S U B J E C T I N D E X
753
Heterochromatin—continued
and differentiation, 173
and D N A synthesis, 437
and gene expression, 4 4 1 - 3
genetic inertness of, 439
location of, 206, 449
nature of, 398, 401, 4 4 5 - 6 , 449
and nucleoli, 432
replication of, 441
and stability o f genes, 432
Heterochromatization,
and gene inactivation, 443
reversible or irreversible, 442-3
and tumour origin, 443
Heteropolysaccharide, 354
Heteropyknosis (Allocycly), 401, 431-46
definition of, 431
and inactivation o f metabolic activities, 441, 443
as physiological response to environment, 448
positive and negative, 433, 445
of whole chromosome, 434
and X-chromosomes, 4 3 4 - 5 , 443, 448
Heterotypic factors,
in differentiation, 477-81
Hexenolactone (Parasorbic a c i d ) ,
and inhibition o f mesenchyme, 46, 683
Hexokinase,
and fructose, 262
and galactose, 247, 262
glucose utilization and, 262
as limiting factor in carbohydrate metabolism, 262
Hexonic acids,
as sources of carbohydrate, 246
Hexosamines,
essential constituents o f mucopolysaccharides, 354
estimation of, 366
from glucose, 377
glutamine and synthesis of, 377-8
in inducing agent, 481
production b y fibroblasts, 165
production b y H e L a and F L cells,
375
released b y papain, 381
released b y trypsin, 376
Hexose monophosphate shunt,
in b o n e cells, 648
Hexose-phosphate,
in glucosamine synthesis, 378
Hexoses,
in mucopolysaccharides, 358
as sources o f carbohydrate, 245
Hexuronic acids,
as sources o f carbohydrate, 246
Hind-brain,
induction of, 558
Histamine,
and corneal epithelium, 51
Histidine,
in Eagle's medium, 280
and heart tissue, 300, 303
and kidney tissue, 303
and liver tissue, 303
and L-strain, 114
required b y cell-strains, 279, 281
as supplement, 109
Histodifferentiation,
in aggregates, 519
Histogenetic pattern (Histogenesis), 490,
494, 505-6, 508-10
Histones,
absence from bacterial D N A , 343
content o f single cells, 331
and D N A as primer, 342-3
inhibitors of nuclear phosphorylation,
344
and neuralization, 543
synthesis of, 222
Histotypic organization,
in aggregates, 505
"cross-feeding" effects in, 491
methods for, 494
H L M cells (Liver), 248, 252, 259
Holtfreter's solution, 5 3 2 - 3 , 539
for fish embryos, 582-3
inducing action in, 544
neuralization in, 543
Homocysteine,
and culture o f skin, 129
and differentiation o f somites, 568
and synthesis o f cystine, 287
Homocystine,
as population dependent metabolite,
286
Homoserine,
and synthesis o f cystine, 287
H o m o t y p i c factors,
in differentiation, 4 7 1 - 7 , 479
Hormones (see also individual hormones),
591-650
autonomic system and, 633
753
Heterochromatin—continued
and differentiation, 173
and D N A synthesis, 437
and gene expression, 4 4 1 - 3
genetic inertness of, 439
location of, 206, 449
nature of, 398, 401, 4 4 5 - 6 , 449
and nucleoli, 432
replication of, 441
and stability o f genes, 432
Heterochromatization,
and gene inactivation, 443
reversible or irreversible, 442-3
and tumour origin, 443
Heteropolysaccharide, 354
Heteropyknosis (Allocycly), 401, 431-46
definition of, 431
and inactivation o f metabolic activities, 441, 443
as physiological response to environment, 448
positive and negative, 433, 445
of whole chromosome, 434
and X-chromosomes, 4 3 4 - 5 , 443, 448
Heterotypic factors,
in differentiation, 477-81
Hexenolactone (Parasorbic a c i d ) ,
and inhibition o f mesenchyme, 46, 683
Hexokinase,
and fructose, 262
and galactose, 247, 262
glucose utilization and, 262
as limiting factor in carbohydrate metabolism, 262
Hexonic acids,
as sources of carbohydrate, 246
Hexosamines,
essential constituents o f mucopolysaccharides, 354
estimation of, 366
from glucose, 377
glutamine and synthesis of, 377-8
in inducing agent, 481
production b y fibroblasts, 165
production b y H e L a and F L cells,
375
released b y papain, 381
released b y trypsin, 376
Hexose monophosphate shunt,
in b o n e cells, 648
Hexose-phosphate,
in glucosamine synthesis, 378
Hexoses,
in mucopolysaccharides, 358
as sources o f carbohydrate, 245
Hexuronic acids,
as sources o f carbohydrate, 246
Hind-brain,
induction of, 558
Histamine,
and corneal epithelium, 51
Histidine,
in Eagle's medium, 280
and heart tissue, 300, 303
and kidney tissue, 303
and liver tissue, 303
and L-strain, 114
required b y cell-strains, 279, 281
as supplement, 109
Histodifferentiation,
in aggregates, 519
Histogenetic pattern (Histogenesis), 490,
494, 505-6, 508-10
Histones,
absence from bacterial D N A , 343
content o f single cells, 331
and D N A as primer, 342-3
inhibitors of nuclear phosphorylation,
344
and neuralization, 543
synthesis of, 222
Histotypic organization,
in aggregates, 505
"cross-feeding" effects in, 491
methods for, 494
H L M cells (Liver), 248, 252, 259
Holtfreter's solution, 5 3 2 - 3 , 539
for fish embryos, 582-3
inducing action in, 544
neuralization in, 543
Homocysteine,
and culture o f skin, 129
and differentiation o f somites, 568
and synthesis o f cystine, 287
Homocystine,
as population dependent metabolite,
286
Homoserine,
and synthesis o f cystine, 287
H o m o t y p i c factors,
in differentiation, 4 7 1 - 7 , 479
Hormones (see also individual hormones),
591-650
autonomic system and, 633