Characteristics of mast cell infiltration in lung adenocarcinoma and its impact on prognosis.

BACKGROUND: The role of mast cells in malignancies remains unclear, and there is no clear correlation between mast cells and tumor microvessels, tumor growth, or lung adenocarcinoma (LUAD) prognosis. This study aims to explore the association between mast cell density (MCD) and intratumoral microvessel density (MVD), clinicopathological parameters, and prognosis in LUAD, by evaluating mast cell infiltration characteristics and their prognostic significance. METHODS: This retrospective investigation involved 238 patients with LUAD undergoing complete resection. Tumor and normal lung tissue sections outside the tumor were immunohistochemically stained for MCD in the intratumoral and outside regions, respectively. CD34 polyclonal antibody was used to measure intratumoral MVD. RESULTS: Intratumoral regions of LUAD had a higher MCD (P < 0.001) than normal lung tissue. In the intratumoral region, MCD and CD34-MVD were positively correlated (r = 0.411, P < 0.001). Intratumoral MCD correlated with sex, smoking history, tumor differentiation, pathological subtype, and tumor size. Female sex (P = 0.012), no smoking history (P = 0.002), acinar predominant type (P = 0.012), and tumor size ≤ 3 cm (P = 0.009) were associated with a higher MCD, whereas poorly differentiated (P = 0.039) and solid/micropapillary predominant types (P = 0.001) were associated with a lower MCD. Higher intratumoral MCD exhibited a marginally improved overall survival, and individuals with higher MCD infiltration ratios (intratumoral MCD/outside the MCD) had higher disease-free and overall survival rates (log-rank P < 0.001). A high MCD infiltration ratio was associated with decreased risk of tumor progression and death following complete resection. CONCLUSION: The tumor microenvironment controls mast cell infiltration in LUAD, and patients with increased intratumoral mast cell infiltration have better prognosis.

Land-use intensification exerts a greater influence on soil microbial communities than seasonal variations in the Taihu Lake region, China.

The Taihu Lake region has undergone intensive land-use conversions from natural wetlands (NW) to conventional rice-wheat rotation fields (RW) and further to greenhouse vegetable fields (GH). Nevertheless, the effects of these conversions on soil microbes, particularly in wetland ecosystem, are not well explicit. To explore the impact of land-use intensification on soil microbial communities, monthly soil samples were obtained from replicate plots representing three land-use types (NW, RW, and GH) in subtropical wetlands and then subjected to amplicon sequencing. Land-use intensification had direct effects on bacterial and fungal community composition, with a more pronounced impact on bacteria than on fungi. These changes in bacterial communities were closely correlated with variations in soil environmental variables, such as NO3--N, pH, and electrical conductivity. Land-use intensification led to a decrease in bacterial deterministic processes, with an opposing trend observed in the fungal community. In addition, arable lands (RW and GH), which are affected by anthropogenic activities, exhibited more complex networks. Potential metabolic functional groups in GH had higher absolute abundance. Seasonal variations significantly influenced microbial diversity, composition, and potential metabolic functional groups within each land-use type, particularly in summer, although the magnitude of this impact was much smaller than the impact of land-use intensification. Our findings emphasize the importance of comprehending the ecological consequences of land-use intensification in wetlands for sustainable resource management and biodiversity conservation.

Clinical outcomes associated with neoadjuvant therapy for the treatment of resectable non-small cell lung cancer in real-world practice.

