Expression pattern of messenger ribonucleic acid for follistatin and the inhibin/ activin subunits during follicular and testicular development in Gallus domesticus. Biol. Reprod

ABSTRACT The expression of mRNA for the activin type II receptors (ActRII and ActRIIB), follistatin, and the inhibin/activin subunits was investigated in the follicles of broiler breeder hens. Total RNA was isolated from individual granulosa and theca layers of the F1 through F5 follicles, a pool of the F6 and F7 follicles, the small yellow follicles, and from the combined granulosa and theca layers of the large white follicles from six birds. Northern blot analysis was performed, and two ActRII mRNA transcripts of 6.5 and 3.7 kb were detected in granulosa and theca samples. Both ActRII transcripts were equally expressed in the granulosa samples, but in the theca samples expression of the 3.7-kb transcript was greater than the 6.5-kb transcript. ActRIIB was not de-tected byNorthern analysis in any of the samples. Expres-sion of themRNA for the activin/inhibin binding protein, follistatin, was detected in theca and granulosa samples (Key words: activin receptor, inhibin, activin follistatin, broiler breeder hen