Sperm nuclear expansion and meiotic maturation in normal and gynogenetic eggs of the scallop, <Emphasis Type="Italic">Chlamys farreri</Emphasis>

Sperm nuclear expansion, meiosis and the association of the male and female pronuclei leading to the four-cell stage in normal Chlamysfarreri eggs were observed under a fluorescence microscope. The effects of ultraviolet （UV） irradiation on the fertilizing sperm were also examined. Both normal and UV-irradiated sperm nuclei enlarged at three distinct phases （phase A, metaphase I; phase B, polar body formation; and phase C, female pronuclear development and expansion） that were temporally correlated with meiotic process of the maternal chromosomes. Sperm nuclei underwent a rapid, initial enlargement during phase A, but condensed slightly during phase B, then re-enlarged during phase C. The effects of UV irradiation were not apparent during transformation of the sperm nucleus into a male pronucleus, and there was not any apparent effect on meiotic maturation and development of the female pronucleus. However, the rate of expansion of the UV-irradiated sperm nuclei and the size of male pronuclei were reduced apparently. Unlike the female pronucleus, the male pronucleus derived from sperm genome inactivated by UV irradiation did not form chromosomes, but became a dense chromatin body （DCB）. At mitotic anaphase, DCB did not participate in the karyokinesis of the first cleavage as evidenced by chromosomal nondisjunction, demonstrating the effectiveness of using UV irradiation to induce gynogenetic scallop embryos.     

卵巢浆浆液癌癌中砂粒粒体矿矿化的矿矿物学学特征征

卵巢癌的卵巢癌伴浆液癌中常提示有较好明砂粒体矿化灶的矿物砂粒体泽,最常见液性乳头状化机制尚不难性导致国择浆液性卵象,利用偏射电子显微对砂粒体矿研究。从北京显砂粒体矿Leica超薄于普通载(Nikon L20mm×20显微镜(Q是女性生殖有钙化(刘见砂粒体钙生存的预后化与癌变之学特征进行呈粒状,常于甲状腺乳囊腺癌中明确,样品内外研究都     

长期低温条件对海蜇横裂生殖的影响

采用实验生态学手段,研究了长期低温条件对海蜇螅状体保育存活率和横裂生殖效率的影响.结果表明:海蜇横裂生殖后的螅状体经过1a的长期低温保育后,其存活率约33%,显著高于不采用低温条件保育螅状体的成活率.横裂生殖后的螅状体经长期低温保育后仍具有横裂生殖能力,碟状幼体释放率仍然高达15%,其横裂生殖能力可与正常螅状幼体相比.采用长期低温环境条件,可以有效地提高海蜇螅状体的存活率,并可以恢复促进海蜇的横裂生殖效率,相关结果可以为海蜇苗种生产提供参考和指导.     

Temperature Effect on the Life History of Three Types of Brachionus calyciflorus Females

The effect of temperature on the life history characteristics of amictic females ( AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated individual cultures at 20℃ ,25℃ and 30℃ , and with algae Scenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cvcle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20℃, were the longest, and the number of eggs produced by an UMF at 30℃ was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF.Only temperature influenced significantly the mean life-span of the three types of females. The duration of juvenile,reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF.     

多世代培养蒙古裸腹溞生长与生殖的比较

本文对蒙古裸腹（MoinamongolicaDaday）一休眠卵所孵化的孤雌生殖个体进行连续15个世代的培养,最终统计、比较不同世代的生长与生殖。结果表明：（1）蒙古裸腹孤雌生殖雌体的体长与日龄呈正对数相关关系,其平均寿命为8．4±5．5d,87．5％的寿命在两周以内。蒙古裸腹产幼前发育期通常为6～7d;一生平均繁殖1胎,每胎产8．2±4．0只幼体。（2）不同世代蒙古裸腹的平均生殖量和净生殖率（R0）随世代数的增加而呈现出衰退趋势;其生长、繁殖次数、内禀增长能力（rm）、世代平均周期（T）以及增长的周限速率（λ）随世代数的不同而有所波动,但与世代数没有明显的相关性。     

联苯菊酯暴露对雄性褐菖鲉精巢发育的干扰

Bifenthrin(BF) is a pyrethroid insecticide that is widely used in agriculture, horticulture, and for residential purposes. However, few studies addressing the reproductive toxicity of BF on fishes are available. The present study was conducted to investigate the effects of BF on testicular development in Sebastiscus marmoratus and to gain insight into its mechanism. After exposure to 1, 10 and 100 ng/L BF for 50 days, there was a reduced number of mature sperm and an abundance of the late stages of spermatocysts in the testes. The levels of 17β-estradiol and testosterone were decreased significantly after BF exposure. The activity of caspase-3 was increased in a dosedependent manner after BF exposure, TUNEL assay indicated that BF exposure resulted in the occurrence of apoptosis in the testes, which might be main reason for the inhibition of spermatogenesis.     

