CHANGES IN THE MESSENGER-RIBONUCLEIC-ACID FOR INSULIN-LIKE GROWTH-FACTOR-I AND -II IN THE PORCINE TESTIS DURING AND BETWEEN 2 WAVES OF TESTICULAR DEVELOPMENT
Am. Clark et al., CHANGES IN THE MESSENGER-RIBONUCLEIC-ACID FOR INSULIN-LIKE GROWTH-FACTOR-I AND -II IN THE PORCINE TESTIS DURING AND BETWEEN 2 WAVES OF TESTICULAR DEVELOPMENT, Biology of reproduction, 50(5), 1994, pp. 993-999
The boar testis was used as a model for examining the possible role of
production of the insulin-like growth factors (IGF) in steroidogenesi
s and/or testicular growth as testicular development occurs in waves.
Blood and testes were sampled from boars at different ages (100-102 da
ys of gestation; 7, 19, and 30 days; and 10 and 25 wk), selected to oc
cur during and between the last two waves of testicular development. S
erum was analyzed for testosterone and RNA was extracted from the test
es for Northern and dot-blot analysis of IGF mRNA. Testosterone concen
trations declined (P = 0.01) from 7 days to 10 wk of age and rebounded
at 25 wk, indicating completion of the second and third waves of test
icular development. The quantity of testicular mRNA for IGF-I increase
d gradually with age, and that for IGF-II decreased. We therefore conc
lude that regulation of the expression of the mRNAs for IGF-I and -II
in the pig testis is not a function of either the waves of testicular
development or the level of steroidogenesis.