BACKGROUND: In order to improve survival outcomes in resectable non-small cell lung cancer (NSCLC), strategies for neoadjuvant therapy need to be revisited. We evaluated and compared the efficacy of different neoadjuvant therapeutic modalities in a real-world setting. METHODS: A total of 258 patients with clinical stage IIA to IIIB NSCLC was included. All the patients underwent surgical resection after one to four cycles of neoadjuvant treatment consisting of chemotherapy (83), immunotherapy (23), and immunotherapy plus chemotherapy (152). RESULTS: The radiologic response rate in the combined immunochemotherapy group was 67.8%, higher than that of 48.2% in the chemotherapy group and 4.3% in the immunotherapy group (p < 0.001). An improved major pathological response (MPR) was also achieved in the combined therapy group compared with the chemotherapy group and the immunotherapy group (53.9% vs. 10.8% vs. 8.7%, p < 0.001). Patients in the combined therapy group had a significant trend toward longer disease-free survival than those in the chemotherapy alone group (3-year disease-free survival [DFS] of 68.79% vs. 50.81%; hazard ratio [HR] for progression or death, 0.477; p = 0.003). Multivariate Cox analysis identified radical surgery (HR, 0.328; p = 0.033), ypN0-1 stage (HR, 0.591; p = 0.038) and MPR result (HR, 0.362; p = 0.007) to be independent prognostic factors for DFS. CONCLUSIONS: Neoadjuvant treatment with a combination of immunotherapy plus chemotherapy appears to achieve higher radiological and pathological responses than monotherapy for IIA-IIIB NSCLC. Log-rank analysis showed that a better outcome could be expected in patients with the addition of immunotherapy to neoadjuvant chemotherapy if compared with patients with chemotherapy alone in terms of DFS.

NosZ I carrying microorganisms determine N2O emissions from the subtropical paddy field under elevated CO2 and strongly CO2-responsive cultivar.

Elevated CO2 (eCO2) decreases N2O emissions from subtropical paddy fields, but the underlying mechanisms remain to be investigated. Herein, the response of key microbial nitrogen cycling genes to eCO2 (ambient air +200 µmol CO2 mol-1) in four rice cultivars, including two weakly CO2-responsive (W27, H5) and two strongly CO2-responsive cultivars (Y1540, L1988), was investigated. Except for nosZ I, eCO2 did not significantly alter the abundance of the other genes. NosZ I was a crucial factor governing N2O emissions, especially under eCO2 and a strongly responsive cultivar. eCO2 affected the nosZ I gene abundance (p < 0.05), for instance, the nosZ I gene abundance of cultivar W27 increased from 1.53 × 107 to 2.86 × 107 copies g-1 dw soil (p < 0.05). In the nosZ I microbial community, the known taxa were mainly Pseudomonadota (phylum) (19.74-31.72 %) and Alphaproteobacteria (class) (0.56-13.12 %). In the nosZ I community assembly process, eCO2 enhanced the role of stochasticity, increasing from 35 % to 85 % (p < 0.05), thereby inducing diffusion limitations of weakly responsive cultivars to dominate (67 %). Taken together, the increase in nosZ I gene abundance is a potential reason for the alleviation of N2O emissions from subtropical paddy fields under eCO2.

Unravelling novel and pleiotropic genes for cannon bone circumference and bone mineral density in Yorkshire pigs.

Leg weakness is a prevalent health condition in pig farms. The augmentation of cannon bone circumference and bone mineral density can effectively improve limb strength in pigs and alleviate leg weakness. This study measured forelimb cannon bone circumference (fCBC) and rear limb cannon bone circumference (rCBC) using an inelastic tapeline and rear limb metatarsal area bone mineral density (raBMD) using a dual-energy X-ray absorptiometry bone density scanner. The samples of Yorkshire castrated boars were genotyped using a 50K single-nucleotide polymorphism (SNP) array. The SNP-chip data were imputed to the level of whole-genome sequencing data (iWGS). This study used iWGS data to perform genome-wide association studies and identified novel significant SNPs associated with fCBC on SSC6, SSC12, and SSC13, rCBC on SSC12 and SSC14, and raBMD on SSC7. Based on the high phenotypic and genetic correlations between CBC and raBMD, multi-trait meta-analysis was performed to identify pleiotropic SNPs. A significant potential pleiotropic quantitative trait locus (QTL) regulating both CBC and raBMD was identified on SSC15. Bayes fine mapping was used to establish the confidence intervals for these novel QTLs with the most refined confidence interval narrowed down to 56 kb (15.11 to 15.17 Mb on SSC12 for fCBC). Furthermore, the confidence interval for the potential pleiotropic QTL on SSC15 in the meta-analysis was narrowed down to 7.45 kb (137.55 to137.56 Mb on SSC15). Based on the biological functions of genes, the following genes were identified as novel regulatory candidates for different phenotypes: DDX42, MYSM1, FTSJ3, and MECOM for fCBC; SMURF2, and STC1 for rCBC; RGMA for raBMD. Additionally, RAMP1, which was determined to be located 23.68 kb upstream of the confidence interval of the QTL on SSC15 in the meta-analysis, was identified as a potential pleiotropic candidate gene regulating both CBC and raBMD. These findings offered valuable insights for identifying pathogenic genes and elucidating the genetic mechanisms underlying CBC and BMD.

