P3 Populations Research Articles

Determination of Yield and Yield Components of Popcorn (Zea mays L. everta) Genotypes

This research was conducted in Samsun Bafra conditions in 2021, using a total of 19 different genotypes of popcorn, which differ from other corn subspecies in terms of grain size and usage area, and have gained popularity for snacking purposes. The experiment was set up in a randomized complete block design with three replications. The study examined plant height, main stem diameter, leaf number, cob length, cob diameter, cob row number, number of kernels per cob, cob weight, kernel weight, and grain yield of the popcorn genotypes. It was determined that there is a statistically significant relationship between these examined parameters and genotypes. According to the results of the experiment, plant height in popcorn genotypes ranged from 128.33 to 207.00 cm, main stem thickness varied between 11.91 and 20.20 mm, leaf number per plant ranged from 8.33 to 12.33, cob length varied from 11.60 to 20.33 cm, cob diameter ranged from 27.63 to 36.49 mm, cob row number varied between 12.00 and 15.67, and the number of kernels per cob ranged from 405.67 to 772.67. The grain yield values ranged from 183.05 to 482.43 kg/da. The research determined that the average grain yields of populations and lines were higher than the overall average of popcorn cultivars. When considering grain yield and yield parameters, the TBCM-6 line stood out. According to the biplot analysis, it was observed that the P2 and P3 populations, along with the TBCM-3, TBCM-4, TBCM-6, TBCM-23, TBCM-44, and TBCM-62 lines, excelled in terms of yield and yield components.

Phenotypic Characterization of Oryza nivara (Sharma et Shastry) Collected from Different Ecological Niches of Sri Lanka

Information on the genetic diversity of wild rice species in Sri Lanka is relatively meagre, though it plays a key role in crop improvement programs of cultivated rice (Oryza sativa L.). The present study was carried out to identify the morphological variation pattern of the wild populations of O. nivara in Sri Lanka. Seven populations (P1 to P7) collected from different agro-ecological regions were characterized in a common garden based on nine morphological traits. The findings revealed a high level of phenotypic variation between populations when compared to within a population. The most variable traits were the flag leaf panicle neck length (FLPNL) and flag leaf angle (FLA), whereas the least variable trait was the flag leaf length (FLL). Box plots clearly illustrated the large differentiation of phenotypic traits in the entire distribution of wild rice populations. The cumulative values of the two principal components, i.e., FLPNL and FLA, explained 58.7% of the total variance. Populations from similar natural habitats clustered together. The P7 was adapted to intercept more sunlight by increasing flag leaf width (FLW) and FLA to compete with weeds and other shrubs. P2 and P5 were the most closely related populations representing approximately similar ecological conditions of the dry zone. The P3 population from the intermediate zone showed a vigorous plant growth with the highest plant height, culm girth and awn length (P < 0.05). Knowledge of such morphological diversity would facilitate designing conservation strategies and basic information for the proper utilization of wild resources in rice genetic improvement.

Improvement of two local populations of corn by the mass selection with checking of the pollen for Chadian producers

The objective of the test was to improve 2 local populations of corn by consistent 2 cycles of a performance selection test with the witness. The plant materials were composed of P1 and P3 populations of corn gotten through the simple recurrent selection and P1A and P3A populations descended of the mass selection and witness T. The test has been led with P1 and P3 populations of corn according to an experimental device of parcel subdivided into 4. It has been followed from a test of performance of T1 and T2 treatments with witness according to an experimental device of blocks of Fisher to 4 repetitions. The genetic gain of row number per ear of P1A was 2.32% ± 0.029 and of P3A was 1.70% ± 0.026. The genetic gain of grain number per row of P1A was of 0.46% ± 0.013 and that of P3A was 0.95% ± 0.024. The genetic gain of weight of the grains of P1A was 6.42% ± 0.016 and that P3A was of 2.26% ± 0.035. The genetic gain of output in grain of P1A was of 7.64% ± 0.02 and P3A was of 5.11% ± 0.025. The best number of grain per row was registered on T1 (43.62 ± 0.135). The best grain output was obtained on T2 (3.21 t ha-1 ± 0.03). The best performances of P1A and P3A will permit to increase the productivity of corn. Also, these populations of corn will act as basis to the program of variety improvement. Key words: Variety improvement, Zea mays L, genetic gain, improved populations, Chad.

