- 1 Lab Attendance
- 2 Individual Assessments
- 2.1 Lab 1
- 2.2 Lab 2
- 2.3 Lab 3
- 2.3.1 Four Research Articles on Spindle Apparatus: Mechanism of Formation from z3369112
- 18.104.22.168 Mechanisms of mitotic spindle assembly and function
- 22.214.171.124 Maize meiotic spindles assemble around chromatin and do not require paired chromosomes
- 126.96.36.199 Mitotic spindle poles are organised by structural and motor proteins in addition to centrosomes
- 188.8.131.52 The chromosomal passenger complex is required for chromatin-inducted microtubule stabilization and spindle assembly
- 2.3.2 Useful Image to be used for Spindle Apparatus: Mechanism of Formation
- 2.3.1 Four Research Articles on Spindle Apparatus: Mechanism of Formation from z3369112
- 2.4 Lab 4
- 2.5 Lab 5
- 2.6 Lab 6
- 2.7 Lab 7
- 2.8 Lab 8
- 2.9 Lab 9
- 2.10 Lab 10
- 2.11 Lab 11
- 3 Links
- 4 Images
- 5 References
Bacterial, archaeal, and eukaryotic cytoskeletons.
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In this study, a physical hydrogel was prepared with a low-molecular-weight hydrogelator and ethanol/water mixture to be used a potential "Trojan Horse" carrier of drug moleculrs into cells. Peptides can infiltrate mammalian cells and often can bring 'cargo' with them. The researchers used a SEM and XRD analysis to determine a complex network structure in the gel formed. However, in order to clearly see the cellular uptake of the transported drug molecules, they had to use confocal laser scanning microscopy. Cellular uptake is represented by green fluorescence seen in the cells' cytoplasm. This microscopy allowed them to see the fluorescent hydrogels prepared (which had fluorescent dansyl moiety introduced into the mixture), as well that all the hydrogels internalize in the IGROV-1 cells tested.
Four Research Articles on Spindle Apparatus: Mechanism of Formation from z3369112
Mechanisms of mitotic spindle assembly and function
This journal (although a review) is a comprehensive source for information on the observations that led to the current models of spindle assembly as well as recent discoveries in the field. Since the section of Mechanism of Formation requires information on the two spindle assembly models (Search and Capture & Microtubule Self-Organisation), it was deemed appropriate. This review centers entirely on the spindle assembly models.
Maize meiotic spindles assemble around chromatin and do not require paired chromosomes
This research article provides a good explanation on how the Microtubule Self-Organisation or Self-Assembly model works. The scientists in this study propose a model for spindle formation in maize meiocytes where microtubules firstly appear around the chromosomes during prometaphase and aids the microtubules to self-organise. The scientists studied the organization of microtubule arrays in wild-type maize meiocytes and three maize meiotic mutants, desynaptic1 (dsy1), desynaptic2 (dsy2) and absence of first division (afd). It also references the Search and Capture model.
Mitotic spindle poles are organised by structural and motor proteins in addition to centrosomes
This study provides results that show that the microtubule micro ends are directed to the spindle poles through mechanisms involving contributions from both centrosomes and microtubule motor proteins. All the observations done in their experiment with Xenopus eggs is discussed in the context of the Search and Capture model, which was useful to the section. The scientists in this article who that a certain antibody disrupts the organisation of microtubule minus ends and localisation of the nuclear mitotic apparatus protein at spindle poles.
The chromosomal passenger complex is required for chromatin-inducted microtubule stabilization and spindle assembly
In relation to the Microtubule Self-Organisation model, it discusses the molecular pathway cascade of Ran-GTP. This assessment does not need to go into as much detail as the study explains, but for the general overview, it was proven useful. In particular, the Introduction section does a good job at explaining its function. Whilst it goes rather indepth into the topic (more than required for Cell Biology), it discuses the complexes required for chromatin-induced microtubule stabilisation and spindle formation (Microtubule Self-Organisation model).
