Genetic variation of microsatellite and mitochondrial DNA markers in broad whitefish (Coregonus nasus) in the Colville and Sagavanirktok rivers in northern Alaska

1997 ◽  
Vol 54 (7) ◽  
pp. 1548-1556 ◽  
Author(s):  
J.C. Patton ◽  
B.J. Gallaway ◽  
R.G. Fechhelm ◽  
M.A. Cronin
1997 ◽  
Vol 54 (7) ◽  
pp. 1548-1556 ◽  
Author(s):  
J C Patton ◽  
B J Gallaway ◽  
R G Fechhelm ◽  
M A Cronin

There has been concern that a causeway leading to oil production facilities in the Alaskan Beaufort Sea could affect the extent of emigration from, and immigration into, a population of broad whitefish (Coregonus nasus) in the Sagavanirktok River. To assess this, we analyzed the genetic relationships of the broad whitefish populations in the Sagavanirktok River, and the nearest adjacent population, in the Colville River. Three microsatellite loci from the nuclear genome, and the NADH-1 gene of mitochondrial DNA (mtDNA), were analyzed. Diploid genotypes were determined with PCR amplification of the microsatellite loci, and mtDNA genotypes were identified with PCR amplification followed by sequencing of 798 nucleotides. Several alleles were identified at each locus and both populations had high levels of genetic variation. There is significant differentiation of the Sagavanirktok River and Colville River broad whitefish stocks for the three microsatellite loci (FST = 0.031) but not mtDNA (FST < 0.001). Possible explanations for the lower level of differentiation of mtDNA than microsatellites include female-mediated gene flow between populations, skewed sex ratios, natural selection, or mutation. The results indicate that there is limited gene flow between the Colville and Sagavanirktok rivers, which represent semi-isolated spawning populations.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
John A. Ohiolei ◽  
Joshua Luka ◽  
Guo-Qiang Zhu ◽  
Hong-Bin Yan ◽  
Li Li ◽  
...  

Abstract Background Cysticercosis caused by the metacestode larval stage of Taenia hydatigena is a disease of veterinary and economic importance. A considerable level of genetic variation among isolates of different intermediate hosts and locations has been documented. Generally, data on the genetic population structure of T. hydatigena is scanty and lacking in Nigeria. Meanwhile, similar findings in other cestodes like Echinococcus spp. have been found to be of epidemiological importance. Our aim, therefore, was to characterize and compare the genetic diversity of T. hydatigena population in Nigeria based on three mitochondrial DNA markers as well as to assess the phylogenetic relationship with populations from other geographical regions. Methods In the present study, we described the genetic variation and diversity of T. hydatigena isolates from Nigerian sheep and goats using three full-length mitochondrial genes: the cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunit 1 (nad1), and NADH dehydrogenase subunit 5 (nad5). Results The median-joining network of concatenated cox1-nad1-nad5 sequences indicated that T. hydatigena metacestodes of sheep origin were genetically distinct from those obtained in goats and this was supported by high FST values of nad1, cox1, and concatenated cox1-nad1-nad5 sequences. Genetic variation was also found to be higher in isolates from goats than from sheep. Conclusions To the best of our knowledge, the present study described the genetic variation of T. hydatigena population for the first time in Nigeria using full-length mitochondrial genes and suggests the existence of host-specific variants. The population indices of the different DNA markers suggest that analysis of long mitochondrial DNA fragments may provide more information on the molecular ecology of T. hydatigena. We recommend that future studies employ long mitochondrial DNA sequence in order to provide reliable data that would explain the extent of genetic variation in different hosts/locations and the biological and epidemiological significance.


2019 ◽  
Vol 58 (2) ◽  
pp. 279-293 ◽  
Author(s):  
Yuan-Yuan Wei ◽  
Zhan-Ping Ren ◽  
Xiao-Ye Jin ◽  
Wei Cui ◽  
Chong Chen ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2086
Author(s):  
Maciej Karpowicz ◽  
Sabina Smolska ◽  
Magdalena Świsłocka ◽  
Joanna Moroz

Our results are the first insight into groundwater copepods of the Polish Lowland. The sampling was conducted in 28 wells in north-eastern Poland, and Copepoda were present in 16 wells. We have identified six Copepoda species and one Cladocera. We have classified four species as stygophiles—Eucyclops serrulatus, Diacyclops bisetosus, Diacyclops crassicaudis, and Cyclops furcifer. These species were frequently found in studied wells of different regions of north-eastern Poland, often in high numbers, and females with egg sacs were observed. We present a detailed morphological description of these species, together with molecular characteristics based on mitochondrial DNA markers (COI gene) for E. serrulatus, D. bisetosus, and D. crassicaudis, and 12S ribosomal RNA for C. furcifer. We also present the development of abnormal structures in one specimen of D. crassicaudis, where the upper part of furcal rami was fused to form a single plate.


1996 ◽  
Vol 121 (3) ◽  
pp. 374-379 ◽  
Author(s):  
Mark W. Farnham

A collection of collard (Brassica oleracea L., Acephala group) germplasm, including 13 cultivars or breeding lines and 5 landraces, was evaluated using randomly amplified polymorphic DNA (RAPD) markers and compared to representatives of kale (Acephala group), cabbage (Capitata group), broccoli (Italica group), Brussels sprouts (Gemmifera group), and cauliflower (Botrytis group). Objectives were to assess genetic variation and relationships among collard and other crop entries, evaluate intrapopulation variation of open-pollinated (OP) collard lines, and determine the potential of collard landraces to provide new B. oleracea genes. Two hundred nine RAPD bands were scored from 18 oligonucleotide decamer primers when collard and other B. oleracea entries were compared. Of these, 147 (70%) were polymorphic and 29 were specific to collard. Similarity indices between collard entries were computed from RAPD data and these ranged from 0.75 to 0.99 with an average of 0.83. Collard entries were most closely related to cabbage (similarity index = 0.83) and Brussels sprouts entries (index = 0.80). Analysis of individuals of an OP cultivar and landrace indicated that intrapopulation genetic variance accounts for as much variation as that observed between populations. RAPD analysis identified collard landraces as unique genotypes and showed them to be sources of unique DNA markers. The systematic collection of collard landraces should enhance diversity of the B. oleracea germplasm pool and provide genes for future crop improvement.


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