18 resultados para MORPHOGENESIS

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The effects of ultraviolet radiation (UVR 280-400 nm) on the germination of Porphyra haitanensis conchospores and on the growth and morphogenesis of the subsequent sporelings were investigated by culturing the released conchospores under natural sunlight from 29 September to 6 October 2005. Germination increased with time and was faster when UV-B was excluded using cut-off filters. There were significant negative effects of UV-B radiation on growth and cell division of sporelings, with decreases up to 18% for thallus length, between 6 and 18% for thallus width, up to 29% for thallus area, and between 6 and 14% for cell size as compared to PAR-controls. UV-A had a significant positive effect on morphogenesis, enhancing the formation of sporelings with cells dividing transversely; on the other hand, UV-B delayed the formation of such sporelings. We also tested the effects of solar UVR on the growth of P. haitanensis juveniles and found no significant effects. Our results indicate that UV-A has an important role in the germination and morphogenesis of the species, but on the other hand, sporelings of P. haitanensis are more sensitive to UV-B radiation than juveniles.

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A pathogenic virus (RGV), isolated from diseased pig frog Rana grylio with lethal syndrome, was investigated with regard to morphogenesis and cellular interactions in EPC cells, a cell Line from fish. Different stages of virus amplification, maturation and assembly were observed at nucleus, cytoplasm and cellular membranes. The matured virus particles, were not only distributed diffusely in nucleus, cytoplasm and cellular surface, but also aggregated as pseudocrystalline arrays in the cytoplasm. Virions were released by budding from the plasma membranes, or following cell lysis. Various types of cell damage, such as small vacuoles, spherical inclusions, and swollen and empty mitochondria, were also found. Some typical characteristics of RGV, such as the symmetrical shape of the virions, replication process involving both nuclear and cytoplasmic phases, budding release from cellular membrane and intracellular membrane, viromatrix and paracrystalline aggregation in cytoplasm, and its acute pathogenic effects, were observed to be similar to that of other iridoviruses. Therefore, the RGV appears to be a member of the Iridoviridae based on these studies. (C) 1999 Elsevier Science B.V. All rights reserved.

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八楞海棠是我国华北地区重要的苹果砧木,河南海棠是选育苹果矮化砧木的良好材料,进行八楞海棠和河南海棠胺芽茎尖培养具有重要的生产实际意义。主要结论如下;1)细胞分裂素和生长素的种类及浓度配比影响分化与增殖; 2)不同物候期的芽对分化增殖也有影响; 3)IBA促进八楞海棠生根。IAA促进河南海棠生根4)不定根起源于维管形成层细胞,其发生、形成与生长素种类。浓度密切相关。结合实验与文献,对蔗糖的作用.PZ和PG的作用,以及试管苗玻璃化现象作了讨论。

