Hormonal Growth Promotion and Evidence for a Size-Related Difference in Response to Estradiol-17β in Yellow Perch (Perca flavescens)

1985 ◽  
Vol 42 (10) ◽  
pp. 1627-1633 ◽  
Author(s):  
Jeffrey A. Malison ◽  
Cody D. Best ◽  
Terrence B. Kayes ◽  
Clyde H. Amundson ◽  
Bernard C. Wentworth

Our studies indicate that estrogen(s) promote growth and may mediate sexually related dimorphic growth in yellow perch (Perca flavescens). (1) Neither 17α-methyltestosterone (MT) at 1.5–60 μg/g diet nor estradiol-17β (E2) at 15–120 μg/g stimulated length or weight gain when fed for 85 d to age 0 perch that were initially 20–35 mm total length (TL) and 0.14–0.25 g total weight (TW). (2) In larger age 0 perch (initially 90–110 mm TL and 8–12 g TW), E2 at 2 or 20 μg/g accelerated length and weight gain; MT, triiodothyronine, and zeranol failed to promote growth at all doses tested. (3) E2 at 20 μg/g had differential effects when fed for 84 d to age 0 perch (initially 30–50 mm TL and 0.5–0.7 g TW) and age 1 perch (initially 90–110 mm TL and 8–12 g TW): E2 stimulated weight gain in the larger fish within the first 28 d, but did not improve growth in the smaller perch until they reached 80–100 mm TL and 5–10 g TW (after day 56). These results demonstrate that E2 promotes perch growth only after a certain size- or age-related maturational status has been reached. We suggest that this status is related to the onset of spermatogenesis, vitellogenesis, and sexually related dimorphic growth and may be linked to the maturation of hormone receptors.


1988 ◽  
Vol 45 (11) ◽  
pp. 1942-1948 ◽  
Author(s):  
Jeffrey A. Malison ◽  
Terrence B. Kayes ◽  
Bernard C. Wentworth ◽  
Clyde H. Amundson

In yellow perch (Perca flavescens) (initially 13–16 g total weight) fed to satiation (3.0–3.5% of body weight per day), estradiol-17β (E2) at 15 μg/g diet stimulated weight gain and food consumption of both sexes but did not influence food conversion efficiency (FCE), as measured by weight gain of fish per weight of food consumed. Females fed to satiation gained more weight, consumed more food, and had higher FCE than males. In perch fed a restricted ration (1.2% of body weight per day), the differences between the sexes in weight gain were reduced and due entirely to differences in FCE, and weight gain was not improved by E2. Spatial segregation or integration of the sexes had no influence on sex-related growth patterns in perch fed either the satiation or restricted ration. Carcass composition of perch treated for 84 d with E2 at 2, 20, or 50 μg/g diet did not differ from that of controls. These data indicate that (1) estrogens promote growth in yellow perch by stimulating food consumption, (2) female perch outgrow males because of both greater food consumption and higher FCE, and (3) growth differences between the sexes are not a consequence of intersexual competition for food.



2015 ◽  
Vol 72 (10) ◽  
pp. 1494-1502 ◽  
Author(s):  
Fan Zhang ◽  
Kevin B. Reid ◽  
Thomas D. Nudds

Older spawning fish were often observed to contribute more recruits to harvested stocks than younger fish. However, effects of spawning stock age structure on recruitment were not universally detected. We tested effects of age-dependent absolute fecundity, age-dependent relative fecundity, and age-related maternal effects on recruitment by Lake Erie yellow perch (Perca flavescens). No effects of age-dependent absolute fecundity and age-dependent relative fecundity, nor positive age-related maternal effects, were detected at multidecadal or finer temporal scales of analysis, between 1975 and 2013. Instead, we found evidence of negative age-related maternal effects, of spatially and temporally varying strength; older cohorts in the spawning stock were sometimes associated with lower offspring survival. Such counterintuitive results imply that biotic and abiotic factors, such as interspecific predation, during larval and juvenile life stages might strongly affect recruitment of Lake Erie yellow perch.



1986 ◽  
Vol 43 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Jeffrey A. Malison ◽  
Terrence B. Kayes ◽  
Cody D. Best ◽  
Clyde H. Amundson ◽  
Bernard C. Wentworth

Morphological and histologial studies demonstrated that estrogens and androgens affect sexual differentiation and can be used to control the phenotypic sex of yellow perch (Perca flavescens). Normal perch larvae of 5–10 mm total length (TL) had paired gonads with no sex-distinguishing features. In normal 16 mm TL perch, the gonads of females had fused into a single sac-shaped organ, while in males the gonads remained paired. Oogenesis had begun in most females of 35 mm TL. Spermatogenesis in males and vitellogenesis in females were first observed at 85 mm TL. Treatment (for 84 d) of perch (initially 20–35 mm TL) with estradiol-17β at 15–120 μg/g diet induced complete germ cell sex inversion in most males. Similar treatment with 17α-methyltestosterone at 1.5 to 60 μg/g diet induced spermatogenesis and the formation of ovotestes in females. Sperm collected from such ovotestes fertilized normal ova, and the resultant offspring were all female. Our findings indicate that in yellow perch: (1) differentiation of the somatic elements of the gonads precedes gametogenesis, (2) gametogenesis begins earlier in females than in males, (3) the attainment of a specific minimum body size (80–100 mm TL) is important to the initial onset of vitellogenesis and spermatogenesis, (4) both estrogens and androgens are probably involved in mediating sexual differentiation of germinal tissues and (5) females are the homogametic sex.



