<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Baur, L.</style></author><author><style face="normal" font="default" size="100%">Nasipak, B.</style></author><author><style face="normal" font="default" size="100%">Kelley, D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sexually differentiated, androgen-regulated, larynx-specific myosin heavy-chain isoforms in Xenopus tropicalis; comparison to Xenopus laevis</style></title><secondary-title><style face="normal" font="default" size="100%">Development Genes and Evolution</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Androgens</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Female</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation: Developmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Larynx</style></keyword><keyword><style  face="normal" font="default" size="100%">Male</style></keyword><keyword><style  face="normal" font="default" size="100%">Metamorphosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Myosin Heavy Chains</style></keyword><keyword><style  face="normal" font="default" size="100%">Organ Specificity</style></keyword><keyword><style  face="normal" font="default" size="100%">phylogenetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Isoforms</style></keyword><keyword><style  face="normal" font="default" size="100%">Sex Characteristics</style></keyword><keyword><style  face="normal" font="default" size="100%">Xenopus</style></keyword><keyword><style  face="normal" font="default" size="100%">Xenopus laevis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jul 1</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=18551305</style></url></web-urls><related-urls><url><style face="normal" font="default" size="100%">http://www.amphibiatree.org/sites/amphibiatree.org/files/BaurETAL209_Xenopus.pdf</style></url></related-urls></urls><number><style face="normal" font="default" size="100%">7</style></number><volume><style face="normal" font="default" size="100%">218</style></volume><pages><style face="normal" font="default" size="100%">371-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We have shown that the sarcoplasmic myosin heavy-chain (MyHC) isoform xtMyHC-101d is highly and specifically expressed in the larynx of the aquatic anuran, Xenopus tropicalis. In male larynges, the predominant MyHC isoform is xtMyHC-101d, while in females, another isoform, xtMyHC-270c, predominates. The X. tropicalis genome has been sequenced in its entirety, and xtMyHC-101d is part of a specific array of xtMyHC genes expressed otherwise in embryonic muscles (Nasipak and Kelley, Dev Genes Evol, in press, 2008). The administration of the androgen dihydrotestosterone increases the expression of xtMyHC-101d in juvenile larynges of both sexes. Using ATPase histochemistry, we found that in adults, X. tropicalis male laryngeal muscle contains only fast-twitch fibers, while the female laryngeal muscle contains a mix of fast- and slow-twitch fibers. Juvenile larynges are female-like in fiber type composition (44% slow twitch, 56% fast twitch); androgen treatment increases the percentage of fast-twitch fibers to 86%. xtMyHC-101d predominates in larynges of dihydrotestosterone-treated juveniles but not in larynges of untreated juveniles. We compared the larynx-specific expression of xtMyHC genes in X. tropicalis to the MyHC gene expressed in X. laevis larynx (xlMyHC-LM) by sequencing the entire xlMyHC-LM gene. The androgen-regulated xtMyHC that predominates in the male larynx of X. tropicalis is not the gene phylogenetically most similar to xlMyHC-LM at the nucleotide level but is instead a similar isoform found in the same MyHC array and expressed in the embryonic muscle.</style></abstract><accession-num><style face="normal" font="default" size="100%">18551305</style></accession-num><custom3><style face="normal" font="default" size="100%">papers://4C7791EC-5103-4C34-8C02-95FADD19FCC6/Paper/p844</style></custom3><auth-address><style face="normal" font="default" size="100%">Department of Biological Sciences, Columbia University, New York, NY 10027, USA.</style></auth-address><label><style face="normal" font="default" size="100%">p00844</style></label></record></records></xml>
