| 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3部分组成,有其独特的结构,总长度为35.75± 1.15µm。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。在精子头部的凸面上,有4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±1.51µm,鞭毛直径为0.17±0.01µm。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,还表现在鳗鲡目其他属的精子;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参考。 |
| 关键词: 星康吉鳗(Conger myriaster) 精子 超微结构 精子形态 |
| DOI：10.11759/hykx20221215001 |
| 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资助项目(20603022021004,20603022023023);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资助项目(CARS-47) |
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| A study on sperm ultrastructure in the whitespotted conger, Conger myriaster |
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SHI Bao1,2, WANG Cheng-gang3, TANG Xiao-hua3, ZHAO Xin-yu1,2, YAN Ke-wen1,2, MA Xiao-dong1,2
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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.Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266071, China;3.Haiyang Yellow Sea Aquatic Product Co., Ltd., Yantai 265100, China
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| Abstract: |
| Whitespotted conger, Conger myriaster, is one of the most valuable fishery resources in the seas around China, Korea, and Japan. Thus, it has become important to protect this species, as the annual commercial catch is decreasing. Despite being an important resource for East Asian countries, little is known about the reproductive biology of C. myriaster. Therefore, only very limited information is available regarding the reproductive characteristics of male C. myriaster. Teleost sperm is very morphologically diverse, particularly the sperm head shape; the shape, location, and number of mitochondria, and the structure and length of the flagellum. This study investigated the ultrastructure and morphology of C. myriaster sperm by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM and TEM images revealed that the sperm were composed of a head, a middle piece, and a flagellum. C.myriaster sperm had a unique structure except for the common sperm characteristics of teleost. The total mean length was 35.75±1.15 µm. The head of the spermatozoon was electron-dense and contained chromatin material forming the nucleus. The nucleus was asymmetrically shaped along the longitudinal axis. We observed nuclear vacuoles in the nucleus, which were not fixed in size or position. The head had no acrosomal structure. A single spherical mitochondrion was located along the longitudinal center line of the nucleus but was offset slightly to one side. The mitochondrion was surrounded by an outer mitochondrial membrane. The inner mitochondrial membrane extended inward, forming rich cristae. Ribonucleoprotein and matrix were scattered in the mitochondrion. The mean head length was 3.33±0.16 µm, and the mean head width was 1.12±0.13 µm. Four striae ran from the caudal portion to the cephalad on the convex surface of the head. Additionally, four striae arose from the proximal centriole. The middle piece was constricted and projected a short rootlet located at the end of the middle piece. The mean middle piece length was 0.55±0.05 µm. The mean length of the rootlet was 1.38±0.08 µm, and the mean diameter was 90.48±6.06 nm. The proximal centriole in the middle piece was located near the caudal portion of the sperm head. The distal centriole was located near the flagellum. A cross-section of the flagellum was thin and appeared round with no side fin. Inner dynein arms were seen on the two subfibrils of each filament on a cross-section of the flagellum, but no outer dynein arms were seen. The two subfibrils of the flagellum near the distal centriole were linked to the plasma membrane by radial Y-shape electron-dense bodies. The flagellum was arranged in a 9+0 axonemal pattern. Some flagella were coiled, but the developmental mechanism was unclear. These flagella were coiled tightly, with about five strata counted from the center to the periphery. The mean flagellum length was 31.16±1.51 µm, and the mean flagellum diameter was 0.17±0.01 µm. These features were seen in C. myriaster and are also evident in other species of Anguilliformes. These findings suggest that these features are common to Anguilliformes. This study revealed the morphological structure of C. myriaster sperm to improve our understanding of the reproductive biology of C. myriaster and provide a theoretical basis for developing methods to artificially reproduce C. myriaster. |
| Key words: Conger myriaster sperm ultrastructure spermic shape |
