The immune gene repertoire of an important viral reservoir, the Australian black flying fox.
BACKGROUND
Bats are the natural reservoir host for a range of emerging and re-emerging viruses, including SARS-like coronaviruses, Ebola viruses, henipaviruses and Rabies viruses. However, the mechanisms responsible for the control of viral replication in bats are not understood and there is little information available on any aspect of antiviral immunity in bats. Massively parallel sequencing of the bat transcriptome provides the opportunity for rapid gene discovery. Although the genomes of one megabat and one microbat have now been sequenced to low coverage, no transcriptomic datasets have been reported from any bat species. In this study, we describe the immune transcriptome of the Australian flying fox, Pteropus alecto, providing an important resource for identification of genes involved in a range of activities including antiviral immunity.


RESULTS
Towards understanding the adaptations that have allowed bats to coexist with viruses, we have de novo assembled transcriptome sequence from immune tissues and stimulated cells from P. alecto. We identified about 18,600 genes involved in a broad range of activities with the most highly expressed genes involved in cell growth and maintenance, enzyme activity, cellular components and metabolism and energy pathways. 3.5% of the bat transcribed genes corresponded to immune genes and a total of about 500 immune genes were identified, providing an overview of both innate and adaptive immunity. A small proportion of transcripts found no match with annotated sequences in any of the public databases and may represent bat-specific transcripts.


CONCLUSIONS
This study represents the first reported bat transcriptome dataset and provides a survey of expressed bat genes that complement existing bat genomic data. In addition, these data provide insight into genes relevant to the antiviral responses of bats, and form a basis for examining the roles of these molecules in immune response to viral infection.
The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC 3052, Australia.
Anthony T
AT
Papenfuss
Michelle L
ML
Baker
Zhi-Ping
ZP
Feng
Mary
M
Tachedjian
Gary
G
Crameri
Chris
C
Cowled
Justin
J
Ng
Vijaya
V
Janardhana
Hume E
HE
Field
Lin-Fa
LF
Wang
D056704:Adaptive Immunity / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001315:Australia; D002685:Chiroptera / Q000235:genetics* / Q000276:immunology* / Q000821:virology; D017124:Conserved Sequence / Q000235:genetics; D004197:Disease Reservoirs / Q000821:virology*; D004199:Disease Vectors; D006649:Histocompatibility Antigens / Q000737:chemistry / Q000235:genetics; D006736:Horses / Q000235:genetics; D006801:Humans; D007107:Immune System / Q000378:metabolism*; D007113:Immunity, Innate / Q000235:genetics; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D059467:Transcriptome / Q000235:genetics
D006649:Histocompatibility Antigens; D012333:RNA, Messenger; D011971:Receptors, Immunologic