Changes in the Expression of Major Histocompatibility Complex Class II mRNA in Response to Inoculation with Salmonella enteritidis in Cultured Hen Ovarian Tissue

Changes in the expression of interleukin-1beta and lipopolysaccharide-induced TNF factor in the oviduct of laying hens in response to artificial insemination

The aim of this study was to determine the physiological significance of interleukin-1beta (IL1B) and lipopolysaccharide-induced TNF factor (LITAF) in the fate of sperm in the oviduct of laying hens after artificial insemination (AI). Laying hens were inseminated with fresh semen, PBS or seminal plasma and tissues from different oviductal segments were collected to observe the general histology, changes in the mRNA expression of IL1B and LITAF and the localization of positive cells expressing immunoreactive IL1B (irIL1B). Semi-quantitative RT-PCR was used to observe the changes in mRNA expression of these molecules in the infundibulum, uterus, utero-vaginal junction (UVJ), and vagina after insemination. Intact sperm in the lumen and between the primary or secondary folds of the vagina were found until 6 h after insemination but were degraded at 12 h. The mRNA expression of IL1B and LITAF was significantly increased in the vagina until 6 h after AI but remained unchanged in the other oviductal segments. In the tissue of the vagina and UVJ, irIL1B was localized in the mucosal stroma. The number of irIL1B-positive cells was increased in the vagina but almost unchanged in UVJ after insemination with semen. Significant changes were not observed in the mRNA expression and irIL1B-positive cells in the vagina after PBS or seminal plasma insemination. The increase of IL1B and LITAF in the vagina may lead to sperm degradation and elimination by cilia of surface epithelium, whereas their lower levels in UVJ may permit sperm to survive in sperm storage tubules.

Changes in the expression of gallinacins, antimicrobial peptides, in ovarian follicles during follicular growth and in response to lipopolysaccharide in laying hens (Gallus domesticus)

The aim of this study was to identify the types of gallinacin genes (GALs) expressed in ovarian follicles and to determine the changes in their expression during follicular growth and in response to lipopolysaccharide (LPS). Follicles at different stages of growth were collected from laying hens (n = 5) and LPS-injected hens (n = 3). The expression of GALs in the theca and granulosa layers was examined by semi-quantitative RT-PCR. The expression of GAL-1, -2, -7, -8, -10, and -12 in the theca layer and GAL-1, - 8, -10, and -12 in the granulosa layer was identified in white and yellow follicles. The expression of these genes was not changed in the theca and granulosa layers during follicular growth except for a decrease in that of GAL-1 in theca. The expression of GAL-1, -7, and -12 in the theca layer of the third largest follicles was increased in response to LPS at a dose of 1 mg/kg body weight and this increase was induced within 3 h and maintained until 12h postinjection. Granulosa layers did not respond to LPS until 12h injection. These results show that six and four types of GALs are expressed in the theca and granulosa layers of healthy follicles respectively, and their levels do not change with follicular growth except for GAL-1 in theca. Elevated levels of GAL-1, -7, and -12 expression in theca in response to LPS suggest that the theca cells expressing these GALs function to eliminate LPS-containing bacteria.

Expression of transforming growth factor-beta isoforms and their receptors in utero-vaginal junction of hen oviduct in presence or absence of resident sperm with reference to sperm storage

Our goal was to determine whether transforming growth factor beta (TGFbeta) isoforms were involved in the process of sperm survivability in the sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) of hen oviduct. The birds were artificially inseminated. The mRNA expressions of three types of TGFbeta isoforms (TGFbeta2, TGFbeta3, and TGFbeta4) and three types of receptors (TbetaR1, TbetaR2, and TbetaR3) were examined in the presence or in the absence of resident sperm in SST by semi-quantitative reverse transcriptase-PCR. The mRNA expression of TGFbetas and TbetaRs in sperm was also examined. Immunocytochemistry and western blot were performed for TbetaR2 to confirm its localization in UVJ. The sperm were observed at least 10 days after insemination by histology. The mRNA expressions of TGFbetas and TbetaRs were significantly increased in UVJ in the presence of resident sperm in SST. The mRNA expressions of TGFbetas and TbetaRs were also observed in sperm. Immunohistochemistry revealed that TbetaR2 were located in lymphocytes in UVJ and SST cells. The presence of TbetaR2 in UVJ was also confirmed by western blot. These results suggest that enhanced expressions of TGFbetas and TbetaRs in UVJ may protect sperm in SST, probably by suppressing anti-sperm immunoreactions.

