scholarly journals Homeotic genes controlling flower development in Antirrhinum

Development ◽  
1991 ◽  
Vol 113 (Supplement_1) ◽  
pp. 149-155
Author(s):  
Enrico S. Coen ◽  
Sandra Doyle ◽  
Jose M. Romero ◽  
Robert Elliott ◽  
Ruth Magrath ◽  
...  
Keyword(s):  
Flower Development ◽  
Homeotic Genes ◽  
Wild Type ◽  
Developmental Pathway ◽  
The Third ◽  
Gene Functions ◽  
Overlapping Domains ◽  
Second Category ◽  
Homeotic Mutations ◽  
Primary Gene

In order to study genes controlling flower development, we have carried out an extensive transposon-mutagenesis experiment in Antirrhinum majus. More than 15 independent homeotic mutations were obtained, allowing three categories of genes to be defined. The first includes floricaula (flo), a primary gene required for the initiation of the floral developmental pathway. In the absence of the wild-type flo product, proliferating inflorescence meristems arise in place of flowers. The flo gene has been isolated and shown to be expressed transiently in a subset of organ primordia in the floral meristem. The second category includes genes that affect the identity, and also sometimes the number, of whorls of organs in the flower. These genes act in overlapping domains so that each whorl has a distinct combination of gene functions, suggesting a model for the genetic control of whorl identity and number. Genes of the third category control differences between organs In the same whorl and hence the overall symmetry of the flower. We discuss how the basic plan of the flower and inflorescence may arise through the interactions between the three categories of genes.

scholarly journals CLAVATA1, a regulator of meristem and flower development in Arabidopsis

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 397-418 ◽  
Author(s):  
S.E. Clark ◽  
M.P. Running ◽  
E.M. Meyerowitz
Keyword(s):  
Flower Development ◽  
Double Mutant ◽  
Apical Meristem ◽  
Expression Patterns ◽  
Floral Meristem ◽  
Homeotic Genes ◽  
Wild Type ◽  
Meristem Identity ◽  
Floral Meristems ◽  
Transition To Flowering

We have investigated the effects on plant development of mutations in the Arabidopsis thaliana CLAVATA1 gene. In clavata1 plants, vegetative, inflorescence and floral meristems are all enlarged relative to wild type. The apical meristem can fasciate in the more severe mutant alleles, and this fasciation can occur prior to the transition to flowering. Flowers of clavata1 plants can have increased numbers of organs in all four whorls, and can also have additional whorls not present in wild-type flowers. Double mutant combinations of clavata1 with agamous, apetala2, apetala3 and pistillata indicate that CLAVATA1 controls the underlying floral meristem structure upon which these homeotic genes act. Double mutant combinations of clavata1 with apetala1 and leafy indicate CLAVATA1 plays a role in establishing and maintaining floral meristem identity, in addition to its role in controlling meristem size. In support of this, RNA expression patterns of AGAMOUS and APETALA1 are altered in clavata1 flowers.

scholarly journals The Culture of the Sakas of Semirechye: Contemporary State and Current Issues of Study

2021 ◽  
Vol 20 (3) ◽  
pp. 22-35
Author(s):  
Ernar A. Estemesov
Keyword(s):  
Iron Age ◽  
Social Groups ◽  
Archaeological Sites ◽  
Radiocarbon Dates ◽  
Funeral Rites ◽  
The Third ◽  
Urgent Task ◽  
Wide Range ◽  
Burial Mounds ◽  
Second Category

Purpose. The article describes the history and analysis of the main issues in the study of archaeological sites of the Saka period in Semirechye. They are presented by three main types on this territory: burial and memorial complexes, settlements and hoards. The first type of monuments includes numerous burial mounds, where the elite burials of “royal” type and ordinary burials are located. Both social groups are combined by the unity of funeral rites, and the main differences are the complexity of architecture, memorial practices, and richness of burial equipment in the “royal” type burial mounds. The second category of monuments is presented by the settlements that are mostly small in size. The constructions like half dugouts were discovered on them, which gave a rich ceramic material. The third type of monuments of the Saka period in Semirechye includes numerous hoards of bronze items. Some of them are represented by the cult objects (sacrificial tables, lamps and cauldrons) that mark the places of worship. A significant percentage of the hoards contain items of weapons, horse equipment and household purposes and, apparently, serve as offerings to the spirits. However, despite the considerable progress in the study of the Saka monuments of the Semirechye Region, the main problem is their cultural attribution at this time. Some researchers suggest that the independent Saka archaeological culture was formed and developed on the territory of Semirechye in the Early Iron Age, while others believe that the Saka monuments of this region belong to the broader historical and cultural community that also covers the neighboring regions of Kyrgyzstan and Xinjiang. Results Another important issue in the study of the Saka sites of Semirechye is to clarify the chronology of burial and memorial complexes. Up to now, the significant database of radiocarbon dates has been accumulated, which allows us to consider the chronological positions of a wide range of monuments in a new way. It was of great importance to obtain such dates from several burials of Karatuma necropolis, which showed that it belonged to the Saka period, since burial monuments of this appearance are traditionally dated back to the Wusun period. Conclusion. The necessity of solution of these problems is an urgent task for further research of burial and settlement objects of the Saka period in this region.

