Eventual Maturation Research Articles

Fruiting Body Heterogeneity, Dimorphism and Haustorium-like Structure of Naematelia aurantialba (Jin Er Mushroom).

Mushroom Jin Er has attracted widespread attention in Asia over the past two decades due to its medicinal properties and nutritional values. In the present study, Jin Er basidiocarps were often found to be surrounded by Stereum hirsutum fruiting bodies in their natural habitat and occasionally in artificial cultivation. The observation of two different kinds of mycelia within the hymenium and analyses of ITS sequences confirmed that Jin Er basidiocarps were composed of two fungal species, Naematelia aurantialba and S. hirsutum. This heterogeneity of Jin Er fruiting bodies is indeed distinct from the homogeneous hypha of Tremella fuciformis found in Yin Er mushroom, although its development also requires the presence of another fungus Annulohypoxylon stygium. Basidiospores can germinate on the surface of basidiocarps and produce mycelia. However, basidiospores in PDA medium can only bud into yeast-like conidia. The yeast-like conidia of N. aurantialba can transform into pseudohyphae with a change in temperature from 20 °C to 28 °C or switch into filamentous cells on an induction medium (IDM) at 20 °C, 25 °C and 28 °C. This dimorphic was reported for the first time in N. aurantialba. Haustorium-like structures were abundantly observed both within the hymenium and in the aerial mycelia cultured on the IDM. The developmental process was documented firstly in this study, involving the formation of protuberances with basal clamp connections, elongation at the protuberances, branch production, and eventual maturation. However, further observation is required to determine whether the haustorium-like structures can penetrate S. hirsutum hyphae. These findings are expected to provide valuable insights into the relationship and interaction between these two fungi, thereby advancing the cultivation of fruiting bodies.

Transcriptomic heterochrony and completely cleistogamous flower development in the mycoheterotrophic orchid Gastrodia.

Cleistogamy, in which plants can reproduce via self-fertilization within permanently closed flowers, has evolved in > 30 angiosperm lineages; however, consistent with Darwin's doubts about its existence, complete cleistogamy - the production of only cleistogamous flowers - has rarely been recognized. Thus far, the achlorophyllous orchid genus, Gastrodia, is the only known genus with several plausible completely cleistogamous species. Here, we analyzed the floral developmental transcriptomes of two recently evolved, completely cleistogamous Gastrodia species and their chasmogamous sister species to elucidate the possible changes involved in producing common cleistogamous traits. The ABBA-BABA test did not support introgression and protein sequence convergence as evolutionary mechanisms leading to cleistogamy, leaving convergence in gene expression as a plausible mechanism. Regarding transcriptomic differentiation, the two cleistogamous species had common modifications in the expression of developmental regulators, exhibiting a gene family-wide signature of convergent expression changes in MADS-box genes. Our transcriptomic pseudotime analysis revealed a prolonged juvenile state and eventual maturation, a heterochronic pattern consistent with partial neoteny, in cleistogamous flower development. These findings indicate that transcriptomic partial neoteny, arising from changes in the expression of conserved developmental regulators, might have contributed to the rapid and repeated evolution of cleistogamous flowers in Gastrodia.

Transcriptomic analysis of hookworm Ancylostoma ceylanicum life cycle stages reveals changes in G-protein coupled receptor diversity associated with the onset of parasitism

