Distinctive expression patterns of 185/333 genes in the purple sea urchin, Strongylocentrotus purpuratus: an unexpectedly diverse family of transcripts in response to LPS, beta-1,3-glucan, and dsRNA.
BACKGROUND
A diverse set of transcripts called 185/333 is strongly expressed in sea urchins responding to immune challenge. Optimal alignments of full-length 185/333 cDNAs requires the insertion of large gaps that define 25 blocks of sequence called elements. The presence or absence of individual elements also defines a specific element pattern for each message. Individual sea urchins were challenged with pathogen associated molecular patterns (PAMPs) (lipopolysaccharide, beta-1,3-glucan, or double stranded RNA), and changes in the 185/333 message repertoire were followed over time.


RESULTS
Each animal expressed a diverse set of 185/333 messages prior to challenge and a 0.96 kb message was the predominant size after challenge. Sequence analysis of the cloned messages indicated that the major element pattern expressed in immunoquiescent sea urchins was either C1 or E2.1. In contrast, most animals responding to lipopolysaccharide, beta-1,3-glucan or injury, predominantly expressed messages of the E2 pattern. In addition to the major patterns, extensive element pattern diversity was observed among the different animals before and after challenge. Nucleotide sequence diversity of the transcripts increased in response to beta-1,3-glucan, double stranded RNA and injury, whereas diversity decreased in response to LPS.


CONCLUSIONS
These results illustrate that sea urchins appear to be able to differentiate among different PAMPs by inducing the transcription of different sets of 185/333 genes. Furthermore, animals may share a suite of 185/333 genes that are expressed in response to common pathogens, while also maintaining a large number of unique genes within the population.
Terwilliger
David P
DP
Department of Biological Sciences, George Washington University, Washington, DC, USA. dave.terwilliger@gmail.com <dave.terwilliger@gmail.com>
Buckley
Katherine M
KM
Brockton
Virginia
V
Ritter
Nicole J
NJ
Smith
L Courtney
LC
D000818:Animals; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D015321:Gene Rearrangement; D005796:Genes; D014644:Genetic Variation; D007113:Immunity, Innate / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D011509:Proteoglycans; D012330:RNA, Double-Stranded / Q000494:pharmacology*; D012333:RNA, Messenger / Q000302:isolation & purification; D047270:Strongylocentrotus purpuratus / Q000235:genetics* / Q000276:immunology; D014947:Wounds and Injuries / Q000235:genetics / Q000276:immunology; D047071:beta-Glucans / Q000494:pharmacology*
D008070:Lipopolysaccharides; D011509:Proteoglycans; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D047071:beta-Glucans; C010770:polysaccharide-K