Tandem repeat sequences expressed in the hemocytes of Litopenaeus vannamei Boone, 1931 (Decapoda: Dendrobranchiata: Penaeidae)

Abstract

There is evidence that tandem repeat sequences (TRS) could have essential roles in cell functioning processes. We aimed to detect and describe minisatellites contained in the sequences of a cDNA library derived from the hemocytes of Litopenaeus vannamei Boone, 1931. Minisatellites, with a repetitive unit of nine or more nucleotides, were detected in both untranslated region (UTR) and open reading frame (ORF) mRNA′s coding for different proteins, some of which with well-defined functions in shrimps such as the antibacterial protein crustin. More than one simple repetition was detected in the same sequence in most cases, including several overlapping repeat sequences. An example of complexity was observed in the coding sequence for single IB domain (SIBD) protein, with nine different overlapping TRS with lengths ranging from 21 to 191 nucleotides. This is the first report on TRS in transcripts of shrimp hemocytes. The biological roles of these types of TRS at the molecular and cellular levels remain unknown although some have been related to the shrimp immune system.