Leydig cell development of pig testis in the early fetal period: An ultrastructural study

Abstract

Leydig cell development in the pig testis occurs in three periods (an early fetal, the perinatal period, and the period from puberty onward). The earliest of these periods was investigated ultrastructurally. The early fetal period starts immediately after gonadal differentiation, approximately 27 days postcoitum (p.c.), and finishes at about 60 days postcoitum. Dates of observation were 35, 52, and 62 days p.c. At 42 days p.c. some animals were decapitated. Leydig cells at 35 days p.c. are characterized by an oval nucleus, vesicular or branched tubular smooth endoplasmic reticulum (SER), and a small quantity of rough endoplasmic reticulum (RER). The RER has two forms: a short and a long profile. The latter is closely coupled with mitochondria. The mitochondria mostly have tubular cristae. From 52 days p.c. onward the degree of coupling lessens, and it vanishes at 62 days p.c. At 52 and 62 days p.c. a very large amount of 10 nm filaments and a slight decrease in SER can be observed. The SER now has a branched tubular form, and the presence of polygonal dense bodies is also characteristic. Decapitation does not disturb normal development of the Leydig cells in the observation period. No obvious differences from controls can be observed.

Leydig cell development in the pig testis during the late fetal and early postnatal period: An electron microscopic study with attention to the influence of fetal decapitation

“…a progressive regression of Leydig cells becomes apparent in decapitated fetuses, and SER is the organelle most affected. This is in contrast to Leydig cells of an earlier fetal period (v. Vorstenbosch et al, 1982). SER is known to be the site of important enzymes involved in steroidogenesis (Christensen and Gillim, 1969).…”

“…During the first wave, Leydig cells show SER exclusively of the simple tubular or branched tubular form, and polygonal lysosome-like bodies appear (v. Vorstenbosch et al, 1982). During the second wave a sudden shift to more elaborate forms of SER can be seen.…”

“…The numbers of animals used, as well as sample data and the number of litters, are shown in Table 1. Materials were handled and processed as reported elsewhere (v. Vorstenbosch et al, 1982). In brief: a double fixation (according to Sabatini et al, 1963) of 2%% glutaraldehyde, -0.1 M phosphate buffer, 2-3 mM MgClz added; storage in 0.1 M phosphate buffer and 0.2 M sucrose, followed by 17 0~04-0.1 M Na cacodylate HCI-2 mM MgClz added all buffers at pH of 7.2-7.3.…”

“…leads to regression of Leydig cells near term (Colenbrander et al, 1979). This suggests a pituitary dependence of Leydig cells, unlike their pituitary independence during the first developmental wave (v. Vorstenbosch et al, 1982).…”

Ultrastructural evidence of mature Leydig cells and Leydig cell regression in the neonatal human testis

“…The reason for this is unknown; however, it is likely that it is related to massive changes in the cytoplasmic organization of the cell. Filaments are also very prominent during regression of the early fetal Leydig cell population in the pig, which has two fetal Leydig cell peaks (van Vorstenbosch et al, 1982(van Vorstenbosch et al, , 1984a.…”