Results 41 to 50 of about 17,804 (167)

Fluctuating salinity during development impacts fish life histories

open access: yesJournal of Animal Ecology, Volume 94, Issue 9, Page 1848-1865, September 2025.
Global freshwater ecosystems are increasingly threatened by salinisation. Salinity levels not only rise but also fluctuate due to extreme climate events and human activities. This study shows that stable elevated salinity accelerates reproduction in a freshwater fish, but fluctuations in salinity reduce reproductive output, with sex‐specific effects on
Meng‐Han Joseph Chung   +4 more
wiley   +1 more source

稀有鮈鲫产卵频次和卵子发育的研究

open access: yes, 1999
对室养条件下20尾雌性稀有 鲫的产卵频次、成熟卵巢卵径分布及卵子补充过程进行了研究。产卵间隔中卵径分布呈现不同的峰值,卵母细胞成熟是分批的,Ⅴ期卵巢中MA、RE卵母细胞的数量代表了即将进行的一次产卵的产卵量;卵子补充速度快,成熟卵巢每隔数天可发育成熟一批卵,一级贮备库在12─33d即更新一次,不同发育时期卵母细胞的补充是连续的。对273批 产卵进行了统计,每尾雌鱼平均4.5d产卵一次,平均批产卵量265.6粒。稀有 ...
王剑伟
core  

SHOT GLASS, an R2R3‐MYB transcription factor, promotes gemma cup and gametangiophore development in Marchantia polymorpha

open access: yesNew Phytologist, Volume 247, Issue 6, Page 2678-2696, September 2025.
Summary Many plants reproduce asexually by generating clonal progeny from vegetative tissues, a process known as vegetative reproduction. This reproduction mode contrasts with sexual reproduction, which enhances genetic diversity. The bryophyte Marchantia polymorpha L.
Yuuki Sakai   +6 more
wiley   +1 more source

エダアシクラゲの卵サイズの計測

open access: yes, 2017
エダアシクラゲ(Cladonema pacificum)には、暗期から明期への移行(明刺激)によって卵や精子を放出する 明タイプと、逆に明期から暗期への移行(暗刺激)によって放出する暗タイプが存在する。明タイプと暗タイプで は、雌の放出する卵のサイズが異なると考えられているが、詳しくは分かっていない。今回、画像解析ソフトであ る ImageJ を用いた卵サイズの計測方法について検討するとともに、両タイプの親および子から得られた卵のデ ータを解析した。departmental bulletin ...
1657   +5 more
core  

人类激肽释放酶基因6在卵巢恶性肿瘤中的表达及其机制研究

open access: yesZhongguo shiyan zhenduanxue, 2014
目的研究人组织激肽释放酶基因6(KLK6)mRNA和蛋白在卵巢肿瘤组织中的表达水平,探讨其在卵巢恶性肿瘤中的作用机制。方法应用RT-PCR和免疫组化SP法分别检测在正常的卵巢组织、卵巢的良性肿瘤、卵巢的交界性肿瘤及卵巢的恶性肿瘤组织中KLK6的mRNA表达及蛋白的表达,探讨该基因的表达与卵巢恶性肿瘤患者的临床病理特征关系。结果本研究显示,在卵巢癌组织中,KLK6mRNA的表达水平与正常卵巢组织相比,显著增高;卵巢癌组织中KLK6蛋白的阳性表达率为69.4%,与正常卵巢组织(13.3%)、良性卵巢肿瘤 ...
成志强   +6 more
doaj  

Faeces, Feathers and Flight: Understanding of Escape Behaviour in Incubating Eurasian Woodcocks (Scolopax rusticola)

open access: yesEcology and Evolution, Volume 15, Issue 7, July 2025.
Using a large dataset of nest photographs from open‐source platforms, we investigated defecation and fright moulting in incubating Eurasian woodcocks (Scolopax rusticola), finding defecation in 54% of nests and feathers in 67%. We suggest these behaviours may aid the female's escape rather than protect the nest, and highlight the importance of ...
Martin Sládeček   +3 more
wiley   +1 more source

银鲫受精卵中卵黄粒和线粒体的超微结构变化

open access: yes, 1986
电镜观察到雌性银鲫肝脏中正在形成的卵黄物质具有晶形主体结构,银鲫卵的卵黄粒内无晶形主体,第一次卵裂前的受精卵卵黄粒内有两种形式的空泡。一种是一些中空的小空泡;另一种是一个大的空泡,泡内含有线粒体和颗粒状的核糖体,泡的边缘有片层状的类脂物。受精卵中的线粒体内部结构多样,有些含有颗粒状物 ...
孙建民,梁绍昌,孙晓白,袁秀平,卞小宇,柯远发
core  

组蛋白去乙酰化酶1在人上皮性卵巢癌组织中的表达

open access: yesZhongguo shiyan zhenduanxue, 2011
目的探讨上皮性卵巢癌组织中组蛋白去乙酰化酶1(HDAC1)的表达及临床意义。方法采用免疫组化SP法,测定40例上皮性卵巢癌组织2、0例交界性卵巢肿瘤,20例卵巢良性肿瘤以及10例正常卵巢组织中HDAC1的表达。结果 HDAC1在在卵巢组织中的阳性表达H-score评分均随组织异型程度的增加而逐渐增高,即正常卵巢组织(1.300±0.948 68)和卵巢良性肿瘤(1.750±0.786 40)
贾妍   +4 more
doaj  

Interpregnancy interval and risk of recurrence following tubal ectopic pregnancy: retrospective cohort study from UK tertiary center

open access: yesUltrasound in Obstetrics &Gynecology, Volume 66, Issue 1, Page 89-95, July 2025.
ABSTRACT Objective To assess the effect of interpregnancy interval on the odds of recurrence of tubal ectopic pregnancy (TEP) following expectant or surgical management. Methods This was a retrospective cohort study conducted at a tertiary early pregnancy unit (EPU) in London, UK.
W. M. Dooley   +6 more
wiley   +1 more source

罗氏沼虾卵母细胞细胞器与卵黄发生的关系

open access: yes, 1999
作者研究了罗氏沼虾卵母细胞细胞器与卵黄发生的关系。细胞核物质通过核孔与细胞质进行物质交换,由核仁而来的核糖体前体物在细胞质中形成大量的核糖体。一部分核糖体附着在内质网囊泡的膜上,形成粗糙型内质网。粗糙型内质同囊泡具有合成和运输卵黄物质的功能。一部分核糖体是游离的,它们可在细胞质中合成致密蛋白质小颗粒,随后这些颗粒逐渐聚集融合成致密的卵黄粒。溶酶体可吞噬这些由游离核糖体形成的蛋白质颗粒团或其它膜状物,并将它们消化、融合,从而形成大的卵黄粒。部分线粒体参与了卵黄粒的合成并最终演变成卵黄体 ...
王玉凤,堵南山,赖伟
core  

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