - s t r a n d e d D NA from d en a t u r e d
s i n g l e - s t r a n d e d D N A in s i t u
(de la C h a p e l l e et al.. 1 971 ).
T h u s it is g e n e r a l l y a c c e p t e d t h a t u n d e r s t r i c t e x p e r i m e n t a l
conditions,
A O c a n be u s e d
for d i f f e r e n t i a t i o n
EB is a b a s i c d y e , the
C
and s i n g l e - s t r a n d e d n u c l e i c a c i d s .
of d o u b l e
r ed f l u o r e s c e n c e o f w h i c h is e n h a n c e d a p p r o x i m a t e l y 5 0 - f o l d ,
w h e n the d y e is b o u n d to d o u b l e - s t r a n d e d n u c l e i c
( L e p e c q and P a o l e t t i 19 6 6 ,
d ouble-stranded nucleic
hybrids* Therefore,
1967).
acids
It s p e c i f i c a l l y r e a c t s w i t h
acids w h e t h e r DNA,
RNA,
or D N A - R N A
the a m o u n t o f d y e w i l l be a m e a s u r e of
t h e d o u b l e - s t r a n d e d r e g i o n of th e m o l e c u l e s t a i n e d
( M o u t s c h s e n 1 9 7 6 ) . T h e b i n d i n g c o n s t a n t of E B is
l i m i t e d by
the p r e s e n c e of p r o t e i n s a t the s u r f a c e of n u c l e i c
a c i d s by
8
the f o l d i n g
of D N A and e v e n by u n k n o w n c o n f i g u r a t i o n
(Moutschsen
1976). T h e f l u o r e s c e n c e t e c h n i q u e of EB was
s t u d i e d by D e
(1977) in d e t a i l an d he c o n c l u d e d t h a t EB
flu o r e s c e n c e was highest w h e n all histo n e s were removed.
Th e
us e of c o l o u r m e r c u r i a l s to d e m o n s t r a t e p r o t e i n
bound s u l f h yd ra l
(SH) g r o u p s h as b e e n r e v i e w e d e x t e n s i v e l y
(19 5 8 ) . C o w d e n a n d C u r t i s
(1970)
o
IIT py
r
Kh ig
h
ar t
ag
pu
r
by B e n n e t t a n d W a t t s
s u g g e s t e d t h a t m e r c u r o c h r o m e a p p e a r s t o be the b e s t dy e for
localizing
(1980)
SH groups. J o c e l y n
(1972) a n d B u y s and O s i n g a
s u g g e s t e d t h a t m e r c u r y ion of m e r c u r o c h r o m e f o r m s
a strong c o m p l e x with s u l f h y d r a l groups
of p r o t e i n s .
P a r a l l e l to the c y t o c h e m i c a l r e a c t i o n the e f f e c t of
antibiotics
on the c h r o m o s o m e
s t r u c t u r e as r e v e a l e d by
i n d u c t i o n of s t r u c t u r a l a b e r r a t i o n s c a n a l s o be a c c e p t e d
as a m e a s u r e of the e f f e c t of t h e d r u g s on c h r o m o s o m a l
organization.
Parchman and Stern
(1969)
observed stickiness
of c h r o m o s o m e s in c u l t u r e d L i l y m i c r o s p o r o c y t e s a f t e r
C
t r e a t m e n t w i t h CH . Y o s h i d a e t al,
tation,
(197 2)
observed
fragmen­
n o n ~ d i s j u n c t i o n o f c h r o m o s o m e s in B a r l e y c h r o m o s o ­
m e s a f t e r t r e a t m e n t w i t h C H and PM. S i m i l a r l y ,
Georgian
(1977)
induced both gaps
and b r e a k s
R o m a n and
in c h r o m a t i d s
in h u m a n p e r i p h e r a l b l o o d c u l t u r e by r i f a m p i c i n . W a g e n a a r
(1983)
i n d u c e d i r r e g u l a r a n a p h a s e s e p a r a t i o n in A l l i u m
s a t i v u m by CH .
In a d d i t i o n t o t h e s e a n t i b i o t i c s ,
other
p r o t e i n - i n h i b i t i n g a n t i b i o t i c s an d a m i n o a c i d a n a l o g u e s
9
also induce chromosomal aberration.
Kemp
(1964)
induced
c h r o m o s o m a l a b e r r a t i o n by e t h i o n i n e in T r i l l i u m .
Ghosh
(1968)
asynapsis,
observed breaks,
in c h r o m o s o m e s
g a ps,
f r a u m e n t s , r, tickine s s ,
of A 1 1 i u m cepa
after treatment with
c h l o r a m p h e n i c o l ap.u 5-met:iyl t r y p t o p h a n .
B h u n y a anu Mann-3
aberrations
De and
Manna
(1969) and M a n n a and B a r d h a n
(1969),
(1972)
induced
in b o n e m a r r o w c e l l s of m i c e b y c h l o r a m p h e n i c o l 0
(1970)
a n d H a y e z - D e l e t t e an d F r e i m a n s
o
IIT py
r
Kh ig
h
ar t
ag
pu
r
O h a m a and K a d o t a n i
(1975)
observed chromosomal aberrations
v i v o by b l e o m y c i n .
