果蠅精子形成是由多個發育階段所組成，包括生殖幹細胞分化，精原細胞生長與分裂，精細胞伸長，精細胞individualization，以及精子釋放到儲精囊。在精子形成的最開始，生殖幹細胞進行不對稱分裂，分化出gonialblast。多種機制曾被發現用來將生殖幹細胞保持在hub周圍，其中包括Cadherin所調控的細胞黏著。Gonialblast進行數次分裂與型態變化，形成64個融合(syncytial)而且伸長的精細胞。伸長的精細胞藉由actin cones的移動將細胞膜重組而individualized。果蠅myosin VI曾被發現參與individualization。Individualized精細胞會被coiled並且釋放到儲精囊。Actin caps會將精細胞的核包捆起來，防止未成熟的精子提前被釋放。Echinoid是一個位於adherens junction調控細胞黏著的細胞黏著分子。在本研究中，我們發現ed1X5/edslH8公果蠅有較低的生殖能力，下降的生殖能力可能源自於在individualization與精子釋放過程的發育缺陷。我們也探討了cyst cell在精細胞發育中的調控角色。

Drosophila spermatogenesis is composed of various developmental stages, including germline stem cell differentiation, spermatogonia growth and division, spermatid elongation, spermatid individualization, and sperm release. At the beginning of spermatogenesis, germline stem cell (GSC) divides asymmetrically to produce gonialblast. Several mechanisms have been found to maintain GSCs at the hub, the GSCs niche, including Cadherin-mediated cell adhesion. Gonialblast undergoes several rounds of division and morphology change to become 64 syncytial and elongated spermatids. Elongated spermatids are individualized through remodeling membranes by movement of actin cones. Drosophila myosin VI has been found to participate in individualization. Individualized spermatid are coiled and released into seminal vesicles. Actin caps bundle spermatid nuclei to prevent premature sperm release. Echinoid is a cell adhesion molecule localized at adherens junction to control cell adhesion. In this study, we found that fertility of ed1X5/edslH8 males is reduced. The reduced fertility may not due to GSCs maintenance but due to developmental failure at individualization and sperm release process. We also examined cyst cell’s control over spermatid development.

Bai, J., Chiu, W., Wang, J., Tzeng, T., Perrimon, N., and Hsu, J. (2001). The cell adhesion molecule Echinoid defines a new pathway that antagonizes the Drosophila EGF receptor signaling pathway. Development 128, 591-601.
Brand, A.H., and Perrimon, N. (1993). Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. Development 118, 401-415.
Brawley, C., and Matunis, E. (2004). Regeneration of male germline stem cells by spermatogonial dedifferentiation in vivo. Science 304, 1331-1334.
Chang, L.-H., Chen, P., Lien, M.-T., Ho, Y.-H., Lin, C.-M., Pan, Y.-T., Wei, S.-Y., and Hsu, J.-C. (2011). Differential adhesion and actomyosin cable collaborate to drive Echinoid-mediated cell sorting. Development 138, 3803-3812.
Chen, D., and McKearin, D.M. (2003). A discrete transcriptional silencer in the bam gene determines asymmetric division of the Drosophila germline stem cell. Development 130, 1159-1170.
Cross, D.P., and Shellenbarger, D.L. (1979). The dynamics of Drosophila melanogaster spermatogenesis in in vitro cultures. J Embryol Exp Morphol 53, 345-351.
de Belle, J.S., Sokolowski, M.B., and Hilliker, A.J. (1993). Genetic analysis of the foraging microregion of Drosophila melanogaster. Genome 36, 94-101.
Desai, B.S., Shirolikar, S., and Ray, K. (2009). F-actin-based extensions of the head cyst cell adhere to the maturing spermatids to maintain them in a tight bundle and prevent their premature release in Drosophila testis. BMC Biology 7, 19.
Escudero, L.M., Wei, S.-Y., Chiu, W.-H., Modolell, J., and Hsu, J.-C. (2003). Echinoid synergizes with the Notch signaling pathway in Drosophila mesothorax bristle patterning. Development 130, 6305-6316.
Fabrizio, J.J., Hime, G., Lemmon, S.K., and Bazinet, C. (1998). Genetic dissection of sperm individualization in Drosophila melanogaster. Development 125, 1833-1843.
Fatima, R. (2011). Drosophila Dynein Intermediate Chain Gene, Dic61B, Is Required for Spermatogenesis. PLoS One 6, e27822.