Leg weakness, a highly prevalent health condition in pig breeding farms, adversely affects the lifespan of breeding pigs. The augmentation of cannon bone circumference (CBC) and bone mineral density (BMD), which are objective measures of limb strength in pigs, can effectively alleviate leg weakness. To identify candidate genes regulating CBC and BMD in pigs, this study performed single-trait genome-wide association studies and multi-trait meta-analysis on all individuals with phenotype data. Additionally, the confidence intervals of quantitative trait locus (QTL) were determined using Bayesian methods. Four CBC-associated QTLs and one BMD-associated QTL were identified. Additionally, one potential pleiotropic QTL associated with both CBC and rear limb metatarsal area BMD (raBMD) was identified. This study demonstrated that DDX42, MYSM1, FTSJ3, and MECOM were candidate genes regulating forelimb CBC, while SMURF2 and STC1 were candidate genes regulating rear limb CBC. Additionally, RGMA was demonstrated to regulate raBMD, while RAMP1 was identified as a potential pleiotropic gene regulating both CBC and raBMD. The findings of this study provide valuable insights into the genetic mechanisms underlying limb growth and bone mineral accumulation.

Genome-wide association analysis revealed new QTL and candidate genes affecting the teat number in Dutch Large White pigs.

Teat number (TNUM) is an important reproductive trait of sows, which affects the weaning survival rate of piglets. In this study, 1166 Dutch Large White pigs with TNUM phenotype were used as the research object. These pigs were genotyped by 50K SNP chip and the chip data were further imputed to the resequencing level. The estimated heritabilities of left teat number (LTN), right teat number (RTN) and total teat number (TTN) were 0.21, 0.19 and 0.3, respectively. Based on chip data, significant SNPs for RTN on SSC2, SSC5, SSC9 and SSC13 were identified using genome-wide association analysis (GWAS). Significant SNPs for TTN were identified on SSC2, SSC5 and SSC7. Based on imputed data, the GWAS identified a significant SNP (rs329158522) for LTN on SSC17, two significant SNPs (rs342855242 and rs80813115) for RTN on SSC2 and SSC9, and two significant SNPs (rs327003548 and rs326943811) for TTN on SSC5 and SSC6. Among them, four novel QTL were discovered. The Bayesian fine-mapping method was used to fine map the QTL identified in the GWAS of the imputed data, and the confidence intervals of QTL affecting LTN (SSC17: 45.22-46.20 Mb), RTN (SSC9: 122.18-122.80 Mb) and TTN (SSC5: 14.01-15.91 Mb, SSC6: 120.06-121.25 Mb) were detected. A total of 52 candidate genes were obtained. Furthermore, we identified five candidate genes, WNT10B, AQP5, FMNL3, NUAK1 and CKAP4, for the first time, which involved in breast development and other related functions by gene annotation. Overall, this study provides new molecular markers for the breeding of teat number in pigs.

Introgression of pigs in Taihu Lake region possibly contributed to the improvement of fertility in Danish Large White pigs.