Free-living nematodes respond to variable and unpredictable environmental stimuli whereas parasitic nematodes exist in a more stable host environment. A positive correlation between the presence of environmental stages in the nematode life cycle and an increasing number of G-protein coupled receptors (GPCRs) reflects this difference in free-living and parasitic lifestyles. As hookworm larvae move from the external environment into a host, they detect uncharacterized host components, initiating a signalling cascade that results in the resumption of development and eventual maturation. Previous studies suggest this process is mediated by GPCRs in amphidial neurons. Here we set out to uncover candidate GPCRs required by a hookworm to recognise its host. First, we identified all potential Ancylostoma ceylanicum GPCRs encoded in the genome. We then used life cycle stage-specific RNA-seq data to identify differentially expressed GPCRs between the free-living infective L3 (iL3) and subsequent parasitic stages to identify receptors involved in the transition to parasitism. We reasoned that GPCRs involved in host recognition and developmental activation would be expressed at higher levels in the environmental iL3 stage than in subsequent stages. Our results support the model that a decrease in GPCR diversity occurs as the larvae develop from the free-living iL3 stage to the parasitic L3 (pL3) in the host over 24–72 h. We find that overall GPCR expression and diversity is highest in the iL3 compared with subsequent parasitic stages. By 72 h, there was an approximately 50% decrease in GPCR richness associated with the moult from the pL3 to the L4. Taken together, our data uncover a negative correlation between GPCR diversity and parasitic development in hookworm. Finally, we demonstrate proof of principal that Caenorhabditis elegans can be used as a heterologous system to examine the expression pattern of candidate host signal chemoreceptors (CRs) from hookworm. We observe expression of candidate host signal CRs in C. elegans, demonstrating that C. elegans can be effectively used as a surrogate to identify expressed hookworm genes. We present several preliminary examples of this strategy and confirm a candidate CR as neuronally expressed.

Quantifying the dynamic evolution of organic, inorganic and biological synergistic fouling during nanofiltration using statistical approaches

The dynamic process of membrane fouling was characterized during relatively long-term (30 d) continuous nanofiltration (NF) of a real wastewater secondary effluent, with the roles of organic, inorganic and biological foulants quantified via statistical analyses. The analyses were based on time-series data of physical properties (morphology, roughness, hydrophilicity and charge), chemical compositions (X-ray and infrared responses) and biomass (adenosine triphosphate, ATP) on the membrane surface during fouling evolution. The individual and interactive contributions of organic factor (typical functional groups), inorganic factor (Ca as a representative) and biological factor (ATP amount) to fouling were quantified via multiple linear regression coupled with variance partitioning analysis. About 78% of the variance of filtration resistance can be explained by these factors, among which 16% was contributed by individual effect of organics (via e.g. physical adsorption), 21% by organic-inorganic binary effect (in the form of e.g. Ca-complex), 13% by organic-biological binary effect (organics as the nutrient/product of microorganisms), and 24% by organic-inorganic-biological ternary interaction. Organic matter was universally involved in these effects. The interrelations among fouling factors, foulant layer properties and filtration time were comprehensively explored via redundancy analysis, which clearly delineated the fouling evolution into three major stages: Stage I (0–1 d) for initial fouling mainly due to rapid organic adsorption; Stage II (1–10 d) mainly for the gradual growth of Ca-organic combined fouling; and Stage III (10–30 d) for the eventual maturation of biofouling. These may provide foundations for a targeted fouling control based on foulant type or fouling stage.

Eliza Haywood’un “Love in Excess or, The Fatal Enquiry” ve Elizabeth Inchbald’un “A Simple Story” Romanlarında Kadın Gücünün İmkân(sızlığ)ı

