Location: Genetics and Animal BreedingTitle: Characterization of the domestic goat yd T cell receptor gene loci and gene usage
|GILLESPI, ALEXANDRA - University Of Massachusetts|
|YIRSAW, AL - University Of Massachusetts|
|GUNASEKARAN, KARTHICK - University Of Massachusetts|
|Smith, Timothy - Tim|
|TURLEY, MICHAEL - University Of Massachusetts|
|CONNELLEY, TIMOTHY - Roslin Institute|
|TELFER, JANICE - University Of Massachusetts|
|BALDWIN, CYNTHIA - University Of Massachusetts|
Submitted to: Immunogenetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2021
Publication Date: 1/21/2021
Citation: Gillespi, A., Yirsaw, A., Gunasekaran, K.P., Smith, T.P., Bickhart, D.M., Turley, M., Connelley, T., Telfer, J.C., Baldwin, C.L. 2021. Characterization of the domestic goat yd T cell receptor gene loci and gene usage. Immunogenetics. 73:187-201. https://doi.org/10.1007/s00251-021-01203-y.
Interpretive Summary: Blood cells in mammals perform a variety of functions, including immune functions. A particular type of blood cell known as a T-cell has particular importance for recognizing and neutralizing invaders of the body including bacteria, viruses, or abnormal cells like cancer cells. The activity of these cells depends on the type and conformation of specific receptors on the cell surface that distinguish between normal cellular proteins in the body and foreign or abnormal substances. The receptors are encoded by genetic locus that varies between species by both number of genes and type of genes. This manuscript describes genetic loci for the TRG and TRD receptors in goats, compares the number and type of genes in the loci, and compares features of the loci to that of other ruminant species. This work helps to establish knowledge for study of the immune response in goats, as well as highlighting evolutionary features of T-cell receptors.
Technical Abstract: Goats and cattle diverged 30 million years ago but retain similarities in immune system genes. Here, the caprine T cell receptor (TCR) gene loci and transcription of its genes were examined and compared to cattle. We annotated the TCR loci using an improved genome assembly (ARS1) of a highly homozygous San Clemente goat. This assembly has already proven useful for describing other immune system genes including antibody and leucocyte receptors. Both the TCRy (TRG) and TCRd (TRD) loci were similarly organized in goats as in cattle and the gene sequences were highly conserved. However, the number of genes varied slightly as a result of duplications and differences occurred in mutations resulting in pseudogenes. WC1+ yd T cells in cattle have been shown to use TCRy genes from only one of the six available cassettes. The structure of that Cy gene product is unique and may be necessary to interact with WC1 for signal transduction following antigen ligation. Using RT-PCR and PacBio sequencing, we observed the same restriction for goat WC1+ yd T cells. In contrast, caprine WC1+ and WC1- yd T cell populations had a diverse TCRd gene usage although the propensity for particular gene usage differed between the two cell populations. Noncanonical recombination signal sequences (RSS) largely correlated with restricted expression of TCRy and d genes. Finally, caprine yd T cells were found to incorporate multiple TRD diversity gene sequences in a single transcript, an unusual feature among mammals but also previously observed in cattle.