SEX CHROMOSOMES IN THE SOCKEYE SALMON: A Y-AUTOSOME FUSION

1978 ◽  
Vol 20 (3) ◽  
pp. 349-354 ◽  
Author(s):  
Gary H. Thorgaard
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Washington State ◽  
Metacentric Chromosome

Chromosomes of 21 sockeye salmon [Oncorhynchus nerka (Walbaum)] from three locations in Washington state were examined. All males had 57 chromosomes, while all females had 58 chromosomes. Both sexes had 104 chromosome arms. It appears that in males of this species the Y chromosome and an autosome have fused to form a metacentric chromosome.

scholarly journals Sphaerospora elwhaiensis sp. n. (Myxosporea: Sphaerosporidae) from landlocked sockeye salmon Oncorhynchus nerka (Salmoniformes: Salmonidae) in Washington State, USA

2011 ◽  
Vol 58 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Simon Jones ◽  
Ivan Fiala ◽  
Gina Prosperi-Porta ◽  
Marcia House ◽  
Sonia Mumford
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Washington State

Comparison of parasite fauna of juvenile sockeye salmon (Oncorhynchus nerka) from southern British Columbian and Washington State lakes

1987 ◽  
Vol 65 (2) ◽  
pp. 420-431 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis
Keyword(s):  
Sockeye Salmon ◽  
Trophic Status ◽  
Oncorhynchus Nerka ◽  
Parasite Fauna ◽  
Washington State ◽  
Nearest Neighbour ◽  
Cluster Analyses ◽  
Modes Of Transmission ◽  
Lake Washington ◽  
Neighbour Analysis

Sixteen species and juveniles of four taxa of parasites (Myxosporea, 4; Monogenea, 1; Trematoda, 5; Cestoda, 4; Nematoda, 2; Acanthocephala, 2; Copepoda, 2) were encountered in 1550 sockeye salmon (Oncorhynchus nerka) smolts and presmolts examined from 15 Fraser River lakes, Nimpkish Lake on Vancouver Island, and Lake Washington, Washington State, U.S.A. The most common taxa were Diphyllobothrium sp. (spp.?) plerocercoids, Philonema agubernaculum, Eubothrium sp., and Proteocephalus sp. Various statistical techniques (K - nearest neighbour and cluster analyses based on Jaccard and percent dissimilarity matrices) were used to compare the parasite fauna in sockeye from the different lakes. K - nearest neighbour analysis demonstrated that considerable overlap existed among many of the studied lakes, whereas little overlap occurred among other lakes. Cluster analyses revealed similar faunas among some lakes within biogeoclimatic zones and lakes of similar trophic status. Cluster analyses also revealed parasites that tended to co-occur. Parasites with similar modes of transmission or geographic range tended to cluster together.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.

scholarly journals X and Y Chromosome Complement Influence Adiposity and Metabolism in Mice

Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xuqi Chen ◽  
Rebecca McClusky ◽  
Yuichiro Itoh ◽  
Karen Reue ◽  
Arthur P. Arnold
Keyword(s):  
Body Weight ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Gonadal Hormones ◽  
Xy Model ◽  
Second Sex ◽  
Metabolic Variables ◽  
Novel Model

Abstract Three different models of MF1 strain mice were studied to measure the effects of gonadal secretions and sex chromosome type and number on body weight and composition, and on related metabolic variables such as glucose homeostasis, feeding, and activity. The 3 genetic models varied sex chromosome complement in different ways, as follows: 1) “four core genotypes” mice, comprising XX and XY gonadal males, and XX and XY gonadal females; 2) the XY* model comprising groups similar to XO, XX, XY, and XXY; and 3) a novel model comprising 6 groups having XO, XX, and XY chromosomes with either testes or ovaries. In gonadally intact mice, gonadal males were heavier than gonadal females, but sex chromosome complement also influenced weight. The male/female difference was abolished by adult gonadectomy, after which mice with 2 sex chromosomes (XX or XY) had greater body weight and percentage of body fat than mice with 1 X chromosome. A second sex chromosome of either type, X or Y, had similar effects, indicating that the 2 sex chromosomes each possess factors that influence body weight and composition in the MF1 genetic background. Sex chromosome complement also influenced metabolic variables such as food intake and glucose tolerance. The results reveal a role for the Y chromosome in metabolism independent of testes and gonadal hormones and point to a small number of X–Y gene pairs with similar coding sequences as candidates for causing these effects.

scholarly journals Telomere-to-telomere assembly of a fish Y chromosome reveals the origin of a young sex chromosome pair

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingzhan Xue ◽  
Yu Gao ◽  
Meiying Wu ◽  
Tian Tian ◽  
Haiping Fan ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Pair ◽  
Sex Chromosome ◽  
Structural Variations ◽  
Recombination Suppression ◽  
Chromosome Differentiation ◽  
Y Chromosomes ◽  
Recent Origin ◽  
Mastacembelus Armatus

Abstract Background The origin of sex chromosomes requires the establishment of recombination suppression between the proto-sex chromosomes. In many fish species, the sex chromosome pair is homomorphic with a recent origin, providing species for studying how and why recombination suppression evolved in the initial stages of sex chromosome differentiation, but this requires accurate sequence assembly of the X and Y (or Z and W) chromosomes, which may be difficult if they are recently diverged. Results Here we produce a haplotype-resolved genome assembly of zig-zag eel (Mastacembelus armatus), an aquaculture fish, at the chromosomal scale. The diploid assembly is nearly gap-free, and in most chromosomes, we resolve the centromeric and subtelomeric heterochromatic sequences. In particular, the Y chromosome, including its highly repetitive short arm, has zero gaps. Using resequencing data, we identify a ~7 Mb fully sex-linked region (SLR), spanning the sex chromosome centromere and almost entirely embedded in the pericentromeric heterochromatin. The SLRs on the X and Y chromosomes are almost identical in sequence and gene content, but both are repetitive and heterochromatic, consistent with zero or low recombination. We further identify an HMG-domain containing gene HMGN6 in the SLR as a candidate sex-determining gene that is expressed at the onset of testis development. Conclusions Our study supports the idea that preexisting regions of low recombination, such as pericentromeric regions, can give rise to SLR in the absence of structural variations between the proto-sex chromosomes.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice

2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Sea Lice

Validation of daily increments and a marine-entry check in the otoliths of sockeye salmon Oncorhynchus nerka post-smolts

2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Daily Increments
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