The influence of Fe^(2+) on growth and development of cells enzy-matically isolated from Porphyra yezoensis blades

Fe2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe2+ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentra- tions of Fe2+. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1–102.1 μg/L, 10–100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentra- tions, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually.

Single-cell sequencing: New insights into pre-implantation development, pluripotency, and germ cells

Early mammalian embryonic development is a complex,dynamic,and heterogeneous process.Although numerous efforts have been made to delineate the mechanism underlying embryonic development,many questions still remain unanswered because of the scarcity of available human materials and the minute amounts of DNA and RNA.In recently years,technical developments in high-throughput single cell sequencing have revolutionized biology and provided a novel and powerful tool to investigate the dynamics of early embryo development in a quantitative and systematic manner.Gene expression networks,epigenetic modification(including DNA methylation and chromatin accessibility),and genetic variation can be recorded simultaneously in a single cell at single base resolution.The present review highlights how the single cell sequencing has provided new insights into mammalian pre-implantation development,embryonic stem cell biology,and germline development.

Making a tooth:growth factors,transcription factors,and stem cells

Mammalian tooth development is largely dependent on sequential and reciprocal epithelial-mesenchymal interactions. These processes involve a series of inductive and permissive interactions that result in the determination, differentiation, and organization of odontogenic tissues. Multiple signaling molecules, including BMPs, FGFs, Shh, and Wnt proteins, have been implicated in mediating these tissue interactions. Transcription factors participate in epithelial-mesenchymal interactions via linking the signaling loops between tissue layers by responding to inductive signals and regulating the expression of other signaling molecules. Adult stem cells are highly plastic and multipotent. These cells including dental pulp stem cells and bone marrow stromal cells could be reprogrammed into odontogenic fate and participated in tooth formation. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regene- ration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.

Histological Observation of Germ Cell Development and Discovery of Spermatophores in Ovoviviparous Black Rockfish(Sebastes schlegeli Hilgendorf) in Reproductive Season

Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.

Growing and aging of hematopoietic stem cells

In the hematopoietic system, a small number of stem cells produce a progeny ofseveral distinct lineages. During ontogeny, they arise in the aorta-gonadmesonephrosregion of the embryo and the placenta, afterwards colonise the liverand finally the bone marrow. After this fetal phase of rapid expansion, thenumber of hematopoietic stem cells continues to grow, in order to sustain theincreasing blood volume of the developing newborn, and eventually reaches asteady-state. The kinetics of this growth are mirrored by the rates of telomereshortening in leukocytes. During adulthood, hematopoietic stem cells undergo avery small number of cell divisions. Nonetheless, they are subjected to aging,eventually reducing their potential to produce differentiated progeny. The causalrelationships between telomere shortening, DNA damage, epigenetic changes,and aging have still to be elucidated.

Morphological and Molecular Dissection of Leaf Development in Wild-Type and Various Morphogenetic Mutants in Rice

Leaf cells undergo two main developmental events;i.e., cell proliferation and cell differentiation, before maturation. These events occur sequentially at specific positions and with specific timing during leaf development. To understand the transition from cell proliferation to cell differentiation of rice leaves, we analyzed rice leaves from both morphological and molecular viewpoints. The results of anatomical, morphological, and histochemical analyses indicated that P4 leaf primordium is the stage when dynamic transition of the cellular state from immature to mature along the proximal-distal axis of the leaf occurs. We screened for marker genes showing a dynamic expression pattern along the proximal-distal axis of the P4 leaf, and applied them to expression analysis in wild-type and various morphogenetic mutants. The changes in expression pattern of the marker genes varied between developmental stages and between mutants. Our analysis reinforced previous data regarding the developmental transition of wild-type rice leaves and indicated that the transition can be monitored using our molecular markers. The results of this study indicate that expression analysis using these molecular markers would be valuable for understanding the genetic effects on leaf development in various leaf morphogenetic mutants.

