Index 
X chromosome {continued) 
Rett syndrome, 142-144 
schematic representation, xxtx 
Xenopus oocyte, thyroid hormone activation, 267-268 
X-linked ichthyosis, X chromosomes, 402 
XLR gene, lymphocyte differentiation, 106 
X-ray crystallography 
cellular regulation, 409-410 
diffraGtion analysis, Ivii-lviii 
enzyme structure, Ivii-lviii 
eukaryotic gene regulation, 67-68 
glycoprotein mechanisms, 475 
hormonal signal transduction, 420-422 
immune response studies, 45-46 
macromolecule structure analysis, Ivii 
molecular replacement, 65 
protein function studies, 253-254 
structural biology and, 65-66 
three-dimensional structure, 109-1 10 
Y chromosome 
genetic inheritance patterns and, xxvi 
mammalian development, 342-344, 401-402 
Yeast artificial chromosomes (YACs) 
fragile X syndrome, 325 
gene inactivation, 131-132 
isolation and molecular diagnostics, 76 
large-scale DNA analysis, 333-334 
MHC structure, 80 
structural studies, xl 
Yeast cells 
RNA genetics, 245-246 
structural studies, xl 
Yersinia, intracellular microorganisms, 211-212 
YY-1 factor, oncogenesis and gene expression, 403-404 
ZEB protein, immunoglobulin heavy chains, 230 
Zellweger syndrome, metabolic pathways, 458 
Zeppelin gene, Drosophila development and, 418 
zi/268 gene, DNA-binding proteins, 339-341 
Zinc finger proteins 
DNA-binding proteins, 339-341 
Drosophila development, 114-116 
growth factor response, 317-318 
regulatory complexes, 186 
structural studies with, lix 
transcription, 441 
Zone of polarizing activity (ZPA), nervous system 
development, 224-226 
520 