Useful Image to be used for Spindle Apparatus: Mechanism of Formation
Beta-Catenin (Ser33/37) Antibody
Commercial supplier website: http://www.abbiotec.com/antibodies/beta-catenin-ser3337-antibody Description: Also known as the Catenin beta-1 or CTNNB, it is involved in the regulation of cell adhesion by binding to the intracellular domain of cadherin and linking it to the actin cytoskeleton. Catenin beta-1 is part of the E-cadherin/catenin adhesion complexes. This antibody's applications include Western Blotting and Enzyme-Linked ImmunoSorbent Assay (ELISA). Its isotype is Rabbit Polyclonal Ig (Immunoglobulin) and it was purified by immunogen affinity chromatography. It cross-reacts with mice (M), rats (R) and Xenopus laevis (X). Beta catenin antibody does not react with the related 83 kDa γ-catenin (plakoglobin) protein. According to the data sheet, it is under the protein family of cytoskeletons. Beta catenin can be found in adherens junctions.
Journal article that uses antibody: Not available
Lab 5 was run by Dr. Anthony Kee. Because of this change, the individual lab assessment for the week was presented in hard-copy form and was submitted at the end of the lab session. The paper consisted of two questions relating to transgenic and gene knock-out mice.
Part 1 Undifferentiated B35 Cells
1) Do you see any changes in phenotypes between Group A and B? As indicated by the graph above, there is a difference of percentages of phenotypes present in Group A (Tropomyosin 4 overexpressing group) and Group B. Group A has a lower percentage of Fan, Broken Fan, Stumped and Pygnotic phenotypes with a higher percentage of Pronged and Stringed phenotypes. Group B on the other hand has a lower Pronged and Stringed phenotype percentage in comparison to Group A.
2) If you see a difference, speculate about a potential molecular mechanism that has led to the change. If you don't see a change, speculate why that could be. Group A shows a larger number of Pronged and Stringed phenotypes (indicated by the long neurites structure) and since Group A is where Tropomyosin 4 is overexpressed, it can be debated that Tropomyosin 4 causes an increase of the neurites structure. This can be caused by the assembly of actin cytoskeleton (which is associated with tropomyosin).
Part 2 Questions for differentiated B35 Cells
1) Do you see any changes in phenotypes between Group A and B? Yes, there was a difference in phenotypes between Group A and B. For Group A, there is a high concentration of Stringed and Pronged phenotypes whilst the other phenotypes (e.g. Fan and Stumped phenotype). For Group B, whilst it also had a high number of Stringed and Pronged phenotypes, it had a lower concentration compared to the first group. Additionally, Group B had more variations of the phenotypes (not perfect examples of Stringed and Pronged phenotypes). It can be deduced that Group A is showing the effect on the phenotypes due to tropomyosin.
2) If you see a difference, speculate about a potential molecular mechanism that has led to the change. If you don't see a change, speculate why that could be. It can be speculated that the potential molecular mechanism leading to the change could be due to the difference in function of tropomyosin. This could then result in the different morphological changes of the B35 cells. A morphological change worth noting is the increased length of the neurites.
This laboratory was divided into two sections: one on Confocal Microscopy (which was conducted in the microscopy lab) and the second half was spent discussing the status of the group project page. Due to time constraints, the assessment Confocal Microscopy hand-out for group 4-7 can be submitted on Friday 10/5/2013 or at the next lecture, Tuesday 13/5/2013.
Critical peer assessment of the six other group projects (excluding Group 4).
The group page discusses regulation of cell division and presents relevant subtopics that will aid in the understanding on the subject. However, upon closer observation of the subheadings, it is noted that it does not include complete information. The introduction section does what it is supposed to do, giving a brief overview as to the process. It ends rather abruptly which provides evidence that the section is not complete yet. Group members should not include notes irrelevant to the material (e.g. “cells dividing movie-need to check copyright”), could be written on discussion page. History table is also missing important recent events. Sections leading up to History of Platelet-Derived Growth Factor seemed to be sufficiently completed with helpful information though lacking enough detail on the transition from metaphase to anaphase. Disease section done poorly and current research points to address should be posted in discussion. While brief, the future research information posted was helpful. Content that was included were all correctly referenced. Though incomplete, tables did provide relevant information and diagrams added did help in the understanding and explanation of the topic. Discussion page does indicate that there was some good brain-storming between the members. Overall, there still has to be some work to be done before the due date in over a week but through the peer review assessment, the group should receive adequate critique to get them on their way.
