Vegetation productivity responses to drought on tribal lands in the four corners region of the Southwest USA

IFPRI3; ISIWCAO; AFRP

Involvement of cAMP-dependent signaling in VIH-2 suppressed <i>Vg</i> mRNA expression in the hepatopancreas of <i>L</i>. <i>vannamei</i>.

<p>A & B: The effects of the AC activator (A) and the cAMP analog (B) on <i>Vg</i> mRNA expressions in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 12 h with increasing doses of forskolin (0.01–1000 nM) or 8-Br-cAMP (0.1–1000 nM). C: Interaction of cAMP-dependent signal pathways and VIH-2 on <i>Vg</i> mRNA expression in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 12 h with VIH-2 (1 μM) in the presence or absence of forskolin (1 μM) or 8-Br-cAMP (1 μM). In this study, the data presented are expressed as the mean±S.E. (n = 4). Experimental groups denoted by the same letter represent a similar level (<i>P</i>>0.05, ANOVA followed by Fisher’s LSD test).</p

Cloning and differential expression of Na,K-ATPase in <i>Penaeus vannamei</i>

<div><p></p><p>To better understand the adaptive strategies of osmotic and ionic regulation in <i>Penaeus vannamei</i>, a full-length cDNA sequence encoding the Na,K-ATPase alpha subunit was isolated and characterized by rapid amplification of the cDNA ends (RACE). The nucleotide sequence was 3953 bp in length and included a 300 bp 5′ untranslated region (UTR), 536 bp 3′ UTR with an AATAA canonical polyadenylation signal sequence and poly (A) tail, and a 3117 bp open reading frame (ORF) encoding a 1038 amino acid protein. The calculated molecular weight of the protein was 115.4 kDa with an estimated pI of 5.29. This sequence was submitted to the National Center for Biotechnology Information (NCBI) GenBank under accession number KF765670. A phenetic analysis showed that the Na,K-ATPase α-subunit of <i>P. vannamei</i> shared a high degree of identity with other species. The relevant mRNA was detected in all of the tissues examined by fluorescent quantitative real-time polymerase chain reaction. The expression level was higher in the gills and hepatopancreas, and lower in the guts, muscles and epithelia. Increased expression of Na,K-ATPase mRNA levels was observed in all of the tissues examined in response to salinity exposure, and there was a significant difference in the tissues of the gills and hepatopancreas (<i>P</i> < 0.05); however, no statistical difference was observed in the epithelia, guts and muscles compared with the controls (<i>P</i> > 0.05). The findings demonstrated that the Na,K-ATPase α-subunit is highly conserved in crustaceans, and differential expression in different tissues of <i>P. vannamei</i> was observed, indicating that the gene might have multiple functions in the shrimp.</p></div

Effects of VIH-2 administration on NO, cGMP and cAMP production in the hepatopancreas of <i>L</i>. <i>vannamei</i>.

<p>A-C: The NO (A), cGMP (B) and cAMP (C) production in the shrimp hepatopancreas after VIH-2 (300 ng/g bwt) injection. D-F: The time-dependent NO (D), cGMP (E) and cAMP (F) productions by VIH-2 treatment in shrimp hepatopancreatic cell cultures. G-I: Dose-dependent NO (G), cGMP (H) and cAMP (I) productions by VIH-2 treatment in shrimp hepatopancreatic cell cultures. For <i>in vitro</i> experiments, hepatopancreatic cells were pretreated with IBMX (0.1 mM) at ~20 min before the substrates were added. In this study, the data presented are expressed as the mean±S.E. (n = 6 and 4 for <i>in vivo</i> and <i>in vitro</i> experiments, respectively). Experimental groups denoted by the same letter represent a similar level (<i>P</i>>0.05, ANOVA followed by Fisher’s LSD test).</p

<i>Vg</i> mRNA expression in the hepatopancreas of <i>L</i>. <i>vannamei</i> during ovarian development.

<p>A: Hepatopancreatic <i>Vg</i> transcript levels of sexually immature male shrimp and female shrimp. The data presented are expressed as the mean±S.E. (n = 6), and significant differences between male and female shrimp were assessed using Student’s <i>t</i>-test (* <i>P</i><0.05, ** <i>P</i><0.01 and *** <i>P</i><0.001). B: Hepatopancreatic <i>Vg</i> transcript levels of female shrimp in different ovarian developmental stages. The data presented are expressed as the mean±S.E. (n = 6), and experimental groups denoted by the same letter represent a similar level (<i>P</i>>0.05, ANOVA followed by Fisher’s LSD test). C: Histological observation of ovarian developmental stages based on H/E staining. The selected ovarian maturation stages of female shrimp include: stage I (previtellogenesis), stage II (primary vitellogenesis), stage III (secondary vitellogenesis), and stage IV (maturation).</p

Working model for the signal transduction mechanism of VIH-2 suppressed <i>Vg</i> mRNA expression in the shrimp hepatopancreas.