Understanding project cancellation risks in U.S. P3 surface transportation infrastructure

Public private partnership (P3) projects can face many internal and external risks affecting their development and implementation. As a result, this research explores the understudied risk factors underlying the U.S.’ cancelled, deferred, and terminated (CDT) P3 projects. A database of CDT projects is developed. Of the projects identified as the U.S. surface transportation P3 population, 46% (31 out of 68) experienced cancellation, deferment or early contract termination. The research then applied a risk typology and a multi-case study method to the troubled cases to identify common risk factors. Data collection focused primarily on the identification of political (public and political voice, bureaucratic complexity) and economic risk factors. The most frequently identified factors across the 31 cancelled, deferred, or terminated cases include political opposition, local opposition, and inadequate demand projections. Since the paper studies the entire U.S. surface transportation P3 project population, the results serve to inform public agencies and private sector actors of possible friction points meriting consideration during P3 procurement planning.

Abstract 1168: Characterization of tumor initiation cells in mammary tissues of C3-1-TAg transgenic mice

Abstract Animal models are powerful tools for the understanding of tumor development and cancer stem cell (CSC) origin. C3-1-TAg transgenic mice are a model for human triple negative breast cancer. Although general patterns of tumor development in this model have been well characterized, the tumor initiation cells of this model have not been defined. The objective of this study was to characterize the stemness and growth properties of mammary tumor cells in context with mammary epithelial cell (MEC) subpopulations of C3-1-TAg transgenic mice to identify the origin of tumor initiation cells. We first isolated MECs from mammary tissues of C3-1-TAg mice at various ages (8, 17, and 23 weeks old) and primary tumor cells from tumors of this model. Flow cytometry analysis with CD24 and CD49f as cell markers showed that cells from mammary tissues were separated into three subpopulations, including luminal, basal, and stromal populations. We found that the percentage of luminal subpopulation increased with age. Analysis of tumor derived cells using the same markers indicated that the majority of the cells in the plots overlapped with the position of luminal epithelial cells, suggesting their mutual connections. Next, we performed FACS sorting of mammary epithelial cells from the glands based on CD24 and CD49f and obtained four subpopulations of cells, including P1(stromal), P2(luminal), P3(CD24high/CD49fhigh, top of basal population on the plot), and P4(CD24mid/CD49fhigh, lower part of basal population), followed by the characterization of each subpopulations. Colony formation cell (CFC) assay and mammosphere assay were used for evaluation of luminal progenitor cells and self-renewal potential, respectively. Data from CFC assays showed that CFC colony numbers were the highest from the P2 population, followed by a few colonies from P3 population. Mammosphere assay showed that cells from P1 population formed typical mammospheres, while as cells from P2 and P3 formed cellular clusters different from typical mammospheres. FACS sorting with cells from C3-1-TAg mammary tumors obtained P2 and P3 subpopulations. Cells from P2, not P3, subpopulation were efficient in mammosphere formation. Because cells in P2 population are luminal mammary epithelial cells and are enriched with luminal progenitor cells, integration of data above suggest that C3-1-TAg mammary tumor cells are mainly derived from luminal progenitor cells. Using CD61, which is a luminal progenitor cell marker, we found that the percentage of luminal progenitor cells (CD61+/CD49fhigh) in the mammary glands was increased with age, and most tumor derived cells were CD61+/CD49fhigh. Taken together, our data demonstrate that the tumor initiation cells in the C3-1-TAg mammary tumors were derived from luminal progenitor cells. These findings lay a foundation for further characterization of cellular basis and molecular analysis of tumorigenesis in C3-1-TAg transgenic models. Citation Format: Qiong Cheng, Amanda B. Parris, Zhikun Ma, Yujie Shi, Lingfei Kong, Xiaohe Yang. Characterization of tumor initiation cells in mammary tissues of C3-1-TAg transgenic mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1168.

Genetska varijabilnost unutar i između generativnih potomstava divlje ruže (Rosa sp.)