Eliza Haywood ve Elizabeth Inchbald’un onsekizinci yüzyıl İngiltere’si ataerkil zemininde erkek karakterler aracılığıyla çeşitli kadın karakterler tanıtan Love in Excess or, The Fatal Enquiry (1719) ve A Simple Story (1791) romanları, kadın sesinin geçerliliğine karşılık kadınlara uygulanan baskı ve bu iki tutum arasında kadınların kurallara biat etmesi konularını tartışmaktadır. Love in Excess, erkek karakter D’Elmont aracılığıyla, onun Alovysa ve Amena gibi çeşitli kadın karakterlerle olan aşk ilişkileri sonucunda değişimini yansıtarak, erkeklerle olan ilişkilerine göre tanımlanan kadınlarla ilgili onsekizinci yüzyıl sosyal, kültürel ve ekonomik gerçekliklerini betimler. Aynı şekilde, A Simple Story, Millner ile kızı Matilda’nın birbirinden farklı hikayesini aktarır. Millner, meydan okuyan ve cesaretli bir kadınken, Matilda babası Dorriforth’un yönettiği itaat ve sessizlik dolu bir hayat içerisinde kaybolmuştur. Yine de, bu romanlarda kadın karakterler bütünüyle itaatkar veya baskı altında resmedilmemiştir, çünkü bazıları halen fikirlerini ifade edebilecek kadınsal bir güce sahiptir ve hareketleri erkeklerde değişimi başlatır. Bu durum ise, kadınların kurallara boyun eğmediğinin kanıtıdır. Öte yandan, kuralları ihlal eden diğer kadın karakterler ölüm veya mutsuzlukla cezalandırılır, ki bu da Haywood ve Inchbald’un romanlarında, büyük olasılıkla güvenli bir zemin olarak kurallara boyun eğme yolunu seçmiş olabileceğini ifade eder. Bu çalışmanın amacı, onsekizinci yüzyıl İngiltere’sinin sosyal ve kültürel zeminini temsil eden Love in Excess ve A Simple Story romanlarında, Amena ve Matilda karakterlerinin sessizliği ve pasifliğine ve Melliora’nın kurallara uygun hareket etmesine karşılık Alovysa, Ciamara, Violetta ve Millner karakterlerinde resmedildiği gibi, kadınların kuralları ihlal etme yoluyla güç kazanmasının mümkün olup olmadığını tartışmaktır.

Differentiating mouse-induced pluripotent stem cells into male germ cells through embryoid bodies

We examined the ability of the hanging drop (HD) method to differentiate induced pluripotent stem cells into male germ cells in the presence of specific growth factors. Over an eight-month period, 130 embryoid bodies (EBs) were created from mouse-induced pluripotent stem cells (miPSCs) using the hanging drop (HD) method. EBs were cultured in HDs after formation and differentiated in a 2-step culture system, each with a specific medium composition. Immunofluorescence staining was used to estimate germ cell appearance. miPSCs were maintained on mouse embryonic fibroblast (MEF) cells until confluent. MEF cells provided a cellular matrix for the miPSCs to grow on. Once confluent, the colonies were isolated by trypsinization. HDs were formed from 25-uL droplets containing miPSCs at a concentration of 1x105 cells/ml. Two male 14-week-old B6D2F1 mice were biopsied for testicular cells. Growth factors were extracted from adult mouse testes and added to the step-one medium containing Activin A, bFGF, and KSR. After 3 days, EBs were transferred to HDs containing step-two medium composed of LIF, BMP4, BMP8b, SCF, EGF, and testicular growth factors. On day 8, EBs were treated with collagenase and stained for OCT4, VASA, and DAZL. OCT4, VASA, and DAZL expression was compared between EBs cultured in the two-stage growth factor-conditioned medium system and control EBs maintained in standard culture medium to determine the stage of spermatogenesis reached. Of the isolated cells cultured from the two-step medium system, 86% were strongly positive for OCT4. In comparison, only 54% of cells isolated from control EBs cultured without differentiating factors were positive for OCT4. In addition, EBs cultured with differentiating factors yielded 31% VASA-positive cells, whereas control EBs only yielded 1% VASA-positive cells. Furthermore, EBs cultured with differentiating factors yielded 4% DAZL-positive cells, while control EBs only yielded 1% DAZL-positive cells. The retained expression of OCT4, along with the presence of VASA-positive and DAZL-positive cells, strongly indicates that the cells reached the spermatogonia/spermatocyte cell stage. Cells that were positive for VASA and DAZL without OCT4 expression also suggest that a fraction of cells were able to progress to the advanced meiotic stages of in vitro spermatogenesis. Our attempt to use the HD method together with the two-step culture system to induce the appearance and eventual maturation of male germ cells has shed light on the mechanisms of spermatogenesis in vitro. Using pluripotent stem cells to generate germ cells may benefit men afflicted by spermatogenic failure.

