PARENT SESSION
OVARIAN FOLLICLE
Laurel
7:30 AM-10:00 AM

(89) ALTERNATIVE SPLICING OF THE FOLLICLE-STIMULATING HORMONE RECEPTOR: EXAMINATION OF THE NOVEL GROWTH FACTOR TYPE-I AND DOMINANT NEGATIVE ALTERNATE TRANSCRIPTS IN THE BOVINE AND PORCINE OVARIES.

Craig, Robin¹, Grieger, David¹, Freeman, Lisa², Rozell, Timothy¹, ¹ Department of Animal Sciences and Industry, Manhattan, KS² Department of Anatomy and Physiology, Manhattan, KS

ABSTRACT- The G-protein coupled form of the FSHR (R1) has long been considered the primary FSHR responsible for the follicle growth promoting actions of FSH via the cAMP-signaling pathway. However, not all stimulatory actions of FSH are mediated by cAMP, leading to the possibility that altered forms of the FSHR may be present within follicles, and thus accounting for potential mechanisms behind FSH coupling to other signaling pathways. Our objective was to determine if two functional FSHR variants, as previously identified in ovine testis, are present within granulosa cells of bovine and porcine follicles. Ovaries from cows or sows were collected from a slaughterhouse and granulosa cells were removed from morphologically healthy follicles. Total RNA was extracted from the granulosa cells, and total cDNA was prepared by reverse transcription. Primer sets were designed to specifically amplify either the R1, or R2 (dominant negative) variant and R3 (growth factor type-1) variant forms of the FSHR, and total cDNA was subjected to PCR using these primer sets. Products of expected size for R1 and R2/R3 were amplified from bovine and porcine granulosa cells and their identity was confirmed by sequencing. Sequence analysis of the PCR products revealed that amplified R1 was distinct from the R2/R3 forms, but that R2 and R3 could not be discriminated from each other using current primer sets. Nonetheless, R1 and R2/R3 forms of the FSHR were present in all classes of follicles examined, thus providing the first known report of expression of functional variant forms of the FSHR other than R1 in the cow and sow.

KEY WORDS: ovary, bovine and porcine granulosa cells, FSHr, alternative splicing