Multiple stimulations for muscle–nerve–blood vessel unit in compensatory hypertrophied skeletal muscle of rat surgical ablation model

Tissue inflammation and multiple cellular responses in the compensatory enlarged plantaris (OP Plt) muscle induced by surgical ablation of synergistic muscles (soleus and gastrocnemius) were followed over 10 weeks after surgery. Contralateral surgery was performed in adult Wistar male rats. Cellular responses in muscle fibers, blood vessels and nerve fibers were analyzed by immunohistochemistry and electron microscopy. Severe muscle fiber damage and disappearance of capillaries associated with apparent tissue edema were observed in the peripheral portion of OP Plt muscles during the first week, whereas central portions were relatively preserved. Marked cell activation/proliferation was also mainly observed in peripheral portions. Similarly, activated myogenic cells were seen not only inside but also outside of muscle fibers. The former were likely satellite cells and the latter may be interstitial myogenic cells. One week after surgery, small muscle fibers, small arteries and capillaries and several branched-muscle fibers were evident in the periphery, thus indicating new muscle fiber and blood vessel formation. Proliferating cells were also detected in the nerve bundles in the Schwann cell position. These results indicate that the compensatory stimulated/enlarged muscle is a suitable model for analyzing multiple physiological cellular responses in muscle–nerve–blood vessel units under continuous stretch stimulation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Intraspecific evolution ofMicroseris pygmaea (Asteraceae,Lactuceae) analyzed by cosegregation of phenotypic characters (QTLs) and molecular markers (RAPDs)

The Chilean annual,Microseris pygmaea, has differentiated in distinct coastal and inland series of populations after long-distance dispersal from western North America. Two plants from the most diverse biotypes were crossed, a large F₂ was raised and analysed for segregation of 30 phenotypic characters. Segregation of molecular markers (47 RAPDs, 1 RFLP, 2 isozymes) was determined in a subpopulation of 45 plants which include all extremes for the phenotypic characters. 32 marker/character cosegregations were significant at the 1% level in t-tests between dominant and homozygous recessive marker genotypes. Considering linkage among markers and pleiotropy of certain marker loci, the number of independent quantitative trait loci (QTLs) is reduced to about 18. Interactions among 2 or 3 QTLs affecting one character have been characterized. The phenotypic differentiation ofM. pygmaea during its evolution from a single founder individual begins to be understood at the level of single-gene mutants.     

Valve morphogenesis in Diploneis smithii (Bacillariophyta)

Diploneis species have perhaps the most complex valve structure among pennate diatoms. The development of this structure was studied in Diploneis smithii and begins with the formation of a primary band, which then develops secondary arms at both poles and the center, as in the classic Chiappino–Volcani model of raphid diatom ontogeny. Spine‐like projections grow out from the primary band and secondary arms to establish the transapical ribs (virgae) of the mature valve and themselves develop spines, which are spaced first oppositely and then alternately and fuse with each other to delimit the stria pores. Subsequently, new pattern and structures develop both externally (formation of bifurcating projections that fuse to delimit the outer, sieve‐like layer of the valve) and internally (growth and fusion of flanges from the first‐formed ribs to create the longitudinal canals and deposition of a hymenate strip over the internal face of each stria). Comparisons are made with morphogenesis in other diatoms. Diploneis smithii ontogeny suggests how very slight developmental changes might have created the very variable external morphology of Diploneis species. It also indicates that the longitudinal canals of Diploneis and Fallacia have different origins, since the porous external wall is not formed as a unilaterally attached flap in Diploneis and the canal is internal to the first‐formed rib–stria system in Diploneis, but external to it in Fallacia.     

Smad3基因剔除小鼠特异性免疫功能的研究

目的　研究Smad3基因剔除小鼠的体液免疫和细胞免疫。方法　采用流式细胞仪对其细胞免疫和体液免疫进行检测 ;并且应用ELISA方法对IgG抗体的吸光度进行测定。结果　纯合型 (- - )小鼠CD8 、CD4 CD8 、IgG雌雄之间差异有显著性 ;CD4 、CD8 、CD3 、CD19 、IgG的值低于野生型 ;结论　CD4 CD8 的比值同野生型比较属于异常 (与人的范围比较 )。因此 ,为在人类免疫疾病研究方面选用该动物提供一定的参考价值     

In vitro PPFD and media composition affect both in and ex vitro performance of Alstroemeria Butterfly-hybrids

The objective was to reduce in vitro production costs while retaining or improving plant quality, in particular the suitability for pot plant production. Plants were grown at photosynthetic photon flux densities (PPFD) of 0–40 μmol m^-2 s^-1 and sucrose concentrations of 3–7% during the multiplication phase and the effects of sucrose, BA, and NAA during root formation were investigated. Ex vitro growth were tested in both experiments. A small reduction in the rhizome multiplication rate was found with increasing PPFD and sucrose concentration. Increasing sucrose concentration reduced the number of aerial shoots. Aerial shoots were etiolated when cultured in darkness and their number increased with increasing PPFD at 3% sucrose, whereas PPFD did not affect the number of aerial shoots at 5 or 7% sucrose. During the multiplication phase a synergistic promoting effect of PPFD and sucrose was observed on root formation. Root formation after transfer to rooting medium was affected by sucrose and PPFD during the multiplication phase. PPFD did not influence root formation after propagation on 7% sucrose, whereas on 3 or 5 % sucrose root formation was gradually inhibited when PPFD was decreased below 17 μmol m^-2 s^-1. The formation of thick roots was promoted by propagation in light, and not influenced by sucrose concentration. Ex vitro growth was not affected by in vitro conditions, except for 7% sucrose during the multiplication phase that reduced flowering. Root formation on rooting medium was reduced by BA and promoted both by NAA and high levels of sucrose. The root inhibiting effect of BA could not completely be overcome by simultaneous application of NAA and high sucrose concentrations. Thick roots were only produced in the presence of NAA, and not affected by sucrose treatment. Ex vitro flowering was negatively influenced by the presence of BA during root formation and by high levels of sucrose if BA was absent in the rooting medium. High sucrose levels and NAA could partially compensate for the negative effect of BA on flowering. This revised version was published online in June 2006 with corrections to the Cover Date.     

