1,930 research outputs found
A Small Conductance Calcium-Activated K<sup>+</sup> Channel in C. elegans, KCNL-2, Plays a Role in the Regulation of the Rate of Egg-Laying
In the nervous system of mice, small conductance calcium-activated potassium (SK) channels function to regulate neuronal excitability through the generation of a component of the medium afterhyperpolarization that follows action potentials. In humans, irregular action potential firing frequency underlies diseases such as ataxia, epilepsy, schizophrenia and Parkinson's disease. Due to the complexity of studying protein function in the mammalian nervous system, we sought to characterize an SK channel homologue, KCNL-2, in C. elegans, a genetically tractable system in which the lineage of individual neurons was mapped from their early developmental stages. Sequence analysis of the KCNL-2 protein reveals that the six transmembrane domains, the potassium-selective pore and the calmodulin binding domain are highly conserved with the mammalian homologues. We used widefield and confocal fluorescent imaging to show that a fusion construct of KCNL-2 with GFP in transgenic lines is expressed in the nervous system of C. elegans. We also show that a KCNL-2 null strain, kcnl-2(tm1885), demonstrates a mild egg-laying defective phenotype, a phenotype that is rescued in a KCNL-2-dependent manner. Conversely, we show that transgenic lines that overexpress KCNL-2 demonstrate a hyperactive egg-laying phenotype. In this study, we show that the vulva of transgenic hermaphrodites is highly innervated by neuronal processes and by the VC4 and VC5 neurons that express GFP-tagged KCNL-2. We propose that KCNL-2 functions in the nervous system of C. elegans to regulate the rate of egg-laying. © 2013 Chotoo et al
Ultracool dwarfs candidates based on six years of the Dark Energy Survey data
We present a sample of 19,583 ultracool dwarf candidates brighter than z
selected from the Dark Energy Survey DR2 coadd data matched to VHS
DR6, VIKING DR5 and AllWISE covering 4,800 . The ultracool
candidates were first pre-selected based on their (i-z), (z-Y), and (Y-J)
colours. They were further classified using a method that compares their
optical, near-infrared and mid-infrared colours against templates of M, L and T
dwarfs. 14,099 objects are presented as new L and T candidates and the
remaining objects are from the literature, including 5,342 candidates from our
previous work. Using this new and deeper sample of ultracool dwarf candidates
we also present: 20 new candidate members to nearby young moving groups (YMG)
and associations, variable candidate sources and four new wide binary systems
composed of two ultracool dwarfs. Finally, we also show the spectra of twelve
new ultracool dwarfs discovered by our group and presented here for the first
time. These spectroscopically confirmed objects are a sanity check of our
selection of ultracool dwarfs and photometric classification method.Comment: 18 pages, 10 figures, 7 tables. Accepted for publication in MNRA
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