Direct evidence that IGF-I has any significant effect on embryo growth is lacking. We therefore studied the effect of administration of IGF-I on the chick embryo in ovo. Five hundred ng pure IGF-I (purified from human plasma) were given to chick embryos on 2 occasions (7 and 14 d) by injection directly into the allantoic sac. Treated and control (saline injected) chicks hatched on the same day ...

The quantitative matching hypothesis of neuronal cell death was tested for the chick hindlimb by determining the relationship between myotube number at the onset of motoneuron cell death and the number of motoneurons that survive in chicks, quail, and chick-quail chimeras. Hindlimb buds, which differ in size between the 2 species, were exchanged at stages 16 1/2-19, myosin ATPase-stained myotub...

S OF PAPERS 231 79 Relationships of egg and chick weight on the performance of progeny from standard and dwarf broiler dams. M. Tahir*1, H. Cervantes3, C. W. Farmer2, and G. M. Pesti2, 1Agricultural University, Peshawar, Khyber Pakhtunkhwa, Pakistan, 2University Georgia, Athens, 3Phibro Animal Health, Ridgefield Park, NJ. Eggs were collected from 2 commercial crosses (42 weeks of age) with the ...

In this study, immunohistochemical analysis has been performed using neuronal markers (GAP43, NCAM and PGP 9.5) to characterize the epithelial invagination in the medial wall of the olfactory pit in the chick embryos. At stages 26-27, the epithelial invagination was primarily composed of characteristic round-shaped cells, which were negative for neuronal markers. These cells were also found in ...

Abstract Background Prestin (SLC26A5) is responsible for acute sensitivity and frequency selectivity in the vertebrate auditory system. Limited knowledge of prestin from experiments using site-directed mutagenesis or domain-swapping techniques after amino acid residues were identified by comparing sequence to those its paralogs orthologs. Frog only representative amphibian lineage studies it qu...

Several ectoparasites parasitise nestlings decreasing their body condition, growth and survival. To minimise any loss of fitness due to ectoparasites, birds have developed a wide variety defence mechanisms, potentially including hatching asynchrony. According the Tasty Chick Hypothesis (TCH), cost parasitism would be reduced if tend eat on less immunocompetent nestlings, typically last-hatched ...

Idiopathic Congenital Talipes Equinovarus, or clubfoot, is a common developmental disorder of the foot, affecting at least 2 in every 1000 live births in Scotland. The defect is characterised by a twisting of the foot and loss of calf muscle. Diagnosis is usually made on postnatal examination and treatment; usually a series of foot manipulations, takes place within the first year. Treatment can...