疑核咽肌运动神经元中SOM和NOS的共存—PRV、SOM、NOS三标记法研究

用ＰＲＶ、ＳＯＭ及ＮＯＳ三标记方法研究了ＳＯＭ和ＮＯＳ样神经元在疑核咽肌运动神经元中的共存。将ＰＲＶ注射入大鼠咽肌后,先进行ＰＲＶ和ＳＯＭ免疫荧光双标记,再进行ＮＡＤＰＨ反应。结果在疑核半致密部中观察到有少量细胞呈ＰＲＶ、ＳＯＭ和ＮＯＳ三标记。ＳＯＭ和ＮＯＳ样神经元在疑核咽肌运动神经元中共存的意义还不清楚,推测可能和咽肌运动的精细调节有关     

ANK repeat-domain of SHN-1 Is indispensable for <Emphasis Type="Italic">in vivo</Emphasis> SHN-1 function in <Emphasis Type="Italic">C. elegans</Emphasis>

Shank protein is one of the postsynaptic density (PSD) proteins which play a major role in proper localization of proteins at membranes. The shn-1, a homolog of Shank in Caenorhabditis elegans, is expressed in neurons, pharynx, intestine, vulva and sperm. We have previously reported a possible genetic interaction between Shank and IP₃ receptor by examining shn-1 RNAi in IP₃ receptor (itr-1) mutant background. In order to show the direct interaction of Shank and IP₃ receptor as well as to show the direct in vivo function of Shank, we have characterized two different mutant alleles of shn-1, which have different deletions in the different domains. shn-1 mutants were observed for Ca²⁺-related behavioral defects with itr-1 mutants. We found that only shn-1 mutant defective in ANK repeat-domain showed significant defects in defecation, pharyngeal pumping and fertility. In addition, we found that shn-1 regulates defecation, pharyngeal pumping and probably male fertility with itr-1. Thus, we suggest that Shank ANK repeat-domain along with PDZ may play a crucial role in regulating Ca²⁺-signaling with IP₃ receptor.     

Evolutionary and developmental origins of the cardiac neural crest: Building a divided outflow tract

The cardiac neural crest cells (CNCCs) have played an important role in the evolution and development of the vertebrate cardiovascular system: from reinforcement of the developing aortic arch arteries early in vertebrate evolution, to later orchestration of aortic arch artery remodeling into the great arteries of the heart, and finally outflow tract septation in amniotes. A critical element necessary for the evolutionary advent of outflow tract septation was the co‐evolution of the cardiac neural crest cells with the second heart field. This review highlights the major transitions in vertebrate circulatory evolution, explores the evolutionary developmental origins of the CNCCs from the third stream cranial neural crest, and explores candidate signaling pathways in CNCC and outflow tract evolution drawn from our knowledge of DiGeorge Syndrome. Birth Defects Research (Part C) 102:309–323, 2014. © 2014 Wiley Periodicals, Inc.     

A comparison of sampling methods for bibionid larvae (Diptera: Bibionidae) in grassland

Three extraction methods were compared for the recovery of bibionid larvae from grassland soil samples. Only wet-sieving followed by flotation in a saturated salt solution yielded bibionids. No larvae were recovered either with modified Tullgren funnels or by slow immersion of soil cores into a saturated salt solution. The efficiency with which larval bibionid populations can be estimated is poor. Generally, smaller cores yielded more larvae per volume of soil. Most bibionids were found in the top 4 cm of soil. It is concluded that 10 cm diameter and 6–8 cm deep soil cores are an acceptable compromise between efficiency and sampling effort but sample size will largely be determined by the resources available for processing of samples.     

