Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.9.3.1 (cytochrome oxidase)
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Reef fishes disperse primarily as oceanic "pelagic" larvae, and debate continues over the extent of this dispersal, with recent evidence for geographically restricted (closed) populations in some species. In contrast, moray eels have the longest pelagic larval stages among reef fishes, possibly providing opportunities to disperse over great distances. We test this prediction by measuring mitochondrial DNA (mtDNA) and nuclear DNA variation in 2 species of moray eels, Gymnothorax undulatus (N = 165) and G. flavimarginatus (N = 124), sampled at 14-15 locations across the Indo-Pacific. The mtDNA data comprise 632 bp of cytochrome b and 596 bp of cytochrome oxidase I. Nuclear markers include 2 recombination-activating loci (421 bp of RAG-1 and 754 bp of RAG-2). Analyses of molecular variance and Mantel tests indicate little or no genetic differentiation, and no isolation by distance, across 22 000 km of the Indo-Pacific. We estimate that mitochondrial genetic variation coalesces within the past about 2.3 million years (My) for G. flavimarginatus and within the past about 5.9 My for G. undulatus. Permutation tests of geographic distance on the mitochondrial haplotype networks indicate recent range expansions for some younger haplotypes (estimated within approximately 600 000 years) and episodic fragmentation of populations at times of low sea level. Our results support the predictions that the extended larval durations of moray eels enable ocean-wide genetic continuity of populations. This is the first phylogeographic survey of the moray eels, and morays are the first reef fishes known to be genetically homogeneous across the entire Indo-Pacific.
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PMID:Phylogeography of two moray eels indicates high dispersal throughout the indo-pacific. 2037 76

Among crocodilians, Crocodylus rhombifer is one of the world's most endangered species with the smallest natural distribution. In Cuba, this endemic species coexists with the American crocodile (Crocodylus acutus). Hybridization between these two species is well known in captivity and might occur in the wild, but has never been demonstrated genetically. Here, we combined molecular data with environmental, geographic, and fossil data to infer the evolutionary history of Crocodylus in the Cuban Archipelago, and to evaluate genealogical support for species boundaries. We analyzed seven microsatellite loci plus DNA sequence data from nuclear (RAG-1) and mitochondrial (cytochrome b and cytochrome oxidase I) genes from 89 wild-caught individuals in Cuba, Grand Cayman Island, Jamaica, and Central America, and two samples from zoo collections. Microsatellites showed evidence of introgression, suggesting potential hybridization among Cuban groups. In Cuba, C. acutus contained one mitochondrial DNA (mtDNA) haplotype, whereas C. rhombifer contained two haplotypes. MtDNA data showed that C. acutus is paraphyletic with respect to C. rhombifer, revealing 1% sequence divergence between species within Cuba vs. 8% divergence between Cuban forms and mainland C. acutus. We suggest that hybridization has been a historical as well as a current phenomenon between C. acutus and C. rhombifer. These findings suggest that long-term conservation of crocodiles in Cuba will require identification of genetically pure and hybrid individuals, and a decrease in anthropogenic activities. We also recommend more extensive morphological and genetic analyses of Cuban population to establish clear boundaries of the hybrid zone between C. acutus and C. rhombifer.
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PMID:Evolutionary history of Cuban crocodiles Crocodylus rhombifer and Crocodylus acutus inferred from multilocus markers. 2146 51