<p>In this case, a membrane receptor GC activation by VIH-2 can generate cGMP and subsequently activate PKG. The downstream MAPK-dependent cascades are then activated by cooperation of JNK phosphorylation and P³⁸MAPK content increase, to inhibit the gene expression of <i>Vg</i> in the hepatopancreas of <i>L</i>. <i>vannamei</i>.</p

Effects of VIH-2 administration on the phosphorylation and mRNA expression of three MAPKs in the hepatopancreas of <i>L</i>. <i>vannamei</i>.

<p>A: Effects of VIH-2 injection on the phosphorylation of P³⁸MAPK, ERK and JNK in shrimp hepatopancreas. B: Effects of VIH-2 treatment on the phosphorylation of P³⁸MAPK, ERK and JNK in shrimp hepatopancreatic cell cultures. C-E: Effects of VIH-2 injection on the <i>P</i>^<i>38</i><i>MAPK</i> (C), <i>ERK</i> (D) and <i>JNK</i> (E) mRNA expressions in the shrimp hepatopancreas. F-H: Effects of VIH-2 treatment on the <i>P</i>^<i>38</i><i>MAPK</i> (F), <i>ERK</i> (G) and <i>JNK</i> (H) mRNA expression in shrimp hepatopancreatic cell cultures. For <i>in vivo</i> experiments, the hepatopancreas were sampled at 0, 1.5, 3, 6, 12 and 24 h after injection of VIH-2 (300 ng/g bwt). For <i>in vitro</i> experiments, the hepatopancreatic cells were treated with VIH-2 (1000 nM) for 0, 0.5, 1, 1.5, 3, 6, 12 and 24 h. In this study, the data presented are expressed as the mean±S.E. (n = 6 and 4 for <i>in vivo</i> and <i>in vitro</i> experiments, respectively), and significant differences between treated and untreated groups were assessed using Student’s <i>t</i>-test (* <i>P</i><0.05, ** <i>P</i><0.01 and *** <i>P</i><0.001).</p

Involvement of cGMP-dependent signaling in VIH-2 suppressed <i>Vg</i> mRNA expression in the hepatopancreas of <i>L</i>. <i>vannamei</i>.

<p>A-C: The effects of the NO donor (A), the GC activator (B) and the cGMP analog (C) on <i>Vg</i> mRNA expression in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 12 h with increasing doses of NOC-18 (0.01–100 μM), A-350619 (0.01–100 μM) or 8-Br-cGMP (0.1–1000 nM). D-F: Effects of NOS inhibitor (D), GC inhibitor (E) or PKG inhibitor (F) on VIH-2-inhibited <i>Vg</i> mRNA expression in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 12 h with VIH-2 (1 μM) in the presence or absence of L-NAME (300 μM), Zn(II)PPIX (5 μM) or Rp-8-Br-PET-cGMPS (5 μM). In this study, the data presented are expressed as the mean±S.E. (n = 4). Experimental groups denoted by the same letter represent a similar level (<i>P</i>>0.05, ANOVA followed by Fisher’s LSD test).</p

Crosstalk of the GC/cGMP pathway with MAPK-dependent cascades in VIH-2 suppressed <i>Vg</i> mRNA expression in the hepatopancreas of <i>L</i>. <i>vannamei</i>.

<p>A: Effects of the GC activator and the cGMP analog on the JNK phosphorylation in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 1 h with increasing doses of A-350619 (0.01–100 μM) or 8-Br-cGMP (0.1–1000 nM). B: Effects of the GC inhibitor and the PKG inhibitor on the VIH-2-induced JNK phosphorylation in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 1 h with VIH-2 (1 μM) in the presence or absence of Zn(II)PPIX (5 μM) or Rp-8-Br-PET-cGMPS (5 μM). C & D: Effects of GC activator (C) and cGMP analog (D) on the <i>P</i>^<i>38</i><i>MAPK</i> mRNA expression in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 3 h with increasing doses of A-350619 (0.01–100 μM) or 8-Br-cGMP (0.1–1000 nM). E & F: Effects of the GC inhibitor and the PKG inhibitor on the VIH-2 induced <i>P</i>^<i>38</i><i>MAPK</i> mRNA expression in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 3 h with VIH-2 (1 μM) in the presence or absence of Zn(II)PPIX (5 μM) or Rp-8-Br-PET-cGMPS (5 μM). G-I: Effects of the P³⁸MAPK inhibitor (G), the ERK inhibitor (H) and the JNK inhibitor (I) on the VIH-2-induced cGMP productions in shrimp hepatopancreatic cell cultures. The hepatopancreatic cells were incubated for 3 h with VIH-2 (1 μM) in the presence or absence of PD169316 (100 nM), or SB02190 (100 nM), PD98059 (10 μM) or U0126 (1 μM), and SP600125 (10 μM) or BI-87G3 (10 μM). In this study, the data presented are expressed as the mean±S.E. (n = 4). Experimental groups denoted by the same letter represent a similar level (<i>P</i>>0.05, ANOVA followed by Fisher’s LSD test).</p