Diversity at the Subcellular Level and Its Significance 151 



Modulations in EMt patterns 



When one speaks of these patterns in this membrane system, one 

 refers of course to the preferred pattern in the normal cell. Modula- 

 tions from this pattern are an expected part of the normal functioning 

 of the cell, and exaggerated expressions of this can be achieved by 

 certain more or less synthetic devices. 



It has been known for some time that the secretory cells of the 

 seminal vesicle- — along with several other epithelia — are responsive to 

 hormonal control and show, as evidence of this, distinct microscopic 

 changes. For example, under the influence of increased endogenous or 

 exogenous androgen, these secretory cells increase in height and baso- 

 philia; whereas after castration both the height and basophilia greatly 

 diminish (Moore, 1939). When these changes are examined for their 

 fine-structural expression, it is discovered that in the castrate the 

 number of vesicles and cisternae of the endoplasmic reticulum is dras- 

 tically reduced (Figs. 11A and 11B). The profiles representing the 

 system retain an orientation with the long dimension parallel to the 

 nuclear envelope, an organization or pattern which is characteristic 

 of the normal cell. The volume of matrix material is possibly about 

 equal to that in the control. The great difference then is in the volume 

 of the ER and the surface area available for the support of ribosomes. 

 In animals stimulated by exogenous androgens, the ER of the secre- 

 tory cells shows the opposite response: it obviously proliferates to 

 produce a system with dimensions in excess of normal. We find then a 

 distinct and perhaps direct response in this system to the presence or 

 absence of hormone (Deane and Porter, 1960). The response is not 

 so much in a change of pattern as in area and volume of this func- 

 tioning system. A morphological hypertrophy accompanies the func- 

 tional stimulation, and the hypertrophy is limited to the system most 

 clearly associated with the function. The modulation, which appears 

 pronounced, is one of extent rather than design. Just how the hor- 

 mone achieves this proliferation or where it lodges in the cell is a 

 problem for future investigation. 



A somewhat similar though less dramatic response is shown by the 

 liver cells of the common fowl cockerel in response to estrogen stimu- 

 lation. In this form, the materials for egg-yolk formation are synthe- 

 sized in the liver. The greater activity of the hen's liver in this regard 

 is expressed in a number of morphological features including a dis- 

 tinctly more extensive development of the endoplasmic reticulum. 

 When a cockerel is injected with estrogenic hormone, lipoproteins 

 and phosphoproteins associated with egg-yolk formation appear in 



