The ghost of hybrids past: fixation of arctic charr ( Salvelinus alpinus ) mitochondrial DNA in an introgressed population of lake trout ( S. namaycush )

1998 ◽  
Vol 7 (1) ◽  
pp. 127-132 ◽  
Author(s):  
CHRIS C. WILSON ◽  
LOUIS BERNATCHEZ
1998 ◽  
Vol 76 (7) ◽  
pp. 1300-1318 ◽  
Author(s):  
Roy G Danzmann ◽  
Raymond P Morgan II ◽  
Matthew W Jones ◽  
Louis Bernatchez ◽  
Peter E Ihssen

Mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) of 2422 brook trout (Salvelinus fontinalis) from 60 units (major drainages, small stream catchments, and isolated lakes) representing 155 populations in eastern North America were examined to test hypotheses regarding postglacial dispersal and recolonization. An analysis of molecular variance (AMOVA) indicated that 38.8% of the variation was partitioned among the units, while approximately 60% was distributed among populations (phiST = 59.3) compared with 40.7% within populations. This distribution of variation suggests a large degree of heterogeneity in population founding events and phylogeographic structuring in this species. Comparisons of mtDNA diversity between fish from putative refugial and recolonization zones for this species indicate that more than one refugial region contributed to northern recolonization. Haplotypic diversities in recolonized regions are greatest in south-central populations (i.e., southern Great Lakes region), while only one haplotype (haplotype 1) predominates in northern, western, and eastern postglacial zones. Large phylogenetic differences were found between northern and southern populations. Populations outside the zone of glaciation were the most genetically heterogeneous and were represented by fish from all six (A-F) of the major evolutionary clades identified. Only fish from the A, B, and C clades were found in glaciated regions, with C lineage fish restricted to south-central glaciation zones. Fish from the C clade are putatively the most ancestral lineage within the species based upon composite shared RFLPs with lake trout (Salvelinus namaycush) and Arctic char (Salvelinus alpinus).


Evolution ◽  
2001 ◽  
Vol 55 (3) ◽  
pp. 573 ◽  
Author(s):  
Patrick C. Brunner ◽  
Marlis R. Douglas ◽  
Alexander Osinov ◽  
Chris C. Wilson ◽  
Louis Bernatchez

1994 ◽  
Vol 51 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Irv Kornfield ◽  
Frederick W. Kircheis

Periods of low water in Floods Pond, Maine, USA, during spawning seasons for an endemic population of landlocked Arctic char, Salvelinus alpinus oquassa, have contributed to several year-class failures. To determine the genetic uniqueness of these fish, samples of Arctic char from five isolated lakes in New England and eastern Canada were examined by restriction endonuclease analysis of mitochondrial DNA (mtDNA) and compared with samples of lake trout (Salvelinus namaycush) and Arctic char from Scandinavia. Results suggest that (1) Arctic char of eastern North America should all be considered members of Salvelinus alpinus oquassa, (2) char from Floods Pond possess a unique mtDNA banding pattern for one restriction enzyme not observed in fish from any other sampled locality (this difference delineates a distinct lineage of Arctic char whose preservation is warranted on genetic grounds), and (3) unique banding patterns did not characterize any other studied char population, including geographic variants (these populations may be viewed as genetically homogeneous, and none warrant individual protection based upon our genetic characterizations). We contend that genetically identified lineages in the early stages of divergence warrant preservation.


Genome ◽  
2012 ◽  
Vol 55 (1) ◽  
pp. 26-32 ◽  
Author(s):  
K. Pomianowski ◽  
M. Jankun ◽  
K. Ocalewicz

Highly polymorphic Arctic charr ( Salvelinus alpinus Linnaeus, 1758) chromosomes were studied using conventional and molecular methods. The diploid chromosome number in the studied individuals was 2n = 81 or 2n = 82, with a fundamental arm number (NF) = 100. These differences are due to Robertsonian fusions. Interindividual variation in the number and size of DAPI and CMA3 positively stained chromatin sites was observed in studied specimens. In the case of two individuals, the subtelomeric region of the long arm (q) of the largest acrocentric chromosome (chromosome number 10) was positively stained by CMA3 fluorochrome. Both primed in situ labelling (PRINS) and fluorescence in situ hybridization (FISH) revealed that this CMA3-positive region was flanked by telomeric sequences. Previously, the subterminal position of interstitial telomeric sequences located in the vicinity of the CMA3-positive guanine-rich chromatin have been described in two other Salvelinus species, brook trout ( Salvelinus fontinalis ) and lake trout ( Salvelinus namaycush ). Moreover, multichromosomal location and variation in size of CMA3 bands have been observed in various Salvelinus taxa, including fishes with internally located telomeric sequences. These results suggest that relocation of CMA3-positive chromatin segments in these species may be facilitated by flanking interstitial telomeric sequences (ITSs).


2005 ◽  
Vol 56 (5) ◽  
pp. 705 ◽  
Author(s):  
T. Niva ◽  
P. Keränen ◽  
J. Raitaniemi ◽  
H. M. Berger

A total of 222 pairs of alizarin red S (ARS)-labelled and 75 pairs of unlabelled sagittal otoliths from six hatchery-reared species, including Arctic charr (Salvelinus alpinus (L.)), lake trout (Salvelinus namaycush (Walbaum)), salmon (Salmo salar L.), brown trout (Salmo trutta L.), whitefish (Coregonus sp.) and pikeperch (Sander lucioperca (L.)), were used in blind tests to determine whether sawing a 0.4-mm thick slice from the otolith would improve the interpretation of labelled otoliths. The fish were labelled in 1995–2002. Fish age at labelling varied from two weeks to three months, immersion time from three to six hours and concentration of ARS 50–100 ppm. Blind tests were arranged so that sawed slices were contrasted with entire otoliths using stereomicroscope under UV epi-illumination. According to blind tests, the accuracy of interpretation of ARS-labelled otoliths was 97.0% from the slices and 92.3% from entire otoliths. The role of different filters in detecting false marks owing to autofluorescence is discussed. Cost-benefits of the method are discussed briefly.


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