Research Progress on the Function of Melatonin and Its Receptor in Animal Reproduction

Melatonin has been a research hotspot in the field of medicine and life sciences for more than 60 years since it was discovered.In order to accelerate the increase of economic animal productivity,a large number of studies also have focused on the regulation of melatonin and its receptors during animal reproduction in recent years.In this paper,the relevant characteristics of melatonin and the latest research progress in animal reproduction were discussed,and the biological functions of melatonin were reviewed from the aspects of germ cells,reproductive endocrine and embryo development,laying a theoretical foundation for further exploring the regulation mechanism of melatonin on reproductive process.

Antenatal taurine reduces cerebral cell apoptosis in fetal rats with intrauterine growth restriction

From pregnancy to parturition, Sprague-Dawley rats were daily administered a low protein diet to establish a model of intrauterine growth restriction. From the 12th day of pregnancy, 300 mg/kg taurine was daily added to food until spontaneous delivery occurred. Brain tissues from normal neonatal rats at 6 hours after delivery, neonatal rats with intrauterine growth restriction, and neo- natal rats with intrauterine growth restriction undergoing taurine supplement were obtained for fur- ther experiments. The terminal deoxyribonucleotidyl transferase （TdT）-mediated biotin-16-dUTP nick-end labeling assay revealed that the number of apoptotic cells in the brain tissue of neonatal rats with intrauterine growth restriction significantly increased. Taurine supplement in pregnant rats reduced cell apoptosis in brain tissue from neonatal rats with intrauterine growth restriction. Immu- nohistochemical staining revealed that taurine supplement increased glial cell line-derived neuro- trophic factor expression and decreased caspase-3 expression in the cerebral cortex of intrauterine growth-restricted fetal rats. These results indicate that taurine supplement reduces cell apoptosis through the glial cell line-derived neurotrophic factor-caspase-3 signaling pathway, resulting in a protective effect on the intrauterine growth-restricted fetal rat brain.

Neurotrophic factors: from neurodevelopmental regulators to novel therapies for Parkinson's disease

Neuroprotection and neuroregeneration are two of the most promising disease-modifying ther- apies for the incurable and widespread Parkinson＇s disease. In Parkinson＇s disease, progressive degeneration of nigrostriatal dopaminergic neurons causes debilitating motor symptoms. Neurotrophic factors play important regulatory roles in the development, survival and maintenance of specific neuronal populations. These factors have the potential to slow down, halt or reverse the loss of nigrostriatal dopaminergic neurons in Parkinsoffs disease. Several neurotrophic fac- tors have been investigated in this regard. This review article discusses the neurodevelopmental roles and therapeutic potential of three dopaminergic neurotrophic factors： glial cell line-derived neurotrophic factor, neurturin and growth/differentiation factor 5.

The biochemical control of the cell cycle by growth regulators in higher plants

The cell cycle is an important research field in cell biology and it is genetically and developmentally regulated in animals and plants. The aim of this study was to review knowledge about the biochemical regulation of the cell cycle by plant growth regulators through molecular checkpoints that regulate the transition from G0-G1-S-phase and G2-M in higher plants. Recent research has shown that zeatin treatment led to the up-regulation of CycD3 in Arabidopsis. Benzyladenine treatment can also shorten the duration of S-phase through recruitment of latent origins of DNA replication. Kinetin is involved in the phosphoregulation of the G2-M checkpoint; the major cyclin-dependent kinase (Cdk) at this checkpoint has recently shown to be dephosphorylated as a result of cytokinin treatment, an effect that can also be mimicked by the fission yeast Cdc25 phos-phatase. Gibberellic acid (GA) treatment induces internode elongation in deepwater rice, this response is mediated by a GA-induced up-regulation of a cyclin-Cdk at the G2-M checkpoint. Recent evidence has also linked abscisic acid to a cy-clin-dependent kinase inhibitor. A new D-type cyclin, recently discovered in Arabidopsis may have a key role in this process. A brief review on plant growth regulator-cell cycle interfacing during development and a cytokinin-induced continuum of cell cycle activation through the up-regulation of a plant D-type cyclin at the G1 checkpoint and the phosphoregulation of the Cdk at the G2/M checkpoint had been concluded. This review could be valuable to research on cell and developmental biology in plants.

