Expression Pattern of Calcitonin Gene-related Peptide-like Immunoreactivity in the Duck Thymus During Embryonic and...

To study the expression pattern of calcitonin gene-related peptide (CGRP)-like immunoreactivity (-ir) in the duck thymus during the embryonic and postembryonic development.

Studies were carried out on Tianfu ducks on 12, 14, 16, 18, 20, 22, 24, and 26 days of age prehatching, and at 0 (hatching), 1, 3, 5, 8, 14, 17, 20, 26, 29, and 32 weeks of age posthatching using high-sensitivity immunocytochemistry.

CGRP-ir was detected in the neuron-like cells, the lymphocytes, the vascular smooth muscle cells, as well as the reticular epithelial cells of Hassall's corpuscle and diffuse forms of Hassall's corpuscle. CGRP-ir cells were predominantly distributed in the medulla and very rarely in the cortex. The distribution density of CGRP-ir cells in the medulla increased progressively from 24 days of age prehatching to 5 weeks of age posthatching, and thereafter showed a tendency to decrease. CGRP-ir nerves, mainly running along the blood vessels, were recognized during the postembryonic development of the thymus.

The expression pattern of CGRP-ir showed obvious age-related changes during the embryonic and postembryonic development of the duck thymus, which might be related to thymus growth and involution.