scholarly journals Excellent Teachers’ Strategies in Managing Students’ Misbehaviour in the Classroom

2020 ◽  
Vol 16 (1) ◽  
pp. 46
Author(s):  
Rosilawati Sueb ◽  
Hamimah Hashim ◽  
Khadijah Said Hashim ◽  
Munirah Mohd Izam
Keyword(s):  
School Districts ◽  
Classroom Management ◽  
Structured Interviews ◽  
Teaching Experiences ◽  
Classroom Activities ◽  
The Third ◽  
First Category ◽  
Excellent Teachers ◽  
Student Misbehavior ◽  
Second Category

The study explores Excellent Teachers’ strategies in managing students’ misbehavior in the classroom. Students’ misbehavior are escalating and getting more variant and serious. The need to investigate how teachers manage the students’ behavior in the classroom is deemed important.  In this study the participants are Excellent Teachers or “Guru Cemerlang”  who earned their title as “Guru Cemerlang”, based on promotional basis, due to their expertise in their teaching areas, exhibition of exceptional qualities in their personality and leadership and accumulation of vast teaching experiences. This is a qualitative study utilized semi-structured interviews and email interviews as its data collection method.  The interviews were conducted on nine (9) Malay Muslim Excellent Teachers; seven (7) females and two (2) males from nine different schools of nine different school districts in Selangor. Their age ranges from thirty seven (37) to fifty three (53) years with teaching experiences ranging from ten (10) to thirty one (31) years. The strategies that Excellent Teachers utilize could be categorized into  three higher categories: the first category pertaining to the preparation and activities that excellent teachers carried out in the classroom, the second category is interaction, which is the communication and reaction of excellent teachers towards student misbehavior and the third category is the presentation of treatment pertaining to pleasant or unpleasant consequences. In this article only discussion on the first category of the strategy which pertain to preparation and activities that excellent teachers carried out in the classroom will be highlighted. The sub- strategies are recognized as early year preparation, conducive learning environment, and classroom activities. Keywords: classroom discipline, classroom management, classroom strategies, excellent teacher.

scholarly journals Studiowanie, kształcenie, oczekiwania – z badań studentów pierwszego roku

2021 ◽  
pp. 73-85
Author(s):  
Stanisław Nowel ◽  
Keyword(s):  
Study Skills ◽  
Professional Life ◽  
The Other ◽  
Student Survey ◽  
Problem Solving Skills ◽  
The Third ◽  
Technical Study ◽  
Creative Problem ◽  
The University ◽  
Second Category

The results of a first year student survey are presented, divided into three categories: studying, education, expectations. In the first category, it was found that students have technical study skills. However, they do not have creative problem solving skills. In the second category, it was found that students accepted the forms and methods of education they at the university. In the third category, it was found that the university meets the students’ expectations regarding their aspirations related to the choice of field and form of study. On the other hand, it is alarming to note that the surveyed students do not feel a significant need for in-depth education, i.e. enriching their personality with qualities necessary in their future professional life.

scholarly journals THE EFFECTS OF HETEROZYGOSITY CHANGES ON VIABILITY IN DROSOPHILA MELANOGASTER

Genetics ◽  
1972 ◽  
Vol 70 (4) ◽  
pp. 595-610
Author(s):  
Ray Moree
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Background ◽  
Laboratory Strain ◽  
Theoretical Expectation ◽  
Wild Type ◽  
Small Deviations ◽  
The Third ◽  
The Difference

ABSTRACT The viability effects of chromosomes from an old and from a new laboratory strain of D. melanogaster were studied in eight factorial combinations and at two heterozygosity levels. The combinations were so constructed that heterozygosity level could be varied in the third chromosomes of the carriers of a homozygous lethal marker, in the third chromosomes of their wild-type segregants, and in the genetic backgrounds of both. Excluding the effect of the marker and the exceptional outcomes of two of the combinations, and taking into account both large and small deviations from theoretical expectation, the following summary is given as the simplest consistent explanation of the results: 1) If total heterozygosities of two segregant types tend toward equality their viabilities tend toward equality also, whether background heterozygosity is high or low; if background heterozygosities is higher the tendency toward equality is slightly greater. 2) If total heterozygosity of two segregant types are unequal the less heterozygous type has the lower viability; the difference is more pronounced when background heterozygosity is low, less when it is high. 3) Differences between segregant viabilities are correlated with differences between the total heterozygosities of the two segregants; genetic background is effective to the extent, and only to the extent, that it contributes to the magnitude of this difference. This in turn appears to underlie, at least partly, the expression of a pronounced interchromosomal epistasis. Thus in this study viability is seen to depend upon both the quantity and distribution of heterozygosity, not only among the chromosomes of an individual but among the individuals of a given combination as well.

