Research article

Genomic organization and phylogenetic utility of deer mouse (Peromyscus maniculatus) lymphotoxin-alpha and lymphotoxin-beta

Tiffany Richens¹ , Aparna D~N Palmer¹ , Joseph Prescott² and Tony Schountz³

¹  Department of Biological Sciences, Mesa State College, Grand Junction, Colorado, 81502, USA

²  Center for Infectious Diseases and Immunity, Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA

³  School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, USA

author email corresponding author email

BMC Immunology 2008, 9:62doi:10.1186/1471-2172-9-62

Published:	31 October 2008

Abstract

Background

Deer mice (Peromyscus maniculatus) are among the most common mammals in North America and are important reservoirs of several human pathogens, including Sin Nombre hantavirus (SNV). SNV can establish a life-long apathogenic infection in deer mice, which can shed virus in excrement for transmission to humans. Patients that die from hantavirus cardiopulmonary syndrome (HCPS) have been found to express several proinflammatory cytokines, including lymphotoxin (LT), in the lungs. It is thought that these cytokines contribute to the pathogenesis of HCPS. LT is not expressed by virus-specific CD4⁺ T cells from infected deer mice, suggesting a limited role for this pathway in reservoir responses to hantaviruses.

Results

We have cloned the genes encoding deer mouse LTα and LTβ and have found them to be highly similar to orthologous rodent sequences but with some differences in promoters elements. The phylogenetic analyses performed on the LTα, LTβ, and combined data sets yielded a strongly-supported sister-group relationship between the two murines (the house mouse and the rat). The deer mouse, a sigmodontine, appeared as the sister group to the murine clade in all of the analyses. High bootstrap values characterized the grouping of murids.

Conclusion

No conspicuous differences compared to other species are present in the predicted amino acid sequences of LTα or LTβ; however, some promoter differences were noted in LTβ. Although more extensive taxonomic sampling is required to confirm the results of our analyses, the preliminary findings indicate that both genes (analyzed both separately and in combination) hold potential for resolving relationships among rodents and other mammals at the subfamily level.