Honors Program


Document Type


Date of this Version

Spring 3-11-2019


Govori, V. 2019. H/L Ratio as a Measurement of Immune Function in Terrapene ornata Species. Undergraduate Honors Thesis. University of Nebraska-Lincoln.


Copyright Vesa Govori 2019.


White blood cells are a key part of the immune system, and changes in white cell count can reveal the overall state of health and the immune systems functional ability of a species. White blood such as heterophils and lymphocytes are essential for being able to fight off infections. Analyzing different cell ratios has been commonly done before as a way to observe immune function in bird species as well as other species. Understanding that there are different functions between the different white blood cells provides an extra interesting perspective to what could be happening in the immune system function of the species studied. In this experiment, the ratio of heterophils and lymphocytes (H/L) from summer-active turtles, and turtles in hibernation were observed, recorded, and analyzed. It was predicted that during hibernation, the white blood cell counts will be low because they are not exposed to potential pathogens. However, hibernation may lead to an increase in cell counts because the lower metabolic rates may result in an increase in cell numbers. If immune function is increased overall, the H/L ratio should remain unchanged and only cell numbers will vary. Although, if heterophil counts increase independent of lymphocyte counts, this would indicate an ongoing immune challenge amongst the Terrapene ornata species, the results showed exactly that. During the summer months, T. ornata showed higher numbers of lymphocytes whereas in the winter months there was a higher number of heterophils. There was a significant difference in the H/L ratio between the summer active and hibernating T. ornata species.

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