Linkage Mapping Data Report Guide

Title:

• A title needs to be appropriate and reflect the experiment that was performed.
• A title should have a moderate length; too short of a length does not provide adequate information about the paper and too long just becomes wordy and provides too much information.
• Do not copy the title of the lab manual; a title should always be in your own words.
• First and foremost this is plagiarism.
• If you copy the lab manual title directly a score of 0 will be assigned for the title section.

Also if we notice a title is the exact same as another student’s title either in your own section or another lab section we are going to suspect that it was copied and this can result in 0 points for the title section.

Purpose of experiment:

• When writing a scientific manuscript there is always the inclusion of the purpose of the experiment. Usually this will occur at the end of the introduction but since there is not introduction with the data reports there will just be a stand-alone purpose.
• A purpose should include the following
• A short paragraph (few sentences, 3-5 max) that give a little bit of background information that leads into the purpose.
• The reason we want to do this is that it sets up the actual purpose of the experiment. Typically in an introduction you will set up a lead into the purpose providing the reader with appropriate information over the course of the introduction so that when the reader gets to the purpose the reader understands why the rational for why the experiment is being conducted.  
• Unfortunately with the data report there is not a traditional introduction therefore we need to provide a little information to segue properly into the purpose of the experiment.
• The next part would be the actual purpose of the experiment.
• This will be a specific purpose statement for the experiment.
• The purpose statement is very concise getting specifically to the point of the experiment. 
• A note is that the purpose does not give major details in terms of methodology.
• You can give a little indication of how this will be accomplished through a brief synopsis of the methods such as the name of the technique.
• A recommendation would be to view some journal articles in the journal of genetics (search recent articles published in the last 5 or so years) and look towards the end of the introduction to find where the author(s) have given a statement of purpose.
• Do take note that a purpose in some articles could be broken into multiple paragraphs.
• Also authors may not use the exact phrase of “the purpose of the study”.

But towards the end of every introduction there is some indication to the purpose of the experiment/study.

Results:

• A results section of a scientific paper will include two portions: a written and tables and/or figures.

• Written portion
• The written portion of results section is used to share general statements about the results
• This section is written in past tense.
• The results section is used to share the major results found with the experiment which often includes results of statistical analyses conducted.
• Additionally what accompany written statements about the results are references to the tables and/or figures that contain those results.
• For the references of tables and/or figures there are a few ways that are commonly done.
• The most common and likely more acceptable way, is to write out the sentence about the results then provide the reference to the table or figure after in paraphrases like this (Figure 1).
• Another way is to make the table or figure reference the subject of the sentence (Ex. Figure 1 shows) but this is not the best of options to use. The Writing in Biology book (chapter 4) does a good job of explaining why this way should generally be avoided. 
• With the written results you should be sharing the major findings from the experiment.
• You will want to share the map units calculated as well as the map units from the Kosambi and Haldane map functions.
• With the Kosambi and Haldane map functions, do not share the actual formulas for these map functions. These are well known map functions and you do not have to share the formulas.
• Share the phenotype numbers
• Figures and Tables
• For this data report here will be a single figure and a single table
• 1 Figure
• A small figure showing the map distance between the two genes where the value is the calculated map units from your data. (example provided on eCourseware)
• 1 Table
• This table will be the F2 counts for each phenotype.
• Make sure with each table and figure that there is a caption that is correctly placed and contains enough information that the reader can fully understand what that table or figure is showing
• In the results section you should never show:
• The calculations that were performed, just report the end values
• This includes not sharing the formulas used.
• This also includes tables as there should be no indication of the calculations performed within the table.
• Explaining/interpreting the results.
• The results section is just for sharing the results found.
• Explaining and interpreting the results is the purpose of the discussion.

 Discussion:

• The discussion is where you interpret and explain your results.
• Here you will give detailed reasons for why each result occurred the way they did.
• What is meant by detailed reason/explanation?
• With a discussion point you want to write a few sentences when explaining each result you intended to being explaining in the discussion.
• Let’s use this quick example to demonstrate an explanation that is lacking detail. (We won’t use one specific to fruit fly pteridines)
• “We found that there was a difference in coloration of wings between two species of butterfly where species A lacks a yellow pigment seen in species B. This is due to genetic mutation in species A.”
• Okay so what is wrong here, a valid reason is provided. Yes, a valid explanation may be provided in genetic mutation but it does not give the level of detail to explain what is going on here to the reader. A genetic mutation could mean anything and does not directly tell what is occurring to affect the coloration in species A. A detailed explanation needs to dig further to be specific about what exactly this mutation is doing and depending on the knowledge of this particular gene what gene may be mutated or missing, etc.
• At the beginning of the discussion you can give a quick, brief summarization of the results found.
• This is often done in a summarization form and does not include actual numbers/statistics.
• In the discussion you should not be restating the exact results.
• This is something students do often is that they just restate the results without giving any type of explanation for them.
• With discussing/explaining the results you generally want to think in terms of simple questions, why, how, and/or what when giving an explanation.
• So why might this type of result occur? What might be occurring to render such result(s)? How might this possible reason be occurring? Just to name a few.
• With this discussion these are some of the talking points you will want to address. Remember you want to give detailed answers that will fully address the points you are making.
• Discuss the difference between the map units you calculated and the actual distance.
• The actual distance can be found in the booklet on Drosophila on the lab benches.
• When discussing/explaining these results make sure you come up with solid reasons as to why differences, if any, occurred. That means being thorough with your explanations, this is the key part being thorough explaining.
• Discuss the estimations from the Haldane and Kosambi functions.
• Were they more and less accurate in terms of the actual map distance?
• Why were they more or less accurate?
• For this you will want to think about the assumptions of each function.
• Talk about potential ways to improve the estimation and accuracy of the map units.
• Be detailed about ways. Do not just say increase the number of offspring counted because just because you increase the number doesn’t necessarily mean it will be more accurate. Give some thought about how estimations could be made more accurate make sure they are realistic.
• Possible discussion point
• Why you may never calculate the exact distance.
• Some things to remember when writing your discussion:
• Using peer-reviewed literature helps to give strength and validity to any explanation/reason that is being put forth.
• Often times peer-reviewed literature is used to provide examples of the point that is trying to be made.
• For example, articles concerning crossing over and the rates of crossing over; this can also include interference. We have provided a start list of relative articles.
• Do remember that any citation you make must be relevant to the topic/point you are trying to make.
• A few general points when writing your discussion
• Never use the word prove always use words like show, demonstrate or other similar words.
• Using the word “prove” leads to an absolute and that is not how scientific experiments work. One thing you always have to remember is someone can do your experiment over again or a derivative of your experiment and come to different conclusions (i.e. they might not find the same results).
• In scientific writing do not use contractions in the writing, write out the words.

Remember this is a general guide; this is a fun, diverse topic to talk about. All it needs is some thought.

Literature Cited: There is no requirement for a literate cited section but it is always a good thing to include. On eCourseware is a starting list of journal articles that are on the topic of biochemical genetics more specifically with fruit fly eyes. There are many, many more articles out there this list is a starting point.