TY - JOUR
T1 - Genetic stock structure of the swordfish (Xiphias gladius) inferred by PCR-RFLP analysis of the mitochondrial DNA control region
AU - Chow, S.
AU - Okamoto, H.
AU - Uozumi, Y.
AU - Takeuchi, Y.
AU - Takeyama, H.
N1 - Funding Information:
Acknowledgements We gratefully acknowledge J. R. Alvarado-Bremer and R. D. Ward for their invaluable comments and suggestions on an earlier draft of this manuscript. We would like to thank the following people for their time and effort collecting swordfish samples: J. R. Alvarado-Bremer and B. Ely, the University of South Carolina; A. F. Amorim, the Institute de Pesca, Brazil; A. Caton, Bureau of Resources Sciences, Australia; A. Di Natale, AQUASTUDIO, Italy; G. De Metrio, the University of Bari, Italy; P. Grewe, Commonwealth Scientific and Industrial Research Organization, Australia; L. Griggs, the National Institute of Water & Atmospheric Research, New Zealand; M. G. Hinton, J. Ganchozo, E. Largacha and J. Parraga, the Inter-American Tropical Tuna Commission, USA; S. Kalish, the Ministry of Agriculture and Fishery, New Zealand; O. Sosa-Nishizaki and J. M. Grijalva-Chon, Centro de Investigacion Cientifica y de Education Superior de Ensenada, Mexico; J. Uchiyama, the National Marine Fisheries Service; and M. Yesaki, the Indo-Pacific Tuna Development and Management Program, Sri Lanka. Thanks are also due to I. Warashina, Y. Tanaka, Y. Nishikawa, Z. Suzuki, and H. Nakano, the National Research Institute of Far Seas Fisheries (NRIFSF), for assisting with sample collection and for reading the manuscript, and M. Goto, the Institute of Cetacean Research for helping with the statistical analysis.
PY - 1997/2
Y1 - 1997/2
N2 - Restriction fragment length polymorphism (RFLP) analysis was performed on PCR amplified DNA fragments containing the control region of the swordfish (Xiphias gladius Linnaeus, 1758) mitochondrial DNA. A total of 456 individuals comprising 13 local samples (six Pacific, three Atlantic, the Mediterranean Sea, two Indian Ocean and the Cape of Good Hope) were surveyed with four endonucleases (Alu I, Dde I, Hha I and Rsa I), yielding a total of 52 composite genotypes. Within-sample genotypic diversity (H) was high ranging from 0.702 to 0.962 with a value of 0.922 for the pooled sample. Significant geographic variation in the frequencies of genotypes and restriction patterns was revealed. The Mediterranean sample was highly distinct from all other samples. Further, Rsa I digestion revealed high levels of polymorphism in all but the Mediterranean samples, indicating that exogenous swordfishes rarely enter that body of water. Heterogeneity between the North and South Atlantic samples was significant, both of which differed from those of the Pacific. In contrast, the Indian Ocean samples were not significantly different from the samples of South Atlantic and Pacific. Genetic differentiation among the Pacific samples was low. The results indicate that the world-wide swordfish population is genetically structured not only among, but also within ocean basins and suggest that gene flow is restricted despite the absence of geographic barriers.
AB - Restriction fragment length polymorphism (RFLP) analysis was performed on PCR amplified DNA fragments containing the control region of the swordfish (Xiphias gladius Linnaeus, 1758) mitochondrial DNA. A total of 456 individuals comprising 13 local samples (six Pacific, three Atlantic, the Mediterranean Sea, two Indian Ocean and the Cape of Good Hope) were surveyed with four endonucleases (Alu I, Dde I, Hha I and Rsa I), yielding a total of 52 composite genotypes. Within-sample genotypic diversity (H) was high ranging from 0.702 to 0.962 with a value of 0.922 for the pooled sample. Significant geographic variation in the frequencies of genotypes and restriction patterns was revealed. The Mediterranean sample was highly distinct from all other samples. Further, Rsa I digestion revealed high levels of polymorphism in all but the Mediterranean samples, indicating that exogenous swordfishes rarely enter that body of water. Heterogeneity between the North and South Atlantic samples was significant, both of which differed from those of the Pacific. In contrast, the Indian Ocean samples were not significantly different from the samples of South Atlantic and Pacific. Genetic differentiation among the Pacific samples was low. The results indicate that the world-wide swordfish population is genetically structured not only among, but also within ocean basins and suggest that gene flow is restricted despite the absence of geographic barriers.
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U2 - 10.1007/s002270050022
DO - 10.1007/s002270050022
M3 - Article
AN - SCOPUS:0031058242
SN - 0025-3162
VL - 127
SP - 359
EP - 367
JO - Marine Biology
JF - Marine Biology
IS - 3
ER -