A simple method to generate germ cells from male embryonic stem cells

Many complex methods are available for creating and maintaining differentiated germ cells. We evaluated the hanging drop (HD) system to expeditely induce germ cell (GC) appearance in an embryonic stem cell culture. Embryoid bodies were induced and maintained in medium supplemented with differentiating factors in either HD or in culture dishes (CD). PGC appearance and differentiation was assessed for germ cell markers by microscopy staining, immunofluorescence, and molecular epigenetic assay by next-generation sequencing (NGS). Male mESCs were maintained on mouse embryonic fibroblast (MEF) cells until confluency was achieved, after which colonies were passaged by trypsinization. Male mESCs were separated from MEF cells by sedimentation. Approximately 1000 feeder-free mESCS were placed in 25 uL HD. Two days later, EBs were either transferred to HD containing retinoic acid (RA) or CD also supplemented with RA. On day 8, EBs were treated with collagenase IV and stained for GCAP/OCT4/DAZL or processed for gene expression analysis by NGS. Of a total of 260 EBs, 100 EBs were re-plated on day 2 to corresponding HD containing RA, while the remaining 160 EBs were transferred to CD supplemented with RA. On day 8, HD-cultured EBs reached approximately 150um in diameter, while EBs in CD reached 280-300um. EBs cultured in HD yielded an average of 77% GCAP positive cells, while those in CD only presented 22% GCAP positivity. EBs were also assessed for OCT4 activity to detect loss of stemness. In HD-cultured EBs, 40% of isolated cells were strongly positive for OCT4, compared to 60% of cells isolated from EBs in CD, indicating a higher level of cell differentiation in the former. To undoubtedly detect male germ cells, EBs were stained for DAZL. EBs cultured in HD and CD yielded 5% and 1% DAZL-positive cells, respectively. RNA sequencing revealed significant upregulation on Gdf9, Sox17, Kit, and Prm2 genes in HD-cultured EBs. These genes are critical for gametogenesis, confirming the presence of pre-meiotic and post-meiotic germ cells. Our attempt to induce the appearance and eventual maturation of male germ cells by the HD approach, by minimizing environment cell-surface interference, appears the most promising. Once the ability of these germ cells to progress through meiosis is confirmed, EB formation through HD may provide an inexpensive and reproducible model to experiment with in vitro gametogenesis.

Dengue and Zika viruses subvert reticulophagy by NS2B3-mediated cleavage of FAM134B

ABSTRACTThe endoplasmic reticulum (ER) is exploited by several diverse viruses during their infectious life cycles. Flaviviruses, including dengue virus (DENV) and Zika virus (ZIKV), utilize the ER as a source of membranes to establish their replication organelles and to facilitate their assembly and eventual maturation along the secretory pathway. To maintain normal homeostasis, host cells have evolved highly efficient processes to dynamically regulate the ER, such as through reticulophagy, a selective form of autophagy that leads to ER degradation. Here, we identify the ER-localized reticulophagy receptor FAM134B as a host cell restriction factor for both DENV and ZIKV. We show that RNAi-mediated depletion of FAM134B significantly enhances both DENV and ZIKV replication at an early stage of the viral life cycle. Consistent with its role as an antiviral host factor, we found that several flaviviruses including DENV, ZIKV, and West Nile virus (WNV), utilize their NS3 virally-encoded proteases to directly cleave FAM134B at a single site within its reticulon homology domain (RHD). Mechanistically, we show that NS3-mediated cleavage of FAM134B blocks the formation of ER and viral protein-enriched autophagosomes, suggesting that the cleavage of FAM134B serves to specifically suppress the reticulophagy pathway. These findings thus point to an important role for FAM134B and reticulophagy in the regulation of flavivirus infection and suggest that these viruses specifically target these pathways to promote viral replication.

The peach HECATE3-like gene FLESHY plays a double role during fruit development.

