Summary

आसमाटिक बचाव में Caenorhabditis एलिगेंस: दो जीन की synaptic समारोह, मानव के Orthologues और Autism के लिए के रूप में उम्मीदवार

Published: December 11, 2009
doi:

Summary

Neurexins और neuroligins झिल्ली न्यूरॉन आसंजन प्रोटीन है जो synaptic भेदभाव और प्रसारण में आवश्यक भूमिका प्रदर्शन कर रहे हैं. Neuroligin की कमी म्यूटेंट<em> सी. एलिगेंस</em> आसमाटिक ताकत का पता लगाने में दोषपूर्ण हैं, लेकिन जब वे भी neurexin कोडिंग जीन में उत्परिवर्तन होते हैं, वे जंगली प्रकार phenotype ठीक हो.

Abstract

Neurexins and neuroligins are cell adhesion molecules present in excitatory and inhibitory synapses, and they are required for correct neuron network function1. These proteins are found at the presynaptic and postsynaptic membranes 2. Studies in mice indicate that neurexins and neurologins have an essential role in synaptic transmission 1. Recent reports have shown that altered neuronal connections during the development of the human nervous system could constitute the basis of the etiology of numerous cases of autism spectrum disorders 3.

Caenorhabditis elegans could be used as an experimental tool to facilitate the study of the functioning of synaptic components, because of its simplicity for laboratory experimentation, and given that its nervous system and synaptic wiring has been fully characterized. In C. elegans nrx-1 and nlg-1 genes are orthologous to human NRXN1 and NLGN1 genes which encode alpha-neurexin-1 and neuroligin-1 proteins, respectively. In humans and nematodes, the organization of neurexins and neuroligins is similar in respect to functional domains.

The head of the nematode contains the amphid, a sensory organ of the nematode, which mediates responses to different stimuli, including osmotic strength. The amphid is made of 12 sensory bipolar neurons with ciliated dendrites and one presynaptic terminal axon 4. Two of these neurons, named ASHR and ASHL are particularly important in osmotic sensory function, detecting water-soluble repellents with high osmotic strength 5. The dendrites of these two neurons lengthen to the tip of the mouth and the axons extend to the nerve ring, where they make synaptic connections with other neurons determining the behavioral response 6.

To evaluate the implications of neurexin and neuroligin in high osmotic strength avoidance, we show the different response of C. elegans mutants defective in nrx-1 and nlg-1 genes, using a method based on a 4M fructose ring 7. The behavioral phenotypes were confirmed using specific RNAi clones 8. In C. elegans, the dsRNA required to trigger RNAi can be administered by feeding 9. The delivery of dsRNA through food induces the RNAi interference of the gene of interest thus allowing the identification of genetic components and network pathways.

Protocol

1: आसमाटिक परिहार परख. परख पहले के बारे में 16-24 घंटे, एक ताजा एन जी एम OP50 ई. युक्त थाली L4 प्रत्येक जीनोटाइप के लार्वा चरण जानवरों लेने कोलाई यह 20 डिग्री सेल्सियस पर andincubate अगले दिन युवा वयस्कों के साथ …

Discussion

Neurexins और neuroligins synaptic 11 पारेषण और synaptic 12 कनेक्शन के भेदभाव में आवश्यक भूमिका प्रदर्शन करते हैं. दोनों अणुओं 13,14 autism के लिए उम्मीदवार जीनों के रूप में पहचान की गई है.

इस वीडियो में हम एक सरल पद?…

Acknowledgements

हम अपने मूल्यवान मदद के लिए धन्यवाद करने के लिए डॉ. एंटोनियो मिरांडा – Vizuete करना चाहते हैं. हम भी मूल्यवान तकनीकी सहायता के लिए सलमा Boulayoune और इसाबेल Caballero के लिए हमारे आभार व्यक्त पसंद है. इस काम के जून्टा डे Andalucia (जैव-272) से एक अनुदान द्वारा वित्त पोषण किया गया था. इस शोध वर्तमान यूरोप में आनुवंशिक प्रयोग से संबंधित कानूनों के साथ समझौते में बाहर किया गया है.

Materials

Table 1. C. elegans strains.

Strain Gene Allele Source
Bristol N2 aCGC
VC228 nlg-1 ok259 CGC
FX00474 nlg-1 tm474 bNBP-JAPAN
VC1416 nrx-1 ok1649 CGC
FX1961 nrx-1 tm1961 NBP-JAPAN
NL2099 rrf-3 pk1436 CGC
CRR21 nrx-1; nlg-1 ok1649; ok259 This work
CRR22 nrx-1; nlg-1 tm1961;ok259 This work

a. Caenorhabditis Genetic Center, University of Minnesota, USA.

b. National Bioresource Project for the Experimental Animal “Nematode C. elegans“. Tokyo Women’s Medical University, Japan.

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Cite This Article
Calahorro, F., Alejandre, E., Ruiz-Rubio, M. Osmotic Avoidance in Caenorhabditis elegans: Synaptic Function of Two Genes, Orthologues of Human NRXN1 and NLGN1, as Candidates for Autism. J. Vis. Exp. (34), e1616, doi:10.3791/1616 (2009).

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