Spermatogenesis of Black Molly and Sailfin Molly (Poeciliidae, Teleostei)

경골어류 난태생 송사리과에 속하는 black molly와 sailfin molly의 정자형성과정

  • Ryu, Seung-Jun (Department of Environmental Medical Biology, Wonju College of Medicine, Yonsei University) ;
  • Kim, Dong-Heui (Department of Environmental Medical Biology, Wonju College of Medicine, Yonsei University)
  • 유승준 (연세대학교 원주의과대학 환경의생물학교실) ;
  • 김동희 (연세대학교 원주의과대학 환경의생물학교실)
  • Received : 2010.09.03
  • Accepted : 2010.09.26
  • Published : 2010.09.30

Abstract

Black molly (Poecilia sphenops) and sailfin molly (Poecilia latipinna) are a teleost belonging to Poeciliidae. The spermatogenesis between two species were investigated by light and electron microscope. The whitish testes of both black molly and sailfin molly were located between intestine and air bladder. The size of testis was major axis 7 mm, minor axis 2 mm. The testis contained numerous testicular cysts. In both black molly and sailfin, primary spermatocytes were comparatively large ellipsoidal, and mitochondria showed a marked development. The secondary spermatocyte was smaller than that of primary spermatocyte, highly condensed according to their development. The nucleus with electron-dense was round shape and flagella started to be formed. In spermiogenesis, chromatin was more condensed. The mitochondria were rearranged along the tail. The number of mitochondria was 2 to 4 in cross section and 8 to 10 in longitudinal section. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins. In conclusion, spermatogenesis and sperm morphologies of these two species were same. These morphological similarity seems to be an indication of the Poeciliidae.

난태생어류인 성숙한 블랙몰리(black molly, Poecilia sphenops)와 세일핀몰리(sailfin molly, Poecilia latipinna)의 정소를 적출하여 정자형성과정과 정자의 미세구조를 광학현미경과 전자현미경을 이용하여 관찰하였다. 정소는 부레와 창자사이에 위치하고 있었고 장축 7 mm, 단축 2 mm 정도의 크기로 흰색을 띠고 있었다. 두 종 모두 정자형성 과정은 정소낭(testicular cyst)에서 이루어졌으며, 각 정소낭 내에 동일한 분화시기의 생식세포가 분포하고 있었다. 제1정모세포는 타원형으로 관찰되었으며, 핵과 세포질의 전자밀도는 다른 생식 세포들에 비해서 매우 낮았고 미토콘드리아는 핵막주위에 분포하고 있었다. 제2감수분열 전기의 태사기에 나타나는 태기사복합체(synaptonemal complex)들이 확인되는 경우도 있었다. 두 종 모두 제2정모세포는 구형으로 정원세포보다 크기는 작았고 인은 발달되어 있지 않았으며, 핵의 전자밀도는 더 높아졌다. 특히 미토콘드리아는 세포질 전체에 분포하고 있었고 정세포가 정자로 발달하는 정자완성과정시기에 편모가 형성되는 경우가 일반적이지만 이미 제2정모 세포시기에 편모형성이 관찰되었다. 정자의 중편부위를 횡단한 결과 미토콘드리아는 2~4개 정도로 관찰되었고 편모의 미세소관 배열은 전형적인 두 종 모두 9+2 구조를 이루고 있었고 편모에 lateral fin이 발견되었다. 성숙한 정자의 두부형태는 구형인 정세포와 달리 장원추형이었으며 염색질 응축이 매우 뚜렷하였고, 두부에서 첨체는 관찰되지 않았으며 중편부의 미토콘드리아는 두 종 모두 8~10개가 종렬로 위치하고 있었다. 이상과 같이 두 종의 정자형성과정과 정자의 형태는 같으며 이런 특징은 난태생 송사리과 어류의 공통적인 특성으로 생각된다.

