The Beaudette strain of avian infectious bronchitis virus propagated in chicken embryo kidney cells is stabilized by exposure to 1 M MgSO(4) at 50 C for 80 min, at pH values ranging from 4 to 10.

Slice cultures can facilitate the manipulation of embryo development both pharmacologically and through gene manipulations. In this reduced system, potential lethal side effects due to systemic drug applications can be overcome. However, culture conditions must ensure that normal development proceeds within the reduced environment of the slice. We have focused on the development of the spinal c...

The capacity to image a growing embryo while simultaneously studying the developmental function of specific molecules provides invaluable information on embryogenesis. However, until recently, this approach was accomplished with difficulty both because of the advanced technology needed and because an easy method of minimizing damage to the embryo was unavailable. Here, we present a novel way of...

The identification of eight previously undescribed polypeptides in chicken embryo cells infected with Sindbis virus is reported. Seven of these polypeptides were distinguishable from the virus structural polypeptides and their precursors by their molecular weights and tryptic peptide maps. The eighth was closely related to pE2 (Schlesinger and Schlesinger, 1973), a precursor to one of the virus...

An exonuclease which degrades native deoxyribonucleic acid at pH 9.2 was induced in chick embryo fibroblast cultures and in human amnion cells by infection with cowpox virus. Highly purified chick embryo interferon suppressed the induction of the enzyme in the homologous cell system but not in the human amnion cell cultures. "Mock" interferon prepared from uninfected chicken eggs and purified i...

Replication-defective vectors derived from reticuloendotheliosis virus were used to transduce exogenous genes into early somatic stem cells of the chicken embryo. One of these vectors transduced and expressed the chicken growth hormone coding sequence. The helper cell line, C3, was used to generate stocks of vector containing about 10(4) transducing units per ml. Injection of 5- to 20-microlite...

Trace minerals, such as Zn, Mn, and Cu, are components of eggs that are essential for broiler breeder performance as well as chicken embryo development [1, 2]. These trace minerals are constituents of several proteins involved in intermediary metabolism, hormone secretion, and the immune system [3] and are required in small amounts in the diet. The effects of Zn, Mn, and Cu deficiencies on bree...

Antigenic molecules termed TOP, which are distributed in a dorsal greater than ventral concentration gradient in chicken retina, are expressed early in development (by 48 hr after fertilization) in the optic cup of chicken embryos and continue to be expressed in retina thereafter. 35S-labeled-TOP-antibody complexes were purified by protein A-Sepharose column chromatography and subjected to NaDo...

Recently expanded knowledge of gene regulation clearly indicates that the regulatory sequences of a gene, usually identified as enhancers, are widely distributed in the gene locus, revising the classical view that they are clustered in the vicinity of genes. To identify regulatory sequences for Sox2 expression governing early neurogenesis, we scanned the 50-kb region of the chicken Sox2 locus f...

The growth kinetics of avian infectious bronchitis (AIB) virus in vitro have been investigated previously using different systems, including embryonated chicken eggs (Hitchner and White, 1955), and cell cultures of chick embryo kidney (Lukert, 1965 ; Bulow, 1966; Akers and Cunningham, 1968) or chick embryo liver (Lukert, 1965). Organ cultures of ciliated epithelium have been employed in various...