Effect of Gestational Diabetes Mellitus on the Growth, Development, and Stem Cells of Offspring

The effects of gestational diabetes mellitus (GDM) on offspring include macrosomia, hypoglycemia, respiratory distress syndrome, cardiovascular disease, neural and mental injury, etc. The effects of GDM on the health status of offspring are sustained although pregnancy has ended. It has been proposed that fetal reprogramming causes long-term consequences to metabolic health in offspring. An intrauterine high-glucose environment may lead to changes in the multi-differentiation proficiency of intracorporal stem cells, showing decreased proliferation and osteogenic ability, increased adipogenic ability, accelerated apoptosis, and occurrence of premature failure. This environment also reduces the mobilization of bone marrow stem cells, whereas it increases that of medullary cells. This results in pro-inflammatory conditions and sustained inflammation in the body, thereby increasing the risk of obesity, cardiovascular and neurological disorders, and metabolic abnormalities. Stem cells derived from the amniotic membrane, umbilical cord, or placenta may be a reliable predictor of the long-term effects of GDM on offspring. The levels of blood glucose during pregnancy should be effectively controlled to reduce harm to the neonate.

拟穴青蟹DDX5基因的表达及功能初步分析

拟穴青蟹(Scylla paramamosain)是我国东南沿海重要的经济养殖蟹类之一。DDX5基因是DEAD-box解旋酶基因家族中的成员,已有研究表明其在生殖细胞的成熟分化及功能维持中起重要的调控作用。我们从拟穴青蟹转录组数据库中筛选获得了DDX5(SpDDX5)基因序列,采用实时荧光定量PCR技术分析了其在成熟青蟹各组织、性腺各发育时期及胚胎各发育时期的表达模式。此外,利用RNAi技术分析了SpDDX5在性腺发育中可能发挥的作用。结果如下:SpDDX5的开放阅读框长1 893 bp,编码630个氨基酸,具有DEXDc和HELICc两个结构域。SpDDX5在拟穴青蟹的各组织中广泛表达,且在精巢中的表达水平明显高于其他组织(P<0.05);在精巢发育过程中,SpDDX5的表达水平逐渐降低;在胚胎发育过程中,SpDDX5的表达水平逐渐升高。干扰SpDDX5后,生殖细胞分子标记基因Vasa和Nanos表达上调,性腺发育相关基因foxl-2表达下调,Dmrt家族基因Dsx表达上调,Dmrt-like和idmrt-2表达下调。根据以上结果,我们推测SpDDX5基因可能在拟穴青蟹生殖细胞发育和精巢发育中发挥重要作用。

蛋白的翻译后修饰调控植物囊泡转运的研究进展

蛋白质翻译后修饰是蛋白质合成后经历的一系列化学修饰过程,这些修饰能够显著影响蛋白质的结构、定位、稳定性和功能。在细胞生物学中,蛋白质翻译后修饰在几乎所有的细胞信号通路和调控网络中扮演着至关重要的角色,尤其是在囊泡转运这一细胞内物质运输的关键过程中,蛋白质翻译后修饰对于蛋白质的运输调控和信号传导具有决定性的影响。囊泡转运是指细胞内物质通过囊泡从一处运输到另一处的过程,这一过程涉及多个步骤,包括囊泡的形成、运输、融合等。在这个过程中,蛋白质的正确修饰和定位对于囊泡的形成和运输方向至关重要。本文首先介绍了几种重要的蛋白翻译后修饰的作用及分类,随后,系统地总结了蛋白质翻译后修饰在囊泡转运中的研究进展,为揭示细胞内囊泡转运的分子机制、深入研究膜蛋白生物学功能提供重要参考。未来,应进一步探索蛋白质翻译后修饰在植物囊泡转运中的具体机制,以及这些机制如何影响植物的生长发育和环境适应性。这一研究将为植物遗传改良和抗逆境育种提供新的策略和方法,有助于提高作物的产量和品质,增强植物对环境变化的适应能力。总之,通过深入研究这一领域,不仅有助于我们揭示植物细胞中特定蛋白质修饰的基本原理,还可能为改良作物性状和提高植物抗逆境能力提供新的策略。

Umbilical cord-derived mesenchymal stem cells regulate thymic epithelial cell development and function in Foxn 1^-/- mice

