Angiotensins stimulate in vitro ovulation and contraction of brook trout (Salvelinus fontinalis) follicles

The effects of salmon angiotensin I (sAI) and human angiotensin II (hAII) on in vitro ovulation of preovulatory (preOV) brook trout (Salvelinus fontinalis) follicles were investigated. Both angiotensins increased levels of ovulation above that in controls after 12 hours of incubation. The increase was statistically significant in incubates with greater than 1 M hAII. The effects of the angiotensins on follicle contraction were also studied indirectly by measuring the decrease in weight of punctured follicles taken prior to germinal vesicle breakdown. At 1 M, both angiotensins significantly decreased the weight of punctured follicles after 16 hours of incubation. The angiotensin-stimulated decrease in weight was not blocked by indomethacin (10 g/ml), indicating that follicle contraction was not prostaglandin-dependent. The data indicate that angiotensins might be directly involved in brook trout ovulation and the stimulatory effects of angiotensins on ovulation may be attributed to their effects on follicle contraction.This work was supported by NIH grant #HD25924-02.     

Effects of unilateral ovariectomy on recruitment and growth of follicles in the rainbow trout,Oncorhynchus mykiss

Virgin female rainbow trout, Oncorhynchus mykiss, were unilaterally ovariectomised at various stages of ovarian development to investigate the effect of the removal of one ovary on subsequent recruitment and growth of follicles in the remaining ovary. The right ovary was removed from groups of 12–15 fish, 12, 7 and 4 months before they were due to ovulate, and the gonadosomatic index and follicle number and size determined just prior to ovulation. There were no differences in fecundity or follicle size in fish unilaterally ovariectomised at 12 and 7 months prior to ovulation compared to the controls. However, in the females unilaterally ovariectomised 4 months prior to ovulation, the remaining ovary either had the normal number of follicles for a single ovary but of a significantly larger size than follicles in the controls, or alternatively had almost 70% more than the normal number of vitellogenic follicles but comprising two distinctly different size populations. Differences in plasma oestradiol-17β concentrations at the final sample were seen only in females unilaterally ovariectomised 4 months prior to ovulation, where the levels were significantly lower than both the sham operated and control fish (p < 0.05). These data show that in the rainbow trout, complete compensatory ovarian hypertrophy following unilateral ovariectomy can occur throughout a major part of ovarian development, but that follicle recruitment is limited to stages up to (and therefore fecundity is determined by) mid-vitellogenesis.     

Morphological characterization and notes on the life cycle of a newly discovered variant of Loma salmonae (Putz, Hoffman & Dunbar) from a natural infection of chinook salmon, Oncorhynchus tshawytscha (Walbaum)

Two variants of Loma salmonae occur in net-pen reared chinook salmon, Oncorhynchus tshawytscha. The typical variant (OA) has a host specificity for salmonids of the genus Oncorhynchus whereas the atypical variant (SV) has a host specificity for brook trout, Salvelinus fontinalis, and in this study, the ultrastructure of the two are compared. In fish at 8 weeks post-exposure xenomas of the SV variant have a very high proportion of mature spores compared with other developmental stages, while in xenomas of the OA variant there are fewer spores and many other developmental stages. Spores of the SV variant had up to 20 turns of their polar tube whereas those of the OA variant only had 17. Furthermore, the spores of the SV variant were significantly larger than those of the OA variant. The sporophorous vesicle for both variants appears to form around a sporogonial plasmodia, which results in many spores developing within the vesicle.     

中华绒螯蟹血淋巴细胞的超微结构

改进常规血液细胞电镜制样技术 ,直接取中华绒螯蟹 (Eriocheirsinensis)血淋巴液固定、脱水、包埋、电镜观察。结果显示 ,中华绒螯蟹血淋巴具有 3类细胞 ,即无颗粒细胞、小颗粒细胞和大颗粒细胞。其中 ,无颗粒细胞的核质比最大 ,异染色质高度浓缩、边缘化 ,几乎没有常染色质 ,胞质内线粒体数目相对较多 ,与高等动物的中幼红细胞结构很相似 ,该细胞数目在中华绒螯蟹血淋巴中最多 ,可能担负着血液的能量转换功能 ;小颗粒细胞核内常染色质较多 ,内质网、高尔基体发达 ,胞质中存在 0 .2～ 0 .4 μm的电子致密颗粒 ,而且胞质中有许多大小不一的空泡 ,细胞表面有许多突起似伪足 ,类似高等动物的单核细胞 ,可能具有吞噬和消化异物的功能 ;大颗粒细胞胞质中的颗粒较大 ,直径 1.4～ 2 .0 μm ,胞质中具空泡 ,细胞表面也常见伪足突起 ,类似高等动物的嗜酸性粒细胞     

