Runx3 is required for hematopoietic development in zebrafish.

We cloned zebrafish runx3/aml2/cbfa3 and examined its expression and function during embryogenesis. In the developing embryo, runx3 is dynamically expressed in hematopoietic, neuronal, and cartilaginous tissues. Hematopoietic expression of runx3 commences late in embryogenesis in the ventral tail intermediate cell mass and later colocalizes with spi1 and lyz in circulating blood cells. In the cloche mutant, hematopoietic expression was absent, suggesting that Runx3 functions downstream of cloche in a hematopoietic pathway. Neuronal tissues expressing runx3 include the trigeminal ganglia and Rohon-Beard neurons. Runx3 appears to contribute to normal development of primitive and definitive hematopoietic cells. When Runx3 function was compromised using morpholino oligonucleotides, a reduction in the number of mature blood cells was observed. Furthermore, Runx3 depletion decreased runx1 expression in the ventral wall of the dorsal aorta and reduced the number of spi1- and lyz-containing blood cells. Conversely, ubiquitous overexpression of runx3 led to an increase in primitive blood cell numbers, together with an increase in runx1-expressing cells in the ventral wall of the dorsal aorta. We propose a role for Runx3 in the regulation of blood cell numbers.     

Maternal factors in zebrafish development.

All processes that occur before the activation of the zygotic genome at the midblastula transition are driven by maternal products, which are produced during oogenesis and stored in the mature oocyte. Upon egg activation and fertilization, these maternal factors initiate developmental cascades that carry out the embryonic developmental program. Even after the initiation of zygotic gene expression, perduring maternal products continue performing essential functions, either together with other maternal factors or through interactions with newly expressed zygotic products. Advances in zebrafish research have placed this organism in a unique position to contribute to a detailed understanding of the role of maternal factors in early vertebrate development. This review summarizes our knowledge on the processes involved in the production and redistribution of maternal factors during zebrafish oogenesis and early development, as well as our understanding of the function of these factors in axis formation, germ layer and germ cell specification, and other early embryonic processes.     

A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from cone-beam computed tomography images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation group (n = 82); posterior rotation group (n = 81)], and differences between groups evaluated. Correlation coefficients showed that sagittal inclination of the temporal bone was significantly (P < 0.01) related to midline flexion, transversal width and anterior-posterior length of the basicranium, to the anterior-posterior positioning of the mandible and maxilla, and posterior midfacial height. Frontal inclination of the temporal bone was significantly related (P < 0.01) to basicranium anterior-posterior and transversal dimensions, and to posterior midfacial height. In comparison with the posterior rotation group, the anterior rotation group presented a less flexed and anterior-posteriorly longer cranial base, a narrower skull, porion and the articular eminence located more superiorly and posteriorly, a shorter posterior midfacial height, the palatal plane rotated clockwise, a more retrognathic maxilla and mandible, and the upper posterior occlusal plane more inclined and posteriorly located. The results suggest that differences in craniofacial morphology are highly integrated with differences in the positional relationship of the temporal bones. The sagittal inclination of the temporal bone seems to have a greater impact on the 3D morphology of the craniofacial complex than frontal inclination.     

A hierarchy of determining factors controls motoneuron innervation

Summary Quail leg buds were grafted in place of chick leg buds or chick wing buds and vice versa at stages 18 to 21 after colonization by muscle precursor cells had been completed. Motor endplate pattern in the plantaris muscle of the grafts was analyzed before hatching by means of esterase and acetylcholinesterase staining techniques. Muscle fibre types were made visual using the myosin ATPase reaction. Investigations are based on the species-specific endplate pattern of the plantaris muscle: multiply innervated fibres in the chick and focally innervated fibres in the quail. Muscle pieces isolated from the adjacent medial gastrocnemius muscle of the grafted legs were histologically examined to judge their species-specific composition. Horseradish peroxidase was injected into the plantaris muscles of both the grafted and the opposite leg as well as in the plantaris muscle of normal quail embryos, in order to be sure that the plantaris muscle of the graft is innervated by appropriate motoneurons. This procedural design offers for the first time a possibility to test experimentally the influences of motoneurons on endplate pattern formation under conditions corresponding to those in normal ontogenesis. It is shown that such appropriate motoneurons of one species which project to the plantaris muscle of the other species dictate the endplate pattern. When the plantaris muscle is innervated by inappropriate motoneurons, the endplate pattern inherent in the muscle primordium itself becomes realized. A sequence of hierarchically acting factors is proposed to bring different results in line. According to this, the neuronally set programme has priority compared with that set in the muscle. This is true for the normal development and might generate the high neuro-muscular specificity. If under experimental conditions the neuronal programme and the peripheral programme differ, the axons and muscle fibres selectively interact with respect to their inherent characteristics and the muscle-specific programme becomes expressed. If there is a lack of a certain axon type, muscle fibres might become innervated by non-corresponding motoneurons which alter the muscle fibre type.Abbreviations PL plantaris muscle - PLD posterior latissimus dorsi muscle - ALD anterior latissimus dorsi muscle - UMD ulnimetacarpalis dorsalis muscle - E days of embryonic development - HRP horseradish peroxidase - LMC lateral motor column - LS lumbosacral The authors wish to thank the DAAD and the Ceskolovenská Lékarská Spolecnost J.E. Purkyné for sponsorship. This work was supported in part by NIH grants to Bruce M. Carlson and to Kathryn Tosney     