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五味子属隶属于木兰亚纲八角目五味子科,全属共15种,呈东亚一北美间断分布,东亚是其分布中心。五味子科因花部器官数目多而不定,螺旋状排列等特征,被确认为原始多心皮类的一员,与八角科、木兰科、Winteraceae等有亲缘关系。同时,因为它具有一些特化的性状,如具3沟或异极6沟型花粉、花单性,而常被视为木兰亚纲中进化水平较高的类群。然而,近年来分子系统学的研究结果显示,五味子科是被子植物最基部的分支之一。这使得该科成为解决原始被子植物起源与演化问题的重要类群之一,而倍受关注。中国是五味子属植物分布最集中的地区,有着得天独厚的资源优势。在论述了该属研究现状和存在问题的基础上,作者重点从花发育形态学和分子系统学,对该类群进行了较为深入的研究,发现了一些重要的新的性状,为该类群的系统发育分析提供了有力的证据。 1. 借助于扫描电镜,对全属成熟雄花的6种变异类型的代表种,进行了全面细致的花形态建成的观察和分析。首次发现该属雄花形态建成的式样有3类,并分别将之命名为柱托型、平托型和球托型,它们的主要特征如下:柱托型在花发育的全过程里,花托部分保持柱状,雄蕊始终螺旋状排列;平托型的花原端在分化出雄蕊原基后,向上的生长减弱而侧向的生长增强,最终形成扁平五边形的花托,雄蕊先螺旋状排列后轮状排列:球托型的雄蕊原基仍是螺旋状向顶发生,但与此同时,雄花花托部分球形膨大,并逐渐在雄蕊着生处产生浅凹和孔穴。显然,这3种式样在花形态发生的早前期相一致,而在雄蕊原基萌动后并开始分化时,它们之间发生分异,导致成熟雄花的形态显著不同。作者认为,雄花形态式样反映了五味子属系统发育的渊源,柱托型是原始类型,平托型和球托型是衍生类型,它们可能在系统发育的较早期就已分异,各自朝不同的方向演化。根据这一新的证据,将五味子属分成3亚属:大花五味子亚属、五味子亚属和团蕊五味子亚属。它们雄花的形态发生式样分别为柱托型、平托型和球托型。还发现在雄花的形态发生同为柱托型的类群中,大花五味子群和少蕊五味子群的雄蕊在成熟时,药室由初始时位于药隔两侧的位置逐渐外转至药隔的背面或侧背面,造成开裂时呈外向或外侧向纵裂:而华中五味子群的雄蕊成熟后,药室仍位于药隔的两侧面,呈侧向纵裂。 南五味子属是五味子属最近缘的类群,以南五味子为代表种,进行了雄花形态发生的研究,该种雄花的形态建成式样属于柱托型,但又不同于五味子属的柱托型,其主要的区别表现在南五味子的雄蕊在成熟时变成轮状排列,该特征使它似乎界于大花五味子群和五味子群之间,呈过渡类型。因而,对于传统分类学中,依据果实的形态将五味子科划分为五味子属和南五味子属,需要重新审视。 2. 根据对花形态发生的观察和分析,文章提出五味子属中雄花形态发生式样为柱托型的大花五味子亚属是最原始的类群,而具平托型和球托型式样的类群演化程度都相对较高。五味子属雄花的演化趋势主要表现在花托从柱状向扁平状和球状演化:雄蕊数目由多数变为少数并最终向定数演化:雄蕊群由螺旋状排列向轮状排列演化。有性生殖过程中的传粉习性可能是导致五味子属雄花形态产生变异的原因。