Microdissection of the Y chromosome and fluorescencein situ hybridization analysis of the sex chromosomes of lake trout,Salvelinus namaycush

1995 ◽  
Vol 3 (4) ◽  
pp. 221-226 ◽  
Author(s):  
K. M. Reed ◽  
S. K. Bohlander ◽  
R. B. Phillips

1985 ◽  
Vol 39 (1) ◽  
pp. 14-18 ◽  
Author(s):  
R.B. Phillips ◽  
P.E. Ihssen


Author(s):  
Alexander Gatch ◽  
Dimitry Gorsky ◽  
Zy Biesinger ◽  
Eric Bruestle ◽  
Kelley Lee ◽  
...  


1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein

We examined data from 1984 to 1994 for five species of Lake Michigan salmonids to explore the relationship between total PCB concentration and percent lipid. When we compared mean species lipid and PCB values, we found a strong linear correlation. When we compared values among individuals, we found modest positive PCB:lipid associations in brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) collected during spawning, but positive associations were not apparent among nonspawning individuals. Lake trout (Salvelinus namaycush) exhibited no discernible PCB:lipid relationship. Our results are not incompatible with previous observations that contaminants are differentially partitioned into lipids within a fish, but these results do suggest that lipids are not a major factor influencing contaminant uptake.



1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.

Criteria for the classification of marks inflicted by sea lamprey (Petromyzon marinus) into nine categories were developed from laboratory studies in an attempt to refine the classification system used in field assessment work. These criteria were based on characteristics of the attachment site that could be identified under field conditions by unaided visual means and by touching the attachment site. Healing of these marks was somewhat variable and was influenced by the size of lamprey, duration of attachment, severity of the wound at lamprey detachment, season and water temperature, and by other less obvious factors. Even under laboratory conditions staging of some wounds was difficult, especially at low water temperatures. If these criteria are to be used effectively and with precision in the field, close examination of individual fish may be required. If the feeding and density of specific year-classes of sea lampreys are to be accurately assessed on an annual basis, close attention to the wound size (as it reflects the size of the lamprey's oral disc) and character of wounds on fish will be required as well as consideration of the season of the year in which they are observed.Key words: sea lamprey, attack marks, lake trout, Great Lakes



Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xuqi Chen ◽  
Rebecca McClusky ◽  
Yuichiro Itoh ◽  
Karen Reue ◽  
Arthur P. Arnold

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.



1989 ◽  
Vol 46 (3) ◽  
pp. 384-388 ◽  
Author(s):  
F. W. H. Beamish ◽  
J. C. Howlett ◽  
T. E. Medland

Juvenile lake trout, Salvelinus namaycush, of similar size were fed one of three isocaloric diets, each differing in protein and lipid content. Oxygen consumption and swimming performance were measured in a recirculating water flume at intervals throughout the 70-d feeding trials (10 °C). Swimming speed was increased by stepwise velocity increments (5 cm∙s−1) and oxygen consumption was measured at each velocity between 20 and 45 cm∙s−1. Oxygen consumption for a given speed did not differ significantly throughout the feeding trial nor among the diets implying a similarity in the quality and quantity of substrate catabolized for energy. Basal metabolism (0 cm∙s−1) was also independent of diet and feeding interval. Critical swimming speed increased with dietary and carcass protein content to suggest a direct association with muscle mass and number of myofilaments.



1997 ◽  
Vol 54 (6) ◽  
pp. 1299-1305 ◽  
Author(s):  
Robert France

The purpose of the present study was to determine if riparian deforestation would expose lake surfaces to stronger winds and therefore bring about deepening of thermoclines and resulting habitat losses for cold stenotherms such as lake trout (Salvelinus namaycush). Removal of protective riparian trees through wind blowdown and two wildfires was found to triple the overwater windspeeds and produce thermocline deepening in two lakes at the Experimental Lakes Area. A survey of thermal stratification patterns in 63 northwestern Ontario lakes showed that lakes around which riparian trees had been removed a decade before through either clearcutting or by a wildfire were found to have thermocline depths over 2 m deeper per unit fetch length compared with lakes surrounded by mature forests. Riparian tree removal will therefore exacerbate hypolimnion habitat losses for cold stenotherms that have already been documented to be occurring as a result of lake acidification, eutrophication, and climate warming.



2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Shauna M. Baillie ◽  
Andrew M. Muir ◽  
Michael J. Hansen ◽  
Charles C. Krueger ◽  
Paul Bentzen


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingzhan Xue ◽  
Yu Gao ◽  
Meiying Wu ◽  
Tian Tian ◽  
Haiping Fan ◽  
...  

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.



1981 ◽  
Vol 38 (12) ◽  
pp. 1738-1746 ◽  
Author(s):  
Terrence R. Dehring ◽  
Anne F. Brown ◽  
Charles H. Daugherty ◽  
Stevan R. Phelps

Patterns of genetic variation among lake trout (Salvelinus namaycush) of eastern Lake Superior were examined using starch gel electrophoresis. We used 484 individuals sampled from three areas, representing three morphological types (leans, humpers, and siscowets). Of 50 loci examined, 44 were monomorphic in all groups sampled. Genetic variation occurs at six loci AAT-1,2, MDH-3,4, ME-1, and SOD-1. The average heterozygosity found (H = 0.015) is low relative to other salmonid species. A significant amount of heterogeneity exists among the 10 lake trout samples. These differences are due to variation within as well as between morphological types. The significance and management implications of these data are discussed.Key words: genetic variation, lake trout, Salvelinus namaycush, Lake Superior



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