2020 ◽  
Vol 17 (2) ◽  
pp. 187-192
Author(s):  
E.A. Novikova ◽  
◽  
O.V. Kostromina ◽  
D.V. Mikhailov ◽  
S.L. Leontiev ◽  
...  

Aim. The aim of the study was to determine the presence of peculiarities of the age structure in patients with various surrogate molecular biological subtypes of breast cancer. Materials and research methods. This work analyzes the age-related characteristics of the occurrence of molecular biological subtypes in 499 patients with invasive breast cancer. All cases were divided into 5 molecular biological subtypes based on immunohistochemical studies of hormone receptors, Her2, Ki-67. The average age of the patients was 53.4±0.39 years, the predominant group was patients from 50 to 60 years (37.2% of the total). Research results. In patients under 40 years old, the triple negative subtype prevailed (44.8%). Luminal A subtype prevailed in the groups 51-60 years old (more than 41.4%) and over 60 years old (39.7%). Luminal B (Her2-) subtype was equally found in all age groups.



1990 ◽  
Vol 126 (3) ◽  
pp. 461-466 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway

ABSTRACT The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0·8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20–38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0·8 mg/kg) or testosterone propionate (0·8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60–74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone. The effect of TBA on corticosterone concentrations differs from that of the natural androgen, testosterone, and does not appear to be mediated by a reduction in plasma concentrations of ACTH. Journal of Endocrinology (1990) 126, 461–466



1995 ◽  
Vol 52 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Todd M. Koel ◽  
John J. Peterka

Laboratory-based bioassays were conducted to determine concentrations of sodium-sulfate type salinities that limit the hatching success of several fish species. Survival to hatching (SH) was significantly lower (P < 0.05) in sodium-sulfate type waters from Devils Lake, North Dakota, of ≥ 2400 mg/L total dissolved solids (TDS) than in fresh water of 200 mg/L. In waters of 200, 1150, 2400, 4250, and 6350 mg/L TDS, walleye (Stizostedion vitreum) SH was 41, 38, 7, 1, and 0%; northern pike (Esox lucius) SH was 92, 68, 33, 2, and 0%; yellow perch (Perca flavescens) SH was 88, 70, 73, 0, and 0%; white sucker (Catostomus commersoni) SH was 87, 95, 66, 0, and 0%; common carp (Cyprinus carpio) SH was 71, 69, 49, 63, and 25%.



1992 ◽  
Vol 49 (12) ◽  
pp. 2474-2482 ◽  
Author(s):  
Jay A. Nelson ◽  
John J. Magnuson

Little is known about the animals that occupy naturally acidic habitats. To better understand the physiological state of animals from temperate, naturally acidic systems, we compared metabolite stores and meristics of two yellow perch (Perca flavescens) populations in northern Wisconsin. One population originated from a naturally acidic, dystrophic lake (Acid-Lake-Perch, ALP) and had previously been shown to have enhanced tolerance to low pH. The second population came from two nearby interconnected circumneutral, mesotrophic lakes (Neutral-Lake-Perch, NLP). Perch were collected throughout the year to account for seasonal effects and to discern whether patterns of metabolite utilization differed between populations. ALP had smaller livers containing less glycogen and greater muscle glycogen content than NLP. The ALP also had significantly greater liver and visceral lipid contents, and females from this population committed a greater fraction of their body mass to egg production. We interpret these results as indicative of physiological divergence at the population level in yellow perch. These results are discussed as possible products of H+ -driven changes in metabolism and as possible products of different life history strategies between populations. Our results also show that perch living in acidic, dystrophic Wharton Lake are not acid stressed.



1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield



1992 ◽  
Vol 126 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Geoffrey R Ambler ◽  
Bernhard H Breier ◽  
Andrzej Surus ◽  
Hugh T Blair ◽  
Stuart N McCutcheon ◽  
...  

We evaluated the interrelationship between, and regulation of, the hepatic growth hormone receptor and serum GH binding protein (GH BP) in pigs treated with recombinant porcine growth hormone (rpGH). Infant and pubertal male pigs (N = 5 per group) received either rpGH 0.15 mg/kg daily or diluent intramuscularly for 12 days. Somatic growth, serum IGF-I and GH BP and [125I]bovine GH (bGH) binding to MgCl2-treated hepatic membrane homogenates were examined. Marked age-related increases were seen in serum GH BP (p<0.001) and [125I]bGH binding to hepatic membranes (p<0.001). GH BP was increased in rpGH treated animals (p = 0.03), from 13.8±1.2 (mean±1 x sem) (controls) to 17.8±2.0% in infants, and from 35.2±2.6 (controls) to 41.8±3.4% in pubertal animals. [125I]bGH binding to hepatic membranes was also increased by rpGH treatment (p<0.05), from 7.0±1.6 (controls) to 15.4±3.6% in infants and from 53.7±7.1 (controls) to 65.1±11.8% in pubertal animals. No significant interaction between age and treatment was seen. Overall, serum GH BP correlated significantly with [125I]bGH membrane capacity (r=0.82, p<0.001), with a correlation of r= 0.83 in the infant animals but no significant correlation in the pubertal animals considered alone (r=0.13). Serum IGF-I correlated significantly with serum GH BP (r=0.93, p<0.001) and [125]bGH membrane binding capacity (r = 0.91, p< 0.001). These observations suggest that serum GH BP levels reflect major changes of hepatic GH receptor status. In addition, the present study demonstrates that the hepatic GH receptor can be induced by GH in the infant pig, despite a developmentally low GH receptor population at this age, suggesting potential efficacy of GH at earlier ages than generally considered.



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