Changes in the expression of estrogen receptor mRNA in the utero-vaginal junction containing sperm storage tubules in laying hens after repeated artificial insemination

The objective was to determine whether expression of estrogen receptor (ER) mRNA in the utero-vaginal junction (UVJ) of laying hens was altered after repeated artificial insemination (AI). Semi-quantitative RT-PCR was used to determine the expression of mRNA of the two types of receptor, ERalpha and ERbeta. Only ERalpha mRNA was expressed in all segments of the oviducts of both virgin and artificially inseminated birds, whereas ERbeta mRNA was expressed in ovarian follicles but not in the oviduct. The expression of ERalpha mRNA in the UVJ was significantly decreased after repeated AI, whereas that in the uterus was not significantly different between virgin and inseminated birds. Since estrogen may be involved in maintaining the sperm storage function of sperm storage tubules, the decreased expression of ERalpha mRNA in the UVJ after repeated AI may contribute to reduced fertility in these birds.

Effects of Age and Gonadal Steroids on the Localization of Antigen Presenting Cells in the Epididymis of the Male Chicken, Gallus domesticus

The goal of this study was to localize antigen presenting cells (APC), which may play roles in defense against pathogens and fertility, and examine the effects of age and gonadal steroids on their population in the rooster epididymis. Healthy White Leghorn male birds (immature 60-day-old birds; matured 150-, 330-, and 550-day-old), and immature birds treated with testosterone propionate (TP) or estradiol benzoate (EB) for 3 or 6 days were used. Cryostat sections of the epididymis and ductus deference were immunostained for Ia to identify APC. RT-PCR was performed to confirm the expression of major histocompatibility complex class II (MHC class II) mRNA in the epididymis. Ia+ cells were localized in the surface epithelium and subepithelial layer of the ductules and occasionally in the luminal content of the epididymis and ductus deference. RT-PCR analysis confirmed expression of MHC class II mRNA in the epididymis, ductus deferens, testis, and spleen. The frequency of Ia+ cells in the subepithelial layer was significantly greater in the proximal efferent ductules than in the other two types of ductules in the epididymis of 550-day-old birds. Although there were no significant differences in the frequencies in the subepithelial layer of the proximal efferent ductules between 60- and 150-day-old birds, the frequencies were significantly greater in 330- and 550-day-old birds than in 60-day-old birds. The frequencies of Ia+ cells in the ductus deferences was increased in the 150-day-old birds compared with the 60-day-old birds, with a larger increase in 330- and 550-day-old birds. The Ia+ cell frequency was significantly increased by EB-injection, but not by TP-injection, on Days 3 and 6 of injection compared with Day 0. These results suggest that the population of APC in the epididymis increases with age after sexual maturation, and estrogen may be one of the factors involved in induction of Ia+ cells.

Effects of age, egg-laying activity, and Salmonella-inoculation on the expressions of gallinacin mRNA in the vagina of the hen oviduct

Gallinacins (Gal) are antimicrobial peptides that play significant roles in innate immunity in chickens. The aim of this study was to examine whether age of birds and egg-laying activity (laying and non-laying caused by feed-regulation) affect the mRNA expression of Gal-1, -2, and -3 in the vagina of hens, and whether their expressions are changed in response to the stimulation with Salmonella enteritidis (SE) and lipopolysaccharide (LPS). White Leghorn hens were divided into groups of young and old laying hens, and groups of laying and non-laying hens after feed-regulation. Vaginal cells were cultured and stimulated with SE or LPS. Expressions of Gal-1, -2, and -3 mRNA in their vaginal mucosa and cultured cells were examined by quantitative real-time RT-PCR. The expressions of Gal-1, -2, and -3 of the vaginal mucosa were significantly greater in old birds than in young birds. Expression of these Gals in the vagina were decreased in the regressed oviduct of non-laying birds compared with laying birds. The expressions of Gal-1, -2, and -3 in the cultured vaginal cells were increased by stimulation with SE or LPS within 24 h. These results suggest that the mRNA expressions of Gal-1, -2 and -3 in the vagina of laying hens increased with age, whereas they decreased in the regressed oviduct during the non-laying phase. Also, synthesis of these antimicrobial peptides in the vagina may increase in response to SE and LPS to eliminate SE bacteria.