果蠅心臟〈背血管〉由104個可分為數群表現不同分子標誌及功能的細胞組成，由於其結構相較簡單因此為一研究心臟發育很好的模式動物，本研究嘗試利用此一模式探討Acer (Angiotensin Converting enzyme- related) 在果蠅心臟發育中的功能。Acer為一個具金屬性胜肽酶活性區〈Metallopeptidase active site〉的酵素，先前報告顯示其在果蠅心臟發育有一定的功能，但其角色為何並未詳加研究。原位雜合實驗証實晚期Acer表現於果蠅胚胎的背血管中。以心臟細胞分子標誌 (如：Tinman、eve和Odd等) 進行抗體染色則顯示，在Acer突變株中顯現心肌及圍心細胞缺失及分布異常的性狀；相反地，過度表現Acer則發現會導致心肌及圍心細胞增多的現象，這樣的性狀與Tin、Pnr非常類似，顯示在心臟發育的過程中Tin、Pnr及Acer 極可能作用於同一路徑，初步研究証實Acer可能與Pnr有交互作用，Acer 是否與tinman 及pnr 交互作用或是單獨作用於果蠅心臟發育，則須更多研究証明。

Heart of Drosophila consists of 104 cells which are classified into different groups according the specific cell markers and functions. As its structure is relative simple, this makes Drosophila is one of the most excellent models to study the cardiogenesis of animals. In this study we plant to study the function of acer in heart development using Drosophila as a model system. Acer is a metallopeptidase. Previous studies suggested that it may function in development heart. Nevertheless, its role in heart morphogenesis has not been characterized in detail. in situ hybridization demonstrates that acer is expressed exclusively in heart of Drosophila (dorsal vessel). Immunocytochemistry stainings using different heart-specific markers, such as tinman, odd and eve, have revealed that cardial and pericardial cells are missing or misplaced in acer mutant embryos. By contrast, overexpression of Acer results in overproduction of cardial and pericardial cells. As the heart phenotypes of acer were similar to that of tinman and pnr, this indicate that acer, tinman and pnr act in the same pathway during heart morphorgenesis in flies. Preliminary studies demonstrated that acer may interact with tin and pnr. Further studies are needed to demonstrate if acer acts in concert with tin and pnr or function along to specify different cardial cell types.

1. Ryan, M. J., and Sigmund C. D. (2004). ACE, ACE Inhibitoes, and Other JNK. Circ. Res. 94, 1-3.
2. Garg, R., and Yusuf, S. (1995). Overview of randomized trails of angiotensin-converting enzyme inhibitors on mortality and morbidity in patients with heart failure. J. Am. Med. Assoc. 273, 1450-1456.
3. Krege, J H. et al. (1995). Male-female differences in fertility and blood pressure in ACE-dificient mice. Nature. 375, 146-148.
4. Esther, C. R. et al. (1996) Mice lacking angiotensin-converting enzyme have low blood pressure, renal pathology and reduced male fertility. Lab. Invest. 74,953-965.
5. Donoghue, M., Hsieh, F., Baronas, E., Godbout, K., Gosselin, M., Stagliano, N., Donovan, M., Woolf, B., Robison, K., Jeyaseelan, R., Breitbart, R.E., and Acton, S. (2000) A novel angiotensin – convertingenzyme - related carboxypeptidase (ACE2) converts angiotensinI to angiotensin 1–9. Circ. Res. 87,E1–E9.
6. Tipnis, S. R., Hooper, N.M., Hyde, R., Karran, E., Christie, G., and Turner,A. J. (2000) A human homolog of angiotensin-converting enzyme. Cloning and functional expression as a captopril - insensitive carboxypeptidase. J. Biol. Chem. 275,33238–33243.
7. Danilczyk, U., Eriksson, U., Crackower, M. A., and Penninger J. M. (2003). A story of two ACEs. J. Mol. Med. 81,227-234.
8. Crackower, M. A., Sarao, R., Oudit, G. Y., Yagil, C., Kozieradzki, I., Scanga, S. E., Oliveira-Dos-Santos, A. J., Da Costa, J., Zhang, L., Pei, Y., Scholey, J., Ferrario, C. M., Manoukian, A. S., Chappell, M. C., Backx, P. H., Yagil, Y., and Penninger, J. M. (2002) Angiotensin-converting enzyme 2 is an essential regulator of heart function. Nature. 417,822–828.