Tight control of cell/tissue identity is essential for a correct and functional organ patterning, an important component of overall fruit development and eventual maturation and ripening. Despite many investigations regarding the molecular determinants of cell identity in fruits of different species, a useful model able to depict the regulatory networks governing this relevant part of fruit development is still missing. Here we described the peach fruit as a system to link the phenotype of a slow ripening (SR) selection to an altered transcriptional regulation of genes involved in determination of mesocarp cell identity providing insight toward molecular regulation of fruit tissue formation. Morpho-anatomical observations and metabolomics analyses performed during fruit development on the reference cultivar Fantasia, compared to SR, revealed that the mesocarp of SR maintained typical immaturity traits (e.g. small cell size, high amino acid contents and reduced sucrose) throughout development, along with a strong alteration of phenylpropanoid contents, resulting in accumulation of phenylalanine and lignin. These findings suggest that the SR mesocarp is phenotypically similar to a lignifying endocarp. To test this hypothesis, the expression of genes putatively involved in determination of drupe tissues identity was assessed. Among these, the peach HEC3-like gene FLESHY showed a strongly altered expression profile consistent with pit hardening and fruit ripening, generated at a post-transcriptional level. A double function for FLESHY in channelling the phenylpropanoid pathway to either lignin or flavour/aroma is suggested, along with its possible role in triggering auxin-ethylene cross talk at the start of ripening.

Immune responses to Schistosoma haematobium infection.

Urogenital schistosomiasis is one of the greatest single infectious sources of human morbidity and mortality known. Through a complex cycle of infection, migration and eventual maturation and mating, S. haematobium (the aetiological agent of urogenital schistosomiasis) deposits highly immunogenic eggs within the bladder and other pelvic organs, activating a wide range of immune programs that determine both infection outcome as well as downstream immunopathology. In this review, we discuss the experimental and observational bases for our current understanding of these immune programs, focusing specifically on how the balance of type 1 and type 2 responses governs subsequent immunopathology and clinical outcome.

ACL Strain and Tensile Forces for Weight Bearing and Non—Weight-Bearing Exercises After ACL Reconstruction: A Guide to Exercise Selection

There is a growing body of evidence documenting loads applied to the anterior cruciate ligament (ACL) for weight-bearing and non-weight-bearing exercises. ACL loading has been quantified by inverse dynamics techniques that measure anterior shear force at the tibiofemoral joint (net force primarily restrained by the ACL), ACL strain (defined as change in ACL length with respect to original length and expressed as a percentage) measured directly in vivo, and ACL tensile force estimated through mathematical modeling and computer optimization techniques. A review of the biomechanical literature indicates the following: ACL loading is generally greater with non-weight-bearing compared to weight-bearing exercises; with both types of exercises, the ACL is loaded to a greater extent between 10° to 50° of knee flexion (generally peaking between 10° and 30°) compared to 50° to 100° of knee flexion; and loads on the ACL change according to exercise technique (such as trunk position). Squatting with excessive forward movement of the knees beyond the toes and with the heels off the ground tends to increase ACL loading. Squatting and lunging with a forward trunk tilt tend to decrease ACL loading, likely due to increased hamstrings activity. During seated knee extension, ACL force decreases when the resistance pad is positioned more proximal on the anterior aspect of the lower leg, away from the ankle. The evidence reviewed as part of this manuscript provides objective data by which to rank exercises based on loading applied to the ACL. The biggest challenge in exercise selection post-ACL reconstruction is the limited knowledge of the optimal amount of stress that should be applied to the ACL graft as it goes through its initial incorporation and eventual maturation process. Clinicians may utilize this review as a guide to exercise selection and rehabilitation progression for patients post-ACL reconstruction.

Rice husk co-firing with coal in a short-combustion-chamber fluidized-bed combustor (SFBC)

This study encompassed the characteristics and performance of co-firing rice husk, a by-product of rice-milling process, with coal in a short-combustion-chamber fluidized-bed combustor (SFBC). Bed phenomena investigated in a cold-flow model combustor showed that with the different mixes of materials, the anticipated offshoot of combustion, the minimum fluidizing velocity ( U mf) was 0.4–0.8 m/s. In concord with axial temperature profiles, axial gas concentration profiles implied that a recirculating ring was able to circumscribe CO within the short-main chamber. The formation, decomposition, and eventual maturity of NO x characterized the NO x evolution, inferred from concentration profiles. The impacts of fluidizing velocity and blending ratio on gas emissions and combustion efficiency ( E c) are described. The fluidizing velocity had consequential effect on gas emissions, except NO x. Surprisingly, NO x did not hinge much on increased N-content of the mixtures with coal. As expected, increased SO 2 was relevant to increased coal mass. Increased fluidizing velocity adversely affected E c while increased coal fraction enhanced E c, mostly >97%.