Thymic microenvironments are essential for the maturation of thymocytes, which can be anatomically compartmentalized into cortical and medullar regions. The absence of the gene encoding the transcription factor forkhead box nl （Foxnl） causes epithelial differentiation to stall in the precursor stage, resulting in the formation of an abnormal thymus. In this study, we used human umbilical cord-derived mesenchymal stem cells （UC-MSCs） to treat Foxn1^-/- mice, and then analyzed the maturation and distribution of thymic epithelial cells in the Foxn1^-/- thymic rudiment and the thymopoiesis of this newly developed rudiment. Our data showed a well-organized cortex-medulla architecture and an obvious improvement in the maturation of thymic epithelial ceils along with the appearance of UEA-1^＋MHCIIhi thymic epithelial cells in the rudiment. We further demonstrated improved thymopoiesis and the enhanced export of mature T cells with increased numbers of regulatory T cells into the peripheral blood. Furthermore, we observed that MSCs can engraft into thymic tissue and express many cytokines or proteins, particularly keratinocyte growth factor （KGF） and CD248, which are essential for thymic development. Collectively, our data identified a new mechanism for MSCs, which may provide a proper microenvironment for the reconstitution and functional maturation of the thymus in Foxn1^-/- mice. Additionally, we elicited additional insights into the therapeutic efficacy of MSCs in several autoimmune diseases.

Foxp3在小鼠肺发育中的动态表达及意义

目的:通过分析叉头样转录因子3(forkhead box protein 3,Foxp3)在小鼠肺发育过程中的表达及其与肺发育相关标志物之间的关系,探讨Foxp3在肺发育中的可能作用。方法:根据小鼠肺发育的进程,选取胎鼠及新生鼠分为6组,分别于孕17.5 d及出生后1、4、7、14、21 d留取肺组织,HE染色观察肺组织形态,免疫组织化学染色检测CD31含量并观察肺微血管密度。qRT-PCR检测Foxp3及肺表面活性蛋白C(surfactant protein C,SP-C)、血管内皮生长因子A(vascular endothelial growth factor A,VEGF-A)、血管生成素-1(angiopoietin 1,Ang-1)mRNA表达,蛋白质印迹法检测Foxp3及SP-C、VEGF-A、Ang-1蛋白表达。结果:肺组织内Foxp3 mRNA在孕17.5 d小管期表达最高,后呈现不断减少趋势。SP-C mRNA在小鼠出生后1 d表达最高,随后逐渐减弱,直至肺泡化晚期。VEGF-A、Ang-1 mRNA在孕17.5 d表达最高,之后呈现不断减少趋势,最终趋于稳定。Foxp3蛋白在小管期已有表达,且在小管期及囊泡期表达最高,其后逐渐趋于平稳,VEGF-A及Ang-1在小管期及囊泡期表达亦最高,后逐渐减少;SP-C表达于出生后1 d达到最高,随后逐渐减少,并于肺泡化中晚期趋于平稳。相关性分析显示,Foxp3与SP-C、VEGF-A及Ang-1存在相关性(r分别为0.661、0.630和0.738)。结论:Foxp3在胎肺期及出生后早期呈现动态表达,Foxp3在小管期及囊泡早中期的高表达与SP-C、VEGF-A及Ang-1呈正相关,提示Foxp3可能促进肺泡上皮细胞及肺血管内皮细胞的增殖,参与肺发育过程。

