Monica Ahsan, Texas Biomedical Research Institute

I interned in the genetics department of the Texas Biomedical Research Institute during the summer of 2011 for Dr. Anthony Comuzzie. Dr. Comuzzie is an anthropologist trained in statistical genetics who focuses his research on the genetics of obesity and diabetes. His lab conducts projects on different populations including Mexican Americans, Alaskan Natives, and Omani Arabs, as well as the baboon colony located on campus.

The number of projects in his lab is so extensive that it is difficult to comprehend. Each major project has subprojects which have subprojects, and different scientists have their own interests within these projects to pursue. This means there is always opportunity for interns and students to step in and assist with virtually anything they want in biomedical research.

The Oman family study is one of the many projects in Dr. Comuzzie’s lab. Ancestral data has been collected from hundreds of individuals living in villages in the Nizwa region of Oman. One important characteristic of this population is that it is the preferred marriage practice to marry your 1st cousin. Over 50 percent of marriages are between first cousins, and polygamy is widely practiced. The preferred practice of marrying 1st cousins makes this population well suited for genetic analyses. With such large inbreeding coefficients, it becomes more likely that heritable traits of complex diseases such as obesity, type 2 diabetes, and hypertension will emerge. This is an excellent example of how useful anthropology is with genetic studies. Knowledge of cultural marriage practices in this case makes all the difference.

I worked with a subset of this data pertaining to hypertension. The subset of data contained individuals with normal range blood pressure readings. They were categorized into 3 groups according to their parents’ blood pressure: both parents normal, one parent normal one hypertensive, or both parents hypertensive. The study group took a mental stress test and a physical stress test in order to see how their cardiac systems responded. Measurements such as blood pressure, heart rate, cardiac index, cardiac output, sympathovagal balance, etc. were taken at varying intervals before, during, and after the tests by scientists outside of Texas Biomed.

My job was to make sure this data set was in proper order and analyze it statistically. The Texas Biomedical Research Institute uses 2 main software programs to perform data management and analysis: PEDSYS and SOLAR. I was trained on both to compare data between the three groups of individuals in this hypertension study. Although all participants in the actual tests had normal blood pressure, this study was concerned with offspring being predisposed to hypertension if one or both parents exhibited the trait.

Dr. Comuzzie’s lab also focuses on diabetes and obesity. The particular interest I worked on dealt with uric acid concentrations and kidney function variation doing lipid quantity comparisons. I worked with samples from 4 diet plans. I pulled serum samples to be tested for uric acid out of the freezers. The samples are frozen to approximately -80̊ C. My job was to pull the samples we were going to test out into separate boxes. This tedious process takes care and organization. I pulled over 450 samples out that had to be organized in the correct order and stored properly until testing time.

In addition, Dr. Comuzzie’s lab has several baboon studies going on that deal with different diets. One of particular interest at the moment is called the “pink” diet. The pink diet is high fat/high cholesterol, but not high carb. This project aims to identify a correlation between a high fat/high cholesterol diet and weight gain. Weight is currently the only trait being measured. It is assumed that there will be considerable variation in weight gain amongst the baboons, and that it will be partially attributed to genetic variation. Eventually, the lab will look at genetic variation and try to identify target genes contributing to weight gain in response to a fatty diet. My first task with this data set was to identify if the diet was indeed causing significant weight gain. In order to analyze this, I looked at baseline weight, weight measurements taken after 18 months on the diet, and a more recent weight after about 2 years on the diet. Using basic Excel functions, I calculated the weight differences in kilograms and the percent weight differences between the diet measurements and baseline weights. I then performed statistical analyses using Systat software.

I tried to analyze the data set from all angles. I ran paired t-tests between baseline weights and the diet weights. Since age and sex were really the only grouping variables I had to work with, I ran correlations between age and weight change, age and percent weight change, sex and weight change, and sex and percent weight change. I also ran an unpaired t test between male and female percent weight changes. I recorded the appropriate p values in my excel tables.

Before discovering this institute and internship, I was unclear of what I really wanted to do in biological anthropology. I felt overwhelmed by too many areas of interest and was looking for something to combine them in a meaningful way. Not only did this internship combine areas of anthropology such as primate studies, different cultures, and population genetics, it also integrated these with other areas of science as well. The opportunities in Dr. Comuzzie’s lab are endless and it really just takes initiative on the intern’s part to be as involved as possible. The faculty were not only friendly and helpful, but have provided me with references and contacts. Dr. Comuzzie’s lab takes great care with interns to help them achieve their goals for the future; in my case this is applying to graduate school. I now have an extensive list of graduate programs and contacts to aid me in this process. Furthermore, I have experience with widely used software and lab equipment.

The basic lab skills I’ve acquired in biology and chemistry labs came in handy. I have a real appreciation for keeping things organized because one misplaced tube can throw everything off. Record keeping is also key in the lab. Everything must be documented and marked so that future lab personnel have adequate knowledge of what they’re working with. I was glad to have previous experience with the instruments in the lab. Things like making sure you’re using a new micropipette tip for each sample have to be habitual when you’re doing something 458 times. Without careful, methodical lab practices, the risk for error and contamination is high. One course I do not think I could have done without is statistics. Because I wanted to be involved with analyzing data sets, a solid foundation in statistics for behavioral sciences was essential. I have only taken the one course, but I used virtually everything I learned in it. Although this internship was suited perfectly for my interest in population genetics, there is something for everyone in biology and anthropology.

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