Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 26, 2001
Publication Date: May 20, 2001
Citation: Lunstra, D.D., Mccoard, S.A., Wise, T.H., Ford, J.J. 2001. Only small changes in Sertoli cell numbers occur during compensatory testicular hypertrophy in boars hemicastrated at different postnatal ages [abstract]. Proceedings Sixth International Conference on Pig Reproduction, Columbia, Missouri, p. 43. (Abstract No. 13) Technical Abstract: Direct evaluation of Sertoli cell number in the testis following hemicastration has not been assessed in the boar. Male piglets (1/2 Meishan x 1/2 White composite, n=132) were assigned as controls (37 boars) or hemicastrated (H) at one of four postnatal ages (17-28/group): d1, 10, 56, and 112. Remaining testes were removed at 220 d of age in all boars. Boars swere stratified by d220 testis weight, and the highest and lowest 1/4 of the boars classified into Large (Lg) or Small testis (Sm) subgroups and assessed for testicular structure and Sertoli cell number, after staining for the nuclear transcription factor GATA4 which specifically stains Sertoli cell nuclei within the boar testis (McCoard et al., 2001, Biol Reprod 64:689). In Lg testis boars at 220 d of age, testis weight was 153%, 136%, 123% and 119% and total Leydig cell numbers/testis were 186%, 175%, 161% and 124% in groups hemicastrated on d1, 10, 56 and 112, respectively, compared to controls. Hypertrophic increases of similar magnitude, albeit numerically different, were observed within respective H groups in Sm testis boars. However, little Sertoli proliferation occurred, and total numbers of Sertoli cells/testis were 116%, 112%, 100% and 98% in Lg testis boars hemicastrated on d1, 10, 56 and 112, respectively, compared to controls. Thus, postnatal testicular hypertrophy in the boar occurred primarily via increased Leydig cell numbers and increased Sertoli cell size without appreciable increase in Sertoli cell numbers. Limited Sertoli proliferation appeared only in boars hemicastrated very early postnatally (d1 and d10), which implies that programming of Sertoli cell numbers occurs prenatally, and that establishment of the blood testis barrier is not the primary factor controlling proliferation of Sertoli cells in the boar.