Gerbasi, V.R., Preall, J.B., Golden, D.E., Powell, D.W., Cummins, T.D., and Sontheimer, E.J. (2011). Blanks, a nuclear siRNA/dsRNA-binding complex component, is required for Drosophila spermiogenesis. Proc Natl Acad Sci U S A 108, 3204-3209.
Hicks, J.L., Deng, W.M., Rogat, A.D., Miller, K.G., and Bownes, M. (1999). Class VI unconventional myosin is required for spermatogenesis in Drosophila. Mol Biol Cell 10, 4341-4353.
Hrdlicka, L., Gibson, M., Kiger, A., Micchelli, C., Schober, M., Schöck, F., and Perrimon, N. (2002). Analysis of twenty-four Gal4 lines in Drosophila melanogaster. genesis 34, 51-57.
Inaba, M., Yuan, H., Salzmann, V., Fuller, M.T., and Yamashita, Y.M. (2010). E-Cadherin Is Required for Centrosome and Spindle Orientation in <italic>Drosophila</italic> Male Germline Stem Cells. PLoS One 5, e12473.
Kawase, E., Wong, M.D., Ding, B.C., and Xie, T. (2004). Gbb/Bmp signaling is essential for maintaining germline stem cells and for repressing bam transcription in the Drosophila testis. Development 131, 1365-1375.
Kellerman, K.A., and Miller, K.G. (1992). An unconventional myosin heavy chain gene from Drosophila melanogaster. Journal of Cell Biology 119, 823-834.
Kiger, A.A., Jones, D.L., Schulz, C., Rogers, M.B., and Fuller, M.T. (2001). Stem cell self-renewal specified by JAK-STAT activation in response to a support cell cue. Science 294, 2542-2545.
Li, L., and Xie, T. (2005). STEM CELL NICHE: Structure and Function. Annual Review of Cell and Developmental Biology 21, 605-631.
Lin, H. (2002). The stem-cell niche theory: lessons from flies. Nat Rev Genet 3, 931-940.
Lin, H.P., Chen, H.M., Wei, S.Y., Chen, L.Y., Chang, L.H., Sun, Y.J., Huang, S.Y., and Hsu, J.C. (2007). Cell adhesion molecule Echinoid associates with unconventional myosin VI/Jaguar motor to regulate cell morphology during dorsal closure in Drosophila. Dev Biol 311, 423-433.
Lindsley, D.L., and Tokuyasu, K.T. (1980). Spermatogenesis, Vol 2b (New York.: Academic Press).
Ma, Z., Liu, Z., and Huang, X. (2010). OSBP- and FAN-mediated sterol requirement for spermatogenesis in Drosophila. Development 137, 3775-3784.
Mermall, V., Bonafe, N., Jones, L., Sellers, J.R., Cooley, L., and Mooseker, M.S. (2005). Drosophila myosin V is required for larval development and spermatid individualization. Dev Biol 286, 238-255.
Noguchi, T., Frank, D.J., Isaji, M., and Miller, K.G. (2009). Coiled-coil-mediated dimerization is not required for myosin VI to stabilize actin during spermatid individualization in Drosophila melanogaster. Molecular Biology of the Cell 20, 358-367.
Noguchi, T., Lenartowska, M., and Miller, K.G. (2006). Myosin VI stabilizes an actin network during Drosophila spermatid individualization. Mol Biol Cell 17, 2559-2571.
Noguchi, T., Lenartowska, M., Rogat, A.D., Frank, D.J., and Miller, K.G. (2008). Proper cellular reorganization during Drosophila spermatid individualization depends on actin structures composed of two domains, bundles and meshwork, that are differentially regulated and have different functions. Molecular Biology of the Cell 19, 2363-2372.
Noguchi, T., and Miller, K.G. (2003). A role for actin dynamics in individualization during spermatogenesis in Drosophila melanogaster. Development 130, 1805-1816.
Ozaki-Kuroda, K., Nakanishi, H., Ohta, H., Tanaka, H., Kurihara, H., Mueller, S., Irie, K., Ikeda, W., Sakai, T., Wimmer, E., et al. (2002). Nectin couples cell-cell adhesion and the actin scaffold at heterotypic testicular junctions. Curr Biol 12, 1145-1150.
