Morphology and Cytology of the Accessory Sex Glands in Invertebrates

TLDR: This chapter explains how the secretory apparatus of accessory sex gland cells is modified to produce their characteristic secretions.

Abstract: Publisher Summary This chapter discusses the morphology and cytology of the accessory sex glands in invertebrates. Gland cells secreting chemically different molecules have been grouped either vertically, each type of gland spatially sufficiently separated from the others and specialized to produce a specific secretion or horizontally, with different secretions being produced by different cells in the same glandular epithelium or by the same cells with or without temporal succession. The complexity of the secretory behavior is well illustrated by L. nuttalli in which the first pair of accessory sex glands of the male produces six different secretions, all of which are used in spermatophore formation. The chapter explains how the secretory apparatus of accessory sex gland cells is modified to produce their characteristic secretions. Gland cells that look alike morphologically may produce different secretions, for example, the ejaculatory duct epithelial cells of Musca secrete at least 12 proteins. A degree of plasticity in the activity of the secretory apparatus may be expected only in these multipotent cells. Accessory sex gland function being indispensable for successful reproduction in nearly all advanced animal groups, it is indeed surprising that correlative studies on the structure, biochemistry, and physiology of the accessory glandular elements are comparatively few.