Recrudescence Mechanisms and Gene Expression Profile of the Reproductive Tracts from Chickens during the Molting Period

Abstract

The reproductive system of chickens undergoes dynamic morphological and functional tissue remodeling during the molting period. The present study identified global gene expression profiles following oviductal tissue regression and regeneration in laying hens in which molting was induced by feeding high levels of zinc in the diet. During the molting and recrudescence processes, progressive morphological and physiological changes included regression and re-growth of reproductive organs and fluctuations in concentrations of testosterone, progesterone, estradiol and corticosterone in blood. The cDNA microarray analysis of oviductal tissues revealed the biological significance of gene expression-based modulation in oviductal tissue during its remodeling. Based on the gene expression profiles, expression patterns of selected genes such as, TF, ANGPTL3, p20K, PTN, AvBD11 and SERPINB3 exhibited similar patterns in expression with gradual decreases during regression of the oviduct and sequential increases during resurrection of the functional oviduct. Also, miR-1689* inhibited expression of Sp1, while miR-17-3p, miR-22* and miR-1764 inhibited expression of STAT1. Similarly, chicken miR-1562 and miR-138 reduced the expression of ANGPTL3 and p20K, respectively. These results suggest that these differentially regulated genes are closely correlated with the molecular mechanism(s) for development and tissue remodeling of the avian female reproductive tract, and that miRNA-mediated regulation of key genes likely contributes to remodeling of the avian reproductive tract by controlling expression of those genes post-transcriptionally. The discovered global gene profiles provide new molecular candidates responsible for regulating morphological and functional recrudescence of the avian reproductive tract, and provide novel insights into understanding the remodeling process at the genomic and epigenomic levels.

Prostaglandin D2 synthase related to estrogen in the female reproductive tract

“…In accordance with results of the previous study [9], we examined effects of varying concentrations of estrogen in blood on expression of PTGDS during the regression and recrudescence phases of the diet-induced molting period. As illustrated in Fig.…”

“…Gene profiling in the previous study [9] revealed that PTGDS expression decreased 60% in the oviduct at Day 12 as compared with Day 0 whereas it increased 5.6-fold in the oviduct on Day 35 as compared to Day 12 of the period of recrudescence of the oviduct. In accordance with results of the previous study [9], we examined effects of varying concentrations of estrogen in blood on expression of PTGDS during the regression and recrudescence phases of the diet-induced molting period.…”

“…Hens (n = 5 per time point) in each subgroup including the molting group (normal feeding group, 6 days and 12 days after onset of zinc feeding) and the recrudescence group (20, 25, 30 or 35 days after onset of zinc feeding, and 8, 13, 18 or 23 days of normal feeding after cessation of egg production and removal from the high zinc diet) were euthanized using 60-70% carbon dioxide prior to collecting the oviduct on each assigned day [9].…”

“…However, little is known about PTGDS gene expression in the female reproductive tract. Our previous gene profiling data using a chicken DNA microarray analyses indicated that expression of the PTGDS gene increased with increases in circulating concentrations of estrogen in plasma of laying hens during the recrudescence phase of oviduct remodeling following diet-induced molting in laying hens [9]. In that study, circulating concentrations of estrogen decreased during regression of the ovary and oviduct during feeding a high zinc diet to laying hens and then concentrations of estrogen increased in blood after feeding of a normal commercial diet resumed and recrudescence of the ovaries and oviduct occurred.…”

Diethylstilbestrol regulates expression of avian apolipoprotein D during regression and recrudescence of the oviduct and epithelial-derived ovarian carcinogenesis

“…For instance, estrogen stimulates proliferation and differentiation of oviduct cells including tubular glands, goblet cells, and ciliated cells during the period of oviduct development [9][10][11], and estrogens also induce synthesis of egg-white proteins such as ovalbumin, ovomucoid, conalbumin, and lysozyme in the tubular glandular cells of the magnum of the oviduct [12]. In addition, estrogen triggers complete remodeling of the reproductive tract to enhance the subsequent rate of egg production after normal or induced regression and recrudescence phases of the molting period [13]. On the other hand, the laying hen is a well-established animal model for research in epithelial-derived ovarian cancer (EOC) which may arise from genetic mutations and damage of the ovarian surface epithelium of laying hens and women [14,15].…”