Rauzi, M., Lenne, P.F., and Lecuit, T. (2010). Planar polarized actomyosin contractile flows control epithelial junction remodelling. Nature 468, 1110-1114.
Rotkopf, S., Hamberg, Y., Aigaki, T., Snapper, S.B., Shilo, B.Z., and Schejter, E.D. (2011). The WASp-based actin polymerization machinery is required in somatic support cells for spermatid maturation and release. Development 138, 2729-2739.
Schulz, C., Kiger, A.A., Tazuke, S.I., Yamashita, Y.M., Pantalena-Filho, L.C., Jones, D.L., Wood, C.G., and Fuller, M.T. (2004). A misexpression screen reveals effects of bag-of-marbles and TGF beta class signaling on the Drosophila male germ-line stem cell lineage. Genetics 167, 707-723.
Shields, G., and Sang, J.H. (1977). Improved medium for culture of Drosophila embryonic cells. Drosophila Information Services 52.
Shivdasani, A.A., and Ingham, P.W. (2003). Regulation of stem cell maintenance and transit amplifying cell proliferation by tgf-beta signaling in Drosophila spermatogenesis. Curr Biol 13, 2065-2072.
Spradling, A., Drummond-Barbosa, D., and Kai, T. (2001). Stem cells find their niche. Nature 414, 98-104.
Tokuyasu, K.T., Peacock, W.J., and Hardy, R.W. (1972a). Dynamics of spermiogenesis in Drosophila melanogaster. I. Individualization process. Zeitschrift fur Zellforschung und mikroskopische Anatomie (Vienna, Austria : 1948) 124, 479-506.
Tokuyasu, K.T., Peacock, W.J., and Hardy, R.W. (1972b). Dynamics of spermiogenesis in Drosophila melanogaster. II. Coiling process. Zeitschrift fur Zellforschung und mikroskopische Anatomie (Vienna, Austria : 1948) 127, 492-525.
Tulina, N., and Matunis, E. (2001). Control of Stem Cell Self-Renewal in Drosophila Spermatogenesis by JAK-STAT Signaling. Science 294, 2546-2549.
Wang, C., Ma, Z., Scott, M.P., and Huang, X. (2011). The cholesterol trafficking protein NPC1 is required for Drosophila spermatogenesis. Dev Biol 351, 146-155.
Wang, H., Singh, S.R., Zheng, Z., Oh, S.-W., Chen, X., Edwards, K., and Hou, S.X. (2006). Rap-GEF Signaling Controls Stem Cell Anchoring to Their Niche through Regulating DE-Cadherin-Mediated Cell Adhesion in the Drosophila Testis. Developmental Cell 10, 117-126.
Wei, S.Y., Escudero, L.M., Yu, F., Chang, L.H., Chen, L.Y., Ho, Y.H., Lin, C.M., Chou, C.S., Chia, W., Modolell, J., et al. (2005). Echinoid is a component of adherens junctions that cooperates with DE-Cadherin to mediate cell adhesion. Dev Cell 8, 493-504.
Winder, S.J., Hemmings, L., Maciver, S.K., Bolton, S.J., Tinsley, J.M., Davies, K.E., Critchley, D.R., and Kendrick-Jones, J. (1995). Utrophin actin binding domain: analysis of actin binding and cellular targeting. Journal of Cell Science 108, 63-71.
Wong, M.D., Jin, Z., and Xie, T. (2005). Molecular mechanisms of germline stem cell regulation. Annu Rev Genet 39, 173-195.
Xie, T., Kawase, E., Kirilly, D., and Wong, M.D. (2005). Intimate relationships with their neighbors: Tales of stem cells in Drosophila reproductive systems. Developmental Dynamics 232, 775-790.
Yamashita, Y.M., Jones, D.L., and Fuller, M.T. (2003). Orientation of Asymmetric Stem Cell Division by the APC Tumor Suppressor and Centrosome. Science 301, 1547-1550.
Zhong, L., and Belote, J.M. (2007). The testis-specific proteasome subunit Prosalpha6T of D. melanogaster is required for individualization and nuclear maturation during spermatogenesis. Development 134, 3517-3525.
Zhou, X., Fabian, L., Bayraktar, J.L., Ding, H.M., Brill, J.A., and Chang, H.C. (2011). Auxilin is required for formation of Golgi-derived clathrin-coated vesicles during Drosophila spermatogenesis. Development 138, 1111-1120.