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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Biosciences & Biotechnology Laboratory » Research » Publications at this Location » Publication #352079
Title: Steroidogenic follicular response differences to LH and FSH treatment in low and high egg producing turkey hens

Author
item BRADY, KRISTEN - University Of Maryland
item Long, Julie
item PORTER, TOM - University Of Maryland

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/10/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Low egg production in turkey hens is correlated with decreased ovulation frequency. Ovulation frequency is governed at the ovarian level by the steroid hormones progesterone and estradiol. The avian ovary is comprised of follicles in varying stages of maturation, which serve specialized roles in steroidogenesis. The F1 follicle of the preovulatory hierarchy is the next follicle in line to ovulate. Cells from the granulosa layer of the F1 follicle (F1G) produce the majority of ovarian progesterone in response to luteinizing hormone (LH). Small white follicles (SWF) are slow growing follicles that have not entered the preovulatory hierarchy and produce the majority of ovarian estradiol in response to follicle stimulating hormone (FSH). We reported previously that mRNA levels for enzymes related to progesterone and estradiol production are differentially expressed within the turkey hen ovary between low egg producing hens (LEPH) and high egg producing hens (HEPH), with HEPH exhibiting higher expression of genes encoding key steroidogenic enzymes when compared to LEPH (p<0.05). In the present study, the main sources of progesterone and estradiol, the F1G and SWF cells, were cultured with LH and FSH, respectively, to determine if cells from HEPH displayed an increased response to LH and/or FSH. F1G cells from LEPH and HEPH (n=4) were cultured with 0, 1, 10, 100, or 1000 ng of LH, while SWF cells from LEPH and HEPH (n=4) were cultured with 0, 1, 10, 100, or 1000 ng of FSH. After 5 hour incubation, media from the F1G and SWF cell cultures were assayed for progesterone and estradiol, respectively, by radioimmunoassay. Results were analyzed by a two-way ANOVA using the mixed models procedure of SAS. F1G cells from HEPH produced more progesterone than cells from LEPH at 10, 100, and 1000 ng of LH treatment (p<0.05). SWF cells from HEPH produced more estradiol than cells from LEPH in response to 10, 100, and 1000 ng of FSH (p<0.05). Cells from HEPH displayed a higher sensitivity than cells from LEPH to both LH and FSH treatment in vitro. The increased sensitivity to LH and FSH, coupled with the up-regulation of genes that support steroidogenesis, may play a role in the increased egg production exhibited by the HEPH. Further examination of the genetic contribution to differences between LEPH and HEPH at the transcript and hormone response level is needed to identify additional factors contributing to increased egg production in turkey hens.