Administration of the Third Dose of Oral Poliomyelitis Vaccine at 6 to 18 Months of Age

PEDIATRICS ◽  
1994 ◽  
Vol 94 (5) ◽  
pp. 774-775 ◽  
Author(s):  
Keyword(s):  
United States ◽  
Health Care Providers ◽  
The United States ◽  
Preschool Age ◽  
Healthy Children ◽  
Care Providers ◽  
Wild Type ◽  
The Third ◽  
Primary Series ◽  
Poliomyelitis Vaccine

This statement describes a modification of the recommended routine schedule for administering trivalent oral poliomyelitis vaccine (OPV). The American Academy of Pediatrics previously has recommended that healthy children receive a three-dose primary series of OPV at 2, 4, and 15 to 18 months of age and a fourth dose at the time of school entry (4 to 6 years of age).1 Available data indicate that the response rates to the third dose of OPV administered at 6 months of age are as good as the rates following administration of this dose at 15 to 18 months of age. Completion of the three-dose primary series at an earlier age will help health care providers induce immunity against poliomyelitis at an early age. Although wild type poliomyelitis has not caused disease in the United States for many years, the virus remains prevalent in many countries. Continued introduction of the virus into the United States by travelers could result in transmission and disease if high levels of immunity are not maintained in preschool age children. For example, wild type poliovirus type 3 was recently introduced into Canada by a religious sect that did not believe in immunization.2 The virus was probably imported from the Netherlands, where a small epidemic of poliomyelitis occurred in members of the same sect in 1992 and 1993.3 SERUM ANTIBODY RESPONSE FOLLOWING OPV ADMINISTRATION After two doses of OPV are administered at 2 and 4 months of age, 89 to 100% of children vaccinated in the United States have evidence of humoral immunity to poliomyelitis types 1 and 3, and 99 to 100% have immunity to type 2 (Table).

Dorsotonals/homothorax, the Drosophila homologue of meis1, interacts with extradenticle in patterning of the embryonic PNS

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 1037-1048 ◽  
Author(s):  
E. Kurant ◽  
C.Y. Pai ◽  
R. Sharf ◽  
N. Halachmi ◽  
Y.H. Sun ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Molecular Mechanisms ◽  
Normal Development ◽  
Protein A ◽  
Ectopic Expression ◽  
Homeotic Genes ◽  
Wild Type ◽  
Protein Activity ◽  
Low Levels ◽  
Restricted Pattern

The homeotic genes of the bithorax complex are required, among other things, for establishing the patterns of sensory organs in the embryonic peripheral nervous system (PNS). However, the molecular mechanisms by which these genes affect pattern formation in the PNS are not understood and other genes that function in this pathway are not characterized. Here we report the phenotypic and molecular analysis of one such gene, homothorax (hth; also named dorsotonals). Mutations in the hth gene seem to alter the identity of the abdominal chordotonal neurons, which depend on Abd-A for their normal development. However, these mutations do not alter the expression of the abd-A gene, suggesting that hth may be involved in modulating abd-A activity. We have generated multiple mutations in the hth locus and cloned the hth gene. hth encodes a homeodomain-containing protein that is most similar to the murine proto-oncogene meis1. The hth gene is expressed throughout embryonic development in a spatially restricted pattern, which is modulated in abdominal segments by abd-A and Ubx. The spatial distribution of the HTH protein during embryonic development is very similar to the distribution of the Extradenticle (EXD) protein, a known modulator of homeotic gene activity. Here we show that the PNS phenotype of exd mutant embryos is virtually indistinguishable from that of hth mutant embryos and does not simply follow the homeotic transformations observed in the epidermis. We also show that the HTH protein is present in extremely low levels in embryos lacking exd activity as compared to wild-type embryos. In contrast, the EXD protein is present in fairly normal levels in hth mutant embryos, but fails to accumulate in nuclei and remains cytoplasmic. Ectopic expression of hth can drive ectopic nuclear localization of EXD. Based on our observations we propose that the genetic interactions between hth and exd serve as a novel mechanism for regulating homeotic protein activity in embryonic PNS development.