Condensation of amino acids to form peptides in aqueous solution induced by the oxidation of sulfur(iv): An oxidative model for prebiotic peptide formation

Condensation of amino acids to peptides is an important step during the origin of life. However, up to now, successful explanations for plausible prebiotic peptide formation pathways have been limited. Here we report that the oxidation of sulfur (IV) can induce the condensation reaction of carboxylic acids and amines to form amides, and the condensation reaction of amino acids to form peptides. This might be a general reaction contributing to prebiotic peptide formation.     

PKCθ is required for hemostasis and positive regulation of thrombin-induced platelet aggregation and α-granule secretion

Platelet activation due to vascular injury is essential for hemostatic plug formation, and is mediated by agonists, such as thrombin, which trigger distinct receptor-coupled signaling pathways. Thrombin is a coagulation protease, which activates G protein-coupled protease-activated receptors (PARs) on the surface of platelets. We found that C57BL/6J and BALB/C mice that are deficient in protein kinase C θ (PKCθ), exhibit an impaired hemostasis, and prolonged bleeding following vascular injury. In addition, murine platelets deficient in PKCθ displayed an impaired thrombin-induced platelet activation and aggregation response. Lack of PKCθ also resulted in impaired α-granule secretion, as demonstrated by the low surface expression of CD62P, in thrombin-stimulated platelets. Since PAR4 is the only mouse PAR receptor that delivers thrombin-induced activation signals in platelets, our results suggest that PKCθ is a critical effector molecule in the PAR4-linked signaling pathways and in the regulation of normal hemostasis in mice.     

Cyclopamine and jervine in embryonic rat tongue cultures demonstrate a role for Shh signaling in taste papilla development and patterning: fungiform papillae double in number and form in novel locations in dorsal lingual epithelium

From time of embryonic emergence, the gustatory papilla types on the mammalian tongue have stereotypic anterior and posterior tongue locations. Furthermore, on anterior tongue, the fungiform papillae are patterned in rows. Among the many molecules that have potential roles in regulating papilla location and pattern, Sonic hedgehog (Shh) has been localized within early tongue and developing papillae. We used an embryonic, tongue organ culture system that retains temporal, spatial, and molecular characteristics of in vivo taste papilla morphogenesis and patterning to study the role of Shh in taste papilla development. Tongues from gestational day 14 rat embryos, when papillae are just beginning to emerge on dorsal tongue, were maintained in organ culture for 2 days. The steroidal alkaloids, cyclopamine and jervine, that specifically disrupt the Shh signaling pathway, or a Shh-blocking antibody were added to the standard culture medium. Controls included tongues cultured in the standard medium alone, and with addition of solanidine, an alkaloid that resembles cyclopamine structurally but that does not disrupt Shh signaling. In cultures with cyclopamine, jervine, or blocking antibody, fungiform papilla numbers doubled on the dorsal tongue with a distribution that essentially eliminated inter-papilla regions, compared with tongues in standard medium or solanidine. In addition, fungiform papillae developed on posterior oral tongue, just in front of and beside the single circumvallate papilla, regions where fungiform papillae do not typically develop. The Shh protein was in all fungiform papillae in embryonic tongues, and tongue cultures with standard medium or cyclopamine, and was conspicuously localized in the basement membrane region of the papillae. Ptc protein had a similar distribution to Shh, although the immunoproduct was more diffuse. Fungiform papillae did not develop on pharyngeal or ventral tongue in cyclopamine and jervine cultures, or in the tongue midline furrow, nor was development of the single circumvallate papilla altered. The results demonstrate a prominent role for Shh in fungiform papilla induction and patterning and indicate differences in morphogenetic control of fungiform and circumvallate papilla development and numbers. Furthermore, a previously unknown, broad competence of dorsal lingual epithelium to form fungiform papillae on both anterior and posterior oral tongue is revealed.     

Radula formation in two species of Conoidea (Gastropoda)

The radula is the basic feeding structure in gastropod molluscs and exhibits great morphological diversity that reflects the exceptional anatomical and ecological diversity occurring in these animals. This uniquely molluscan structure is formed in the blind end of the radular sac by specialized cells (membranoblasts and odontoblasts). Secretion type, and the number and shape of the odontoblasts that form each tooth characterize the mode of radula formation. These characteristics vary in different groups of gastropods. Elucidation of this diversity is key to identifying the main patterns of radula formation in Gastropoda. Of particular interest would be a phylogenetically closely related group that is characterized by high variability of the radula. One such group is the large monophyletic superfamily Conoidea, the radula of which is highly variable and may consist of the radular membrane with five teeth per row, or the radular membrane with only two or three teeth per row, or even just two harpoon-like teeth per row without a radular membrane. We studied the radulae of two species of Conoidea (Clavus maestratii Kilburn, Fedosov & Kantor, 2014 [Drilliidae] and, Lophiotoma acuta (Perry, 1811) [Turridae]) using light and electron microscopy. Based on these data and previous studies, we identify the general patterns of the radula formation for all Conoidea: the dorsolateral position of two groups of odontoblasts, uniform size, and shape of odontoblasts, folding of the radula in the radular sac regardless of the radula configuration. The morphology of the subradular epithelium is most likely adaptive to the radula type.