9. Coates, D., Isaac, R. E., Cotton, J., Siviter, R., Williams, T. A., Shirras, A., Corvol, P., and Dive, V. (2000) Function conservation of the Active Sites of Human and Drosophila AngiotensinⅠ-converting Enzyme. Biochemistry 39, 8963–8969.
10. Tatei, K., Cai, H., Ip, Y. T., and Levine, M. (1995) Race : a drosophila homologoue of the angiotensin converting enzyme. Mech. Dev. 51, 157-168.
11. Hurst, D., Rylett, C. M., Isaac, R. E., and Shirras, A. D. (2003) The drosophila angiotensin-converting enzyme homologue Ance is required for spermiogenesis. Dev. Biol. 254, 238-247.
12. Rusch, J., and Levine, M. (1997) Regulation of a dpp target gene in the Drosophila embryo. Develpoment 124,303-311.
13. Ashe, H. L., Mannervil, M., and Levine, M. (2000) Dpp signaling thresholds in the dorsal ectoderm of the Drosophila embryo. Development 127, 3305-3312.
14. Stathopoulos, A., Drenth, M. V., Erives, A., Markstein, M., and Levine, M. (2002) Whole-genome analysis of dorsal-ventral patterning in the Drosophila embryo. Cell 111, 687-701.
15. Cornell, M. J., Williams, T. A., Lamango, N. S., Coates, D., Corvol, P., Soubrier, F., Hoheisel, J., Lehrach, H., and Isaac,R. E. (1995) Cloning and expression of an evolutionary conserved single-domain angiotensin converting enzyme from Drosophila melanogaster. J. Biol. Chem. 270, 13613-13619.
16. Taylor, C. A. M., Coates, D., and Shirras, A. D. (1996) The Acer gene of Drosophila codes for an angiotensin-converting enzyme homologue. Gene 181, 191-197.
17. Houard, X., Williams, T.A., Michaud, A., Dani, P., Isaac, R.E., Shirras, A.D., Coates, D., and Corvol, P. The Drosophila melanogaster-related angiotensin I-converting enzymes Acer and Ance: distinct enzymic characteristics and alternative expression during pupal development. Eur. J. Biochem. 257, 599–606.
18. Siviter, R. J., Nachman, R. J., Dani, M. P., Keen, J. N., Shirras, A. D., and Isaac, R. E. (2002) Peptidyl dipeptidases ( Ance and Acer) of Drosophila melanogaster: major differences in the substrate specificity of two homologs of human angiotensin Ⅰ-converting enzyme. Peptides 23, 2025-2034.
19. Brooks, D. R., Appleford, P. J., Murray, L., and Isaac, R. E. (2003) An essential role in molting and morphogenesis of Caenorhabditis elegans for ACN-1,a novel member of the angiotensin-converting enzyme family that lacks a metallopeptidase active site. J. Biol. Chem. 278, 52340-52346.
20. Rizki, T. M. (1978). The circulatory system and associated cells and tissues. In The Genetics and Biology of Drosophila. (ed. M. Ashburner and T. R. F. Wright), pp. 397-452. New York: Academic Press.
21. Curtis, N. J., Ringo, J. M. and Dowse, H. B. (1999). Morphology of the pupal heart, adult heart and associated tissues in the fruit fly Drosophila melanogaster. J. Morphol. 240, 225-235.
22. Molina, M. R. and Cripps, R. (2001). Ostia, the inflow tracts of the Drosophila heart, develop from a genetically distinct subset of cardiac cells. Mech. Dev. 109, 51-59.
23. Bodmer, R. and Frasch, M. (1999). Genetic determination of Drosophila heart development. In Heart development (ed. R. P. Harvey and N. Rosenthal), pp. 65-90. London: Academic Press.
24. Dunin-Borkowski, O., Brown, N. and Bate, M. (1995). Anteroposterior subdivision and the diversification of the mesoderm in Drosophila. Development 121, 4183-4193.
25. Frémion, F., Astier, M., Zaffran, S., Guillén, A., Homburger, V. and Sémériva, M. (1999). The heterotrimeric protein Go is required for the formation of heart epithelium in Drosophila. J. Cell Biol. 145, 1063-1076.
26. Ruggendorff, A., Younossi-Hartenstein, A. and Hartenstein, V. (1994). Embryonic origin and differentiation of the Drosophila heart. Roux’s Arch. Dev. Biol. 203, 266-280.
27. Zaffran, S., Astier, M., Gratecos, D., Guillén, A. and Sémériva, M. (1995). Cellular interactions during heart morphogenesis in the Drosophila embryo. Biol. Cell. 84, 13-24.