Impact of software engineering research on the practice of software configuration management

Software Configuration Management (SCM) is an important discipline in professional software development and maintenance. The importance of SCM has increased as programs have become larger, more long lasting, and more mission and life critical. This article discusses the evolution of SCM technology from the early days of software development to the present, with a particular emphasis on the impact that university and industrial research has had along the way. Based on an analysis of the publication history and evolution in functionality of the available SCM systems, we trace the critical ideas in the field from their early inception to their eventual maturation in commercially and freely available SCM systems. In doing so, this article creates a detailed record of the critical value of SCM research and illustrates how research results have shaped the functionality of today's SCM systems.

Différenciation lymphoïde T méthodes d'exploration des lymphocytes T et applications aux lymphoproliférations T/NK

T-cells are generated in thymus from hematopoietic precursor cells. T-cell differentiation includes T-cell receptor gene rearrangement, positive and negative selection processes, and eventual maturation steps. T-cells recently emigrated from thymus are integrated into the pool of naive cells, which have not yet encountered their antigen. Apart from cytological examination, blood investigation in search of T/NK lymphoma is based on (i) immunophenotypic characterization of T and NK subsets using flow cytometry, allowing to suspect the diagnosis, but globally less determining than in the setting of B-cell proliferations ; and on (ii) detection of a T-cell clone, most often realized through a molecular — based technique, involving PCR. However, due to rarity and great variety of different entities encompassed by the wide term of T/NK lymphoma, the diagnosis should be firmly established only when taking into account the whole clinical, morphological, immunophenotypic, and molecular data.

Tissue remodeling as a feature of persistent asthma

A chronic inflammatory process is almost invariably associated with tissue damage and healing. Healing results in repair and replacement of dead or damaged cells by viable cells. Repair usually involves 2 distinct processes: regeneration, which is the replacement of injured tissue by parenchymal cells of the same type, and replacement by connective tissue and its eventual maturation into scar tissue. In many instances both processes contribute to the healing response. Chronic inflammatory disease can therefore lead to a wide variety of consequences, from complete or partial restitution of organ structure and function to fibrosis. Asthma is characterized by a chronic inflammatory process of the airways. The ensuing healing process results in structural alterations referred to as a remodeling of the airways. The mechanisms underlying these structural alterations are still largely unknown. They are likely to be heterogeneous, leading—through the highly dynamic process of cell de-differentiation, migration, differentiation, and maturation—to changes in connective tissue deposition and to the altered restitution of airways structure, resulting in mucus gland hyperplasia, neovascularization, fibrosis, and an increase in smooth muscle mass. (J Allergy Clin Immunol 2000;105:1041-53.)

Structural consequences of airway inflammation in asthma

Asthma represents a chronic inflammatory process of the airways followed by healing, the end-result of which is an altered structure referred to as a remodeling of the airways. Repair usually involves 2 distinct processes: regeneration (which is the replacement of injured tissue by parenchymal cells of the same type) and replacement by connective tissue and its eventual maturation into scar tissue. In many instances both processes contribute to the healing response and inflammation. In asthma the processes of cell dedifferentiation, migration, differentiation, and maturation and connective tissue deposition can be followed either by complete or altered restitution of airway structure and function, the latter often seen as fibrosis and increase in smooth muscle and mucus gland mass. These features result in an increased resistance to airflow, particularly when there is bronchial contraction and bronchial hyperresponsiveness. The effect on airflow is compounded by the presence of increased mucous secretion and inflammatory exudate, which not only blocks the airway passages but also causes an increased surface tension that favors airway closure. (J Allergy Clin Immunol 2000;105:S514-17.)