Notochord of chick embryos secretes short-form type IX collagen prior to the onset of vertebral chondrogenesis.

The notochord of embryonic chicks produces type IX collagen, as well as type II collagen, prior to the onset of vertebral chondrogenesis. To address the question of whether the notochord secretes the "long-form" type IX collagen found in cartilage or the "short-form" type IX found in the cornea and vitreous humor, we examined immunoreactivity of the notochordal type IX collagen using two different monoclonal antibodies. The antibody 2C2 recognizes an epitope close to the carboxyl-terminus of the HMW fragment, which is present in both the long- and short-form type IX collagens, whereas another antibody 4D6 recognizes an epitope in the NC4 domain of the long-form type IX collagen, which is absent in the short-form type IX collagen. Therefore, the long-form is recognized by its reaction with both 2C2 and 4D6, while the short-form by its reaction with only 2C2 and no reaction with 4D6. Immunostaining of vertebral sections with 2C2 shows an identical distribution of staining with that for type II collagen, although the staining with 2C2 is less intense. The 2C2-reactive type IX collagen is found within the notochord at stage 14 and in the notochordal sheath at stage 20. Deposition of this collagen in the perinotochordal matrix increases with time and reaches a level comparable with that for type II at stage 31. In contrast, the 4D6-reactive type IX collagen is not found within the notochord nor in the notochordal sheath.(ABSTRACT TRUNCATED AT 250 WORDS)     

转录因子RUNX1在结直肠癌中的表达及作用

目的应用在线公共数据库分析转录因子RUNX1的表达,研究其表达的临床意义。方法通过Oncomine、GEPIA公共数据库分析结直肠癌中RUNX1基因mRNA的表达情况,通过HPA(Human Protein Atlas)数据库分析RUNX1基因的蛋白表达情况,通过GEPIA分析RUNX1表达与肿瘤病理分期的关系以及RUNX1表达与患者生存期的关系。结果RUNX1 mRNA和蛋白在结直肠癌表达水平上调,与结直肠癌分期无显著相关。RUNX1表达与结肠癌(COAD)患者总体生存率(OS)和无病生存率(DFS)显著相关,其表达量越高,患者生存期越短;但与直肠癌(READ)患者OS和DFS无显著相关。结论RUNX1参与结肠癌的发病机制,是治疗结肠癌的潜在靶点。     

Rabbit lymphocyte factors modulate prostaglandin biosynthesis in alveolar macrophages.

We have previously shown that alveolar macrophages from BCG-infected rabbits release less prostaglandins (PG) and arachidonic acid than normal resident macrophages. In order to investigate the possible role of lymphocytes in modulating PG secretory activity of macrophages, we added the supernatant of spleen lymphocyte culture to alveolar macrophages prelabelled with [14C] arachidonic acid, and subsequently quantitated the release of PGs and arachidonic acid by macrophages. It was found that lymphocytes stimulated by phytohaemagglutinin (PHA) released soluble factors which inhibited arachidonic acid release and PG synthesis by macrophages. This inhibition was not seen with either supernatant of lymphocytes cultured without PHA, or when PHA was added at the end of lymphocyte incubation. The inhibitor factors were pronase-sensitive and exhibited molecular weight heterogeneity. Production of these could be enhanced by indomethacin treatment. These lymphokines might play a regulatory role in the suppression of macrophage PG synthesis in cell-mediated immunity.     

