Genomic Identification and Functional Analysis of JHAMTs in the Pond Wolf Spider, Pardosa pseudoannulata

Juvenile hormone (JH) plays a critical role in many physiological activities of Arthropoda. Juvenile hormone acid methyltransferase (JHAMT) is involved in the last steps of JH biosynthesis as an important rate-limiting enzyme. In recent studies, an increasing number of JHAMTs were identified in arthropods, but no JHAMT was reported in spiders. Herein, eight JHAMTs were identified in the pond wolf spider, Pardosa pseudoannulata, all containing the well conserved S-adenosyl-L-methionine binding motif. JHAMT-1 and the other seven JHAMTs were located at chromosome 13 and chromosome 1, respectively. Multiple alignment and phylogenetic analysis showed that JHAMT-1 was grouped together with insect JHAMTs independently and shared high similarities with insect JHAMTs compared to the other seven JHAMTs. In addition, JHAMT-1, JHAMT-2, and JHAMT-3 were highly expressed in the abdomen of spiderlings and could respond to the stimulation of exogenous farnesoic acid. Meanwhile, knockdown of these three JHAMTs caused the overweight and accelerated molting of spiderlings. These results demonstrated the cooperation of multi-JHAMTs in spider development and provided a new evolutionary perspective of the expansion of JHAMT in Arachnida.

Effect of methyl farnesoate and farnesoic acid during 5th zoea and megalopa metamorphosis in the mud crab Scylla paramamosain Estampador, 1950 (Decapoda, Brachyura, Portunidae)

The mud crab Scylla paramamosain is one of the economically important aquaculture species in China. The larval development of the mud crab is characterized by two significant morphological changes, from the 5th zoea (Z5) to the megalopa (M) stage and from the M to the first juvenile crab (C1) stage. In this study, we found that methyl farnesoate (MF) could prohibit the Z5 to M metamorphosis in a concentration-dependent manner, and that a concentration of 10 μM MF could completely prohibit the Z5 metamorphosis. Farnesoic acid (FA) could also prohibit the Z5 metamorphosis, but its effects seemed to be concentration-independent. In addition, MF could delay rather than prohibit the M to C1 metamorphosis, while FA had no effect on the M to C1 metamorphosis at all. To summarize, it is hypothesized that either absence of MF and FA, or at least very low levels of these substances, might be necessary for a successful Z5 to M metamorphosis.

Cytoplasmic translocation of nuclear lysine-specific demethylase-1 (LSD1/KDM1A) in human hepatoma cells is induced by its inhibitors

ABSTRACTHistone-modifiable lysine-specific demethylase-1 (LSD1/KDM1A) is often upregulated in many cancers, including hepatoma, and is regarded as oncoprotein. We previously reported that the hepatoma-preventive geranylgeranoic acid (GGA) inhibits KDM1A activity at the same IC50as that of the clinically used drug tranylcypromine, a verified inhibitor of KDM1A. Here, we report that these inhibitors induced cytoplasmic translocation of nuclear KDM1A in a human hepatoma-derived cell line. Immunofluorescence studies revealed cytoplasmic localization of KDM1A, 3 h after addition of GGA or tranylcypromine in HuH-7 cells. Geranylgeraniol and all-transretinoic acid were both unable to induce translocation of nuclear KDM1A, whereas farnesoic acid showed the weak activity. Furthermore, GGA did not affect subcellular localization of another histone lysine-specific demethylase, KDM5A. This suggests that the inhibitor-induced translocation of nuclear KDM1A to the cytoplasm is specific for KDM1A. These data demonstrate for the first time that KDM1A inhibitors specifically induce the cytoplasmic translocation of nuclear KDM1A.AbbreviationsATRAall-transretinoic acidCoRESTcorepressor for element 1-silencing transcription factorDICdifferential interference contrastFAfarnesoic acidGGOHgeranylgeraniolGGAgeranylgeranoic acidLSD1/KDM1Alysine-specific demethylase-1pHH3phospho-histone H3(Ser10)TCPtrans-2-phenylcyclopropylamine