Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.7/519
Título: Niflumic acid disrupts marine spermatozoan chemotaxis without impairing the spatiotemporal detection of chemoattractant gradients
Autor: Guerrero, Adán
Espinal, Jesús
Wood, Christopher D
Rendón, Juan M
Carneiro, Jorge
Martínez-Mekler, Gustavo
Darszon, Alberto
Palavras-chave: Ca 2+ signaling
Chemotaxis
Niflumic acid
Sperm
Data: 15-Mar-2013
Editora: Company of Biologists
Citação: Niflumic acid disrupts marine spermatozoan chemotaxis without impairing the spatiotemporal detection of chemoattractant gradients Adán Guerrero, Jesús Espinal, Christopher D. Wood, Juan M. Rendón, Jorge Carneiro, Gustavo Martínez-Mekler, Alberto Darszon J Cell Sci 2013 126: 1477-1487; doi: 10.1242/jcs.121442
Resumo: In many broadcast-spawning marine organisms, oocytes release chemicals that guide conspecific spermatozoa towards them through chemotaxis. In the sea urchin Lytechinus pictus, the chemoattractant peptide speract triggers a train of fluctuations of intracellular Ca(2+) concentration in the sperm flagella. Each transient Ca(2+) elevation leads to a momentary increase in flagellar bending asymmetry, known as a chemotactic turn. Furthermore, chemotaxis requires a precise spatiotemporal coordination between the Ca(2+)-dependent turns and the form of chemoattractant gradient. Spermatozoa that perform Ca(2+)-dependent turns while swimming down the chemoattractant gradient, and conversely suppress turning events while swimming up the gradient, successfully approach the center of the gradient. Previous experiments in Strongylocentrotus purpuratus sea urchin spermatozoa showed that niflumic acid (NFA), an inhibitor of several ion channels, drastically altered the speract-induced Ca(2+) fluctuations and swimming patterns. In this study, mathematical modeling of the speract-dependent Ca(2+) signaling pathway suggests that NFA, by potentially affecting hyperpolarization-activated and cyclic nucleotide-gated channels, Ca(2+)-regulated Cl(-) channels and/or Ca(2+)-regulated K(+) channels, may alter the temporal organization of Ca(2+) fluctuations, and therefore disrupt chemotaxis. We used a novel automated method for analyzing sperm behavior and we identified that NFA does indeed disrupt chemotactic responses of L. pictus spermatozoa, although the temporal coordination between the Ca(2+)-dependent turns and the form of chemoattractant gradient is unaltered. Instead, NFA disrupts sperm chemotaxis by altering the arc length traveled during each chemotactic turning event. This alteration in the chemotactic turn trajectory disorientates spermatozoa at the termination of the turning event. We conclude that NFA disrupts chemotaxis without affecting how the spermatozoa decode environmental cues.
Peer review: yes
URI: http://hdl.handle.net/10400.7/519
DOI: 10.1242/jcs.121442
Versão do Editor: http://jcs.biologists.org/content/126/6/1477
Aparece nas colecções:QOB - Artigos

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
1477.full.pdfartigo principal2,23 MBAdobe PDFVer/Abrir


FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Degois 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.