Dog rose (Rosa canina L.) is a cosmopolitan plant species that due to its nutritional, medical and cosmetic values deserves more attention. Dog roses are cultivated in Croatia on very small scale and most of the rose hip used in the domestic processing industry is imported. In this study, three dog rose F1 progeny populations developed from selected plants collected in Korcula, Malesnica and Prigorje Brdovecko, originating from two climatic regions (P1 - Mediterranean and P2 and P3 - continental) have been studied as a part of a field experiment for two growing seasons, in order to assess the level of genetic variability for pomological and agronomic traits. In addition, genetic variation within and among examined three dog rose populations has been assessed using 6 polymorphic SSR markers. The highest variability, as well as the most desirable agronomic traits were found within the P3 population, while the lowest ones were present in the P1 population. Most desirable properties and highest values for commercially important traits were detected in the genotype RC29 (P3). Molecular data was sufficient to separate three studied populations but not all individuals within the populations. Through selection and hybridization of perspective genotypes of dog roses from Croatia, it would be possible to create clonally propagated varieties suitable for commercial cultivation.

Cross-resistance to diflufenican and picolinafen and its inheritance in oriental mustard (Sisymbrium orientale L.).

An oriental mustard population (P40) was identified as resistant to diflufenican by screening at the field rate. As diflufenican and picolinafen both target phytoene desaturase (PDS), cross-resistance to picolinafen was suspected. The mechanism of resistance and its inheritance to diflufenican and picolinafen were investigated. At the lethal dose (LD50 ) level, population P40 was 237-fold more resistant to diflufenican and seven-fold more resistant to picolinafen compared to two susceptible populations. Population P40 also had a significantly higher resistance to diflufenican (237-fold) than a previously described P3 population (143-fold). In addition to the Leu-498-Val mutation in PDS identified in all individuals of the P3 and P40 populations, a Glu-425-Asp mutation was also found in P40. Neither mutation was detected in any individuals of the susceptible population. As the segregation of phenotype and genotype of the F2 individuals fitted the model for a single dominant allele, resistance to both diflufenican and picolinafen is likely encoded on the nuclear genome and is dominant. Resistance to diflufenican and picolinafen in the P40 population is likely conferred by Leu-498-Val and Glu-425-Asp mutations in the PDS gene. Inheritance of resistance to these herbicides is managed by a single dominant gene. © 2018 Society of Chemical Industry.

Functionally Distinct Cell Populations Characterize Cord Blood Derived Megakaryocytes

A fundamental understanding of platelet biology requires functional assessment of megakaryocyte-platelet expressed genes and transcripts. The need for gene functional studies has recently increased with unbiased genome wide associations with platelet phenotypes. Animal models with an over-expressed or knocked-out gene have been particularly valuable systems, although species differences may preclude optimal evaluation. Assessing protein function in human platelets can be accomplished with pharmacologic inhibitors, although inhibitor availability and specificity can plague this approach. Studies with primary human megakaryocytes (MKs) are greatly challenged by inaccessibility, low yields and contamination with other cells. Cultured human megakaryocyte-like cell lines (e.g., Meg-01, HEL and others) have proven valuable, but these cells poorly recapitulate platelet physiology. Increasingly, investigators are using cultured human MKs to study gene function. CD34+ hematopoietic stem cells from human cord blood are routinely used to generate megakaryocytes in culture. This system has advantages of being human, relatively easy to obtain, cultured from primary cells and able to be genetically manipulated. Although cord blood-derived megakaryocytes (CBDMs) have proven useful for studying aspects of megakaryocyte/platelet biology, there is little information about the heterogeneous cell populations observed in CBDMs. In the course of our studies with CBDMs we observed multiple distinct cell populations by flow cytometry. Similar populations were also observed in the megakaryocytic Meg-01 cell line. The largest cells (called P1) were the most abundant (consisting of nearly 100% of cells) at day 3 in culture. P2 cells, which are smaller and more granular than P1, appeared at day 6 and by day 13 were ~50% of the total. P3 appeared at day 6 and are the smallest, with size and granularity roughly similar to platelets; by day 13 these were ~30% of the total. P1 but not P2 nor P3 became CD61/CD41/CD42 positive and CD34 negative over 13 days in culture. Ninety-seven percent and 93% of P2 and P3 cells, respectively, were phosphatidyl serine (PS) positive, whereas 93% of P1 cells were PS negative. Electron microscopy revealed many typical features of bone marrow MKs in the PS negative (P1) cells, including large size, polyploid nucleus, mitochondria and immature granules. However, the demarcation membrane system was poorly developed. Virtually all of the PS positive (P2) cells were apoptotic, lacked granules and had no discernable nuclei. Purification of P1 and P2 populations followed by re-culturing revealed that P1 gives rise to both the P2 and P3 populations, whereas P2 gave rise to no other population. CD34+ cells cultured with the pan-caspase inhibitor Z-VAD-FMK developed a much smaller proportion of P2 cells with a corresponding increase in P1 cells. Stimulation of these 3 populations with collagen related peptide, thrombin, protease activated receptor 1-activating peptide (PAR1-AP) and PAR4-AP showed strong integrin activation in P1 cells, but not in P2 nor P3 cells. To assess which population was susceptible to genetic manipulation, day 3 cultures were infected with a lentiviral construct containing a shRNA to talin. Talin knockdown prevented agonist-induced integrin activation in P1 cells and as expected, had no effect on the P2 or P3 population. In summary, these data indicate that only a portion of CBDMs are functional and only the P1 population should be used to assess MK gene function. Over time, the majority of CBDMs become apoptotic and the smaller P3, platelet-like particles have minimal response to agonist compared to peripheral blood platelets. These results may partially explain the difficulties in generating functional platelets in vitro and are consistent with the need to restrain apoptosis for successful megakaryocytopoiesis. DisclosuresNo relevant conflicts of interest to declare.