BACKGROUND: Eurasian pigs have undergone lineage admixture throughout history. It has been confirmed that the genes of indigenous pig breeds in China have been introduced into Western commercial pigs, providing genetic materials for breeding Western pigs. Pigs in Taihu Lake region (TL), such as the Meishan pig and Erhualian pig, serve as typical representatives of indigenous pig breeds in China due to their high reproductive performances. These pigs have also been imported into European countries in 1970 and 1980 s. They have played a positive role in improving the reproductive performances in European commercial pigs such as French Large White pigs (FLW). However, it is currently unclear if the lineage of TL pigs have been introgressed into the Danish Large White pigs (DLW), which are also known for their high reproductive performances in European pigs. To systematically identify genomic regions in which TL pigs have introgressed into DLW pigs and their physiological functions, we collected the re-sequencing data from 304 Eurasian pigs, to identify shared haplotypes between DLW and TL pigs. RESULTS: The findings revealed the presence of introgressed genomic regions from TL pigs in the genome of DLW pigs indeed. The genes annotated within these regions were found to be mainly enriched in neurodevelopmental pathways. Furthermore, we found that the 115 kb region located in SSC16 exhibited highly shared haplotypes between TL and DLW pigs. The major haplotype of TL pigs in this region could significantly improve reproductive performances in various pig populations. Around this genomic region, NDUFS4 gene was highly expressed and showed differential expression in multiple reproductive tissues between extremely high and low farrowing Erhualian pigs. This suggested that NDUFS4 gene could be an important candidate causal gene responsible for affecting the reproductive performances of DLW pigs. CONCLUSIONS: Our study has furthered our knowledge of the pattern of introgression from TL into DLW pigs and the potential effects on the fertility of DLW pigs.

[Application characteristics and modern research progress of "bone-approaching" acupuncture].

The paper explores the evolution of "bone-approaching" acupuncture, its effect target and mechanism. The concrete operation procedure of "bone-approaching" method is recorded originally in Huangdi Neijing (Inner Canon of Yellow Emperor) as short needling and Shu needling (referring to the category of the five needling technique). The periosteum is the most effective stimulation target of "bone-approaching" acupuncture for analgesia, regaining consciousness and regulating spirit. The "bone-approaching" acupuncture is not only prominently effective on bone bi syndrome, but also has the unique effect on painful, encephalogenic and emotional diseases. The paper summarizes and improves "bone-approaching" acupuncture, i.e. "touching bone surface" with needle tip by slow insertion, "touching bone surface" without pain by swift insertion and "touching bone" with needle body by oblique insertion. It contributes to the inheritance, development and supplementation to the bone needling techniques in Huangdi Neijing and is significant for broadening the clinical application range of acupuncture.

Circ_0007429/miR-637/TRIM71/Ago2 axis participates in the regulation of proliferation, migration, invasion, apoptosis, and aerobic glycolysis of HCC.

CircRNAs play an important role in the progression of hepatocellular carcinoma (HCC), however, the role of circ_0007429 in HCC remains unknown. Using bioinformatics tools, we selected circ_0007429 that was most highly expressed in HCC tissues and investigated its role in HCC progression. Immunohistochemistry, plasmid transfection, real-time quantitative PCR, and western blot analysis were used to identify the relationship between circ_0007429 and its potential target, miR-637, and TRIM71. The regulatory effect of circ_0007429 on miR-637/TRIM71/Ago2 signaling and its key role in HCC progression were studied in vitro. A nude mouse xenograft model was used to examine tumor growth in vivo. Circ_0007429 and TRIM71 expression were upregulated, while miR-637 expression was downregulated in HCC tissues and cells compared with their expression in control groups. Knockdown of circ_0007429 enhanced apoptosis in HCC cells, while impeded proliferation, migration, invasion, and aerobic glycolysis, which were reversed by miR-637 inhibitor. High levels of circ_0007429 correlated with a poor survival rate of HCC patients. Additionally, circ_0007429 interfering inhibited tumor growth in vivo. TRIM71 directly bound to miR-637 and inhibited Ago2 expression. Moreover, circ_0007429 promotes aerobic glycolysis in HCC cells through the miR/TRIM71/Ago2 axis. Circ_0007429 promotes HCC progression by promoting cell proliferation, migration, invasion, and aerobic glycolysis and by inhibiting cell apoptosis through the miR/TRIM71/Ago2 axis. These results provide molecular insights into the mechanism of HCC and suggest that circ_0007429 could be a therapeutic target for HCC.

