Identification of a putative tetrasporophyte-specific gene in <Emphasis Type="Italic">Gracilaria lemaneiformis</Emphasis> (Gracilariales,Rhodophyte)

A putative tetrasporophyte-specific gene, designated as SSH466 (GenBank accession No. DQ019223), was one of the genes identified in this work using suppression subtractive hybridization (SSH) method in Gracilaria lemaneiformis. The full length of the gene was obtained using SMART RACE strategy. Sequence analysis revealed that the gene had 1 019 nucleotides, including an open reading frame of 498 nucleotides encoding 166 amino acid residues, 158 nucleotides of 5′ untranslated region and 363 nucleotides of 3′ non-coding region. Protein motif and secondary structure prediction showed that there existed a transmembrane domain with a unique β-sheet. Thus, SSH466 protein might be a cross-membrane protein. Sequence homology search in the public GenBank databases did not reveal any significant match with SSH466. Virtual Northern blot analysis confirmed that it was a tetrasporophyte-specific gene.     

不同积温情况下栉孔扇贝雌性生殖腺中磷脂、核酸及水分的含量变化

为研究某些生化组分与栉孔扇贝(Chlamys farreri)雌性生殖腺成熟情况的关系,在亲贝促熟的后期,对不同积温情况下栉孔扇贝雌性生殖腺中的磷脂、核酸及水分的含量进行测定。结果表明,磷脂含量、RNA/DNA值及水分含量均随着积温升高(从210℃到300℃)而增加,但成熟的卵子一经产出后,雌性生殖腺中的磷脂含量、RNA/DNA值及水分含量均降到最低。组织切片的结果表明雌性生殖腺中的卵子在成熟过程中体积明显增大,以至于滤泡中充分成熟的卵子被挤压成不规则形状,细胞核的核膜和核仁在卵子排出去之前一般都消失。成熟卵子产出后的滤泡中出现空泡,未能排出的卵子部分被滤泡吸收,形态模糊。     

基于女性地理学视角的中国城市女性居民社会-生活空间研究综述

城市化的快速发展导致当代中国城市社会问题日益复杂和多元化。在以人为本、追求社会公平、公正的"新人本主义"发展观思潮下,学术界需要对城市女性这样一个重要的亚群体单元加以关注,以提高城市中女性群体生活质量。女性地理学在西方国家经过近40年的发展,从以人为本、重视差异的后现代人本主义思潮中汲取丰富的养分,在理论以及实践上都趋于成熟。尝试性从女性地理学视角回顾目前中国多元化社会、快速城市化发展下的城市女性居民社会-生活空间问题的现有研究成果,分别从城市女性家庭行为空间、城市女性工作行为空间、城市女性购物行为空间、城市女性休闲娱乐空间4个方面进行梳理总结以期得出相关启示。     

《左传》女性形象探微

左传>在中国文学史上第一次塑造了众多走进国家政治生活、参与国家事务的女性形象,全面、真实地展现了她们在历史事件中的地位与作用.这一时期,女性能够走进国家政治生活、参与国家事务,主要有历史环境、政治联姻、自身因素等方面的原因.这些女性形象具有如下特点:多具杰出的政治才干、强烈的权力意识及鲜明的宗国观念.     

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.     

Observation of female gamete (Carpogonia) germination of Porphyra yezoensis and P. oligospermatangia

Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture ofPorphyra. Study on samples of wild and cultivatedPorphyra yezoensis andP. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells ofPorphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing leafy thalli. This project was sponsored by the NSFC (No. C-0205-05-39770593)     

大磷虾临产个体卵母细胞数量及组成特点研究

本文利用１９８９／１９９０至１９９２／１９９３年度南大洋考察于普里兹湾邻近海域所获大磷虾标本，分析了南极磷虾临产个体卵母细胞的数量及与体长、体重的关系，以及卵母细胞的组成和发育特点。结果表明：卵母细胞的数量（怀卵量）波动在２１８８－９２６３个之间，平均为５２８３个；连续４年的平均怀卵量没有显著差异；怀卵量与体重呈较好的正相关关系；与眼径及尾肢长度的相关关系较差；卵母细胞的组成可分为４个不同的发育期，各发育期数量的比例不尽然相同，似与卵巢发育程度和产卵时间有关。     

Different sperm allocation strategies in two populations of the semiterrestrial crab Neohelice granulata (Brachyura,Grapsoidea, Varunidae)

Sperm reserves are costly to produce and so the development of different sperm allocation strategies may be advantageous. Knowledge of sperm allocation strategies is important from an evolutionary perspective because they contribute to characterize mating systems. However, population differences in sperm allocation strategies of the same species have rarely been assessed. Here, we studied the male sperm allocation strategies in two different populations of Neohelice granulata in Mar Chiquita Lagoon (MCL) and San Antonio Oeste (SAO), Argentina. We found that the quantity of ejaculate transferred by N. granulata males depended on different factors such as male size and female receptivity duration, while it was independent of female size, at both study areas. Regarding the operational sex ratio factor, the amount of ejaculate transferred depended on it in MCL but not in SAO. Thus, N. granulata males may have the capacity to regulate the quantity of ejaculate transferred based on individual factors such as their own size and female receptivity duration, and population factors such as operational sex ratio, which varies in the two populations studied.