Viral induced encephalitis initiates distinct and functional CD103+ CD11b+ brain dendritic cell populations within the olfactory bulb. (168.8)

Abstract Dendritic cells (DC) are antigen presenting cells found in both lymphoid and non-lymphoid organs, including the brain (bDC) of Cd11c/eyfp transgenic C57Bl/6 mice. Using an intranasal vesicular stomatitis virus infection, we demonstrated that EYFP+ cells amass in areas associated with viral antigens, take on an activated morphology, and project their processes into infected neuronal tissue within the olfactory bulb. These bDC separated into three EYFP+ CD45+ CD11b+ populations: EYFP+ CD45int CD11bhi (P1), EYFP+ CD45hi CD11bhi (P2) and EYFP+ CD45hi CD11bint (P3) populations. All but the P1 population were able to functionally promote both T lymphocyte proliferation and TH1 cytokine production using an OT transgenic antigen presentation assay. Using radiation chimeras, P1 was shown to emanate from the brain, while P2 was established to be peripherally derived. Interestingly, the P3 population was of indeterminate origin, being both radiosensitive and not replenished by donor bone marrow. Finally, each EYFP+ population contained CD11b+ CD103+ sub-populations, and could be distinguished in terms of M-CSFR, Gr-1, and Ly-6C expression. Such phenotypic analysis point to P1 as an activated sub-population of microglia, while P2 was more typical of mucosal DC subsets and P3 appeared to be similar to monocyte-derived DC lineages.

Genetic Mapping of Resistant Genes in Brassica pekinensis Against Plasmodiophora brassicae Race 6

Inbred lines of Chinese cabbage KU-101 (resistant line against Plasmodiophora brassicae race race 6) and CS-113 (susceptible line) were crossed and their progeny lines F<TEX>$_1$</TEX>, BC<TEX>$_1$</TEX>F<TEX>$_1$</TEX>, F<TEX>$_2$</TEX>, and F<TEX>$_3$</TEX> were produced for the construction of the genetic linkage map of R brassicae race 6-resistant Brassica campestris ssp. pekinensis genome. Restriction fragment length polymorphism (RFLP) was applied to compare between parents and their f<TEX>$_2$</TEX> progenies with a total of 192 probes and 5 restriction enzymes. The constructed RFLP map covered 1,104 cM with a mean distance between genetic marker of 8.0 cM, and produced 10 linkage groups having 121 genetic loci. The loci of P. brassicae race 6 (CR6)-resistant Brassica genome were determined by interval mapping of quan-titative trait loci (QTL), which resulted from bioassay using the same race of the fungi in P3 population. Resistant loci were estimated in numbers 1 (Gl) and 3 (G3) linkage groups. In the regression test, Gl had a value of4.8 logarithm of odd (LOD) score, while C3 had values of 4.2-7.2. Given these results, the location of the CR6-resistant loci within the Brassica genome map can now be addressed.

