A comparative analysis of the rainbow trout genome with 2 other species of fish (Arctic charr and Atlantic salmon) within the tetraploid derivative Salmonidae family (subfamily: Salmoninae)

Genome ◽  
2005 ◽  
Vol 48 (6) ◽  
pp. 1037-1051 ◽  
Author(s):  
Roy G Danzmann ◽  
Margaret Cairney ◽  
William S Davidson ◽  
Moira M Ferguson ◽  
Karim Gharbi ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Linkage Group ◽  
Atlantic Salmon ◽  
Segregation Distortion ◽  
Recombination Rate ◽  
Chromosome Structure ◽  
Arctic Charr ◽  
Salmonid Fishes ◽  
Linkage Groups ◽  
Recombination Rates

We updated the genetic map of rainbow trout (Oncorhynchus mykiss) for 2 outcrossed mapping panels, and used this map to assess the putative chromosome structure and recombination rate differences among linkage groups. We then used the rainbow trout sex-specific maps to make comparisons with 2 other ancestrally polyploid species of salmonid fishes, Arctic charr (Salvelinus alpinus) and Atlantic salmon (Salmo salar) to identify homeologous chromosome affinities within each species and ascertain homologous chromosome relationships among the species. Salmonid fishes exhibit a wide range of sex-specific differences in recombination rate, with some species having the largest differences for any vertebrate species studied to date. Our current estimate of female:male recombination rates in rainbow trout is 4.31:1. Chromosome structure and (or) size is associated with recombination rate differences between the sexes in rainbow trout. Linkage groups derived from presumptive acrocentric type chromosomes were observed to have much lower sex-specific differences in recombination rate than metacentric type linkage groups. Arctic charr is karyotypically the least derived species (i.e., possessing a high number of acrocentric chromosomes) and Atlantic salmon is the most derived (i.e., possessing a number of whole-arm fusions). Atlantic salmon have the largest female:male recombination ratio difference (i.e., 16.81:1) compared with rainbow trout, and Arctic charr (1.69:1). Comparisons of recombination rates between homologous segments of linkage groups among species indicated that when significant experiment-wise differences were detected (7/24 tests), recombination rates were generally higher in the species with a less-derived chromosome structure (6/7 significant comparisons). Greater similarity in linkage group syntenies were observed between Atlantic salmon and rainbow trout, suggesting their closer phylogenetic affinities, and most interspecific linkage group comparisons support a model that suggests whole chromosome arm translocations have occurred in the evolution of this group. However, some possible exceptions were detected and these findings are discussed in relation to their influence on segregation distortion patterns. We also report unusual meiotic segregation patterns in a female parent involving the duplicated (homeologous) linkage group pair 12/16 and discuss several models that may account for these patterns.Key words: linkage analysis, genetic markers, polyploidy, tetrasomic inheritance, segregation distortion, recombination rate.

Sex chromosome polymorphisms in Arctic charr and their evolutionary origins

Genome ◽  
2011 ◽  
Vol 54 (10) ◽  
pp. 852-861 ◽  
Author(s):  
Eva Küttner ◽  
Jan Nilsson ◽  
Skúli Skúlason ◽  
Snorri Gunnarsson ◽  
Moira M. Ferguson ◽  
...  
Keyword(s):  
Linkage Group ◽  
Atlantic Salmon ◽  
Sex Chromosome ◽  
Arctic Charr ◽  
Current Data ◽  
Fraser River ◽  
Salmonid Fishes ◽  
Sex Linkage ◽  
Linkage Groups ◽  
Evolutionary Origins

Current data on the Y-specific sex-determining region of salmonid fishes from genera Salvelinus , Salmo , and Oncorhynchus indicate variable polymorphisms in the homologous chromosomal locations of the sex-specific determining region. In the majority of the Atlantic lineage Arctic charr, including populations from the Fraser River, in Labrador Canada, as well as Swedish and Norwegian strains, the sex-determining locus maps to linkage group AC-4. Previously, sex-linked polymorphisms (i.e., variation in the associated sex-linked markers on AC-4) have been described in Arctic charr. Here, we report further evidence for intraspecific sex linkage group polymorphisms in Arctic charr (i.e., the detection of the SEX locus on either the AC-1 or AC-21 linkage group) and a possible conservation of a sex linkage arrangement in Icelandic Arctic charr and Atlantic salmon, involving sex-linked markers on the AC-1/21 homeologs and the European AS-1/6 homeologous linkage groups in Atlantic salmon. The evolutionary origins for the multiple sex-determining regions within the salmonid family are discussed. We also relate the variable sex-determining regions in salmonids to their ancestral proto-teleost karyotypic origins and compare these findings with what has been observed in other teleost species in general.

scholarly journals Do rainbow trout and Atlantic salmon discriminate kin?

1992 ◽  
Vol 70 (8) ◽  
pp. 1636-1640 ◽  
Author(s):  
Grant E. Brown ◽  
Joseph A. Brown
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Coho Salmon ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Salmonid Fishes ◽  
Kin Discrimination ◽  
Significant Preference ◽  
Rainbow Trout Oncorhynchus Mykiss

The purpose of this study was to determine if juvenile Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) can discriminate kin from non-kin, since other salmonid species (coho salmon (Oncorhynchus kisutch) and Arctic charr (Salvelinus alpinus)) have been shown to possess this ability. When tested in water conditioned by conspecifics (kin and non-kin) and heterospecifics in a two-choice tank, both rainbow trout and Atlantic salmon demonstrated a significant preference for kin over non-kin and heterospecifics, indicating that these species possess kin-discrimination abilities. This ability appears to be widespread among salmonid fishes.