Abhayvardhani
in human cells
Srivas+ava and Sarma
(1980)
(1981) r e v o l t e d c h r o m o s o m a l
alg al cells by penicillin,
streptomycin,
in
an d S a r m a and
aberrations
in
tetracycline,
m i t o m y c i n an d p o l y m y x i n .
In a d d i t i o n to the s t u d y of e f f e c t of a n t i b i o t i c s on
chromosomes
structure,
the present report records
v e m e n t as w e l l as a n a l y r i s
on i m p r o ­
of a m e t h o d of d e m o n s t r a t i o n of
chromosome core.
C
H o w e l l an d H s u
AgNO^ staining
(1979)
first demonstrated
the c o r e by
at the l e v e l of l i g h t m i c r o s c o p y ,
Satya-
P r a k a s h e^t aj.. (1980)
i m p r o v e d th e t e c h n i q u e by a p p l i c a t i o n
i
of a l k a l i - S S C p r e t r e a t m e n t . R u f e s a n d G o s a l v e z ( 1 9 8 2 ) ,
R u f a s e t a_l. ( 1 9 8 2 )
and S e n t i s e t a_l.(l984) u s e d a d i f f e r e n t
p r o t o c o l f o r t h e r e v e l a t i o n of c o r e . L a t e r N o k k a l a
N o k k a l a a nd N o k k a l a
(198 5)
an d H a a p a l a
(1985)
f u l l y d e m o n s t r a t e d the c o r e b y A g N O ^ s t a i n i n g .
workers,
however,
(198 5 ) ,
also success­
Some
b e l i e v e t h a t t h e c o r e is an a r t e f a c t u a l
10
p r o d u c t of th e p r e p a r a t o r y m e t h o d s
B u r k h o l d e r 1 9 82,
( H a d l a c z k y et a l . 1 9 8 1 b .
1983, B u r k h o l d e r and K a i s e r m a n
It is to be a p p r e c i a t e d t h a t e a c h
1982).
s t e p or t r e a t m e n t
in a g i v e n p r o t o c o l for d e m o n s t r a t i o n of c o r e h a s a d e f i n i t e
p u r p o s e . A r e p l a c e m e n t or an o m i s s i o n or m o d i f i c a t i o n of a
single step,
if f o l l o w e d m e t h o d i c a l l y o r s y s t e m a t i c a l l y
o
IIT py
r
Kh ig
h
ar t
ag
pu
r
c a n y i e l d a w e a l t h of i n f o r m a t i o n on the a c t u a l o r o c e s s
w h i c h l e a d s to v i s u a l i s a l i o n of the c o r e D T h u s th e e f f e c t
of D N a s e ,
R N a s e and t r y p s i n ,
t i o n of h i s t o n e s and n u c l e i c
hot TCA, d i f f e r e n t i a l e x t r a c ­
a c i d s can a l l l e a d to a
v e r y m e a n i n g f u l dat a.
Finally,
chemical
fluorescence microscope with
s p e c i f i c i t y and c a p a c i t y
its i n n a t e
to p r o v i d e a d d i t i o n a l i n ­
f o r m a t i o n c a n be a d v a n t a g e o u s l y u s e d on s i l v e r n i t r a t e
stained core
The
to y i e l d a d d i t i o n a l i n f o r m a t i o n .
p r e s e n t w o r k d e a l s w i t h the d e m o n s t r a t i o n of
C
chromosome core structure
Acrida
in the m e i o t i c c h r o m o s o m e s of
t u r r j t a . A f t e r d e t e r m i n i n g the k a r y o t y p e of the
experimental material,
the e f f e c t of C H , P M and R M w e r e
s t u d i e d on t h e b a s i s of p r o t e i n s t a i n a b i l i t y b o t h by l i g h t
and f l u o r e s c e n c e m i c r o s c o p y . T h e d r u g s
synthesis
inhibited protein
an d e x h i b i t e d b o t h m e i o t i c an d
somatic
mal aberrations when administered properly.
the s i l v e r s t a i n i n g m e t h o d w a s
In a d d i t i o n ,
s t a n d a r d i s e d and
s t e p s w e r e a n a l y s e d to g i v e an i n s i g h t to
chromoso­
its v a r i o u s
the a c t u a l
11
m e c h a n i s m f o r r e v e l a t i o n of c h r o m o s o m e
co r e . F i n a l l y ,
a
m e t h o d has b e e n d e v e l o p e d to d e m o n s t r a t e the p r e s e n c e of
a c o r e of a s i l v e r - s t a i n e d s p e c i m e n by
fluorochroming with acridine
fluorescence microscopy.
c h r o m o s o m e w i t h AO,
shows
at all s t a g e s of m e i o s i s
subsequently
o r a n g e as v i s u a l i z a t i o n by
Fluorochroming
t h a t the c o r e
by t r a n s mi tt ed -
of A g N O ^
stained
is d i s c e r n i b l e
l i gh t
o
IIT py
r
Kh ig
h
ar t
ag
pu
r
e x c i t a t i o n a n d is s u r r o u n d e d by e p i c h r o m a t i n m a d e of
C
DNA.