168. TGFβ 2-BETAGLYCAN REGULATE FOETAL TESTIS DEVELOPMENT IN VITRO
M. A. Sarraj A , A. Umbers A , J. K. Findlay A and K. L. Stenvers AReproductive Development, Prince Henry’s Institute, Clayton, VIC, Australia.
Reproduction, Fertility and Development 22(9) 86-86 https://doi.org/10.1071/SRB10Abs168
Published: 6 September 2010
Abstract
Betaglycan is a co-receptor for the TGFβ superfamily, known to modulate TGFβ binding in target cells. We have previously found that betaglycan null murine testes at 12.5-13.5 dpc display poorly delineated seminiferous cords and disrupted Leydig cell development (1). Both TGFβs and inhibins are expressed by the fetal testis and it is currently unclear which regulate its development. We tested the hypothesis that loss of betaglycan compromises the functions of TGFβ2 in the differentiating fetal testis as TGFβ2 is known to bind poorly to its type II receptor in the absence of betaglycan. We tested the effect of TGFβ2 on betaglycan wildtype and null foetal gonad/mesonephros complexes using hanging drop or agar block culture methods. From each embryo, one gonad acted as a control; the other was treated. Gonads were cultured in the presence or absence of TGFβ2 (2.5-5 ng/mL) for 48 hours (n =3 pairs). In both culture methods, development in the absence of exogenous growth factor recapitulated normal cord development in wildtype testis and the disrupted cord phenotype in null testes. TGFβ2-treated cultures, 13.5 dpc wildtype mouse testes displayed a 14-35% reduction in total area compared to untreated cultures. Null testes exhibited significantly smaller reductions in gonadal area (2-13%; P < 0.01), indicating that betaglycan null testes exhibit reduced sensitivity to TGFβ2-mediated growth inhibition. However, preliminary observations suggest that TGFβ2 treatment partly rescued cord formation in two of three betaglycan knockout testes in vitro, with testis morphology confirmed by laminin and AMH immunostaining. These data support the notion that TGFβ2 acts via betaglycan to regulate cord development during foetal testis development.
Supported by the New Investigator NHMRC (AUS) grant #550915 to MS, JKF Fellowship (#441101, #550915, #338516; #241000) and Victorian Government infrastructure funds.
(1) Sarraj et al., 2010. Biol Reprod; 82(1): 153–62.
