Cytodifferentiation in the accessory glands of Tenebrio molitor. I. Ultrastructure of the tubular gland in the post‐ecdysial adult male

Abstract

The tubular accessory reproductive glands of the male mealworm beetle consist of a secretory epithelium surrounded by a thin muscular sheath. Each columnar secretory cell is divisible into three zones: basal which is adjacent to the muscle layer and contains rough endoplasmic reticulum and Golgi, intermediate, which contains endoplasmic reticulum and Golgi zones in the immature gland and is filled with secretory vesicles in the mature gland, and apical. Maturation also involves proliferation and organization of the rough endoplasmic reticulum in the basal and intermediate zone. The process appears to be complete at four days after ecdysis. Parallels with other insect glands and with the mammalian prostate are striking.

Male reproductive system structure and accessory glands ultrastructure of two species of Triatoma (Hemiptera, Reduviidae, Triatominae)

“…The occurrence of both secretion pathways is a common phenomenon in insects, as already reported in the male accessory glands of Leptinotarsa decemlineata (De Loof and Lagasse, 1972), Periplaneta americana (Adiyodi and Adiyodi, 1974), Tenebrio molitor (Gadzama et al, 1977), T. rubrofasciata (Freitas et al, 2007a) and others insects suggesting that different substances are being produced in different times.…”

Structure of the male reproductive accessory glands ofPterostichus nigrita(Coleoptera: Carabidae), their role in spermatophore formation

“…These beetles have the simplest male duct morphology of the Coleoptera (Kaulenas 1992) in contrast to other beetle species which can have two, three, or five pairs of glands (Gerber et al 1971;Huignard 1975;Gadzama et al 1977;Happ et al 1977;Singh 1978;Cassier and Huignard 1979;Glitho and Huignard 1990).…”

“…Surprisingly, little is known about the secretions and tissue structure of the accessory glands of Coleoptera, especially at a fine structural level. To date, information is available from four species only, Leptinotarsa decemlineata (Chrysomelidae) (De Loof and Lagasse 1972), Tenebrio molitor (Tenebrionidae) (Gadzama et al 1977;Dailey et al 1980;Grimes and Happ 1980;, Acanthoscelides obtectus (Bruchidae) (Huignard 1975;Cassier and Huignard 1979), and Bruchidius atrolineatus (Glitho and Huignard 1990).…”

“…In contrast to the accessory glands, four types of secretory cell were identified in the epithelium of the posterior vas deferens of P. nigrita. This greater gland cell diversity means that this region of the male reproductive tract is more like the accessory glands of Culex, Drosophila, Locusta, Schistocerca, and the bean-shaped glands of Tenebrio (Gadzama et al 1977).…”

“…The number of morphological types of secretory cell in tubular accessory glands of male insects is highly variable. Those of L. decemlineata (De Loof and Lagasse 1972), Periplaneta americana (Adiyodi and Adiyodi 1974), Tenebrio molitor (Gadzama et al 1977;, and Frankiniella occidentalis (Dallai et al 1997) have one type only. By contrast, the tubular accessory glands of other male insects can be divided into distinct regions, each region with a different type of secretory cell and/or secretion (Ramalingam and Craig 1978;Riemann and Thorson 1979;Lai-Fook 1982;Marchini et al 2009).…”