Hematopoietic growth factors: the scenario in zebrafish

Humoral regulation by ligand/receptor interactions is a fundamental feature of vertebrate hematopoiesis. Zebrafish are an established vertebrate animal model of hematopoiesis, sharing with mammals conserved genetic, molecular and cell biological regulatory mechanisms. This comprehensive review considers zebrafish hematopoiesis from the perspective of the hematopoietic growth factors (HGFs), their receptors and their actions. Zebrafish possess multiple HGFs: CSF1 (M-CSF) and CSF3 (G-CSF), kit ligand (KL, SCF), erythropoietin (EPO), thrombopoietin (THPO/TPO), and the interleukins IL6, IL11, and IL34. Some ligands and/or receptor components have been duplicated by various mechanisms including the teleost whole genome duplication, adding complexity to the ligand/receptor interactions possible, but also providing examples of several different outcomes of ligand and receptor subfunctionalization or neofunctionalization. CSF2 (GM-CSF), IL3 and IL5 and their receptors are absent from zebrafish. Overall the humoral regulation of hematopoiesis in zebrafish displays considerable similarity with mammals, which can be applied in biological and disease modelling research.     

Monocyte factors modulate in vitro T-lymphocyte mitogenesis in protein malnutrition.

This study investigated changes in T-lymphocyte mitogenesis and immunoregulatory cytokines during protein malnutrition. In vitro T cell response to concanavalin A was compared among protein deprived (PD), energy restricted pair fed control (PF), and ad libitum control (C) rabbits. Cell cultures were supplemented with crude monocyte supernatants (CMS) from PD, PF or C animals at either 1% or 8% final concentration in culture. Prostaglandin E2 (PGE2) concentration of unstimulated or stimulated lymphocyte culture supernatants and CMS was determined. Lymphocyte cultures from PD, PF and C animals had enhanced 3H-thymidine incorporation when supplemented with C and/or PF derived CMS. Addition of 8% CMS from PD rabbits inhibited proliferation below levels observed in mitogen-only stimulated groups in all cultures. At the 1% concentration, inhibition was seen in PD and C derived cells cultures and modest enhancement was seen in PF cultures. PGE2 concentration in supernatants from stimulated and unstimulated lymphocyte cultures from PD rabbits were higher than in C and PF cell cultures. These results suggest (a) that under appropriate culture conditions lymphocytes from PD donors are capable of enhanced proliferation and (b) that depressed T cell mitogenesis observed in protein malnutrition may reflect alterations in immunoregulatory signals. The role of interleukin 1 (IL-1) and PGE2 in the modulation of this response is discussed.     

A preliminary study of craniofacial classification.

Cephalographic evaluations often hinge on univariate statistical analyses of their component dimensions. These analyses generally depict a progressive increase in cephalometric form with age. Such analyses are, however, complicated by the varied inter-dimensional correlations. But when the cephalometric dimensions were combined together in cluster analysis, complex associations between various age groups were noted in the 1-18 year range. Such multivariate analyses revealed far more complex craniofacial age changes than traditionally envisaged. These data therefore indicated the need for further investigation of such "normocephalic gold standards" before their value in craniofacial evaluation can be established.     

Variation and causal factors of craniofacial robusticity in Patagonian hunter-gatherers from the late Holocene.

Fueguian-Patagonian skulls have been characterized as some of the most robust of any modern crania. However, the causal factors of such robusticity remain unsettled. We assess within- and among-sample cranial robusticity of seven samples from continental Patagonia and Tierra del Fuego, using geometric morphometric techniques. In addition, the biomechanical, phylogenetic, and climatic hypotheses proposed to account for robusticity in such samples are discussed. Two Amerindian samples of farmers and two early middle Holocene samples from South America were included. The results show: 1) large variation in craniofacial robusticity among Patagonian samples, with the highest robusticity in samples from south continental Patagonia and Isla Grande of Tierra del Fuego, whereas central and north Patagonian samples display the same degree of robusticity as farmer samples; 2) that early middle Holocene samples display lower levels of robusticity than South Patagonian samples; and 3) strong association between latitude and craniofacial robusticity, with the most robust craniofacial morphologies occurring at the highest latitudes. In consequence, neither masticatory stress nor retention of ancestral features is supported by the morphological evidence analyzed. Hence it is hypothesized that endocrine changes related to cold climate may be a plausible explanation for several craniofacial features found in Fueguian and south continental Patagonian samples, such as their large masticatory component, and pronounced supraorbital ridge and glabellar region.