Patterning of the third pharyngeal pouch into thymus/parathyroid by Six and Eya1

Previous studies have suggested a role of the homeodomain Six family proteins in patterning the developing vertebrate head that involves appropriate segmentation of three tissue layers, the endoderm, the paraxial mesoderm and the neural crest cells; however, the developmental programs and mechanisms by which the Six genes act in the pharyngeal endoderm remain largely unknown. Here, we examined their roles in pharyngeal pouch development. Six1-/- mice lack thymus and parathyroid and analysis of Six1-/- third pouch endoderm demonstrated that the patterning of the third pouch into thymus/parathyroid primordia is initiated. However, the endodermal cells of the thymus/parathyroid rudiments fail to maintain the expression of the parathyroid-specific gene Gcm2 and the thymus-specific gene Foxn1 and subsequently undergo abnormal apoptosis, leading to a complete disappearance of organ primordia by E12.5. This thus defines the thymus/parathyroid defects present in the Six1 mutant. Analyses of the thymus/parathyroid development in Six1-/-;Six4-/- double mutant show that both Six1 and Six4 act synergistically to control morphogenetic movements of early thymus/parathyroid tissues, and the threshold of Six1/Six4 appears to be crucial for the regulation of the organ primordia-specific gene expression. Previous studies in flies and mice suggested that Eya and Six genes may function downstream of Pax genes. Our data clearly show that Eya1 and Six1 expression in the pouches does not require Pax1/Pax9 function, suggesting that they may function independently from Pax1/Pax9. In contrast, Pax1 expression in all pharyngeal pouches requires both Eya1 and Six1 function. Moreover, we show that the expression of Tbx1, Fgf8 and Wnt5b in the pouch endoderm was normal in Six1-/- embryos and slightly reduced in Six1-/-;Six4-/- double mutant, but was largely reduced in Eya1-/- embryos. These results indicate that Eya1 appears to be upstream of very early events in the initiation of thymus/parathyroid organogenesis, while Six genes appear to act in an early differentiation step during thymus/parathyroid morphogenesis. Together, these analyses establish an essential role for Eya1 and Six genes in patterning the third pouch into organ-specific primordia.     

Hexapeptide library as a universal tool for sample preparation in protein glycosylation analysis

Recent analytical advancements allow for large-scale glycomics and glycan-biomarker research with N-glycans released from complex protein mixtures of e.g. plasma with a wide range of protein concentrations. Protein enrichment techniques to obtain samples with a better representation of low-abundance proteins are hardy applied. In this study, hexapeptide ligands previously described for enrichment of low-abundance proteins in proteomics are evaluated for glycan analysis. A repeatable on-bead glycan release strategy was developed, and glycans were analyzed using capillary sieving electrophoresis on a DNA analyzer. Binding of proteins to the hexapeptide library occurred via the protein backbone. At neutral pH no discrimination between protein glycoforms was observed. Interestingly, glycan profiles of plasma with and without hexapeptide library enrichment revealed very similar patterns, despite the vast changes in protein concentrations in the samples. The most significant differences in glycosylation profiles were ascribed to a reduction in immunoglobulin-derived glycans. These results suggest that specific and sensitive biomarkers will be hard to access on the full plasma level using protein enrichment in combination with glycan analysis. Instead, fractionation techniques or profiling strategies on the glycopeptide level after enrichment are proposed for in-depth glycoproteomics research.     

Development of the mandibular, hyoid arch and gill arch skeleton in the Chinese barb Puntius semifasciolatus: comparisons of ossification sequences among Cypriniformes

The morphogenesis and sequence of ossification and chondrification of skeletal elements of the jaws, and hyoid arch and gill arches of Puntius semifasciolatus are described. These data provide a baseline for further studies and enable comparisons with other described cypriniforms. Some general patterns of ossification in the hyoid arch and branchial arches in cypriniforms were notable. First, the overall development is from anterior to posterior, with the exception of the fifth ceratobranchial bone, which ossifies first. Second, where ossification of iterated elements is sequential, it tends to proceed from posterior to anterior, even when more posterior chondrifications are the smallest in the series. Ossification of the ceratobranchial, epibranchial and pharyngobranchial bones tends to proceed from ventral to dorsal. The comparisons revealed small sets of skeletal elements whose ossification sequence appears to be relatively conserved across cyprinid cypriniforms. Several potentially key timing changes in the ossification sequence of the jaws, hyoid arch and gill arches were identified, such as the accelerated timing of ossification of the fifth ceratobranchial bone, which may be unique to cypriniforms.