Vitelline membrane outer layer
protein 1 (VMO1), a basic
protein present in the outer layer of the vitelline membrane of eggs, plays essential roles in separating the yolk from the egg white and preventing
infection from bacteria by forming a barrier of fibrous layers in avian eggs. Although VMO1 is expressed in the oviduct of hens, little is known about endocrine regulation of transcription of VMO1 in the oviduct and its expression in cancerous ovaries of laying hens. Results of present study indicated that expression of VMO1
mRNA increased in the chick oviduct in response to
diethylstilbestrol (DES, a synthetic non-steroidal
estrogen). VMO1
mRNA and
protein were particularly abundant in the glandular epithelium (GE) and
luminal epithelium (LE) of the magnum of the oviducts of chicks treated with DES. Also, during the regression and recrudescence phases of the oviduct during induced molting with
zinc feeding, VMO1 expression decreased as the oviduct regressed and increased with remodeling and recrudescence of the oviduct in laying hens. In addition, changes in relative expression of specific
microRNAs (miR-1623, miR-1552-3p, miR-1573, miR-22-3p, miR-124a and miR-1764) regulating VMO1 gene were detected in the oviducts during the molting period. Moreover, abundant expression of VMO1 was found in GE of cancerous, but not normal ovaries of laying hens. Results of the present study suggest that VMO1 is regulated by
estrogen and target
microRNAs in the chicken oviduct and that it is a potential diagnostic marker of
ovarian cancer in laying hens.