条浒苔蛋白核超微结构和Rubisco及其活化酶分子定位

研究了条浒苔蛋白核超微结构及其Rubisco和Rubisco活化酶金相免疫分子定位。超微结构显示,条浒苔细胞具有形态及组成相同的1～2个蛋白核,每个蛋白核被淀粉鞘所包围。蛋白核中央均有1条由1个类囊体构成的纵向孔道,并有时局部特别膨大。纵向孔道两端与叶绿体基质相连接。小球藻Rubisco抗体对条浒苔Rubisco的Western印迹图谱显示仅为1条带,其位置与SDS-PAGE电泳图谱上的主带相对应,分子量大约为55kD。金相免疫分子定位的结果显示,条浒苔Rubisco金标颗粒主要分布于叶绿体的蛋白核(71.86%)和淀粉鞘(27.94%)部位中,按面积密度计算二者总和占99.8%,极少分布在叶绿体类囊体和基质中(0.2%)。Rubisco活化酶分子定位也显示其主要分布于蛋白核和淀粉鞘中。这些结果均表明条浒苔蛋白核(及淀粉鞘)与单细胞绿藻的蛋白核相同,具有光合作用功能。条浒苔Rubisco初始活性和总活性的测定结果表明,其活化率较高,高达77.62%。     

Role of oocyte‐derived paracrine factors in follicular development

Mammalian oocytes secrete transforming growth factor β (TGF‐β) superfamily proteins, such as growth differentiation factor 9 (GDF9), bone morphogenetic protein 6 (BMP6) and BMP15, and fibroblast growth factors (FGFs). These oocyte‐derived paracrine factors (ODPFs) play essential roles in regulating the differentiation and function of somatic granulosa cells as well as the development of ovarian follicles. In addition to the importance of individual ODPFs, emerging evidence suggests that the interaction of ODPF signals with other intra‐follicular signals, such as estrogen, is critical for folliculogenesis. In this review, we will discuss the current understanding of the role of ODPFs in follicular development with an emphasis on their interaction with estrogen signaling in regulation of the differentiation and function of granulosa cells.     

Sperm maturation and capacitation in the open thelycum shrimp Litopenaeus (Crustacea: Decapoda: Penaeoidea)

Transmission electron microscopy was applied to sperm removed from males and females belonging to Litopenaeus vannamei, L. stylirostris and L. occidentalis. It was discovered that a region named filamentous meshwork (FM), located between the nucleus and the hemispherical cap, develops differently in these three closely related species. In L. vannamei, the FM is synthesized in the male reproductive system, but seems to complete its formation after mating. In L. stylirostris, the FM region was not present in spermatophores collected from males or in sperm from the thelycum. In L. occidentalis, the FM region is fully developed in male sperm. It is suggested that completion of the FM is required for acrosome maturation, and the process continues after mating in some species of Litopenaeus. In vitro induction of the acrosome reaction in sperm from males and females of L. occidentalis demonstrated for the first time that reactivity is significantly superior in sperm cells that have been attached to the open thelycum for some hours, as compared to sperm in males (prior to transfer). This finding suggests that matured sperm cells of L. occidentalis become capacitated to react against egg water after mating.     

