New Genes for Male Accessory Gland Proteins in Drosophila melanogaster

Abstract

The accessory gland of male insects produces components of the seminal fluid that alter the behavior, physiology and life span of the mated female, and contribute to her efficient storage and utilization of sperm. As a step towards understanding how this occurs, we have isolated genes encoding 12 previously unreported accessory gland-specific mRNAs from the fruit fly Drosophila melanogaster. We report here the restriction maps of the new genes, the chromosome positions--which are all autosomal--of the 11 non-repetitive genes, their expression patterns, and the sequences of the accessory gland proteins (Acps) encoded by nine of the genes. Eight of the proteins predicted from these sequences begin with putative secretion signals. Following their signal sequences, three of the predicted molecules are peptides and the other five are larger polypeptides with characteristics of cleavable prohormones. The ninth molecule, which has an N-terminal hydrophobic region but no consensus signal peptide cleavage site, is predicted to be a 716 amino acid glycoprotein. Of the nine proteins, two have intriguing similarities to sequences in protein databases. Acp76A is a 388 amino acid pro-protein which contains a signature sequence for the serpin class of protease inhibitors. The 115 amino acid Acp62F has a 28 amino acid region of high sequence similarity to a neurotoxin of the Brazilian armed spider Phoneutria nigriventer. Models are discussed in which Acp76A plays a role in the observed regulation of Acp proteolysis and/or in the coagulation of seminal fluid to form a mating plug, and in which Acp62F contributes to the reported toxicity of Drosophila seminal fluid.

A Role for Acp29AB, a Predicted Seminal Fluid Lectin, in Female Sperm Storage inDrosophila melanogaster

“…Acp29AB is produced in the male accessory gland and localizes to the female spermathecae and hemolymph following mating: Western blot analysis using affinity-purified antibodies against Acp29AB detects a 29-kDa protein in extracts of CS male accessory glands, but not in extracts of DTA-E males that lack accessory gland main cells (Kalb et al 1993) (Figure 1A), consistent with the initial identification of Acp29AB as a male accessory gland-specific transcript (Wolfner et al 1997). The predicted molecular weight of Acp29AB (excluding the putative signal peptide) is 24.8 kDa.…”

“…The Acp29AB gene was first identified in a screen for genes differentially expressed in the male accessory gland (Wolfner et al 1997) and is predicted to encode a 234-amino-acid-secreted Ca 21 -dependent (C-type) lectin (Wolfner et al 1997;Mueller et al 2004). Three lines of evidence suggest that Acp29AB might play a role in sperm storage.…”

Genetics and genomics of Drosophila mating behavior

“…The female can accept the male or reject him by moving away. Successful copulation is accompanied by the transfer of sperm and seminal fluids that stimulate the release of oocytes by the ovary (6) and reduce female receptivity to other males (7,8). Components of the seminal fluids are associated with the reduced lifespan of mated females (9), setting up an intersexual conflict (10).…”

The consequences of genetic variation in sex peptide expression levels for egg laying and retention in females

“…Similarly, variation in amounts of stored sperm could affect retention of SP. SP is actively cleaved from sperm within the female (Monsma et al, 1990), and so interactions between female enzymes that cleave SP (Pilpel et al, 2008) or male enzymes that inhibit enzyme activity (Wolfner et al, 1997) could also dramatically alter the measureable amounts of SP in the female reproductive tract relative to male SP expression levels. Here, we tried to minimise the effect of female variation by using females from the same genetic isoline for all our tests.…”