
differentiation of explanted fragments of
early chick blastoderm
ii. culture on protein-deficient medium
enriched with rna
posterior fragments of head process
blastoderms were cultured in vitro for two
days on a protein-deficient medium sup-
plemented with various rna's, after which
they were grafted over the chorio-allantoic
membrane for eight to nine days.
pancreatic (adult) rna enhanced
the development of the entodermal epi-
thelium.
heart (adult) rna caused hyper-
plasia of the epidermis with, in some cases,
keratinized papillary projections.
brain (embryonic) rna produced a
papillomatous epidermis with giant epi-
dermal cysts that were keratinized and
fibrillar as in feather formation.
liver (embryonic) rna had no vis-
ible tissue modifications.
in the controls there was no keratini-
zation, nor papillary formation of the epi-
dermis.  the epidermal cysts were very
small, unkeratinized and devoid of fibrillar
organization.
the results are discussed in terms of
relationships of proteins from brain, mus-
cle and skin.
