Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/2/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: There are very limited data for serum concentration of AMH in pigs. AMH is a marker of several fertility traits in mammalian females. In boars, testicular expression of AMH, a marker of differentiating Sertoli cells, decreases dramatically after 120 days of age, but it is unknown how this relates to concentrations of AMH is serum. Gonadal development of KISS1 knockout pigs (KISS1-/-) remains in a juvenile state, making this an excellent model to dissect the effects of gonadal development and age on serum concentrations of AMH in pigs. Serum was collected from crossbred boars at 40, 130, and 220 days of age (n = 8, 12, and 8 respectively for KISS1+/+, KISS1+/- and KISS1-/-), and gilts at 40, 100, and 160 days of age (n = 8, 12, and 4 respectively for KISS1+/+, KISS1+/- and KISS1-/-). A porcine specific ELISA was used to quantify AMH in serum and a mixed model with repeated measures was used to estimate differences between age and genotype for boars and gilts separately. Animal within genotype was used as the subject, the covariance was modeled as compound symmetric, and Tukey-Kramer was used for post-hoc comparisons. There was a genotype by age interaction (P < 0.0001) for AMH in boars and gilts. Serum AMH in KISS1+/+ boars decreased from 40 days to 220 days of age (804.5 ng/ml and 2.42 ng/ml, respectively; pooled SE = 64.6 ng/ml; P < 0.05). A similar decrease in circulating AMH was observed for KISS1+/- boars, which did not differ from KISS1+/+ boars. Serum AMH did not differ with age in KISS1-/- boars and was less at 40 days of age (325.39 ± 55.97 ng/ml) but greater at 220 days of age (446.5 ± 59.7 ng/ml) than in KISS1+/+ or KISS1+/- boars (P < 0.05). Serum AMH was undetectable in all gilts at 40 d of age. Circulating AMH in KISS1+/+ gilts increased from 100 days to 160 days of age (1.70 ± 0.48 ng/ml and 5.59 ± 0.48 ng/ml, respectively; P < 0.0001). The KISS1+/- gilts had a similar increase in serum AMH and did not differ from KISS1+/+ gilts. Circulating AMH in KISS1-/- gilts remained undetectable until 160 d of age when 2 of 4 gilts had detectable AMH in serum (1.48 ± 0.2 ng/ml). Age related changes in serum concentrations of AMH in boars reflect known patterns of AMH expression in the testis. Elevated AMH in KISS1-/- boars at older ages indicates Sertoli cells that are not terminally differentiated and reflects the immature gonadal phenotype. Increasing AMH as gilts age is indicative of increased activation of primordial follicles and growth to the antral stage as puberty approaches. Detection of AMH in KISS1-/- gilts at 160 d of age suggests that some follicle activation occurs in these KISS1 knockout pigs. FFAR grant No. 552176.