Diverse Interleukin-7 mRNA Transcripts in Chinese Tree Shrew (Tupaia belangeri chinensis)

Abstract

Interleukin-7 (IL7) is a pleiotropic cytokine that is actively involved in the immune system. The Chinese tree shrew (Tupaia belangeri chinensis) has been proposed as an alternative experimental animal to primates in biomedical research. However, there is a lack of biological knowledge about the immune system of the tree shrew. In this study, we cloned the IL7 gene (tIL7) in the Chinese tree shrew and quantified the expression of mRNA transcripts in eight tissues (heart, liver, spleen, lung, kidney, intestine, skeletal muscle and brain) from 20 individuals. Eleven tIL7 mRNA transcripts were identified in different tissues. The canonical form (tIL7c) had a length of 1817 bp and encoded a predicted gene product with 177 amino acids. Phylogenetic analyses based on the amino acid sequences revealed a considerably large genetic difference between tree shrew and human. Quantification of mRNA expression of transcripts tIL7c, tIL7-sv1, tIL7-sv2 and tIL7-sv3 showed that these transcripts were expressed in all tissues, albeit the expression levels varied in different tissues. Transcripts tIL7c, tIL7-sv1, and tIL7-sv2 had the lowest expression in brain, and tIL7-sv3 had a dramatically high mRNA expression in skeletal muscle and heart. The mRNA expression levels of tIL7c and tIL7-sv1 were significantly increased upon ploy(I:C) stimulation in tree shrew primary renal cells. As with human full-length IL7, tIL7c, tIL7-sv1, tIL7-sv2 and tIL7-sv3 showed similar a subcellular localization pattern. Our results identified diverse tIL7 transcripts in the Chinese tree shrew, which may play a potential role in modulating IL7-regulated biological effects.

Infectivity of Zika virus on primary cells support tree shrew as animal model

“…The primary hepatocytes were prepared by two-step collagenase perfusion [44] to get the primary hepatocytes cells (TSHC). The different tissues including kidney, lung, skin and the thoracic aorta, were collected to isolate the primary cells as described previously [45–47]. Primary rat skin and aorta cells were isolated and cultured in similar protocol to the Tree Shrews.…”

Construction of complete Tupaia belangeri transcriptome database by whole-genome and comprehensive RNA sequencing

“…In a previous report, Yu et al . also determined the tree shrew IL7 mRNA sequences 23 , and the CDS predicted by our method matched the canonical form of tree shrew IL7 mRNA transcript (accession number: JQ182399). These results showed that gene sequence predictions based on the combination of genome and RNA sequencing were more accurate than those based on genome sequencing alone.

Figure 2Analysis of the accuracy of the gene sequences predicted on the basis of the combined genome and RNA sequencing.

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A study of Epstein-Barr virus infection in the Chinese tree shrew(Tupaia belangeri chinensis)

“…Then, 500 ng of RNA was reverse transcribed to cDNA using the EasyScript One-Step gDNA Removal and cDNA Synthesis SuperMix (TransGen Biotech, Beijing, China).RT-PCR was performed with a PCR Mix(Invitrogen, USA) according to the manufacturer’s protocol. The expression of BZLF1,LMP1,EBNA1,EBNA2 and EA was determined by RT-PCR using the primers,including 4 primers we designed for RT-PCR, as follows:BZLF1: 5′-GCG GAC AAA AAT CAG GCG TT-3′ and 5′-GAA AAT GCC GGG CCA AGT TT-3′; LMP1:5′-AAT TTG CAC GGA CAG GCA TT-3′ and 5′-AAG GCC AAA AGC TGC CAG AT-3′; EBNA2: 5′-AAC TCC TGG CCC ATC CAA TG-3′ and 5′-GGA GGG GCG AGG TCT TTT AC-3′; EA: 5′-AAC GAG CAG ATG ATT GGG CA-3′ and 5′-CGT GGT GAC GTA GAG ATC CG-3′ and 1 primers previously reported [ 60 ]: EBNA1: 5′-GTC ATC ATC ATC CGG GTC TC-3′ and 5′-TTC GGG TTG GAA CCT CCT TG-3′.The “housekeeping gene” β-actin was amplified as an internal control using the primers previously described [ 61 ], and cDNA from B95–8 cells was used as a positive control.…”