Williams_Stephanie_The Diversity of Endogenous Retroviruses in Wyoming Mule Deer

Open Access
Author:
Williams, Stephanie Nicole
Area of Honors:
Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Mary Poss, Thesis Supervisor
  • Daniel Cosgrove, Honors Advisor
Keywords:
  • Endogenous Retroviruses
  • ERV
  • Mule Deer
  • Genetics
  • CrERV
  • integration
  • virus
  • viruses
  • phylogenetic tree
Abstract:
Endogenous retroviruses (ERVs) are RNA viruses that integrate, by chance, into the germ cells of a host, permitting vertical transmission. The number of ERV integration sites within the genome can vary between individuals within a species due to unique, germ-line infections or expansion caused by retrotransposition, a process during which DNA copies of an initial ERV integrate into the host genome at different locations via an RNA transcript intermediate. Over time, ERVs can be lost from the population, actively silenced, or remain in the genome and become fixed. ERVs within mule deer (CrERVs) are insertionally polymorphic and transcriptionally active. We currently have data describing the distribution and location of CrERVs within the genomes of mule deer in Montana (MT). The data suggests that, on average, mule deer within Wyoming (WY) have more integrations than MT mule deer. This study strove to explore possible explanations for the observed difference in the number of CrERV integration sites within Wyoming (WY) and Montana (MT) mule deer. During these investigations, transcript data and a small survey of CrERV unique to WY mule deer provided no evidence to support the presence of novel CrERV in WY mule deer. However, evidence to suggest expansion via retrotransposition of one CrERV family was found in the WY mule deer. Because ERVs are capable of insertional mutagenesis, such information is critical in the investigation of whether or not CrERVs could contribute to the presence and distribution of diseases that affect mule deer. One such disease is Chronic Wasting Disease, which is endemic in wild mule deer populations in Wyoming (WY) and Northern Colorado (CO), but absent from populations to the north and west of this area, like Montana (MT), despite the high mobility and migratory habits of mule deer. Endogenous retroviruses (ERVs) are RNA viruses that integrate, by chance, into the germ cells of a host, permitting vertical transmission. The number of ERV integration sites within the genome can vary between individuals within a species due to unique, germ-line infections or expansion caused by retrotransposition, a process during which DNA copies of an initial ERV integrate into the host genome at different locations via an RNA transcript intermediate. Over time, ERVs can be lost from the population, actively silenced, or remain in the genome and become fixed. ERVs within mule deer (CrERVs) are insertionally polymorphic and transcriptionally active. We currently have data describing the distribution and location of CrERVs within the genomes of mule deer in Montana (MT). The data suggests that, on average, mule deer within Wyoming (WY) have more integrations than MT mule deer. This study strove to explore possible explanations for the observed difference in the number of CrERV integration sites within Wyoming (WY) and Montana (MT) mule deer. During these investigations, transcript data and a small survey of CrERV unique to WY mule deer provided no evidence to support the presence of novel CrERV in WY mule deer. However, evidence to suggest expansion via retrotransposition of one CrERV family was found in the WY mule deer. Because ERVs are capable of insertional mutagenesis, such information is critical in the investigation of whether or not CrERVs could contribute to the presence and distribution of diseases that affect mule deer. One such disease is Chronic Wasting Disease, which is endemic in wild mule deer populations in Wyoming (WY) and Northern Colorado (CO), but absent from populations to the north and west of this area, like Montana (MT), despite the high mobility and migratory habits of mule deer.