Differential responses of soil bacterial communities to elevated CO2 between strongly CO2-responsive and weakly CO2-responsive rice cultivars.

Effects of elevated CO2 (eCO2) on paddy soil microbial communities remain unclear, particularly when different rice cultivars exposed to eCO2. We thus compared responses of soil bacterial communities to ambient CO2 (aCO2) and eCO2 (aCO2 + 200 µmol CO2 mol-1) between two weakly CO2-responsive (Wuyunjing27, W27; Huaidao5, H5) and two strongly CO2-responsive rice cultivars (Yongyou1540, Y1540; LongIIyou1988, L1988) throughout six growth stages (early tillering, late tillering, jointing, heading, grain filling and ripening) in a paddy field in Jiangdu, China in 2018. No significant changes in soil bacterial diversities were observed between eCO2 and aCO2 or between cultivars for any single growth stage at the OTU level, but α diversity significantly changed at the phylum level except for the ripening stage. For a single cultivar, particularly two strongly CO2-responsive cultivars, over their whole growth stage, eCO2 enhanced differences in bacterial ß diversity at both OTU and phylum levels under H5, Y1540 and L1988. Soil bacterial community complexity at the phylum level under eCO2 was weakened under W27, H5 and Y1540, but enhanced under L1988. eCO2-induced changes in soil DOC under these four cultivars had significantly positive impact on bacterial abundances. However, structural equation modeling illustrated that changes in soil DOC induced by eCO2 significantly decreased soil bacterial community richness. eCO2 did not significantly affect relationships between soil bacterial community diversities and rice yields, but displayed significantly negative correlations between strongly CO2-responsive rice cultivars' yields and relative abundances of Proteobacteria at the ripening stage. Dynamics that how soil microbial communities can differentiate their eCO2 responses between strongly- and weakly-responsive rice cultivars will provide a new insight into promoting rice productivity and soil health.

Investigation of Rice Yields and Critical N Losses from Paddy Soil under Different N Fertilization Rates with Iron Application.

The application of iron powder stimulated the growth of iron-reducing bacteria as a respiratory substrate and enhanced their nitrogen (N)-fixing activity in flooded paddy soils. High N fertilization (urea) in the flooded paddy soils has caused adverse environmental impacts such as ammonia (NH3) volatilization, nitrous oxide (N2O) emissions, and nitrate (NO3-) leaching. This study aims to investigate the effects of N fertilization rates in combination with an iron amendment on rice yields and N losses from flooded paddy fields. We performed a 2-year field plot experiment with traditional rice-wheat rotation in China's Yangtze River Delta. The investigation consisted of seven treatments, including 100%, 80%, 60%, and 0% of the conventional N (urea and commercial organic manure) fertilization rate, and 80%, 60%, and 0% of the conventional N with the iron powder (≥99% purity) amendment. The rice yields decreased with a reduction in the conventional N fertilization rate, whereas they were comparable after the iron application under the 80% and 60% conventional N rate. The critical N losses, including NH3 volatilization, N2O emissions, and NO3- and NH4+ leaching, generally decreased with a reduction in the conventional N fertilization rate. These N losses were significantly greater after the iron amendment compared with the non-amended treatments under the 80% and 60% conventional N fertilization rate in the first rice-growing season. However, it was comparable between the iron-amended and the non-amended treatments in the second season. Furthermore, NO3- leaching was the most significant N loss throughout the two rice seasons, followed by NH3 volatilization. The iron amendment significantly increased soil Fe2+ content compared with the non-amended treatments irrespective of N fertilization, suggesting the reduction of amended iron by iron-reducing bacteria and their simultaneous N fixation. A combination of the iron application with 60-80% of the conventional N fertilization rate could maintain rice yields similar to the conventional N fertilization rate while reducing the critical N losses in the flooded paddy field tested in this study. Our study leads to the establishment of novel and practical rice cultivation, which is a step towards the development of green agriculture.

