, 1993, Selleckchem GSK126 Giorgi et al., 1999, Zhao et al., 2005 and Oliveira et al., 2008). Subpopulations of yolk granules of various sizes, densities, and contents have been described in several oviparous models (Wallace, 1985 and Fausto et al., 2001), and have been linked with the triggering of yolk degradation by hydrolases (Liu and Nordin, 1998, Cho et al., 1999 and Fialho et al., 2002). Acid

phosphatases (AP) (EC 3.1.3.2) are typical lysosomal enzymes that catalyze the hydrolysis of orthophosphoric monoesters from a wide range of substrates. They are also one of the best studied hydrolases stored in animals’ eggs. The presence of AP in yolk granules and its role in yolk mobilization was first described in the axolotl Ambystoma mexicanum ( Lemansky and Aldoroty, 1977), and was later described in the yolk granules of several insects ( Steinert and Hanocq, 1979, Kawamoto et al., 2000 and Fialho et al., 2002). Nevertheless, the range of substrates of AP remains controversial. While several yolk proteins are strongly dephosphorylated by AP during embryo development ( Wimmer et al., 1998, Silveira et al., 2006 and Oliveira and Machado, 2006), lysosomal AP typically hydrolyzes a broad range of substrates.

For instance, in vitro assays have shown that egg AP from the kissing bug Rhodnius prolixus (rpAP) dephosphorylate inorganic polyphosphate (PolyP), which are polymers of phosphate residues that inhibit an egg aspartic protease in R. prolixus ( Gomes et al., 2010). Curiously, rpAP are initially stored in small vesicles in separation ICG-001 from the main population of yolk granule – a pattern also observed among other invertebrate models ( Ribolla et al., 2001) – and depend on Ca2+-mediated fusion to be transferred into yolk granules ( Ramos et al., 2007). A general model suggests that, upon fusion, rpAP hydrolyzes yolk granule PolyP, liberating aspartic protease activity, which in turn triggers yolk mobilization ( Gomes et al., 2010). In the present report, we analyzed the presence and physiological function of an AP found in the eggs of the velvet bean caterpillar Anticarsia gemmatalis (Hübner) Protirelin – the major insect

soybean pest in the Americas ( Kogan and Turnipseed, 1987). Despite its economical importance, little is known about the general biology of Anticarsia and there are no published aspects of its reproductive and embryonic biology. Here, we characterized an acid phosphatase mainly present in a population of small vesicles inside eggs of A. gemmatalis (agAP). Inhibitor profile suggests it is a typical lysosomal acid phosphatase; also able to dephosphorylate phosphotyrosine and short chain PolyP. We also detected significant PolyP storage inside the yolk granules of Anticarsia eggs, and evidenced the inhibition profile of an egg cysteine protease by PolyP. Together, our data suggest that agAP is involved in yolk mobilization by hydrolysis of both yolk proteins and PolyP during animal development.