Determination of the Female-Biased Sex Ratio in Some Young-of-the-Year and Spawner Samples of the Threespine Stickleback Gasterosteus aculeatus by Environmental, Not Genetic, Factors

2021 ◽  
Vol 48 (5) ◽  
pp. 577-587
Author(s):  
V. S. Artamonova ◽  
N. V. Bardukov ◽  
P. V. Golovin ◽  
T. S. Ivanova ◽  
M. V. Ivanov ◽  
...  
1995 ◽  
Vol 52 (6) ◽  
pp. 1307-1317 ◽  
Author(s):  
Jeffrey V. Baumgartner

Phenotypic, genetic, and environmental variances and covariances for 33 morphometric traits were estimated for a population of threespine stickleback, Gasterosteus aculeatus, from the Brush Creek drainage, California, by sib analysis of laboratory-bred families. Heritabilities of the morphometric traits ranged from −0.28 to 0.78, and were moderately low (mean h2 = 0.26); the mean and range of heritabilities for five phenotypic eigenvectors were similar. The average coefficient of genetic determination of the traits and eigenvectors was high (0.57 and 0.63, respectively), indicating a substantial genotypic contribution to variation in body morphology. The defensive complex, a functional set of bony armor structures, was genetically and environmentally integrated: genetic factors (e.g., pleiotropy) are reinforced by environmental factors to produce a functional phenotype. Other components of morphology, including body form, were environmentally, but not genetically, integrated. Given the importance of genetic factors to evolutionary change under natural selection, these results implicate natural selection in the evolution of the defensive complex; the role of natural selection in the evolution of other components of morphology is equivocal. Genetic integration of functionally (phenotypically) independent traits suggests that stochastic processes or pleiotropic mutation also have played a role in the evolution of morphology in this population of sticklebacks.


1977 ◽  
Vol 55 (3) ◽  
pp. 590-594 ◽  
Author(s):  
E. T. Garside ◽  
D. G. Heinze ◽  
S. E. Barbour

Thermal preferences were determined in spacious thermal gradients of fresh water and sea water (32‰ salinity (S))for acclimations of 5, 15, and 25 °C in sea water, for samples of threespine stickleback Gasterosteus aculeatus L. Preferred temperatures increased through acclimations of 5–25 °C, with those for the freshwater tests being about 2 °C lower at each acclimation. Final preferenda were 16 and 18 °C for freshwater tests and seawater tests, respectively. The final preferendum in such haloplastic species is defined as the highest obtainable preferendum that equals acclimation temperature. A later series of disjunct preference determinations in approximately isosmotic water (10.5‰ S) for subjects acclimated to 7, 15, and 20 °C yielded mean values of 17.7, 18.2, and 18.7 °C, respectively. A final preferendum has not been designated since the samples were of separate origins. A parallel exists between these responses and the response of this and other haloplastic species in the determination of upper lethal temperatures. The immediate cause appears to be differentials in metabolic loading occasioned by l stresses.


2021 ◽  
Vol 66 (3) ◽  
Author(s):  
Ahmed Dorgham ◽  
Ulrika Candolin ◽  
Tatiana Ivanova ◽  
Mikhail Ivanov ◽  
Ekaterina Nadtochii ◽  
...  

Sexual dimorphism (SD) in the threespine stickleback Gasterosteus aculeatus reflects the different roles of the sexes in reproduction and their adaptations to different ecological niches. We quantified SD in one population of marine stickleback from the White Sea, collected during the spawning period from three spawning grounds, each at a distance of 5 km or less from the others. We used a landmark-based approach to quantify variation in 44 morphometric linear traits. In total, 749 females and 693 males were analyzed. In males, anterior body parts are larger — the base of the caudal fin and armor structures such as the first and second dorsal spines and the pelvic spine. Females have larger posterior bodies — the abdomen, pelvic girdle and the third dorsal spine. The SD of caudal body parts exhibits complex patterns. In White Sea threespine stickleback, SD patterns are generally similar to other populations of the species, but more often show male-biased patterns. Female-biased size SD may be associated with the female biased sex ratio of White Sea stickleback.


2008 ◽  
Vol 90 (4) ◽  
pp. 269-276 ◽  
Author(s):  
Natacha S. Hogan ◽  
Cheryl A. Wartman ◽  
Megan A. Finley ◽  
Jennifer G. van der Lee ◽  
Michael R. van den Heuvel

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 211
Author(s):  
Anna Malkova ◽  
Dmitriy Kudlay ◽  
Igor Kudryavtsev ◽  
Anna Starshinova ◽  
Piotr Yablonskiy ◽  
...  

