Abstract

A dolphin PBL cDNA microarray has been printed and validated. The microarray contains genes biased towards stress and immune responses and consists of 1343 unigenes (archived and annotated at www.marinegenomics.org) plus 52 stress- and immune-function genes targeted for cloning by PCR, plus ESTs of unknown sequence from T and B cells. A total of 3700 dolphin genes have been printed in side-by-side duplicates. The full microarray has been printed in 2 replicates per slide such that the total number of features/slide, with all the controls, is 19200. The microarray has been validated technically and shown to be a useful tool for investigating the PBL transcriptome of both wild and captive dolphins. Surprisingly, the microarray is also a useful tool for investigating the transcriptome of tissues such as the skin, and can distinguish, through traditional double-cluster analysis, between the transcriptomes of wild and captive dolphin PBL, and between the transcriptomes of PBL and of skin cells. The dolphin blood samples used in the study to be presented have been collected in Charleston, SC and Indian River Lagoon, FL under the permit of the Health and Risk Assessment (HERA) project (NOAA Permit 998-1678-00). Two blood samples were collected for each animal: a "pre" sample, right after the animal was captured, and a "post" sample, after the collection of other samples and before the animal was released. The microarray was used to interrogate gene expression using RNA samples extracted from PBL in "pre" and "post" blood samples for each animal. The data analysis was performed by accessing apparent differential expression with reference to the variability observed between replicate arrays. The samples have been collected from animals with different sex, age and health condition and the hypotheses tested in this study are that the transcriptional signatures of dolphin PBL will be informative of the age, sex, health and stress of the animal.