摘要
雄性三倍体鱼的精巢发育比较一致,都完成了由精原细胞、初级精母细胞经减数分裂形成精子细胞的过程,有些还见有变态中的异形精子,个别的还观察到少量类似于正常的成熟精子。雌性三倍体鱼的卵巢发育相当复杂,分化多样,已辨别出卵巢发育分别停留在卵原细胞分化、初级卵母细胞形成、少量卵母细胞生长发育和较多卵母细胞生长发育的四种异常类型,其共同特点是都含有一些败育和趋于败育的细胞,后两类卵巢中普遍含有类似于三倍体鱼精巢中的组织细胞结构。
Some morphological and cytological characteristics about the gonadal development of artificial triploid transparent colored crucian carp (Carassius auratus transparent colored variety) produced from hydrostatic pressure shock were studied by the technique of histological section.Most of the testes of triploid males were almost similar to that of diploid controls both in shape and in size at one year of age, but the color of testes of triploid males was more pink than that of diploid controls, and no milt was stripped out in triploid males. The seminiferous tabules have formed within the testes of all triploid males examined. Spertnatogonia, primary spermatocytes, prophase cells of first meiosis, spermatids and abnormal spermatozoa were observed in most of histological sections. Aborted primary spermatocytes and spermatids were also found in some histological sections. The shape of abnormal spermatozoa varied, such as tadpole-like, stick-like or shuttle-like. A few mature spermatozoa similar to the normal spermatozoa of diploid fish were also observed within testicular tissue of one triploid male in which the testis is obviously abnormal.Significant differences and development diversification of ovaries were found among triploid females. Four types of anomalous ovaries were distinguished among the female triploid individuals examined. Some individuals had only thin string-like ovaries enclosed by large white fat bodies. The bulk of the thin string-like ovarian tissue was composed of many small undifferentiated cells, diferentiating cells and some oogonia. A small number of primary oo-cytes were also present, Some aborted cells without nucleus aborting cells were observed in the ovaries. Some individuals had still string-like ovaries but thickened slightly. The ovarian tissues had differentiated and contained enlarging primary oocytes. The aborted cells were often seen in the second type of ovaries. The tissues of the third type of ovaries had strongly differentiated. The ovaries contained a few growing and developing oocytes, some being at primary growth stage, some at true vitellogenesis stage, whereas a large number of oocytes in the ovaries remained still at the stage of primary oocytes. Additionallf, the ovaries were found to have many ovarian lamellae filled with many simultaneously dividing cells which were similar to prophase cells of meiosis in male triploid testes. Yellow-red sticky oil drops can be stripped out in some individuals, and a small number of unequal size tangerin eggs can be seen with the naked eye. The ovaries of these triploid females contained oocytes at different growing and maturing stages, including the oocytes of 4 principal stages: primary growth, yolk vesicle formation, true vitellogenesis and maturation. Some ovarian lamellae filled with simultaneously dividing cells of meiotic prophase were also found in the fourth type of ovaries. A maturing oocy-te with peculiar structure was found within ovary of one triploid female. The peculiar structure was encircled by a layer of membrane and was deeply stained as purplish red color by De-lafield's haematoxylin. A large number of colored chromosome-like substances were observed within the peculiar structure.Furthermore, one triploid female with normally developed ovary filled with normal eggs was found in about more than 500 triploid fishes.The results obtained from testicular histological and cytological investigation seem to indicate that the obstacles of spermatogenesis in male triploid transparent colored crucian carp occurred mainly at three stages, i.e. the stage of transition from primary spermatocytes to commencement of meiosis, the stage from meiosis to formation of spermatids and the stage of metamorphosis from spermatids to spermatozoa. The mechanism about the development diversification of ovaries among the triploid females were briefly discussed. The evidences suggested that the diversification might be related to the influence of hydrostatic pressure shock on chromosomes and genes, especially the latter. Various genes controlling ovari
出处
《动物学报》
SCIE
CAS
CSCD
1991年第3期297-304,共8页
ACTA ZOOLOGICA SINICA
基金
中国科学院青年科学基金(862001)
中国科学院院长基金
关键词
三倍体鱼
水晶彩鲫
性腺
Artificial triploid fish, Tetis, Ovary, Histological cytology, Gametogene-sis.