Arctic charr (Salvelinus alpinus) is a suitable host for Gyrodactylus salaris (Monogenea, Gyrodactylidae) in Norway

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 257-267 ◽  
Author(s):  
G. ROBERTSEN ◽  
H. HANSEN ◽  
L. BACHMANN ◽  
T. A. BAKKE
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
First Record ◽  
Mitochondrial Haplotype ◽  
Stock Management ◽  
New Host ◽  
Mitochondrial Haplotypes ◽  
In The Wild

Gyrodactylus specimens infecting both anadromous Arctic charr (Salvelinus alpinus) from River Signaldalselva (northern Norway) and resident Arctic charr from Lake Pålsbufjorden (southern Norway) were identified as G. salaris using molecular markers and morphometrics. The infection in Pålsbufjorden represents the first record of a viable G. salaris population infecting a host in the wild in the absence of salmon (Salmo salar). G. salaris on charr from Signaldalselva and Pålsbufjorden bear different mitochondrial haplotypes. While parasites infecting charr in Signaldalselva carry the same mitochondrial haplotype as parasites from sympatric Atlantic salmon, G. salaris from charr in Pålsbufjorden bear a haplotype that has previously been found in parasites infecting rainbow trout (Oncorhynchus mykiss) and Atlantic salmon, and an IGS repeat arrangement that is very similar to those observed earlier in parasites infecting rainbow trout. Accordingly, the infection may result from 2 subsequent host-switches (from salmon via rainbow trout to charr). Morphometric analyses revealed significant differences between G. salaris infecting charr in the 2 localities, and between those on sympatric charr and salmon within Signaldalselva. These differences may reflect adaptations to a new host species, different environmental conditions, and/or inherited differences between the G. salaris strains. The discovery of G. salaris on populations of both anadromous and resident charr may have severe implications for Atlantic salmon stock-management as charr may represent a reservoir for infection of salmon.

scholarly journals A Microsatellite Linkage Map of Rainbow Trout (Oncorhynchus mykiss) Characterized by Large Sex-Specific Differences in Recombination Rates

Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1331-1345 ◽  
Author(s):  
Takashi Sakamoto ◽  
Roy G Danzmann ◽  
Karim Gharbi ◽  
Pamela Howard ◽  
Akiyuki Ozaki ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Linkage Map ◽  
Genetic Linkage Map ◽  
Linkage Groups ◽  
Tetrad Analysis ◽  
Recombination Rates ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Male Specific ◽  
Microsatellite Linkage

Abstract We constructed a genetic linkage map for a tetraploid derivative species, the rainbow trout (Oncorhynchus mykiss), using 191 microsatellite, 3 RAPD, 7 ESMP, and 7 allozyme markers in three backcross families. The linkage map consists of 29 linkage groups with potential arm displacements in the female map due to male-specific pseudolinkage arrangements. Synteny of duplicated microsatellite markers was used to identify and confirm some previously reported pseudolinkage arrangements based upon allozyme markers. Fifteen centromeric regions (20 chromosome arms) were identified with a half-tetrad analysis using gynogenetic diploids. Female map length is ~10 M, but this is a large underestimate as many genotyped segments remain unassigned at a LOD threshold of 3.0. Extreme differences in female:male map distances were observed (ratio F:M, 3.25:1). Females had much lower recombination rates (0.14:1) in telomeric regions than males, while recombination rates were much higher in females within regions proximal to the centromere (F:M, 10:1). Quadrivalent formations that appear almost exclusively in males are postulated to account for the observed differences.

A genetic linkage map for Arctic char (Salvelinus alpinus): evidence for higher recombination rates and segregation distortion in hybrid versus pure strain mapping parents

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 304-315 ◽  
Author(s):  
R A Woram ◽  
C McGowan ◽  
J A Stout ◽  
K Gharbi ◽  
M M Ferguson ◽  
...  
Keyword(s):  
Linkage Map ◽  
Segregation Distortion ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Salvelinus Alpinus ◽  
Linkage Groups ◽  
Recombination Rates ◽  
Pure Strain ◽  
Female Hybrid ◽  
Map Distance

We constructed a genetic linkage map for Arctic char (Salvelinus alpinus) using two backcrosses between genetically divergent strains. Forty-six linkage groups (expected = 39–41) and 19 homeologous affinities (expected = 25) were identified using 184 microsatellites, 129 amplified fragment length polymorphisms (AFLPs), 13 type I gene markers, and one phenotypic marker, SEX. Twenty-six markers remain unlinked. Female map distance (9.92 Morgans) was substantially higher than male map distance (3.90 Morgans) based on the most complete parental information (i.e., the F1 hybrids). Female recombination rates were often significantly higher than those of males across all pairwise comparisons within homologous chromosomal segments (average female to male ratios within families was 1.69:1). The female hybrid parent had significantly higher recombination rates than the pure strain female parent. Segregation distortion was detected in four linkage groups (4, 8, 13, 20) for both families. In family 3, only the largest fish were sampled for genotyping, suggesting that segregation distortion may represent regions possessing influences on growth. In family 2, almost all cases showing segregation distortion involved markers in the female hybrid parent.Key words: salmonid fishes, polyploidy, homeology, genetic markers.

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