BPGM下调对静原鸡成肌细胞生长发育的影响

旨在探讨二磷酸甘油酸变位酶(BPGM)对鸡成肌细胞生长发育的影响。对宁夏大学动物科技学院张娟课题组前期转录组学和蛋白组学数据进行联合分析,筛选出可能影响生长发育的差异表达基因,探究其对成肌细胞增殖、凋亡和相关标志基因表达水平的影响,并对糖酵解通路上下游基因的表达进行定量分析。ELISA检测肌苷酸(IMP)含量;比色法检测腺苷三磷酸(ATP)含量,深入揭示关键候选基因对静原鸡肌肉发育和肉质风味的重要作用。结果表明,静原鸡胸肌与腿肌间共鉴定到差异表达基因/蛋白139个,其中在转录组和蛋白组同时上调的差异基因/蛋白75个,在转录组和蛋白组同时下调的差异基因/蛋白45个,在转录组上调蛋白组下调的差异基因/蛋白13个,在蛋白组上调转录组下调的差异基因/蛋白6个;从糖酵解/糖异生通路筛选出7个差异表达基因,分别是BPGM、磷酸甘油酸激酶1基因(PGK1)、葡萄糖-6-磷酸异构酶基因(GPI)、磷酸甘油酸变位酶基因(PGAM1)、乳酸脱氢酶A基因(LDHA)、乳酸脱氢酶B基因(LDHB)、磷酸丙糖异构酶1基因(TPI1),结合KEGG通路富集分析和蛋白网络互作分析筛选出差异表达基因BPGM。BPGM在静原鸡母鸡组织中均有表达,在胸肌中的表达量最高,且在成肌细胞分化过程中呈上调趋势。用分离培养的原代成肌细胞进行细胞转染,干扰BPGM抑制了成肌细胞的增殖而促进细胞凋亡,并调控糖酵解通路上下游基因的表达,同时抑制了IMP和ATP的生物合成。综上所述,下调BPGM可以抑制成肌细胞的生长发育及IMP和ATP的生物合成。

Single cell atlas of developing mouse dental germs reveals populations of CD24^(+)and Plac8^(+)odontogenic cells

The spatiotemporal relationships in high-resolution during odontogenesis remain poorly understood.We report a cell lineage and atlas of developing mouse teeth.We performed a large-scale(92,688 cells)single cell RNA sequencing,tracing the cell trajectories during odontogenesis from embryonic days 10.5 to 16.5.Combined with an assay for transposase-accessible chromatin with high-throughput sequencing,our results suggest that mesenchymal cells show the specific transcriptome profiles to distinguish the tooth types.Subsequently,we identified key gene regulatory networks in teeth and bone formation and uncovered spatiotemporal patterns of odontogenic mesenchymal cells.CD24^(+)and Plac8^(+)cells from the mesenchyme at the bell stage were distributed in the upper half and preodontoblast layer of the dental papilla,respectively,which could individually induce nonodontogenic epithelia to form tooth-like structures.Specifically,the Plac8^(+)tissue we discovered is the smallest piece with the most homogenous cells that could induce tooth regeneration to date.Our work reveals previously unknown heterogeneity and spatiotemporal patterns of tooth germs that may lead to tooth regeneration for regenerative dentistry.

Arabinan Metabolism during Seed Development and Germination in Arabidopsis

Arabinans are found in the pectic network of many cell walls, where, along with galactan, they are present as side chains of Rhamnogalacturonan I. Whilst arabinans have been reported to be abundant polymers in the cell walls of seeds from a range of plant species, their proposed role as a storage reserve has not been thoroughly investigated. In the cell walls of Arabidopsis seeds, arabinose accounts for approximately 40% of the monosaccharide composition of non- cellulosic polysaccharides of embryos. Arabinose levels decline to -15% during seedling establishment, indicating that cell wall arabinans may be mobilized during germination. Immunolocalization of arabinan in embryos, seeds, and seedlings reveals that arabinans accumulate in developing and mature embryos, but disappear during germination and seedling establishment. Experiments using 14C-arabinose show that it is readily incorporated and metabolized in growing seedlings, indicating an active catabolic pathway for this sugar. We found that depleting arabinans in seeds using a fungal arabinanase causes delayed seedling growth, lending support to the hypothesis that these polymers may help fuel early seedling growth.

XTH家族基因在植物生长发育及胁迫响应中的研究进展

木葡聚糖内转糖基酶/水解酶(xyloglucan endotransglucosylase/hydrolase, XTH)是参与植物细胞壁的重塑的关键酶之一,可以切割和重新连接木葡聚糖。许多物种中都已经鉴定出了XTH基因家族,发现其广泛参与植物生命周期各种生命活动的调节。因此,研究XTH基因家族对理解植物的生长发育有着重要的意义。在这里,我们综述了XTH家族基因在植物生长发育中的作用,主要包括参与植物根、茎、叶的生长,花器官的开放与脱落,果实的成熟与软化等;还讨论了XTHs在非生物胁迫和生物胁迫响应中的作用,为深入研究XTHs的功能和作用机制提供参考。