在白垩纪,鞘翅目昆虫仍是最主要的传粉媒介,它们在起到传粉作用的同时,也对植物的花器官造成严重损害。五味子属植物的祖先类群为了适应这种传粉习性,采取了不同的策略。雄花花托柱状,雄蕊螺旋状排列的类群,以多数雄蕊保证传粉得以完成:而在雄蕊数目少的类群中,则补偿性地增大花器官的营养组织部分,达到保护花药的目的。 关于五味子属植物单性花的性质,常被认为是较进化的性状。本研究结果显示,雄花中未出现雌性部分的残存,雌花中也未出现雄性部分的痕迹。因此,在形态上,五味子属表现出完全单性的特征。作者认为,五味子属的单性花性质不同于由两性花退化所形成的单性花,它可能反映了被子植物祖先类群花的另一种演化路线。 另外,作者通过对五味子属雌花形态发生的研究,比较和分析了诸多原始被子植物类群心皮的形态及其发生过程,赞成Endress认为离生多心皮类中既有对折心皮,也有囊状心皮,它们在原始类群中并存的观点。五味子属植物雌花的形态较一致,心皮在原基腹面基部的活动不明显,成熟心皮具明显的腹缝,腹缝两侧形成柱头脊,在类型上属于对折型心皮,体现了该属的原始性。 3. 作者选取了核基因组的rrs区和叶绿体基因组的trnL-F区,对五昧子属的10个种(代表了全部雄花类型)和南五味子属的4个种(分属2个组)以及作为外类群的华中八角,首次进行了序列分析。结果表明,从代表不同基因组的两个片段得到的分支图非常一致,都显示出:a) 五味子属的类群分别聚在3个不同的支上,并且这3个支完全对应于花形态发生的3种式样:b) 南五味子属的成员与五味子群聚在一起并得到Bootstrap分析很高的支持率,说明它们可能是单系的。该结果支持基于花形态发生研究所得到的结论。作者认为过去的分类中,将五味子属和南五味子属分割成两个属可能是不妥当的,值得深入研究。 4. 通过花发育形态学和分子系统学的研究,结合其它方面的资料,作者认为传统分类依据果实形态划分成的五味子属和南五味子属,可能都不是严格的单系类群。南五味子属的类群与五味子属中雄花花托为扁平五边形的类群显示出有很强的相关性。将两个属共同处理,分为3个亚属,似较适宜。由于尚需对南五味子属扩大取样研究,目前暂不对它进行处理。本文仅对传统意义上的五味子属的系统处理如下: 五味子属Schisandra Michx. 亚属1大花五味子亚属 Subgen.1 Pleiostema (Smith)Law 组1大花五味子组 Sect.1 PleiostemaSmith 组2华中五味子组 Sec.2 Sinoschisandra(Law)Liu 组3少蕊五味子组 Secc.3 Maximowiczia(Rupr.)Nakai 亚属2五味子亚属 Subgen.2 Schismxtm 亚属3团蕊五味子亚属 Subgen.3 Sphaerostema(Bl.)Law 5. 五味子科(或包括南五味子属在内的广义五味子属)现代分布格局显示,中国华中、华东和西南至印度支那北部的地域是该类群的多样性中心,而在整个分布区的外围,则零星散布着一些演化水平较高的类群。因此,五味子科很可能是在东亚大陆起源、分化后,往四周扩散。通过白令陆桥或欧美大陆到达北美:受第四纪冰川影响,形成东亚一北美间断分布。在东喜马拉雅、印度尼西亚的分布也都是扩散的结果。