Differential utilization of VLA-4 (α4β1) and -5 (α5β1) integrins during the development of mouse bone marrow-derived mast cells

Cytokines have been shown to have major roles in the development of mast cells from bone marrow progenitors. Immature mast cells derived from bone marrow thus leave the blood system to complete their course of maturation within tissues. However, it is now clear that VLA (β1) integrins with function in mediating cell-cell and cell-extracellular matrix protein interactions have effects on the growth and differentiation of diverse cell types. At present, the involvement of VLA integrins during mast cell development is still unclear. In this study, we report the preparation of a new monoclonal antibody (mAb) against mouse VLA-5 (α5β1) integrin. Together with mAb R1-2, we characterized the expression of VLA-4 (α4β1) and VLA-5 integrins, the two major fibronectin receptors, on two long-term cultured mast cell lines, CFTL-15 and MC/9. CFTL-15 cells were found to express both VLA-4 and -5 integrins whereas MC/9 cells expressed only VLA-5 but not VLA-4. We speculated that VLA integrin expression may be related to mast cell development. Thus bone marrow-derived mast cells (BMMC) were characterized after varying periods of development induced by IL-3. During the first 3 weeks the expression of VLA-4 and VLA-5 increased progressively and both were involved in mediating adhesion of BMMC to fibronectin. At time periods of greater than 3 weeks, the expression of VLA-4 declined gradually to little, if any, by week 13. In comparison, VLA-5 remained stably expressed and functioned as the major receptor for fibronectin. Results from this study therefore suggest that BMMC differentially utilize VLA-4 and VLA-5 integrins during IL-3-induced development. Differential expression of VLA integrins may have effects on the recirculation properties, tissue distribution and eventual maturation of progenitors to fully matured mast cells.

CD3 δ and ϵ gene expression in CD3 t-CD16 + natural killer cell clones derived from thymic precursors

To better understand the maturational stages during T-cell development, we studied the expression of CD3δ and CD3ϵ genes, as well as the presence of TCR gene rearrangements, within CD3 −CD16 + NK clones derived from thymic precursors in vitro. Northern blot analysis revealed that CD3 −CD16 + clones derived from CD7 + CD3 −CD4 −CD8 − (TN) thymocytes expressed transcripts for the CD3ϵ gene; however, no transcripts for the CD38 gene were detected. Importantly, both the CD3ϵ and CD3δ genes were expressed in TN thymocytes examined prior to cloning. A CD7 +CD8 +CD3 −CD4 − thymocyte population that makes up only 0.4% of the total thymocyte pool was also isolated from human thymus. We determined the maturation potential of this CD7 + CDS + CD3 −CD4 − population by limiting dilution cloning and found that 67% of the clones generated in vitro had a CD3 −CD16 + CD8 + phenotype. In contrast to the NK clones derived from TN precursors, most CD3 −CD16 + clones derived from CD7 + CD8 + CD3 −CD4 − thymocytes expressed transcripts for both CD3ϵ and CD3δ genes. Southern blot analysis of the NK clones derived from either thymic precursor population revealed no rearrangement of the TCR β or γ genes. These results demonstrate that the TN progenitor population and their CD3 −CD16 + progeny differ in their expression of the CD38 transcript and during in vitro culture there is loss of CD38 expression and acquisition of surface CD16 within these NK clones. Furthermore, the CD3 −CD16 + clones derived from TN versus CD7 + CD8 +CD3 −CD4 − thymocytes differed in their expression of the CD38 gene. The signaling events regulating the expression of the CD3 invariant chain genes within immature lymphoid progenitor cells may be important in determining their eventual maturation into T-cell and NK-cell lineages in vivo.

