| 摘要: |
| 为探讨星康吉鳗(Conger myriaster)精子的超微结构和形态,应用扫描电镜和透射电镜对星康吉鳗精子结构进行观察。结果表明,精子由头部、中段和鞭毛三部分组成,有其独特的结构,总长度为35.75±1.15 μm。 精子头部为新月形,主要由细胞核构成,细胞核内有核泡,无顶体结构。精子头部的质膜内包含单一的线粒体。精子头部长为3.33±0.16 um,头宽为1.12±0.13 um。在星康吉鳗精子头部的凸面上,有四条从中段到头端的条纹。精子中段伸出一支根,支根位于精子的中段末端。精子中段长度为0.55±0.05 um,支根长度为1.38±0.08 um、直径为90.48±6.06 nm。精子尾部鞭毛细长,鞭毛横切面呈圆形,无侧鳍,鞭毛的轴丝结构为“9+0”型；一些鞭毛的末端呈现卷曲状,发育机制尚不明确。精子鞭毛长为31.16±1.51 μm,鞭毛直径为0.17±0.01 μm。通过比较分析发现精子的这些形态学特征不仅表现在星康吉鳗精子,还表现在鳗鲡目其它属的精子；表明是鳗鲡目精子的共同特征。本研究揭示了星康吉鳗精子的形态结构,为突破星康吉鳗人工繁殖技术提供了理论依据。 |
| 关键词: 星康吉鳗 精子 超微结构 精子形态 |
| DOI： |
| 分类号:S962 |
| 基金项目:中国水产科学研究院黄海水产研究所基本科研业务费(20603022021004, 2020TD47);山东省重点研发计划项目(2021LZGC028);国家重点研发计划项目(2019YFD0900503) ; 国家现代农业产业技术体系(CARS-47) |
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| A study on sperm ultrastructure in the whitespotted conger Conger myriaster |
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SHI Bao1, WANG Chen-gang2, TANG Xiao-hua2, ZHAO Xin-yu1, YAN Ke-wen1, MA Xiao-dong1
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1.Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Key Laboratory of Sustainable Development of Marine Fisheries,Ministry of Agriculture and Rural Affairs;2.Haiyang Yellow Sea Aquatic Product Co,Ltd
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| Abstract: |
| Several species of anguilliformes are commercially important in fisheries and aquaculture. Whitespotted conger Conger myriaster which is also an anguilliformes is one of the most valuable fishery resources in the seas around China, Korea and Japan. Moreover, it has become important to protect this species, as the annual commercial catch is decreasing. Despite it being an important resource for East Asian countries, little is known about its reproductive biology. Therefore, only very limited information is available regarding reproductive characteristic in the male C. myriaster. A large diversity in morphology and structure of teleost species sperm has been observed. In general, this diversity is observed in sperm head shape; the shape, location and number of mitochondrion; and the structure and length of the flagellum. The current study investigated the ultrastructure and morphology of the C. myriaster sperm by using scanning electron microscope (SEM) and transmission electron microscope (TEM). SEM and TEM images revealed that sperm could be differentiated into three major parts: a head, middle piece and flagellum. It has been observed that the sperm of C. myriaster has it"s unique structure except the common sperm characteristics of teleost. Total mean length was approximately 35.75±1.15 μm. The head of the spermatozoon was electron dense and contained chromatin material forming the nucleus. The shape of nucleus was asymmetric along the longitudinal axis. We observed the nuclear vacuoles were present in the nucleus. And the position and size of nuclear vacuoles is not fixed. The head had no the acrosomal structure. A single spherical mitochondrion was not located along the longitudinal centre line of the nucleus but rather was offset slightly to one side. Mitochondrion was surrounded by outer mitochondrial membrane. Inner mitochondrial membrane extended inward forming rich cristae. Ribonucleoprotein and matrix scattered in the mitochondrion.The mean head length is 3.33±0.16 um. The mean head width is 1.12±0.13 um. On the convex surface of the head, four striae running from the caudal portion to the cephalad were seen. And, the four striae arised from the proximal centriole. Middle piece was somewhat constricted. Moreover, middle piece of sperm projected a short rootlet which was located at the end of the middle piece. The mean middle piece length is 0.55±0.05 um. The rootlet is 1.38±0.08 um mean long and 90.48±6.06 nm in mean diameter. In the middle piece, the proximal centriole located at the near caudal portion of the sperm head. At the same distal centriole located at the near flagellum. Cross section of the flagellum which was slim and thin appeared to be round and no side fin. In cross section of flagellum, the inner dynein arms on the two subfibrils of each filament were seen but outer dynein arms were not seen. In the flagellum near to the distal centriole, the two subfibrils were linked to the plasma membrane by radial Y-shape electron dense bodies. The flagellum showed a 9+0 axonemal pattern (9 double outer tubules and no central tubule). Some flagella showed a coiled form, the developmental mechanism of which was unclear. Under these circumstances, the flagella were coiled tightly with about 5 strata as counted from the center to the periphery. The mean flagellum length is 31.16±1.51 μm. And the mean flagellum diameter is 0.17±0.01 μm. These features were seen not only in the C. myriaster but also in other species of other genera in Anguilliformes. On the basis of these findings, it is suggested that these features be considered as common to Anguilliformes. This study revealed the morphological structure of C. myriaster sperm to enrich our understanding of the reproductive biology of C. myriaster and provided a theoretical basis for developing methods for the artificial reproduction of C. myriaster. |
| Key words: Conger myriaster sperm ultrastructure spermic shape |