Introduction concisely describes what cytokinesis briefly is about. It does not use complex terms that will confuse the reader and even provides a nice picture. The history does list important events and is referenced correctly but clearly is lacking a few more recent key events (ends in 1972). Not quite sure what “ZEN-4 is required for cytokinesis9778533” is for, but that should be noted in the discussion page and not left there. The Assembly of the Central Spindle section does provide helpful information on the topic and linking important terms to the Glossary was a brilliant and helpful formatting decision. The diagram provided also aids in the understanding as there are several complex terms used in this section. The following sections in the Mechanism subheading provide appropriate information but it was incredibly difficult to read due to the huge wall of text each subsection had. Adding some pictures and diagrams would do a much better job at engaging the reading and probably explaining the topic. The microfilament organisation and animal/plant cell cytokinesis section would be better with a diagram as well, since it is a step-by-step process. Including cytokinesis failure made the wiki page well-rounded as it is important to discuss the malfunctions and problems that can arise. Diagrams were helpful and explanation was not too complicated despite the complex terms. Current/future research section was good as it easily summarised the various journals found and what it all meant in reference to the topic, but the referencing might need to be changed. External links and glossary were incredibly helpful. Images section should not be left empty. Discussion page is filled with images but some discussion about what to include. Overall, with the inclusion of more images, the wiki page should be complete soon.
Introduction clearly states what the page will discuss and includes a short passage summarising the history, location and function of the Golgi apparatus in a way that keeps the reader engaged. Image included is useful. Structure section does its job, although the diagram provided is not in a dynamic colour that would catch the readers’ eyes. In contrast to the previous sections, the function section lacks a diagram which though might not be appropriate, makes the function section seem boring and a wall of text. A better format would be listing out dot points and/or highlighting key terms. History section, like other pages, was displayed in a table. It listed important events but grouped recent events into ‘After the 1990s’. As it still does provide a good idea of the timeline, this is fine. Some photos would be nice. Another section that would benefit greatly from pictures would be the models of division. The word ‘model’ itself brings a diagram to mind and this section lacked it. Minor spelling mistake in Morphology and Molecular ‘Mechannisms’ which can easily be fixed but aside from that, was quite impressed with this section. Diagrams were useful, references done properly. Current Models was done well and explained each model to an appropriate level of detail and the limitations of the current model was a really good idea. It provides the evidence that these models are in fact still under study and can change. Area of future research seems like a helpful section. Through reading the whole wiki, there are many complex terms used and the glossary should include more of them. Sufficient discussion was done, with even comments about how to improve the material that was already posted on the page, shows that the group actively communicates with each other.
The topic of the nuclear envelope during cell division was explained first with an introduction. The diagram was helpful but the text already did a good job at providing an overview of the topic. The timeline presented in a table, though short, did provide important events leading up to the current understanding of the nuclear envelope. It could use some pictures as it talks about interesting studies such as octagonal structure which would have cool pictures. This carries on into the structure section. Despite being divided into three sections, there is only one diagram. The description is very clear and concise but diagrams would make it easier to understand. The following subheadings took a long time to read mainly because it just seemed to be walls of text. It would benefit greatly from diagrams here or at least breaking up the text better in more paragraphs. I would recommend doing that before proceeding with finishing the last two subheadings. Aside from the lack of diagrms, the information seems to very clear and detailed. Since there are many complex terms used, I would recommend bolding them just to make it easier to read. Glossary needs to be completed, but referencing is all done well. Significant discussion is done including posting written text on this page before posting on Wiki. This is a good idea as members can comment about it without the incomplete text being on the main wiki page. A very impressive effort by this group.
