Ultrastructural and functional analysis of secretory goblet cells in the midgut of the lepidopteran Anticarsia gemmatalis
- 516 Downloads
Defoliation caused by Anticarsia gemmatalis larvae affects the commercial production of the soybean. Although regulation of the digestion of soybean components has become part of the suggested strategy to overcome problems caused by Anticarsia larvae, few studies have focused on the morphological and cellular aspects of Anticarsia intestinal tissue. We have therefore further analyzed the morphology and ultrastructure of the midgut of 5th instar larvae of A. gemmatalis. Dissected midgut was subjected to chemical or cryo-fixation and then to several descriptive and analytical techniques associated with both light and electron microscopy in order to correlate anatomical and physiological aspects of this organ. Histological analysis revealed typical anatomy composed of a cell layer limited by a peritrophic membrane. The identified lepidoptera-specific goblet cells were shown to contain several mitochondria inside microvilli of the goblet cell cavity and a vacuolar H+-ATPase possibly coupled to a K+-pumping system. Columnar cells were present and exhibited microvilli dispersed along the apical region that also presented secretory characteristics. We additionally found evidence for the secretion of polyphosphate (PolyP) into the midgut, a result corroborating previous reports suggesting an excretion route from the goblet cell cavity toward the luminal space. Thus, our results suggest that the Anticarsia midgut not only possesses several typical lepidopteran features but also presents some unique aspects such as the presence of a tubular network and PolyP-containing apocrine secretions, plus an apparent route for the release of cellular debris by the goblet cells.
KeywordsGoblet cell Polyphosphate Ultrastructure Midgut Lepidoptera Anticarsia gemmatalis
We express our gratitude to Prof. Helmut Wieczorek and Dr. Markus Huss, University of Osnabrück for providing antibodies of the subunit e M. sexta and to Dr. Eduardo Fox and Prof. Wanderley de Souza for proofreading.
- Bird CH, Sutton VR, Sun J, Hirst CE, Novak A, Kumar S, Trapani JA, Bird PI (1998) Selective regulation of apoptosis: the cytotoxic lymphocyte serpin proteinase inhibitor 9 protects against granzyme B-mediated apoptosis without perturbing the Fas cell death pathway. Mol Cell Biol 18:6387–6398PubMedGoogle Scholar
- Cioffi M (1984) Comparative ultrastructure of arthropod transporting epithelia. Am Zool 24:139–156Google Scholar
- Cioffi M, Harvey WR (1981) Comparison of potassium transport in three structurally distinct regions of the insect midgut. J Exp Biol 91:103–116Google Scholar
- Dow JAT(1986) Insect midgut function. In: Evans PD, Wigglesworth VB (eds) Advances in insect physiology, vol 19. Academic Press, London, pp 187-328Google Scholar
- Harvey W, Cioffi M, Wolfersberger M (1981) Portasomes as coupling factors in active ion transport and oxidative phosphorylation. Am Zool 21:775–791Google Scholar
- Korayem AM, Fabbri M, Takahashi K, Scherfer C, Lindgren M, Schmidt O, Ueda R, Dushay MS, Theopold U (2004) A Drosophila salivary gland mucin is also expressed in immune tissues: evidence for a function in coagulation and the entrapment of bacteria. Insect Biochem Mol Biol 34:1297–1304PubMedCrossRefGoogle Scholar
- Medema JP, Schuurhuis DH, Rea D, Van Tongeren J, De Jong J, Bres SA, Laban S, Toes REM, Toebes M, Schumacher TNM (2001) Expression of the serpin serine protease inhibitor 6 protects dendritic cells from cytotoxic T lymphocyte-induced apoptosis: differential modulation by T helper type 1 and type 2 cells. J Exp Med 194:657–668PubMedCrossRefGoogle Scholar
- Ramos IB, Miranda K, Pace DA, Verbist KC, Lin F-Y, Zhang Y, Oldfield E, Machado EA, de Souza W, Docampo R (2010) Calcium- and polyphosphate-containing acidic granules of sea urchin eggs are similar to acidocalcisomes, but are not the targets for NAADP. Biochem J 429:485–495PubMedCrossRefGoogle Scholar
- Silverman G, Whisstock J, Askew D, Pak S, Luke C, Cataltepe S, Irving J, Bird P (2004) Human clade B serpins (ov-serpins) belong to a cohort of evolutionarily dispersed intracellular proteinase inhibitor clades that protect cells from promiscuous proteolysis. Cell Mol Life Sci 61:301–325PubMedCrossRefGoogle Scholar