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被子植物中,花对称性进化的一个重要方面就是从两侧对称向次生辐射对称的演化。唇形目是被子植物中以两侧对称花为主的类群,次生辐射对称花频繁发生。然而在分子发育水平上,除了模式植物金鱼草(Antirrhinum majus)和少数其他种外,从两侧对称花向次生辐射对称花演化的机制仍然是一个巨大的未被探索的领域。 在金鱼草和柳川鱼(Linaria vulgaris)中,腹部化反常整齐花的形成各自是由于CYC和LCYC的沉默所引起,这些基因沉默分别是由于转座子插入和DNA广泛甲基化所导致。在豆科(legumes)中,辐射对称花的形成是由于legCYC基因在所有五个花瓣均有表达,这相似于金鱼草中CYC基因同源异位表达所形成的背部化辐射对称花。然而,自然界中起源于不同的两侧对称花支系的许多次生辐射对称花好像并不是因为简单的花对称性基因功能丢失或者获得。因此,以模式植物突变体表型特征的分子机制作为研究出发点,通过对自然发生的次生辐射对称花进行详细研究探讨,有可能揭示两侧对称花向次生辐射对称花转变的新的演化途径,包括花对称性发育过程中不同基因的参与以及他们的表达在时间上的变化等。 苦苣苔科(Gesneriaceae)是唇形目(Lamiales sensu lato)其他类群的姊妹群, 以较弱的两侧对称花为特征,并拥有相当数量的次生辐射对称花种类;该科所拥有的辐射对称花属在唇形目所有科中占的比例最大。在苦苣苔科中,五数苣苔(Bournea leiophylla)是次生辐射对称花类群中具有两侧对称痕迹的代表类群,其花的发育过程显示出五数苣苔花经历了由花器官发育早期的两侧对称向成熟时期辐射对称的形态转变。这种发育模式暗示着五数苣苔的花可能起源于一个两侧对称花祖先;五数苣苔中控制花背腹非对称性的CYC类基因应该是有功能的,至少在花发育的早期是这样的。由于苦苣苔科和婆婆纳科(Veronicaceae)(金鱼草属于婆婆纳科)亲缘关系较近,而且CYC类基因的基本功能之一是导致背部雄蕊退化;因此五数苣苔中辐射对称花的形成很可能既不是由于CYC类基因失去,也不是因为CYC-类基因功能获得延伸或加强所致。在五数苣苔花发育过程中,从早期的两侧对称到成熟花的辐射对称的发育转变可能牵涉到TCP和MYB基因家族成员相互调节作用在时间和空间上的改变。因此,五数苣苔是探讨被子植物中次生辐射对称花新的进化途径的一个理想的候选材料。针对解决这一问题,我们对五数苣苔花进行了以下实验研究: 1 花器官发生过程的观察 成熟的五数苣苔花是辐射对称花,但是对花发育过程中花原基电镜扫描结果表明:在花器官起始和发育的早期,五数苣苔花是显著的两侧对称;但是随着进一步发育,这种两侧对称性逐步减弱,最后形成具有微弱两侧对称性痕迹的辐射对称花。 2 花对称性基因的克隆 我们应用RACE技术克隆得到了五数苣苔花对称性同源基因:BlDIV1、BlDIV2和BlRAD的翻译区全序列及其上下游非翻译区,得到了BlCYC1的3‘端翻译区和非翻译区序列。为了确定这些基因内含子的有无和位置,我们也从DNA中得到了相应同源基因的DNA序列,并且补全了BlCYC1的5‘端序列。同时也克隆到了一个没有在mRNA中得到的CYC同源基因BlCYC2。在该实验中我们第一次在金鱼草以外的类群中克隆得到了DIV和RAD的同源基因。 3 序列比较和分子系统发育分析 运用不同的比较软件和分子系统发育分析工具对五数苣苔的花对称性基因进行了比较和分析。结果表明:五数苣苔各种类型的花对称性基因和金鱼草的花对称基因在序列上是高度同源的,在分子系统发育上是非常近缘的。暗示着五数苣苔花对称性基因和金鱼草花对称性基因功能上的同源性。 4 花对称称性基因表达模式的分析 我们第一次运用组织原位杂交和RT-PCR技术对在金鱼草以外类群中所有已知类型花对称性同源基因的表达模式进行了实验研究。结果表明:五数苣苔花对称性基因的表达模式在花发育的早期类似于金鱼草;但是早期以后,BlCYC1和BlRAD被负调节,BlDIV的表达特异地在每个花瓣侧部边缘表达;这种表达结果和花的形态发生过程有很好的吻合。 上述研究表明:和金鱼草花对称基因的表达模式相比,五数苣苔三种类型花对称性基因在花发育过程中的时间和空间表达模式发生了改变;并且这种表达模式变化和五数苣苔花对称性由发育起始时期的两侧对称向成熟时期的辐射对称的转变是相互关联的。五数苣苔具有两侧对称性痕迹的辐射对称花和其他类群辐射对称花的比较显示:在五数苣苔中发育早期的两侧对称性应该是两侧对称性的遗迹;这是由于BlCYC1和BlRAD基因早期表达的保守性造成的。我们的结果揭示了一个新的花对称性演化路径:在花发育过程中,被CYC-like基因推动的RAD和DIV同源基因之间相互调节作用在时间和空间上的变化是花对称性从两侧对称向辐射对称转变或演化的基础;我们的发现还预示着:在一个调节网络的动态变化过程中,一个预先存在的两侧对称发育程序的修饰调节可能在被子植物次生辐射对称花多样性的形成中扮演重要角色。

