Molecular Characterization and Antibacterial Activity Analysis of Two Novel Penaeidin Isoforms from Pacific White Shrimp, Litopenaeus vannamei

Abstract

Penaeidins were important immunity effector molecules, which played a crucial role in innate immunity system of penaeid shrimp. Here, we reported two penaeidin isoforms from Litopenaeus vannamei, which were named as Lva-PEN 2 and Lva-PEN 3 according to the respective structure features. The results of amino acid sequence multiple alignments showed that high similarities existed among these penaeidins. A signal peptide sequence and a cysteine-rich domain which contained six cysteine amino acid residues existed in each penaeidin at the same time. Besides, there was a proline-rich motif which was composed of eight proline residues existed in each penaeidin. After the expression profile analysis was studied, we found that both Lva-pen 2 and Lva-pen 3 transcripts were up-regulated at 48 h after bacteria challenge. Except for the antibacterial activity against Gram-positive bacteria like other penaeidins, these two penaeidins could strongly bind to bacteria and possessed antiproteinase activity. It was speculated that these two penaeidins could prevent bacteria pervasion through bacteria-binding activity and antiproteinase activity. Meantime, the proline-rich motif played a crucial role in these biological processes.

Comparative transcriptome and potential antiviral signaling pathways analysis of the gills in the red swamp crayfish, Procambarus clarkii infected with White Spot Syndrome Virus (WSSV)

“…Gills were also collected from ten controls, uninfected crayfish designated as the Group normal (GN). All gills were immediately frozen in liquid nitrogen after collection, and samples were temporarily stored at −80°C until total RNA extraction ( Du and Jin, 2015 ).…”

“…The amplification procedure was comprised of an initial denaturation step at 95°C for 3min, followed by 40 cycles of 95°C for 15s, 58°C for 40 s, and melting from 65°C to 95°C. Three parallel experiments were performed ( Du et al , 2015 ). Furthermore, the differentially expressed levels of the target genes between the groups were calculated by the 2 -ΔΔCT analysis method ( Livak and Schmittgen, 2001 ).…”

In-depth comparative transcriptome analysis of intestines of red swamp crayfish, Procambarus clarkii, infected with WSSV

“…These samples constituted the normal group (GN). Then, these two sets of samples were temporarily stored at −80 °C for total RNA extraction27.…”

“…P. clarkii (approximately 15–20 g) were purchased from a commercial aquaculture market in Hangzhou, Zhejiang Province, China. The collected crayfish were originally cultured in water tanks at 26–28 °C for at least 5 days and fed twice daily with artificial food throughout the experiment 27 . For WSSV infection, WSSV (3.2 × 10 7 particles per crayfish) was injected into the abdominal segment of each crayfish 1 28 29 .…”

Comparative transcriptome analysis reveals three potential antiviral signaling pathways in lymph organ tissue of the red swamp crayfish, Procambarus clarkii

“…The lymph organs were also removed from at least 10 normal crayfish and frozen immediately in liquid nitrogen [Group normal (GN)]. The two sets of samples were temporarily stored at -80°C for total RNA extraction (Du and Jin, 2015).…”