漂白粉蓄积对日本蟳4种组织超微结构的影响

根据急性毒性试验确定了漂白粉对日本蟳的安全质量浓度为0．6mg／L，采用透射电镜技术研究了该质量浓度下漂白粉蓄积对日本蟳4种组织细胞(肌肉、鳃、肝胰脏和心脏)超微结构的影响。试验结果表明：漂白粉主要损伤日本蟳的鳃和肝胰脏，其次是心脏，肌肉基本无损害。鳃细胞的损害表现为鳃丝水肿，细胞器溶解，角质层变薄，线粒体、内质网的肿胀、解体；肝胰脏细胞的主要损害特征为肝管微绒毛减少、线粒体水肿解体、内质网扩张、细胞核空泡化、核膜水肿、脂肪滴增加；心脏细胞的毒理变化为线粒体内嵴肿胀、瓦解，肌原纤维不规则，内质网溶解。安全质量浓度的漂白粉经16d蓄积后，虽没有导致日本蟳死亡，但已对其体内的鳃、肝胰脏、心脏等组织细胞的超微结构产生了不同程度的影响。     

墨兰品种健叶与感染胶孢炭疽菌病叶的表面结构及氨基酸含量比较

【目的】明确墨兰品种健叶与感染胶孢炭疽菌病叶的叶片表面结构及氨基酸含量的变化,为墨兰品种抗病性利用提供理论依据。【方法】以中感墨兰品种太平洋为样本,利用扫描电镜观察感染胶孢炭疽菌墨兰叶片表面超微结构的变化;以不同感病水平墨兰品种金华山(低感品种)、太平洋(中感品种)和万代福(高感品种)为样本,利用氨基酸自动分析仪检测感病墨兰叶片除色氨酸外其余17种氨基酸含量的变化。【结果】中感墨兰品种太平洋感染胶孢炭疽菌后,叶片表面超微结构发生明显改变,蜡质层破裂,表皮细胞受损,气孔功能渐失,严重影响叶片功能与整体观感。3种不同感病水平的墨兰品种感染胶孢炭疽菌后,氨基酸种类未发生改变,但总氨基酸含量均明显提高,其中以低感墨兰品种金华山提高最多,高感墨兰品种万代福提高最少,3个品种间差异显著;各种氨基酸在不同感病水平墨兰品种间的变化量差异显著,甲硫氨酸(Met)在高感墨兰品种中变化量最大,胱氨酸(Cys)在中感墨兰品种中变化量最大,天门冬氨酸(Asp)、组氨酸(His)和赖氨酸(Lys)在高感与低感墨兰品种中变化量较大,甘氨酸(Gly)和苏氨酸(Thr)在中感与低感墨兰品种中变化量较大,其他10种氨基酸则均在低感墨兰品种中变化量最大;丙氨酸(Ala)、谷氨酸(Glu)、苯丙氨酸(Phe)、缬草氨酸(Val)、丝氨酸(Ser)、精氨酸(Arg)和苏氨酸(Thr)7种氨基酸是影响墨兰品种感病强弱的主要氨基酸种类。【结论】胶孢炭疽菌侵染影响墨兰品种叶片表面结构和氨基酸含量,营养物质变化量与墨兰品种感病水平高低有关。     

干旱胁迫对3种苹果属植物叶片解剖结构、微形态特征及叶绿体超微结构的影响

采用树脂包埋块半薄/超薄切片技术,通过光镜（LM）、扫描电镜（SEM）和透射电镜（TEM）方法,研究了轻度、中度和严重干旱胁迫对楸子（Malus prunifolia）、新疆野苹果（M. sieversii）和平邑甜茶（M. hupehensis）叶片组织解剖结构、表皮微形态特征（气孔密度、大小及角质层厚度）及叶绿体超微结构的影响。光镜观察结果表明,与对照相比,干旱胁迫条件下3种苹果属植物叶片厚度、栅栏组织厚度及叶肉组织结构紧密度（CTR）都显著减小（P＜0.05）,而海绵组织厚度与叶肉组织结构疏松度（SR）均显著增加（P＜0.05）。扫描电镜观察结果显示,3种苹果属植物幼叶气孔密度在干旱胁迫下显著增大（P＜0.05）,而气孔宽度、开张比及其开张度明显下降。透射电镜观察结果表明,在干旱胁迫下,楸子和新疆野苹果上下角质层厚度逐渐增加,而平邑甜茶的随干旱胁迫程度增加呈先增后减的变化;在轻度和中度水分胁迫下,叶绿体膨胀变形,淀粉粒变小消失,基粒片层排列松散减少,类囊体腔扩大;在严重胁迫条件下,叶绿体膨胀近圆形,叶绿体膜破裂,类囊体严重泡化开始解体。与平邑甜茶相比,严重水分胁迫下楸子和新疆野苹果叶绿体超微结构损伤较小,能较好地保持细胞结构的完整性。