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The edible blue-green alga, Nostoc sphaeroides Kutzing, is able to form microcolonies and spherical macrocolonies. It has been used as a potent herbal medicine and dietary supplement for centuries because of its nutraceutical and pharmacological benefits. However, limited information is available on the development of the spherical macrocolonies and the environmental factors that affect their structure. This report described the morphogenesis of N. sphaeroides from single trichomes to macrocolonies. During the process, most structural features of macrocolonies of various sizes were dense maculas, rings, the compact core and the formation of liquid core; and the. laments within the macrocolonies showed different lengths and arrays depending on the sizes of macrocolonies. Meanwhile temperature and light intensity also strongly affected the internal structure of macrocolonies. As microcolonies further increased in size to form 30 mm macrocolonies, the colonies differentiated into distinct outer, middle and inner layers. The. laments of the outer layer showed higher maximum photosynthetic rates, higher light saturation point, and higher photosynthetic effciency than those of the inner layer; whereas the. laments of the inner layer had a higher content of chlorophyll a and phycobiliproteins than those of the outer layer. The results obtained in this study were important for the mass cultivation of N. sphaeroides as a nutraceutical product. (c) 2008 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

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Endogenous yolk nutrients are crucial for embryo and larval development in fish, but developmental behavior of the genes that control yolk utilization remains unknown. Apolipoproteins have been shown to play important roles in lipid transport and uptake through the circulation system. In this study, EcApoC-I, the first cloned ApoC-I in teleosts, has been screened from pituitary cDNA library of female orange-spotted grouper (Epinephelus coioides), and the deduced amino acid sequence shows 43.5% identity to one zebrafish (Danio rerio) hypothetical protein similar to ApoC-I, and 21.2%, 21.7%, 22.5%, 20%, and 22.5% identities to Apo C-I of human (Homo sapiens), house mouse (Mus musculus), common tree shrew (Tupaia glis), dog (Canis lupus familiaris) and hamadryas baboon (Papio hamadryas), respectively. Although the sequence identity is low, amphipathic alpha-helices with the potential to bind to lipid were predicted to exist in the EcApoC-I. RT-PCR analysis revealed that it was first transcribed in gastrula embryos and maintained a relatively stable expression level during the following embryogenesis. During embryonic and early larval development, a very high level of EcApoC-I expression was in the yolk syncytial layer, indicating that it plays a significant role in yolk degradation and transfers nutrition to the embryo and early larva. By the day 7 after hatching, EcApoC-I transcripts were observed in brain. In adult, EcApoC-I mRNA was detected abundantly in brain and gonad. In transitional gonads, the EcApoC-I expression is restricted to the germ cells. The data suggested that EcApoC-I might play an important role in brain and gonad morphogenesis and growth.

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Fetuin-B has recently been cloned and identified from rats, mice, and humans; their expression patterns, however, have not been elucidated yet. In this study, Cagfetuin-B has been cloned in gibel carp. RT-PCR and Western blot detection revealed that Cagfetuin-B is first transcribed from the blastula stage and at a relatively stable level afterward during embryogenesis and the larval stage. Cagfetuin-B transcripts are predominantly distributed over the yolk syncytial layer in the early embryos and later restricted to the cells of liver and brain in newly hatched larvae. Moreover, a dynamic distribution of Cagfetuin-B protein was observed in brain, kidney, liver, and skin during morphogenesis. In adult fish, Cagfetuin-B transcripts are restricted in liver and ovary. Our work, for the first time, revealed the extra-hepatic transcription and a dynamic distribution of fetuin-B during embryogenesis and in adults, which indicates the potential roles of fetuin-B in fish organogenesis.

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Viral envelope proteins have been proposed to play significant roles in virus infection and assembly. In this study, an envelope protein gene, 53R, was cloned and characterized from Rana grylio virus (RGV), a member of the family Iridoviridae. Database searches found its homologues in all sequenced iricloviruses, and sequence alignment revealed several conserved structural features shared by virus capsid or envelope proteins: a myristoylation site, two predicted transmembrane domains and two invariant cysteine residues. Subsequently, RT-PCR and Western blot detection revealed that the transcripts encoding RGV 53R and the protein itself appeared late during infection of fathead minnow cells and that their appearance was blocked by viral DNA replication inhibitor, indicating that RGV 53R is a late expression gene. Moreover, immunofluorescence localization found an association of 53R with virus factories in RGV-infected cells, and this association was further confirmed by expressing a 53R-GFP fusion protein in pEGFP-N3/53R-transfected cells. Furthermore, detergent extraction and Western blot detection confirmed that RGV 53R was associated with virion membrane. Therefore, the current data suggest that RGV 53R is a novel viral envelope protein and that it may play an important role in virus assembly. This is thought to be the first report on a viral envelope protein that is conserved in all sequenced iridoviruses.

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A novel fish-specific apolipoprotein (apo-14 kDa) has been recently cloned from eel and pufferfish. However, its expression pattern has not been elucidated. in this study, EcApo-14 has been screened from hypothalamic cDNA library of male orange-spotted grouper, which shows 62.9%, 51%, 46.9%, 43.2%, and 31.9% identities to Apo-14 of European flounder, pufferfish, Japanese eel, gibel carp, and grass carp, respectively. RT-PCR analysis reveals that this gene is first transcribed in neurula embryos and maintains a relatively stable expression level during the following embryogenesis. EcApo-14 transcripts are at a very high level during embryonic and early larval development in the yolk syncytial layer (YSL), and decrease in YSL and form intense staining in liver at 3 days after hatching. In adult tissues, EcApo-14 is predominantly expressed in liver and brain. The data suggested that EcApo-14 might play an important role in liver and brain morphogenesis and growth. (c) 2005 Elsevier Inc. All rights reserved.

