A 17-kilobase (kb) region of the zucchini (Cucurbita pepo) genome has been sequenced and contains two genes, CP-ACCIA and CP-ACCIB, encoding 1-aminocyclopropane-1-carboxylate synthase (ACC synthase; S-adenosyl-Lmethionine methylthioadenosine-lyase, EC 4.4.1.14). The genes are transcribed convergently and are separated by a 5.7-kb intergenic region. Their coding regions are interrupted by four introns located in identical positions. While the DNA

BackgroundIn neonatal binocular animals, the developing retina displays patterned spontaneous activity termed retinal waves, which are initiated by a single class of interneurons (starburst amacrine cells, SACs) that release neurotransmitters. Although SACs are shown to regulate wave dynamics, little is known regarding how altering the proteins involved in neurotransmitter release may affect wave dynamics. Synaptotagmin (Syt) family harbors two Ca2+-binding domains (C2A and C2B) which serve as Ca2+ sensors in neurotransmitter release. However, it remains unclear whether SACs express any specific Syt isoform mediating retinal waves. Moreover, it is unknown how Ca2+ binding to C2A and C2B of Syt affects wave dynamics. Here, we investigated the expression of Syt I in the neonatal rat retina and examined the roles of C2A and C2B in regulating wave dynamics.Methodology/Principal FindingsImmunostaining and confocal microscopy showed that Syt I was expressed in neonatal rat SACs and cholinergic synapses, consistent with its potential role as a Ca2+ sensor mediating retinal waves. By combining a horizontal electroporation strategy with the SAC-specific promoter, we specifically expressed Syt I mutants with weakened Ca2+-binding ability in C2A or C2B in SACs. Subsequent live Ca2+ imaging was used to monitor the effects of these molecular perturbations on wave-associated spontaneous Ca2+ transients. We found that targeted expression of Syt I C2A or C2B mutants in SACs significantly reduced the frequency, duration, and amplitude of wave-associated Ca2+ transients, suggesting that both C2 domains regulate wave temporal properties. In contrast, these C2 mutants had relatively minor effects on pairwise correlations over distance for wave-associated Ca2+ transients.Conclusions/SignificanceThrough Ca2+ binding to C2A or C2B, the Ca2+ sensor Syt I in SACs may regulate patterned spontaneous activity to shape network activity during development. Hence, modulating the releasing machinery in presynaptic neurons (SACs) alters wave dynamics.

BackgroundDeveloping retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs) and retinal ganglion cells (RGCs). The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A2A receptor (A2AR) regulates retinal waves and whether A2AR regulation of retinal waves acts via presynaptic SACs.Methodology/Principal FindingsWe showed that A2AR was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A2AR decreased the frequency of spontaneous Ca2+ transients, suggesting that endogenous A2AR may up-regulate wave frequency. To investigate whether A2AR acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca2+ transient frequency was increased by expressing wild-type A2AR (A2AR-WT) in SACs, suggesting that A2AR may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A2AR-WT increased the frequency of wave-associated postsynaptic currents (PSCs) or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A2AR may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A2AR mutant (A2AR-ΔC) in SACs, the wave frequency was reduced compared to the A2AR-WT, but was similar to the control, suggesting that the full-length A2AR in SACs is required for A2AR up-regulation of retinal waves.Conclusions/SignificanceA2AR up-regulates the frequency of retinal waves via presynaptic SACs, requiring its full-length protein structure. Thus, by coupling with the downstream intracellular signaling, A2AR may have a great capacity to modulate patterned spontaneous activity during neural circuit refinement.