Keywords

References

  1. Billard R: Spermiogenesis in the rainbow trout (Salmo gairdneri) An ultrastructural study. Cell Tissue Res 223 : 265-284, 1983.
  2. Brusle S: Ultrastructure of Spermiogenesis in Liza aurata Risso, 1810 (Teleostei, Mugilidae). Cell Tissue Res 217 : 415-424, 1981.
  3. Deung YK, Kim DH, Reu DS: Ultrastructure of gametes in the threespine stickleback, Gasterosteus aculeatus aculeatus. Korean J Electron Microscopy 29(2) : 177-187, 1999. (Korean)
  4. Deurs BV, Lastein U: Ultrastructure of the spermatozoa of the teleost Pantodon buchholzi Peters, with particular reference to the midpiece. J Ultrastr Res 42 : 517-533, 1973. https://doi.org/10.1016/S0022-5320(73)80024-3
  5. Favard P, Andre J: The mitochondria of spermatozoa. In: Baccetti B, ed, Comparative Spermatology, pp. 415-429, Academic Press, New York, 1970.
  6. Grier HJ: Ultrastructure of the testis in the teleost Poecilia latipinna. J Ultrastr Res 45 : 82-92, 1973. https://doi.org/10.1016/S0022-5320(73)90034-8
  7. Gwo JC, Gwo HH: Spermatogenesis in the black porgy, Acanthopagrus schlegeli (Teleostei: Perciformaes: Sparidae). Mol Reprod Dev 36 : 75-83, 1993. https://doi.org/10.1002/mrd.1080360111
  8. Hourigan TF, Nakamura M, Nagahama Y, Yamauchi K, Grau EG: Histology, ultrastructure, and in vitro viteroidogenesis of the testes of two male phenotypes of the protogynous Fish, Thalassoma duperrey (Labridae). General and Comparative Endocrinology 83 : 193-217, 1991. https://doi.org/10.1016/0016-6480(91)90023-Y
  9. Jones PR, Butler RD: Spermatozoon ultrastructure of Platichthys flesus. J Ultrastr Mol Struc Res 98 : 71-82, 1988. https://doi.org/10.1016/S0889-1605(88)80935-2
  10. Kim DH, Chang BS, Kim WJ, Lee MS, Teng YC, Kim S, Lee KJ: The Spermatogenesis of Chinese minnow, Leuciscinae, Teleostei. Korean J Electron Microscopy 40(1) : 1-8, 2010. (Korean)
  11. Kim DH, Deung YK, Kim WJ, Reu DS, Kang SJ: Comparative ultrastructures of the fertilized egg envelopes from three-spot gourami, pearl gourami and marble gourami, Belontiidae, Teleost. Korean J Electron Microscopy 29(3) : 343-351, 1999. (Korean)
  12. Kim DH, Deung YK, Lee KJ: Ultrastructure of the fertilized egg envelope from Hyphessobrycon serpae, Characidae, Teleost. Korean J Electron Microscopy 35(2) : 89-96, 2005. (Korean)
  13. Kim DH, Lee KJ, Kim S, Deung YK: A study on the oogenesis of False dace (Pseudorasbora parva). Korean J Electron Microscopy 37(2) : 65-72, 2007. (Korean)
  14. Kim DH, Reu DS, Deung YK: An ultrastructural study on the spermatogenesis of Xiphophorus maculatus. Korean J Electron Microscopy 33(4) : 267-274, 2003. (Korean)
  15. Lee KJ, Chang BS, Teng YC, Kim S, Song MS, Joo KB, Kim DH: The spermatogenesis of Cichlasoma managuensis. Cichlidae, Teleost. Korean J Microscopy 39(3) : 219-226, 2009. (Korean)
  16. Medina A, Megina C, Abascal FJ, Calzada A: The sperm ultrastructure of Merluccius merluccius (Teleostei, Gadiformes): phylogenetic considerations. Acta Zoologica 84(2) : 131-137, 2003. https://doi.org/10.1046/j.1463-6395.2003.00138.x
  17. Miura T, Yamauchi K, Nagahama Y, Takahashi H: Introduction of permatogenesis in male Japanese eel, Anguilla japonica, by a single injection of human chorionic gonadotropin. Zool Sci 8 : 63-73, 1991.
  18. Rossouw GJ, Vanessen LD: Spermatogenesis in the male white spotted houndshark, Mustelus palubes Smith, 1957. South African J Sci 89 : 244-246, 1993.
  19. Santos RN, Andrade CC, Santos LN, Santos AFGN, Arauujo FG: Testicular maturation of Oligosarcus hepsetus (Cuvier) (Actinopterygii, Characidae) in a Brazilian tropical reservoir. Braz J Biol 66(1A) : 143-150, 2006. https://doi.org/10.1590/S1519-69842006000100018
  20. Todd PR: Ultrastructure of the spermatozoa and spermiogenesis in New Zealand freshwater eels (Anguillidae). Cell Tissue Res 171 : 224-232, 1976.
  21. Wolenski JS, Hart NH: Scanning electron microscopic studies of sperm incorporation into the zebrafish (Brachydanio) egg. J Exp Zool 243 : 259-273, 1987. https://doi.org/10.1002/jez.1402430211