Requirement of phospholipase Cdelta4 for the zona pellucida-induced acrosome reaction

Several phospholipase C (PLC) isoforms have been found in male and female mammalian gametes, and splicing isoforms of PLCdelta4 are predominantly expressed in testis. Here we report that male mice in which the PLCdelta4 gene had been disrupted either produced few small litters or were sterile. In vitro fertilization studies showed that insemination with PLCdelta4-/- sperm resulted in significantly fewer eggs becoming activated and that the calcium transients associated with fertilization were absent or delayed. PLCdelta4-/- sperm were unable to initiate the acrosome reaction, an exocytotic event required for fertilization and induced by interaction with the egg coat, the zona pellucida. These data demonstrate that PLCdelta4 functions in the acrosome reaction that is induced by the zona pellucida during mammalian fertilization.     

红小豆胚胎学研究Ⅱ.大孢子发生与雌配子体发育

为给红小豆栽培、育种提供理论依据,系统研究了红小豆大孢子发生,雌配子体发育过程。结果表明,孢原细胞起源于紧接珠心表皮之下的珠心细胞,几个孢原细胞平周分裂向内形成造孢细胞,其中只有一个发育成大孢子母细胞,原珠心,线型四分体,近合端一个形成单核胚囊。胚囊发育为蓼型,开花前两极核融合成次生核,反足细胞早期退化。     

矮生菜豆胚珠和胚囊的发育

本文观察了矮生菜豆（Ｐｈａｓｅｏｌｕｓｖｕｌｇａｒｉｓｖａｒ．ｈｕｍｉｌｉｓ）胚珠和胚囊的发育。通常大孢子母细胞减数分裂形成三个直线排列的细胞，合点端大孢子具功能，功能大孢子发育成蓼形胚囊。成熟胚囊中，三个反足细胞已消失。两助细胞分别在受精前后退化。两极核受精前融合或不融合。卵细胞的细胞质中有少量淀粉粒。珠孔端及合点端的胚囊壁均具发达的壁内突。成熟胚珠为弯生型、双珠被、厚珠心。四核胚囊形成后，淀粉粒依次出现在珠被组织，珠心组织及中央细胞中，至开花前２～３天达到高峰。开花前一天，珠心和中央细胞中淀粉粒开始减少。     

林蛙输卵管糖蛋白的纯化方法研究

林蛙输卵管糖蛋白是由输卵管上皮细胞分泌的一类高分子量的特异性蛋白质,对配子的成熟和运输、受精以及早期胚胎发育具有重要影响。长白山林蛙输卵管糖蛋白具有特殊药用价值和广泛的应用前景,目前对其提取和纯化工艺的研究也比较深入。简述输卵管糖蛋白的性质及生物学功能,着重论述分离纯化方法。     

短生育期‘骄阳’百合的育性分析及2n配子诱导

  目的  探究百合远缘杂种‘骄阳’百合的花粉与雌配子的育性,通过诱导提高、恢复配子的育性,在多倍体优秀种质渗入育种中加以应用。  方法  以‘骄阳’百合为试验材料,通过醋酸洋红染色法观测花粉育性,观察其花粉母细胞减数分裂进程,采用秋水仙素注射法诱导2n配子,通过与兰州百合杂交以验证2n花粉育性;为探究雌配子的育性,以‘骄阳’百合为母本与兰州百合杂交,通过直接授粉法与切割柱头授粉法,以子房膨大率、有胚种子数、发芽率加以衡量雌配子的育性。  结果  ‘骄阳’百合在花粉母细胞减数分裂过程中存在染色体与细胞质不均等分离的现象,产生大量非整倍体小孢子,不能发育成可育的花粉,雄配子没有育性。通过秋水仙素处理后,产生部分有活力的2n花粉,适宜的秋水仙素诱导浓度为0.10%,最高诱导率为86.00%,与兰州百合杂交时未能结实。当‘骄阳’百合作母本与兰州百合杂交时可以结实,雌配子具有育性并产生非整倍配子,通过切割柱头法授粉,子房膨大率由11.91%提高至65.02%。  结论  ‘骄阳’百合的花粉不育,利用秋水仙素可以诱导2n花粉的产生并恢复一定的育性;而雌配子可育,作为母本杂交能获得有胚种子并发芽。研究‘骄阳’百合的育性有助于进一步对不同杂种系间百合进行种质渗入,对培育综合性状优良的百合新品种具有重要价值。      