Observations on the oral organelle, cytopharynx, and subpellicular structure of a Dileptus sp.

We used scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to observe the oral organelle, cytopharynx, and subpellicular structure of a Dileptus sp. The main results were as follows: (a) the cytostome was located on the ventral surface of the base of the beak, surrounded by a periportal matrix that integrated 135 microtube bundles. When these microtube bundles contract, radially arranged into a disk, the cytostome was closed. When these microtube bundles were stretch, they fell into the cytostome and opens. The diameter of the cytostome was about 16 µm regardless of its closure or opening, indicating that the contraction or elongation of these microtube bundles did not change the size of the cytostome, which was only related to whether it blocked the cytostome, thus determining the opening and closing of the cytostome. There were many microtube bundles on two sides of the feeding trough, which could widen or narrow the feeding trough and facilitate beak feeding. (b) The cytopharynx was basket-like without a bottom with a diameter of about 6 µm and was woven from two kind fibers about 0.08 and 0.19 µm. (c) There were two types of extrusomes under the pellicle. Using transmission electron microscopy，the Type I extrusomes showed narrow and long egg shape, its cross section was circular which is composed by various electronic density of concentric. Using the scanning electron microscope, they were two slightly thin clavate, the length was about 5 µm, the diameter of the middle section was about 0.75 µm, and the diameter of the two ends was about 0.32 µm, they were distributed abundantly between the microtubule fasciculi which were located on both sides of the gap on the feeding groove. Using transmission electron microscopy, the Type II extrusomes showed egg shape. Using the scanning electron microscopy, they were about 1.6 × 0.8 µm in size, they were distributed abundantly under the body pellicle while rarely the proboscis. In addition, many different of developmental stages two types of extrusomes could be also seen in the cytoplasm. (d) There were very well-developed fibrous systems under the pellicle that were woven from fibers about 0.14 µm in diameter that attached to the pellicle and bound some organelles in the cytoplasm (e.g., mitochondria, extrusomes) and other structures to the cytoplasm and maintained cell morphology. The results of this study not only supplement and enrich the morphological contents of the Dileptus sp., but also provide the basis for the study of the taxonomy of the Dileptus sp. It also provides a new method for researchers to explore the morphology and structure of ciliate cells under the cortex by SEM.

Morphology and systematics of two freshwater Frontonia species (Ciliophora, Peniculida) from northeastern China, with comparisons among the freshwater Frontonia spp.

The morphology and infraciliature of two Frontonia species, F. shii spec. nov. and F. paramagna Chen et al., 2014, isolated from a freshwater pond in northeastern China, were investigated using living observation and silver staining methods Frontonia shii spec. nov. is recognized by the combination of the following characters: freshwater Frontonia, size in vivo about 220-350 × 130-250 µm, elliptical in outline; 128-142 somatic kineties; three or four vestibular kineties, six or seven postoral kineties; peniculi 1-3 each with four kineties; single contractile vacuole with about 10 collecting canals. The improved diagnosis for F. paramagna is based on the current and previous reports. Comparisons among freshwater Frontonia are also provided. The small subunit ribosomal rRNA gene (SSU rDNA) sequences of the two species are characterized and phylogenetic analyses based on these sequences show that both species fall into the core clade of the genus Frontonia, and this genus is not monophyletic.

Morphology and systematics of two freshwater urostylid ciliates, with description of a new species (Protista, Ciliophora, Hypotrichia).

The morphology of two freshwater urostylid species, Neourostylopsis flava spec. nov. and Pseudourostyla subtropicaChen et al., 2014, isolated from freshwater ponds in northern and southern China, respectively, was investigated following examination of specimens in vivo and following protargol staining. Neourostylopsis flava spec. nov. is distinguished from its congeners by the following characteristics: body size 150-220 × 50-75 µm in vivo; yellow in colour; bright yellow to yellow-brownish spherical cortical granules densely arranged along marginal cirral rows and in irregular short rows on dorsal side; adoral zone with 40-55 membranelles; six to eight frontal, three or four buccal, two pretransverse ventral and seven to nine transverse cirri; 27-40 midventral pairs extending to about anterior 55% of cell; four or five left and four right marginal rows; freshwater habitat. A redescription of a freshwater population of P. subtropica is also provided. Phylogenetic analyses based on small subunit ribosomal DNA sequences shows that P. subtropica and N. flava spec. nov. group with their congeners and both Neourostylopsis and Pseudourostyla are monophyletic.