Geraniol 10-hydroxylase (G10H), a cytochrome P450 monooxygenase, has been reported to be involved in the biosynthesis of terpenoid indole alkaloids. The gene for Catharanthus roseus G10H (CrG10H) was cloned and heterologously expressed in baculovirus-infected insect cells. A number of substrates were subjected to assay the enzyme activity of CrG10H. As reported in a previous study, CrG10H hydroxylated the monoterpenoid geraniol at the C-10 position to generate 10-hydroxygeraniol. Interestingly, CrG10H also catalyzed 3'-hydroxylation of naringenin to produce eriodictyol. Coexpression of an Arabidopsis NADPH P450 reductase substantially increased the ability of CrG10H to hydroxylate naringenin. The catalytic activity of CrG10H was approximately 10 times more efficient with geraniol than with naringenin, judged by the k(cat)/K(m) values. Thus, G10H also plays an important role in the biosynthetic pathway of flavonoids, in addition to its previously described role in the metabolism of terpenoids.

Light-harvesting and conversion ability is important to promote plant growth, and especially when resources are limited. A near-infrared (NIR) nanophosphor embedded with mesoporous silica nanoparticles (MSN), ZnGa 2 O 4 :Cr 3+ ,Sn 4+ (ZGOCS), was developed and its optical properties were harnessed to enhance the photosynthetic ability of Brassica rapa spp. chinensis. The broad excitation of ZGOCS from the ultraviolet to the visible region allowed the conversion of extra light into near-infrared light (650-800 nm) and thus promoted the dual photosystem via the Emerson effect. ZGOCS@MSN was spherical with a size of 65 AE 10 nm and good dispersion. A light conversion ability of up to 75 % under different wavelengths was achieved. Moreover, the electron transfer rate of photosynthesis increased by 100 % with a suitable ZGOCS@MSN concentration. Plant and animal models were used to explore the effects of the nanophosphor. ZGOCS@MSN distribution was tracked by monitoring its NIR emission in plant and animal tissues, demonstrating that this nanophosphor can be potentially utilized in plant growth.

The YWK-II cDNA, RSD-2, encoding a sperm membrane protein was isolated from a rat testis cDNA expression library. Using the RSD-2 insert in combination with rapid amplification of cDNA ends (RACE), the corresponding human gene was isolated from a human testis cDNA expression library. The human testis cDNA, HSD-2, is 3654 bp in length and contains an open reading frame of 763 codons. Hydropathicity analysis showed that the deduced polypeptide is a single strand transmembrane protein. The deduced polypeptide has partial homology with the amyloid precursor protein (APP) and high homology with the amyloid precursor homologue, APLP2/APPH. The YWK-II gene was mapped and assigned to human chromosome locus: 11q24-25. Northern blotting of various human tissue RNAs using the HSD-2 cDNA as a probe showed that the gene is transcribed ubiquitously. The cytoplasmic domain of HSD-2 was expressed in Escherichia coli. In-vitro studies showed that the recombinant polypeptide bound to a GTP-binding protein (G(o)) and was phosphorylated by protein kinase C and cdc2 kinase. In mammalian F11 cells, the recombinant polypeptide was found to be coupled to G(o). Thus, the YWK-II component has the characteristics of a G(o)-coupled receptor and may be involved in G(o)-mediated signal transduction pathway. Protein kinase C and cdc2 kinase may regulate this pathway in spermatozoa by phosphorylating the cytoplasmic domain of the YWK-II component.

CRL 618 is a well-studied pre-planetary nebula. It has multiple highly collimated optical lobes, fast molecular outflows along the optical lobes, and an extended molecular envelope that consists of a dense torus in the equator and a tenuous round halo. Here we present our observations of this source in CO J=3-2 and HCN J=4-3 obtained with the Submillimeter Array at up to ∼ 0 ′′ . 3 resolutions. We spatially resolve the fast molecular-outflow region previously detected in CO near the central star and find it to be composed of multiple outflows that have similar dynamical ages, and are oriented along the different optical lobes. We also detect fast molecular outflows further away from the central star near the tips of the extended optical lobes and a pair of equatorial outflows inside the dense torus. We find that two episodes of bullet ejections in different directions are needed, one producing the fast molecular outflows near the central star, and one producing the fast molecular outflows near the tips of the extended optical lobes. One possibility to launch these bullets is the magneto-rotational explosion of the stellar envelope.

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