The Kemp's ridley sea turtle (Lepidochelys kempi) is restricted to the warm temperate zone of the North Atlantic Ocean, whereas the olive ridley turtle (L. olivacea) is globally distributed in warm-temperate and tropical seas, including nesting colonies in the North Atlantic that nearly overlap the range of L. kempi. To explain this lopsided distribution, Pritchard (1969) proposed a scenario in which an ancestral taxon was divided into Atlantic and Pacific forms (L. kempi and L. olivacea, respectively) by the Central American land bridge. According to this model, the olive ridley subsequently occupied the Pacific and Indian Oceans and recently colonized the Atlantic Ocean via southern Africa. To assess this biogeographic model, a 470 bp sequence of the mtDNA control region was compared among 89 ridley turtles, including the sole L. kempi nesting population and 7 nesting locations across the range of L. olivacea. These data confirm a fundamental partition between L. olivacea and L. kempi (p = 0.052-0.069), shallow separations within L. olivacea (p = 0.002-0.031), and strong geographic partitioning of mtDNA lineages. The most divergent L. olivacea haplotype is observed in the Indo-West Pacific region, as are the central haplotypes in a parsimony network, implicating this region as the source of the most recent radiation of olive ridley lineage. The most common olive ridley haplotype in Atlantic samples is distinguished from an Indo-West Pacific haplotype by a single nucleotide substitution, and East Pacific samples are distinguished from the same haplotype by two nucleotide substitutions. These shallow separations are consistent with the recent invasion of the Atlantic postulated by Pritchard (1969), and indicate that the East Pacific nesting colonies were also recently colonized from the Indo-West Pacific region. Molecular clock estimates place these invasions within the last 300,000 years.
Diaprepes abbreviatus L. is a polyphagous weevil affecting more than 270 species of plants. The larvae feed on roots of the trees causing damage that can kill the plant. Originally from the Caribbean, this weevil was first found in the United States in Apopka, Florida in 1964(Woodruff 1964 and it currently infests 23 counties in Florida. In 2000, D. abbreviatus was discovered in the Rio Grande Valley, Texas (Skaria & French 2001) and in 2005 in southern California (California Department of Food and Agriculture, CDFA, 2007).Different control measurements, which are specific to a particular life stage of the weevil, are currently in use (McCoy et al. 2007). However, when egg masses or larvae are found, the diagnosis of infestation is often delayed due to lack of reliable methods that allow one to identify nonadult stages. The objective of this study was to develop a method for species identification of immature stages of D. abbreviatus based on DNA barcoding technique. DNA barcoding consists of sequencing of a DNA segment from a specified region of the genome, and the "barcode" sequences are compared to those available in a reference database to determine the species represented by the sample. The mitochondrial gene cytochrome oxidase I (COI) is extensively used for barcoding of metazoans (Hebert et al. 2003). Moreover, COI sequences are the most commonly used for quarantine and forensic applications involving insects, Tetranychus mites (Lee & Lee 1997), Liriomyza leafminers (Scheffer et al. 2001) and Calliphora blowflies (Ames et al. 2006). In this study, a reliable method based on PCR and sequencing of the COI gene was developed to identify immature specimens of D. abbreviatus and to differentiate them from another common root weevil, Pantomorus cervinus (Boheman) Kuschel.Eight egg-masses of D. abbreviatus were provided by S. Frazer at the Division of Plant Industry (DPI) (Florida Department of Agriculture and Consumer Services) rearing facility and kept at -20°C. Another clutch of eggs collected at Fairbanks Ranch (California) by D. Arena (CDFA) was reared by J. Bethke (University of California) and neonates were stored in 95% ethanol immediately
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.