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Syncytin is a placenta-specific protein and generally believed to play a pivotal role in syncytiotrophoblast morphogenesis. In this study, transcripts of this gene were quantified by real-time RT-PCR and the translated products were measured by an indirect immunofluorescence assay. Results showed that syncytin was found to be expressed in all nine leukemia and lymphoma cell lines studied albeit at different levels and in 43 peripheral blood samples of 57 leukemia or lymphoma patients. Neither the transcripts nor the translated syncytin was detected in blood samples of normal individuals. In conclusion, peripheral blood syncytin may serve as a marker for leukemia and lymphoma. ©

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Little is known about the effects of space radiation on the human body. There are a number of potential chronic and acute effects, and one major target for noncarcinogenic effects is the human vasculature. Cellular stress, inflammatory response, and other radiation effects on endothelial cells may affect vascular function. This study was aimed at understanding the effects of space ionizing radiation on the formation and maintenance of capillary-like blood vessels. We used a 3D human vessel model created with human endothelial cells in a gel matrix to assess the effects of low-LET protons and high-LET iron ions. Iron ions were more damaging and caused significant reduction in the length of intact vessels in both developing and mature vessels at a dose of 80 cGy. Protons had no effect on mature vessels up to a dose of 3.2 Gy but did inhibit vessel formation at 80 cGy. Comparison with gamma radiation showed that photons had even less effect, although, as with protons, developing vessels were more sensitive. Apoptosis assays showed that inhibition of vessel development or deterioration of mature vessels was not due to cell death by apoptosis even in the case of iron ions. These are the first data to show the effects of radiation with varying linear energy transfer on a human vessel model. (C) 2011 In Radiation Research Society

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田间试验研究不施N和施N(90kg/hm2)条件下“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”等8种不同基因型冬小麦中后期生理特性及其叶片形态的差异结果表明,抽穗期倒二叶和灌浆期旗叶的净光合速率、气孔导度、蒸腾速率及瞬时水分利用效率在不同基因型间存在显著差异,施N仅能显著降低抽穗期倒二叶的蒸腾速率,而对功能叶的其他生理指标无明显影响。小麦成熟期旗叶和倒二叶的长度、宽度及叶面积在不同基因型间也存在极显著差异,施N对这些叶片形态指标有极显著地促进作用,基因型和N肥同时影响灌浆期旗叶的SPAD值,而叶片衰老指数主要受基因型调控。总体上看,冬小麦叶片形态指标同时受施N和基因型影响,而生理指标主要受基因型影响,N肥的影响相对较小。

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Insulin-like growth factor-binding protein (IGFBP)-3 is the major insulin-like growth factor (IGF) carrier protein in the bloodstream. IGFBP-3 prolongs the half-life of circulating IGFs and prevents their potential hypo-glycemic effect. IGFBP-3 is also expressed in many peripheral tissues in fetal and adult stages. In vitro, IGFBP-3 can inhibit or potentiate IGF actions and even possesses IGF-independent activities, suggesting that local IGFBP-3 may also have paracrine/autocrine function(s). The in vivo function of IGFBP-3, however, is unclear. In this study, we elucidate the developmental role of IGFBP-3 using the zebrafish model. IGFBP-3 mRNA expression is first detected in the migrating cranial neural crest cells and subsequently in pharyngeal arches in zebrafish embryos. IGFBP-3 mRNA is also persistently expressed in the developing inner ears. To determine the role of IGFBP-3 in these tissues, we ablated the IGFBP-3 gene product using morpholino-modified antisense oligonucleotides (MOs). The IGFBP-3 knocked down embryos had delayed pharyngeal skeleton morphogenesis and greatly reduced pharyngeal cartilage differentiation. Knockdown of IGFBP-3 also significantly decreased inner ear size and disrupted hair cell differentiation and semicircular canal formation. Furthermore, reintroduction of a MO-resistant form of IGFBP-3 "rescued" the MO-induced defects. These findings suggest that IGFBP-3 plays an important role in regulating pharyngeal cartilage and inner car development and growth in zebrafish.