Intercellular communication in the mammalian ovary: oocytes carry the conversation

The production of functional female gametes is essential for the propagation of all vertebrate species. The growth of oocytes within ovarian follicles and their development to mature eggs have fascinated biologists for centuries, and scientists have long realized the importance of the ovarian follicle's somatic cells in nurturing oogenesis and delivering the oocyte to the oviduct by ovulation. Recent studies have revealed key roles of the oocyte in folliculogenesis and established that bidirectional communication between the oocyte and companion somatic cells is essential for development of an egg competent to undergo fertilization and embryogenesis. The challenge for the future is to identify the factors that participate in this communication and their mechanisms of action.     

Synthetic clonal reproduction through seeds

Cloning through seeds has potential revolutionary applications in agriculture, because it would allow vigorous hybrids to be propagated indefinitely. However, asexual seed formation or apomixis, avoiding meiosis and fertilization, is not found in the major food crops. To develop de novo synthesis of apomixis, we crossed Arabidopsis MiMe and dyad mutants that produce diploid clonal gametes to a strain whose chromosomes are engineered to be eliminated after fertilization. Up to 34% of the progeny were clones of their parent, demonstrating the conversion of clonal female or male gametes into seeds. We also show that first-generation cloned plants can be cloned again. Clonal reproduction through seeds can therefore be achieved in a sexual plant by manipulating two to four conserved genes.     

Gametes from embryonic stem cells: a cup half empty or half full?

When first reported 4 years ago, gametogenesis from embryonic stem (ES) cells promised an accessible in vitro model to facilitate molecular analysis of the germ lineage. Formation of primordial germ cells is robust, but terminal gametogenesis remains inefficient and doubts about gamete function persist. Although useful for research, clinical use of ES cell-derived gametes appears a distant prospect.     

“十里香”茶大小孢子发生发育的细胞学研究

 本文报道了"十里香"茶大小孢子发生和雌雄配子体的形成过程。"十里香"茶花粉母细胞减数分裂为"同时型",四分体为"田"字形或四面体形,其外胼胝质壁的形成和溶解都是向心的。雄配子体形成和发育过程中其核的形态和位置变化均具有规律性。中轴胎座,倒生胚珠,双珠被,薄珠心,胚囊属双胞型胚囊,其发育类型为"葱"型。二极核在受精前融合,反足细胞宿存至受精,合点端具承珠盘。     

Male germline stem cells: from mice to men

The production of functional male gametes is dependent on the continuous activity of germline stem cells. The availability of a transplantation assay system to unequivocally identify male germline stem cells has allowed their in vitro culture, cryopreservation, and genetic modification. Moreover, the system has enabled the identification of conditions and factors involved in stem cell self-renewal, the foundation of spermatogenesis, and the production of spermatozoa. The increased knowledge about these cells is also of great potential practical value, for example, for the possible cryopreservation of stem cells from boys undergoing treatment for cancer to safeguard their germ line.     

序贯共培养体系对小鼠体外受精胚胎发育效果的影响

采用体外分离培养的兔输卵管上皮细胞和子宫内膜细胞构建了序贯共培养体系,并与体外受精得到的受精卵进行共培养。试验结果表明,HTF液受精率显著高于T6液(P<0.05),更适用于卵母细胞的体外受精。序贯共培养体系和输卵管上皮细胞培养组2-细胞率都显著高于单独培养液组和子宫内膜细胞培养组(P<0.05),二者均可克服2-细胞阻滞。序贯共培养体系胚胎的囊胚体外发育率显著高于其他共培养组(P<0.05)。表明序贯共培养体系比单一体细胞共培养体系能更好地模拟体内环境,提高早期胚胎的体外发育率。     

A Correlation between Gametophytic and Sporophytic Characteristics in Zea mays L

If a mixture of types of corn pollen, identified by genetic markers, is applied to the silks of other inbred lines, the rate of pollen tube growth often varies with type of pollen. This gametophytic differential is correlated with a sporophytic differential-relatively heavier seeds in seed mixtures result from fertilization by gametes from faster growing tubes. The increased seed weight is due to greater competitive ability of the zygotes thus formed.     