28. Kremser, T., Gajewski, K., Schulz, R. and Renkawitz-Pohl, R. (1999). Tinman regulates the transcription of the beta3 tubulin gene (betaTub60D) in the dorsal vessel of Drosophila. Dev. Biol. 216, 327-339.
29. Nasonkin, I., Alikasifoglu, A., Ambrose, C., Cahill, P., Cheng, M., Sarniak, A., Egan, M. and Thomas, P. M. (1999). A novel sulfonylurea receptor family member expressed in the embryonic Drosophila dorsal vessel and tracheal system. J. Biol. Chem. 274, 29420-29425.
30. Gajewski, K., Choi, C. Y., Kim, Y. and Schulz, R. A. (2000). Genetically distinct cardiac cells within the Drosophila heart. Genesis 28, 36-43.
31. Lo, P. C. H. and Frasch, M. (2001). A role for the COUP-TF-related gene seven-up in the diversification of cardioblast identities in the dorsal vessel of Drosophila. Mech. Dev. 104, 49-60.
32. Jagla, K., Frasch, M., Jagla, T., Dretzen, G., Bellard, F. and Bellard, M. (1997). Ladybird, a new component of the cardiogenic pathway in Drosophila required for diversification of heart progenitors. Development 124, 3471-3479.
33. Lue H.C. CCM, Hsu J.Y., Chen C.L. (1976). The prevalence and type of congenital heart disease in Chinese. J Formosan Med Asso, 75, 53-9.
34. Chiu I.S. HSW, Wang J.K., Wu M.H., Chu S.H., Lue H.C., Hung C.R. (1988). Clinical implications of atrial isomerism. Br Heart J 60, 72-7.
35. Lue H.C. CCM, Hsu J.Y., Chen C.L. (1986). Is subpulmonic ventricular septal defect an oriental disease; In: Subpulmonic ventricular septal defect. Spinger-Verlag: 1-8.
36. Bodmer, R. (1995). Heart development in Drosophila and its relationship to vertebrate systems. Trends Cardiovasc. Med. 5, 21-27.
37. Harvey, R. P. (1996). NK-2 homeobox genes and heart development. Dev. Biol. 178, 203-216.
38. Olson, E. N., and Srivastava, D. (1996). Molecular pathways controlling heart development. Science. 272, 671-676.
39. Ponzielli, R., Astier, M., Chartier, A., Gallet, A., Therond, P., and Semeriva, M. (2002). Heart tube patterning in Drosophila requires integration of axial and segmental information provided by the Bithorax Complex genes and hedgehog signaling. Development. 129, 4509-4521.
40. Klinedinst, S. L., and Bodmer, R. (2003). Gata factor Pannier is required to estabolish competence for heart progenitor formation. Development. 130, 3027-3038.
41. Ranganayakulu, G., /Elliott, D. A., Harvey, R. P. and Olsen, E. N. (1998). Divergent roles for NK-2 class homeobox genes in cardiogenesis in flies and mice. Development 113, 35-54.
42. Fu, Y., Yan, W., Mohun, T. J. and Evans, S. M. (1998). Vertebrate tinman homologues XNK2-3 and XNK2-5 are required for heart formation in a functionally redundant manner. Development 124, 4439-4449.
43. Haenlin, M., Cubadda, Y., Blondeau, F., Heitzler, P., Lutz, Y., Simpson, P. and Ramain, P. (1997). Transcriptional activity of Pannier is regulated negatively by heterodimerization of the GATA DNA-binding domain with a cofactor encoded by the u-shaped gene in Drosophila. Genes Dev. 11, 3096-3108.
44. Lockwood, W. and Bodmer, R. (2002). Patterns of wingless, decapentaplegic and tinman positions the Drosophila heart. Mech. Dev. 114,13-26.
45. Han, Z., Fujioka M., Su, M., Liu, M., Jaynes, J. B., Bodmer, R. (2002) Transcriptional Integration of Competence Modulated by Mutual Repression Generates Cell-Type Specificity within the Cardiogenic Mesoderm. Dev. Bio. 252, 225-240.
46. Spradling, A. C. et al. (1999) The Berkekey Drosophila Genome Project gene disruption project: Single P-element insertion mutating 25% of vital Drosophila genes. Genetics 153, 135-177.
47. Cripps, R. M. and Olson, E. N. (2002) Control of Cardiac Development by an Evolutionarily Conserved Transcriptional Network. Dev. Bio. 246, 14-28.