The Kiss in a Box

The Kiss in a Box Richard Rotert (bio) "Long ago I thought like you that my mother would always keep the window open for me; so I stayed away for moons and moons and moons, and then flew back; but the window was barred, for mother had forgotten all about me, and there was another little boy sleeping in my bed." —Peter Pan (106) In spite of Peter Pan's history of recurrent amnesia—he says of pirates, "I forget them after I kill them," (161)—the distressing memory of being barred from returning to his mother persists. Considering the preponderance of material purged or repressed in the adolescent mind, it is crucial for an analysis of subsequent behavior to identify which details of a child's life escape general oblivion. What remains in conscious memory is likely the most significant element in that whole period of life, regardless of whether it possessed such importance at the time or gained importance from the influence of later events (Freud, Character 193). In the traumatic memory cited above, Peter acknowledges his estrangement from the mother imago, an estrangement that persists without hope of redress. The barred window excludes Peter as participant in the previously abandoned familial context of mother and child in a nursery. Peter's personal story, mirroring that of the text, begins and ends with a flight from and return to the nursery window, the locus of his unresolved dilemma. Peter Pan was—and is—on the outside looking in. By returning to this locus Peter acknowledges his deprivation and reveals the purpose of his original flight. "'Wendy, I ran away the day I was born. . . . It was because I heard father and mother,' he explained in a low voice, 'talking about what I was to be when I became a man.' He was extraordinarily agitated now. 'I don't ever want to be a man,' he said with passion" (26). Peter's repudiation [End Page 114] of "manhood" may also be affirmed in the conspicuous absence of the father from the iterative nursery scene, an absence indicative of the fulfilled wish by a son who sees the father as denying access to the mother. The normal wish to eliminate the father imago is revealed in a wistful encounter with a dead father in a wood, later to be identified as the Island of Neverland. "Children have the strangest adventures without being troubled by them. For instance, they may remember to mention, a week after the event happened, that when they were in the wood they met their dead father and had a game with him" (8). Here the apparent merriment of the children suggests the ultimate resurrection or replacement of the father, or adult, in their own eventual maturity. But Peter Pan permanently rejects fatherliness, including his own, by refusing to enter the prerequisite order of manhood. By denying his manhood, Peter also denies the possibility of a mature, loving relationship with any of the female characters, considering them only surrogates for the desired but inaccessible mother. Peter's necessary conflict with a specular image of the father is displaced onto Neverland battles with pirates whose captain, James Hook, is associated by parallel episodes to the one identifiable father in the text, Mr. Darling. In a nursery scene with Michael, Mr. Darling invokes parental authority by demanding the consumption of medicine by his son. "Strong man though [Mr. Darling] was, there is no doubt that he had behaved rather foolishly over the medicine. . . . When Michael dodged the spoon in Nana's mouth, he had said reprovingly, 'Be a man, Michael . . . when I was your age I took medicine without a murmur' (16). Later, in Neverland, Captain Hook adds a poisonous concoction to Peter's medicine in an effort to murder the boy: "But what was that? The red in his eye had caught sight of Peter's medicine standing on a ledge within easy reach. Lest he should be taken alive, Hook always carried about his person a dreadful drug . . . which was probably the most virulent poison in existence. Five drops of this he now added to Peter's cup" (122-23). The father-pirate analogy exposes the tyranny...

Comparison of flowering time and embryogenesis in Spanish and Portuguese populations of Lupinus albus L. (Leguminosae)

AWOPETU, J. A., 1988. Comparison of flowering time and embryogenesis in Spanish and Portuguese populations of Lupinus albus L. (Leguminosae). Investigations were carried out on flowering-time, leaf or node number on the primary stem and embryo morphogenesis in 16 land races of Lupinus albus collected from the Iberian peninsula, using ‘Kali’ and ‘Kievskij Mutant’ as early-flowering reference cultivars. Observations showed that none of the Spanish or Portuguese introductions equalled ‘Kali’ and ‘Kievskij Mutant’ with respect to earliness in flowering and low leaf or node number, as well as shorter rate of embryo development and eventual pod maturation. However, genetic variability was established within the land races to indicate intermediate and late-flowering types that could respond to selection for eventual adaptation to central and northern Europe.