Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism f...

In order to analyse the spinal tract formation at early stages of development in avian embryos, chick-quail spinal cord chimeras were prepared and species-specific monoclonal antibodies (MAb) were developed. MAbs CN, QN and CQN uniquely stained chick, quail, and both chick and quail nervous tissues, respectively. All three antibodies appeared to bind to the same membrane molecule, but to differ...

dlPA105 is a spontaneous variant of Rous sarcoma virus, subgroup E, which carries a deletion in the N-terminal portion of the v-src gene coding sequence. This virus was isolated on the basis of its ability to induce proliferation of quiescent quail neuroretina cells. The altered v-src gene encodes a phosphoprotein of 45,000 daltons which possesses tyrosine kinase activity. DNA sequencing of the...

A study was undertaken to analyze the spatio-temporal pattern of mesenchymal cell proliferation in the developing palate of quail. Quail embryos were grown in shell-less culture. The developing palates were labelled with 3H-thymidine between culture days 2-6 (which corresponded in vivo incubation days 5-9), and processed for light microscopic autoradiography. Percent labelled mesenchymal cells ...

During embryonic development, and before functional innervation, a highly stereotypic pattern of slow- and fast-contracting primary muscle fibers is established within individual muscles of the limbs, from distinct populations of myoblasts. A difference between the fiber-type pattern found within chicken and quail pectoral muscles was exploited to investigate the contributions of somite-derived...

It is currently accepted that stem cells of the definitive blood cell lines originate from the yolk-sac blood islands. Experiments were devised to examine the validity of this theory in the avian embryo. These involved grafting two-day-old quail embryos on to chick yolk-sacs of comparable developmental stages, i.e. before or shortly after the establishment of vascularization. The conclusions of...

The objectives of this experiment were to study the effects of different environmental temperatures during the rearing phase on the heat tolerance and behavioral responses of two Japanese quail lines to heat stress. A total of 192 chicks from two lines were randomly distributed between eight brooding cages. Each line was divided into 4 treatments. Each treatment was different in experimental pe...

The Japanese quail belongs to the order Galformes, family Phasidae, genus Coturnix and species japonica. Several aspects account for the utility of this bird. First, it has attained economic importance as an agricultural species producing eggs and meat that are enjoyed for their unique flavor. Egg production is important in Japan and Southeast Asia, while meat is the main product in Europe. Sec...

To investigate the effect of hypothyroidism on gonadal and adrenal functions in male Japanese quail (Coturnix japonica), hypothyroidism was induced in male adult Japanese quail by daily administration of 2-Mercapto-1-methylimidazole (methimazole) in their drinking water. Four weeks after methimazole treatment, the Japanese quail were sacrificed, and the plasma concentrations of free triiodothyr...