Effects of the amyloid precursor protein Glu693→Gln ‘Dutch’ mutation on the production and stability of amyloid β-protein

Hereditary cerebral haemorrhage with amyloidosis, Dutch type (HCHWA-D), is a cerebral amyloidosis characterized by prominent vascular deposits and fatal haemorrhages. The disorder is caused by a point mutation in codon 693 of the gene encoding the amyloid precursor protein (APP), resulting in a Glu → Gln amino acid substitution at position 22 of the amyloid β-protein (Aβ) region. The pathogenetic mechanisms of HCHWA-D are unknown but could involve alterations in the proteolytic processing of APP and in amyloid fibril formation. We examined Aβ production and stability by using cultured human embryonic kidney 293 cells stably expressing wild-type or ‘Dutch’ APP. Radiosequencing and quantitative immunoprecipitation experiments showed that cells expressing Dutch APP secreted increased quantities of Aβ peptides beginning at Asp1, and of truncated peptides beginning at Val18 and Phe19. The ratio of levels of 4 kDa (Aβ) to 3 kDa (p3) peptides remained constant due to co-ordinate decreases in other peptide species. Novel truncated or elongated peptides were not observed. Pulse-chase experiments showed that the Dutch mutation did not affect the stability of the Aβ or p3 populations. These results are consistent with a disease process in which the Dutch mutation results in the production of Aβ peptides with enhanced propensities for fibrillogenesis, leading to accelerated vascular deposition and disease.

Effects of the amyloid precursor protein Glu693→Gln ‘Dutch’ mutation on the production and stability of amyloid β-protein

Hereditary cerebral haemorrhage with amyloidosis, Dutch type (HCHWA-D), is a cerebral amyloidosis characterized by prominent vascular deposits and fatal haemorrhages. The disorder is caused by a point mutation in codon 693 of the gene encoding the amyloid precursor protein (APP), resulting in a Glu-->Gln amino acid substitution at position 22 of the amyloid beta-protein (Abeta) region. The pathogenetic mechanisms of HCHWA-D are unknown but could involve alterations in the proteolytic processing of APP and in amyloid fibril formation. We examined Abeta production and stability by using cultured human embryonic kidney 293 cells stably expressing wild-type or 'Dutch' APP. Radiosequencing and quantitative immunoprecipitation experiments showed that cells expressing Dutch APP secreted increased quantities of Abeta peptides beginning at Asp1, and of truncated peptides beginning at Val18 and Phe19. The ratio of levels of 4 kDa (Abeta) to 3 kDa (p3) peptides remained constant due to co-ordinate decreases in other peptide species. Novel truncated or elongated peptides were not observed. Pulse-chase experiments showed that the Dutch mutation did not affect the stability of the Abeta or p3 populations. These results are consistent with a disease process in which the Dutch mutation results in the production of Abeta peptides with enhanced propensities for fibrillogenesis, leading to accelerated vascular deposition and disease.

Diencephalic Neuronal Populations Projecting Axons into the Basal Plate in a Lizard (Gallotia galloti)

Lizard diencephalic populations sending axons into the basal plate were studied by the in vitro HRP technique in the lizard Gallotia. Retrograde labeled cells were concentrated in distinct neuronal groups within alar plates of prosomeres p1 and p3, whereas the alar plate of p2 was poorly labeled. Efferent fibers from alar p1 and p3 populations entered the basal plate of the diencephalon along topologically dorsoventral courses, bifurcating thereafter into longitudinal ascending (rostral) and descending (caudal) trajectories. Thus, diencephalic segments p1 and p3 have alar cell populations contributing to the longitudinal premotor connectivity of the neural axis , whereas the alar p2 segment projects via the fasciculus retroflexus, the efferent tract of the epithalamus. However, the axons from the habenular complex bifurcate within or adjacent to the floor plate and not within the basal plate.

Effect of different carbon dioxide concentrations on ferrous iron and pyrite oxidation by a mixed culture of iron and/or sulfur-oxidizing bacteria

In batch systems, the effect of CO 2 on the kinetics of three bacterial populations (P1, P2, and P3) involved in bioleaching was studied on synthetic and pyritic medium. The behavior of these three populations was not identical in the presence of different concentrations of CO 2. At 0.03% in CO 2, P1 and P2 were the first populations to start growth in the reactor. They grew rapidly at first but immediately after showed a rapid decline, regardless of the medium; at 2 and 4% CO 2, we could observe a decrease in the initial number of the P1 and P2 cells throughout the experiments. When the biomass concentration of the P1 and P2 populations became negligible in the medium, it was always the turn of the P3 population to grow. The results show that P3 was the dominant population in all the experiments and was mainly responsible for ferrous iron and pyrite oxidation. However, its growth was dependent upon the CO 2 concentration in the medium. At 2% CO 2, the P3 population showed a maximal biomass concentration higher than that obtained for 0.03 and 4% in CO 2 in the two media.