沙拐枣属4种植物同地栽培开花物候与生殖特性比较

 选取吐鲁番沙漠植物园同地栽培的沙拐枣属（Calligonum L.）4种植物,在群体、个体、枝条、同化枝和单花5个水平上,2007—2009年连续进行开花物候和生殖特性研究。主要结论如下:①4 a中4种沙拐枣的各项开花物候参数相似,2010年各项物候参数明显推迟,4月中旬的温度是影响开花时间的主要因素。②在个体和群体水平上,泡果沙拐枣(C. calliphysa)和红皮沙拐枣(C. rubicundum)相似,表现为“集中开花模式”,花期重叠指数较高,达79.99％～100%,密刺沙拐枣(C. densum)和艾比湖沙拐枣(C. ebinuricum)相似,表现为“持续开花模式”,花期重叠指数较高,为51.79％～79.82%,4个种的共有重叠期较短。③在枝条水平上,泡果沙拐枣和红皮沙拐枣开花物候特征也表现相似,为开放集中,开花振幅高;密刺沙拐枣和艾比湖沙拐枣表现相似,为开放时间长,开花振幅低。④在同化枝水平上,开花数、持续时间和同化枝长度在种间和年际间均有不同程度的差异,同化枝水平的始花位置种间也具有差异,表现为泡果沙拐枣、红皮沙拐枣、密刺沙拐枣始花位置主要集中在第2、3关节,艾比湖沙拐枣通常在第4关节。⑤在单花水平上,泡果沙拐枣、红皮沙拐枣、密刺沙拐枣、艾比湖沙拐枣的单花开放持续时间分别为(9.14±0.26)h、(12.95±1.07)h、(10.69±1.75)h、(22.40±1.92)h。⑥在同化枝水平上,4种沙拐枣开花高峰期的坐果率较高,开花数目与坐果数显著正相关;坐果数和开花位置有一定的关系,表现为着生花多的关节坐果数也高,其中,泡果沙拐枣的花和果主要集中在第2、3、4关节,红皮沙拐枣集中在第3、4、5关节,密刺沙拐枣集中在第2、3、4、5关节,艾比湖沙拐枣集中在第4、5、6关节。     

绵刺(Potaninia mongolica)无融合生殖的胚胎学研究

研究绵刺（Potaninia mongolica)的胚胎发育过程，首次报道其有性生殖模式为无融合生殖的体细胞无孢子生殖（Apospory)，由合点端珠心细胞形成3－7个无孢子孢原，孢原细胞体积增大，形成单核胚囊，后经3次有丝分裂形成多个八核七细胞的成熟胚囊，胚囊发育属山柳菊型，但一般只有一个胚囊可发育出成胚，胚囊发育过程中具极性，由合点端向珠孔端延伸，未观察到有性生殖胚囊的发育。     

扁平钳蛤性腺发育的组织学研究

通过石蜡切片对扁平钳蛤进行性腺发育组织学观察,结果表明,扁平钳蛤雌雄性腺的发育都可分为增殖期、生长期、成熟期、排放期和休止期5个时期。增殖期为滤泡形成期,出现了精原细胞和卵原细胞,贴近滤泡壁分布;在生长期,性腺面积、滤泡数目和生殖细胞数目都明显增大,卵母细胞和精母细胞形成;成熟期雌性滤泡内充满卵细胞,其生发泡透亮,核仁清晰可见,雄性滤泡内充满着蓝紫色的精子,精子尾部聚集在滤泡中央,呈鲜红色;排放期滤泡破损,卵细胞和精子排放,性腺面积减小;休止期滤泡腔萎缩,基本无生殖细胞残留。扁平钳蛤生殖周期为一年,5—6月处于性腺发育增殖期;7—10月性腺进入繁殖期,包括生长期、成熟期和排放期;11月进入休止期;其他月份性腺基本不发育。