title: Cytochrome b sequences in black-crowned night-herons (Nycticorax nycticorax) from heronries exposed to genotoxic contaminants.
abstract: DNA sequence analysis of a 215 base-pair region of the mitochondrial cytochrome b gene was used to examine genetic variation and search for evidence of an increased mutation rate in black-crowned night-herons. We examined five populations exposed to environmental contamination (primarily PAHs and PCBs) and one reference population from the eastern U.S. There was no evidence of a high mutation rate even within populations previously shown to exhibit increased variation in DNA content among somatic cells as a result of petroleum exposure. Three haplotypes were observed among 99 individuals. The low level of variability could be evidence for a genetic bottleneck, or that cytochrome b is too conservative for use in population genetic studies of this species. With the exception of one population from Louisiana, pair-wise Phist estimates were very low, indicative of little population structure and potentially high rates of effective migration among populations.
authors.affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Dahl
authors.forename: J W
authors.initials: JW
authors.lastname: Bickham
authors.forename: J K
authors.initials: JK
authors.lastname: Wickliffe
authors.forename: T W
authors.initials: TW
authors.lastname: Custer
mesh_terms: D000818:Animals; D001717:Birds / Q000235:genetics*; D003573:Cytochrome b Group / Q000235:genetics*; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000235:genetics*; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000009:adverse effects*; D011078:Polychlorinated Biphenyls / Q000009:adverse effects*; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects*; D017422:Sequence Analysis, DNA
chemical_list: D003573:Cytochrome b Group; D004272:DNA, Mitochondrial; D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D011078:Polychlorinated Biphenyls