不同因素对南阳牛卵泡卵母细胞体外成熟的影响

探讨了卵母细胞的不同采集方法对南阳牛卵母细胞体外成熟的影响。结果表明，抽吸法是合适的卵母细胞采集方法。同时还探讨了卵丘细胞层数和不同激素对南阳牛卵母细胞体外成熟的影响。结果表明激素对南阳牛卵母细胞的成熟率和卵裂率无显著影响；具有2～8层卵丘细胞的卵母细胞获得了较高的成熟率和卵裂率；具有8层以上卵丘细胞的卵母细胞的成熟率和卵裂率比较低；裸卵和半裸卵几乎不能够成熟和卵裂。     

A small-RNA perspective on gametogenesis, fertilization, and early zygotic development

Transient populations of cis- and trans-acting small RNAs have recently emerged as key regulators of extensive epigenetic changes taking place during periconception, which encompasses gametogenesis, fertilization, and early zygotic development. These small RNAs are not only important to maintain genome integrity in the gametes and zygote, but they also actively contribute to assessing the compatibility of parental genomes at fertilization and to promoting long-term memory of the zygotic epigenetic landscape by affecting chromatin. Striking parallels exist in the biogenesis and modus operandi of these molecules among diverse taxa, unraveling universal themes of small-RNA-mediated epigenetic reprogramming during sexual reproduction.     

Molecular mechanisms controlling seed set in cereal crop species under stress and non-stress conditions

Maximizing seed yield is the ultimate breeding goal in important cereal crop species. Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yield potential, and can be severely affected by abiotic and biotic stresses. However, seed set can also be substantially reduced by genetic factors even under optimal fertilization conditions. The underlying molecular genetic mechanisms are still obscure. In this review, we elucidate the process of seed set of cereal crop species in detail, including development of floral structures, formation of viable gametes, double fertilization, seed development, and abortion. We discuss how genetic and non-genetic factors affect seed set in different development stages. Finally, we will propose novel strategies to study genetic mechanisms controlling seed set and exploit genetic resources to improve seed set in cereal crop species.     

在硬粒小麦-簇毛麦双二倍体与普通小麦杂种F1中的染色体配对及传递

对初级六倍性硬粒小麦－簇毛麦双二倍体与来源于四川的三个地方品种（系）和一个栽培普通小麦品种（包括ｐｈ１ｂ中国春小麦）所形成的杂种Ｆ１在减数分裂中期Ｉ的配对行为进行了研究。结果表明,小麦亲本不同,杂种Ｆ１之间的染色体配对存在明显的差异。四川的地方品种群体中可能存在ｐＨ或类似于ｐｈ的基因,促进染色体的配对,另外,在杂种Ｆ１（ＡＡＢＢＤＶ）中,单倍性染色体组Ｄ和Ｖ的存在部分地扰乱了Ａ和Ｂ染色体组的同源配     

Development of mouse ova in explanted oviducts: fertilization, cultivation, and transplantation

The development of fertilized ova in explanted parts of oviducts was studied from 12 to 36 hours after fertilization, and from 36 to 84 hours after fertilization. No egg mortality during cultivation, nor any slowing of development could be detected in either experiment. It may be presumed that the mortality of mouse ova during the period before implantation has no essential effect on the resulting fertility. During cultivation of oviducts for 144 hours, there occurred in most blastocysts herniation of their walls resulting in a formation similar to the blastocyst, and a migration of a disorganized mass of cells, some of which resembled the giant trophoblastic cells. After transplantation of ova fertilized in vitro to recipients, in four cases there occurred nidation and subsequent normal development of the embryo.     