Immediately, what sticks out is the fact that the formatting is different from all the other pages. It is missing the table with all the subheadings, should immediately be fixed. Because of this, the heading formatting is thrown off on the page. Either way, introduction does a good job at explaining what the topic is about. The picture is nice too but should be aligned better or resized as well as include a title as I am unsure as to what I am looking at. The Meiosis versus mitosis section would be better represented in a table as they are comparing two processes. History table is clearly incomplete as it stops at 1943. Might be due to time constraints that it is not complete and should be done so soon. MAT section was good as well as process of sister chromatid separation and anaphase to telophase. While diagrams were included, it would be better at a larger size as the picture itself is not too colourful and would not distract. Following sections cover their respective topics well but seem to have too many references for things like one simple sentence ‘meiotic cell like oocytes does not contain centrosomes’ has three references. Defects resulting… section seems to be better formatted than the previous sections but still is a large wall of text. Dot points help, but the random statement about referencing should be removed. Since current research is divided by year, it might be a good idea to present it as a table and include photos of the relevant studies. Suggested research section does suggest that the group has explored all aspects of the topic and found relevant journals, along with the further reading section. Glossary is impressive, except for the ‘blah’ definitions. Lots of good discussion went on, although the formatting was a little weird and took some getting used to. Seems like they should be on their way to finishing a good wiki page soon.
Straight away, there is an error for one of the photos in the introduction. Should be resolved. Aside from that, introduction was well-written and explained the topic of cell division mitochondria well. Structure information was well-written except for the end where it tapered off. Picture should be aligned properly and at least labelled to say it was a mitochondria. This seems to be the case with most of the photos and diagrams in the page. Quite impressed with the function section as it was divided into different parts and well explained under each. Breaking up the sections really helped in reading all that text. History table then followed which was a little odd (the flow) but the table was complete with relevant events. It could use some images so that it does not look just like a bunch of sentences. The During Cell Division section did seem to explain the stage very well but once again, lacked images so it was very difficult to read. As for the fusion section, it was a good idea to break up the fusion and fission sections but maybe this would be better in a table so one can clearly see that it is two different stages. Other proteins section could be formatted better. Physiological significance part was written well but it seemed a little odd to have mitochondria division in human diseases as a sub-heading underneath it. May be a formatting mistake. Information on the diseases was well-written but would benefit from images of how the diseases manifests in the human body. Almost all of the information in the page is present in the discussion page which is good but there is also some discussion as well. Either way, this page could add more subsections to their topic because it seems to be slightly narrow, but still does a good job.
This week's lab covered Stem Cell Therapy and the assessment was the form of a written quiz which was submitted at the end of the session.
There was no individual lab assessment this week as the group WIKI page assessment was submitted today.
This week's lab covered Microarray and the assessment was presented in the format of a written worksheet which was submitted at the end of the session.
- Bill Wickstead, Keith Gull The evolution of the cytoskeleton. J. Cell Biol.: 2011, 194(4);513-25 PubMed 21859859
- Nicola Castellucci, Giorgio Sartor, Natalia Calonghi, Carola Parolin, Giuseppe Falini, Claudia Tomasini A peptidic hydrogel that may behave as a "Trojan Horse". Beilstein J Org Chem: 2013, 9;417-24 PubMed 23503149
- Claire E Walczak, Rebecca Heald Mechanisms of mitotic spindle assembly and function. Int. Rev. Cytol.: 2008, 265;111-58 PubMed 18275887
- A Chan, W Z Cande Maize meiotic spindles assemble around chromatin and do not require paired chromosomes. J. Cell. Sci.: 1998, 111 ( Pt 23);3507-15 PubMed 9811565
- T Gaglio, M A Dionne, D A Compton Mitotic spindle poles are organized by structural and motor proteins in addition to centrosomes. J. Cell Biol.: 1997, 138(5);1055-66 PubMed 9281583
- Srinath C Sampath, Ryoma Ohi, Oliver Leismann, Adrian Salic, Andrei Pozniakovski, Hironori Funabiki The chromosomal passenger complex is required for chromatin-induced microtubule stabilization and spindle assembly. Cell: 2004, 118(2);187-202 PubMed 15260989