According to an analysis of published data, only 20% of patients with the new coronavirus infection develop severe life-threatening complications. Currently, there are no known biomarkers, the determination of which before the onset of the disease would allow assessing the likelihood of its severe course. The purpose of this literature review was to analyze possible genetic factors characterizing the immune response to the new coronavirus infection that could be associated with the expression of angiotension-converting enzyme 2 (ACE-2) and related proteins as predictors of severe Corona virus disease 2019 (COVID-19). We analyzed original articles published in Medline, PubMed and Scopus databases from December 2019 to November 2020. For searching articles, we used the following keywords: New coronavirus infection, Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), COVID-19, severe course, complications, thrombosis, cytokine storm, ACE-2, biomarkers. In total, 3714 publications were selected using the keywords, of which 8 were in congruence with all the criteria. The literature analysis of the association of immunogenic characteristics and the expression of ACE-2 and related proteins with the development of severe COVID-19 revealed following genetic factors: HLA-B*46:01 genotype, CXCR6 gene hypoexpression, CCR9 gene expression, TLR7, rs150892504 mutations in the ERAP2 gene, overexpression of wild-type ACE-2, TMPRSS2 and its different polymorphisms. Genes, associated with the severe course, are more common among men. According to the analysis data, it can be assumed that there are population differences. However, the diagnostic significance of the markers described must be confirmed with additional clinical studies.


Author(s):  
Ester Premate ◽  
Špela Borko ◽  
Simona Kralj‐Fišer ◽  
Michael Jennions ◽  
Žiga Fišer ◽  
...  
Keyword(s):  

Zoomorphology ◽  
2020 ◽  
Author(s):  
Harald Ahnelt ◽  
David Ramler ◽  
Maria Ø. Madsen ◽  
Lasse F. Jensen ◽  
Sonja Windhager

AbstractThe mechanosensory lateral line of fishes is a flow sensing system and supports a number of behaviors, e.g. prey detection, schooling or position holding in water currents. Differences in the neuromast pattern of this sensory system reflect adaptation to divergent ecological constraints. The threespine stickleback, Gasterosteus aculeatus, is known for its ecological plasticity resulting in three major ecotypes, a marine type, a migrating anadromous type and a resident freshwater type. We provide the first comparative study of the pattern of the head lateral line system of North Sea populations representing these three ecotypes including a brackish spawning population. We found no distinct difference in the pattern of the head lateral line system between the three ecotypes but significant differences in neuromast numbers. The anadromous and the brackish populations had distinctly less neuromasts than their freshwater and marine conspecifics. This difference in neuromast number between marine and anadromous threespine stickleback points to differences in swimming behavior. We also found sexual dimorphism in neuromast number with males having more neuromasts than females in the anadromous, brackish and the freshwater populations. But no such dimorphism occurred in the marine population. Our results suggest that the head lateral line of the three ecotypes is under divergent hydrodynamic constraints. Additionally, sexual dimorphism points to divergent niche partitioning of males and females in the anadromous and freshwater but not in the marine populations. Our findings imply careful sampling as an important prerequisite to discern especially between anadromous and marine threespine sticklebacks.


1989 ◽  
Vol 67 (8) ◽  
pp. 2078-2080 ◽  
Author(s):  
Robert Poulin ◽  
Gerard J. FitzGerald

Females of the ectoparasitic crustacean Argulus canadensis must leave their fish hosts at least temporarily to deposit their eggs on the substrate. To test the hypothesis that this difference in reproductive behaviour between the two sexes could result in male-biased sex ratios on their stickleback hosts, we sampled sticklebacks in tide pools of a Quebec salt marsh from early July to early September 1986. During this period, fish harboured significantly more male than female A. canadensis. Laboratory experiments were done to test two alternative hypotheses offered to explain this biased sex ratio. The first hypothesis was that male A. canadensis were more successful than females in attacking their stickleback hosts; however, we found no differences in attack success on their hosts between the two parasite sexes. The second hypothesis was that sticklebacks ate more female than male A. canadensis. Although males were less vulnerable to fish predation than females, the difference was not significant. We conclude that sexual differences in reproductive behaviour, i.e., egg deposition behaviour of females, can account for the male-biased sex ratio of A. canadensis on sticklebacks.


Author(s):  
L. Leveelahti ◽  
P. Leskinen ◽  
E.H. Leder ◽  
W. Waser ◽  
M. Nikinmaa

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