Patterning of angiogenesis in the zebrafish embryo

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 973-982 ◽  
Author(s):  
Sarah Childs ◽  
Jau-Nian Chen ◽  
Deborah M. Garrity ◽  
Mark C. Fishman
Keyword(s):  
Zebrafish Embryo ◽  
Regular Pattern ◽  
Wild Type ◽  
Cell Fates ◽  
Mutagenesis Screen ◽  
The Third ◽  
Shaped Cell ◽  
Vessel Growth ◽  
Lateral Posterior ◽  
Lineage Analysis

Little is known about how vascular patterns are generated in the embryo. The vasculature of the zebrafish trunk has an extremely regular pattern. One intersegmental vessel (ISV) sprouts from the aorta, runs between each pair of somites, and connects to the dorsal longitudinal anastomotic vessel (DLAV). We now define the cellular origins, migratory paths and cell fates that generate these metameric vessels of the trunk. Additionally, by a genetic screen we define one gene, out of bounds (obd), that constrains this angiogenic growth to a specific path. We have performed lineage analysis, using laser activation of a caged dye and mosaic construction to determine the origin of cells that constitute the ISV. Individual angioblasts destined for the ISVs arise from the lateral posterior mesoderm (LPM), and migrate to the dorsal aorta, from where they migrate between somites to their final position in the ISVs and dorsal longitudinal anastomotic vessel (DLAV). Cells of each ISV leave the aorta only between the ventral regions of two adjacent somites, and migrate dorsally to assume one of three ISV cell fates. Most dorsal is a T-shaped cell, based in the DLAV and branching ventrally; the second constitutes a connecting cell; and the third an inverted T-shaped cell, based in the aorta and branching dorsally. The ISV remains between somites during its ventral course, but changes to run mid-somite dorsally. This suggests that the pattern of ISV growth ventrally and dorsally is guided by different cues. We have also performed an ENU mutagenesis screen of 750 mutagenized genomes and identified one mutation, obd that disrupts this pattern. In obd mutant embryos, ISVs sprout precociously at abnormal sites and migrate anomalously in the vicinity of ventral somite. The dorsal extent of the ISV is less perturbed. Precocious sprouting can be inhibited in a VEGF morphant, but the anomalous site of origin of obd ISVs remains. In mosaic embryos, obd somite causes adjacent wild-type endothelial cells to assume the anomalous ISV pattern of obd embryos. Thus, the launching position of the new sprout and its initial trajectory are directed by inhibitory signals from ventral somites. Zebrafish ISVs are a tractable system for defining the origins and fates of vessels, and for dissecting elements that govern patterns of vessel growth.

scholarly journals Determination of the Factor V Leiden Single-Nucleotide Polymorphism in a Commercial Clinical Laboratory by Use of NanoChip Microelectronic Array Technology

2002 ◽  
Vol 48 (9) ◽  
pp. 1406-1411 ◽  
Author(s):  
Jess G Evans ◽  
Cindy Lee-Tataseo
Keyword(s):  
Clinical Laboratory ◽  
Factor V Leiden ◽  
Factor V ◽  
Third Wave ◽  
Wild Type ◽  
Wave Analysis ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
The Third ◽  
Array Technology

Abstract Background: Methods for analysis of the single-nucleotide polymorphism (SNP) known as factor V Leiden (FVL) are described. The technique provides rapid, highly accurate detection of the point mutation that encodes for replacement of arginine-506 with glutamine. After formal assay qualification, 758 clinical samples that had previously been analyzed by the InvaderTM Monoplex Assay were tested as research samples in a commercial clinical laboratory. Methods: Primers specific for factor V (FV) were prepared, and PCR was performed. Samples were analyzed using the NanoChip® Molecular Biology Workstation with fluorescently labeled reporters for wild-type and SNP sequences. Results: Of the 635 samples classified by the Third WaveTM assay as FV wild type, 10 were identified as heterozygous FVL by the NanoChip technique. Similarly, of the 114 putative heterozygous samples, 4 were wild type, and of the 9 reported homozygous samples, 6 were homozygous, 2 were heterozygous, and 1 was FV wild type by the NanoChip assay. All 17 results that were discordant with the Third Wave analysis were confirmed by DNA sequencing to be correctly classified by the NanoChip technology. The Nanochip system was 100% accurate in characterizing wild-type, heterozygous, and homozygous samples compared with accuracies of 99.2%, 90.2%, and 100% for the comparable Third Wave analysis. Conclusions: The NanoChip microelectronic chip array technology is an accurate and convenient method for FVL screening of research samples in a clinical laboratory environment.

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