血管内皮生长因子对水牛卵母细胞体外受精的影响

[目的]探讨血管内皮生长因子（Vascular endothelial growth factor,VEGF）对水牛卵母细胞体外受精的影响,为优化水牛卵母细胞体外培养体系及提高水牛体外胚胎生产效率奠定基础.[方法]以带有3层以上卵丘细胞的卵丘—卵母细胞复合体（COCs）为材料,分别在水牛卵母细胞体外成熟液和受精液中添加重组人VEGF165,研究VEGF对水牛卵母细胞体外成熟、体外受精和早期胚胎发育的影响.[结果]在成熟液中添加10ng/mLVEGF,水牛卵母细胞的第一极体排出率由57.3％提高到72.3％,差异显著（P＜0.05,下同）;体外受精后的受精卵分裂率由41.0％显著提高到53.3％.在受精液中添加10 ng/mL VEGF,水牛体外受精的受精卵分裂率由41.9％提高到63.0％,差异极显著（P＜0.01,下同）,囊胚形成率由17.0％显著提高到32.6％.在成熟液和受精液中同时添加10ng/mLVEGF,水牛体外受精的受精卵分裂率和囊胚形成率由43.4％和19.0％极显著提高到64.3％和27.2％,囊胚细胞数由89.5显著提高到106.8.[结论]VEGF能促进水牛卵母细胞体外成熟、体外受精及早期胚胎的发育,因此可将VEGF用于水牛卵母细胞体外受精体系的优化,提高水牛体外胚胎生产效率.     

Sex determination in malaria parasites

A century ago, W. G. MacCallum identified distinct male and female forms in malaria parasites of both birds and humans. Since then, scientists have been puzzled by the high female-to-male ratios of parasites in Plasmodium infections and by the mechanism of sex determination. The sex ratio of malaria parasites was shown to become progressively more male as conditions that allow motility and subsequent fertilization by the male parasites become adverse. This resulted from an increased immune response against male gametes, which coincides with intense host erythropoietic activity. Natural and artificial induction of erythropoiesis in vertebrate hosts provoked a shift toward male parasite production. This change in parasite sex ratio led to reduced reproductive success in the parasite, which suggests that sex determination is adaptive and is regulated by the hematologic state of the host.     

PAIRING AND TRANSMISSION OF CHROMOSOMES OF THE HYBRIDS BETWEEN AMPHIDIPLOID OF TRITICUM DURUM DESF.-DASYPYRUM VILLOSUM(L.)CANDARGY AND TRITICUM AESTIVUM(L.)

对初级六倍性硬粒小麦－簇毛麦双二倍体与来源于四川的三个地方品种（系）和一个栽培普通小麦品种（包括ｐｈ１ｂ中国春小麦）所形成的杂种Ｆ１在减数分裂中期Ⅰ的配对行为进行了研究。结果表明,小麦亲本不同,杂种Ｆ１之间的染色体配对存在明显的差异。四川的地方品种群体中可能存在ｐｈ或类似干ｐｈ的基因,促进染色体的配对。另外,在杂种Ｆ１（ＡＡＢＢＤＶ）中,单倍性染色体组Ｄ和Ｖ的存在部分地扰乱了Ａ和Ｂ染色体组的同源配对。末期Ⅱ中,除了正常的四分体外,还存在二分体、三分体、五分体及六分体。对杂种Ｆ２和ＢＣ１Ｆ１的染色体计数研究表明,其染色体数目的变化范围为２ｎ＝２９至２ｎ＝６５,有的植株的染色体数目超过了预期的染色体数目,说明染色体通过杂种Ｆ１的传递偏离了随机模式。部分二、三、五或六分体所形成的配子参与了受精结实。因而在硬粒小麦－簇毛麦双二倍体与普通小麦的杂种后代中,不仅可望获得混合有Ｄ、Ｖ染色体结构的２ｎ＝４２的植株,而且还可能获得其它高倍性（８ｘ）和低倍性（４ｘ）的植株,从而为物种的进化指出了一种可能的途径。