Identification of biochemical association of phycobilisome with photosystems in cyanobacterial state transition.

State transition is a short-term balance mechanism of energy distribution between photosystem II (PSII) and PSI. Although light-induced state transition in cyanobacteria has been suggested to depend completely on the phycobilisome (PBS) movement between PSII and PSI, the biochemical evidence has not been clearly shown. In this study, we locked the association of PBS with PSII or PSI using glycinebetaine when cells attain State 1 or 2 by exposure to light of blue or green, respectively. Subsequently, the PBS-reaction centers were resolved by blue native polyacrylamide gel electrophoresis and two-dimensional electrophoresis, and then identified by western blot analysis. The results showed that in wild-type (WT) Synechocystis sp. strain PCC 6803, the PBS core always co-migrates with the PSII dimer during light-induced State 1-State 2 transition, but its rod leaves the PSII dimer in State 2 regardless of its co-migration in State 1. In the light-induced State 2, the co-migration of PBS rod with PSI trimer was observed in WT, but not in ΔndhB (M55), a State-2-transition-deficient mutant. This study first provided the biochemical evidence for the association of PBS with photosystems during cyanobacterial state transition.

Morphology and Phylogeny of a New Frontonia Ciliate, F. paramagna spec. nov. (Ciliophora, Peniculida) from Harbin, Northeast China.

This paper describes a new Frontonia ciliate, F. paramagna spec. nov., sampled from freshwater in Harbin, northeast China, based on its morphology, infraciliature, ultrastructure and small subunit ribosomal RNA gene information. The new species is defined by the following features: large sized freshwater form, 400-610 × 110-160 µm in vivo, about 179-201 somatic kineties, three peniculi, each with four kineties, three vestibular and six or seven postoral kineties, one elongated-elliptical macronucleus, centrally-located, a single contractile vacuole, without canals, located right-dorsally in the posterior half of the body. Sequence alignment and phylogenetic analyses based on the small subunit ribosomal RNA (SSU rRNA) gene indicated that the new species has characters distinct from its known congeners. The ultrastructure of the trichocyst and other extrusomes, and the subpellicular fibre system, were observed by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Much of the ultrastructure is here given for the first time by SEM, and these features provide complementary data for taxonomic purposes.

Morphogenesis of the freshwater ciliate Neokeronopsis spectabilis (Kahl 1932) Warren et al., 2002, based on a China population (Ciliophora: Urostylidae).

The morphogenesis of the stichotrichous ciliate, Neokeronopsis spectabilis, collected from a freshwater pond near Harbin, north China, was observed following protargol impregnation. The overall morphogenetic events are characterized by: (1) the new oral primordium originates in association with the transverse cirri; (2) the proter's undulating membrane anlage is formed following the dedifferentiation of the parental endoral and paroral membranes, while the old adoral zone of membranelles is retained; (3) the fronto-ventral-transverse cirral anlagen originate independently on the right of the proter's undulating membrane anlage; (4) the left and right marginal cirri are derived from new anlagen that originate within the old marginal rows; (5) the generation of the dorsal kineties is of the "two-group-mode" with fragmentation and hence an oxytrichid pattern; and (6) similar to that in oxytrichids, the caudal cirri are formed at the posterior ends of the rightmost and two leftmost kineties of the group 1. Some new morphological data for N. spectabilis are also presented and the systematic position of the genus Neokeronopsis is briefly discussed. We conclude that its position among the urostylids is peripheral and that it very likely represents an intermediate form between the oxytrichids and urostylids.