scholarly journals Some endocrine traits of transgenic rabbits. I. Changes in plasma and milk hormones

2008 ◽  
pp. 735-744
Author(s):  
AV Sirotkin ◽  
P Chrenek ◽  
J Rafay ◽  
R Omelka ◽  
H Vetr ◽  
...  

The aim of these studies was to compare some endocrine and non-endocrine characteristics of transgenic (carrying mammary gland-specific mWAP-hFVIII gene construct) and non-transgenic rabbits. The concentrations of corticosterone, progesterone, testosterone, estradiol, insulin-like growth factor I (IGF-I) and human factor VIII (hFVIII) in the blood plasma of adult females (9 months of age, 3rd generation transgenic animals), adult males, and young females (1-2 months of age, 4th generation of transgenic animals), as well as in the milk of lactating adult females, were analyzed by using RIA. In addition, litter size and body mass of pups born by transgenic and non-transgenic females from the 3rd generation were compared. Transgenic animals were compared with their non-transgenic siblings (the same genetic and epigenetic background). Transgenesis did not influence plasma hFVIII, but significantly increased corticosterone (in all animals), reduced IGF-I (in adult males and females), testosterone and estradiol, (in young females) and altered progesterone (increase in adult males and decrease in adult females) concentrations in blood plasma. In addition, transgenic females had higher milk concentrations of testosterone, but not progesterone or IGF-I than their nontransgenic sisters. These endocrine changes were not associated with changes in litter size. Transgenic male (but not female) pups have smaller body mass than control animals. These observations demonstrate the influence of transgenesis per se on the animal growth and endocrine system (secretion of reproductive and stress steroid hormones as well as growth factors) over four generations.

1989 ◽  
Vol 37 (6) ◽  
pp. 627 ◽  
Author(s):  
C Kemper ◽  
DJ Kitchener ◽  
WF Humphreys ◽  
RA How ◽  
LH Schmitt ◽  
...  

Breeding, population dynamics and seasonal changes in physical and physiological parameters were examined in Isoodon macrourus at the Mitchell Plateau between September 1981 and November 1982. Females gave birth to litters of 2.5 � 1.0 (16) young between September and April. They produced up to three litters in a breeding season with an average interval between successive litters of 89.5 (51-108) days. Adult testosterone levels and scrota1 size began to increase in July and peaked in September 1982. The overall ratio of adult males to adult females was 1:0.54; it was 1:0.80 for pouch young. Females were more frequently trapped on sequential trips than were males. Density on the grids increased towards the end of the dry season (July and September 1982)-mostly as a result of increased numbers of females. Adult males and females moving onto the grids during the dry season tended to select different habitats. Adult males moved significantly more in the wet season (September 1981, January and April) than they did in the dry season (July and September 1982); they also moved significantly more than adult females in the wet season. Seasonal variations were recorded for most physical and physiological parameters. During the wet period from September 1981 to January 1982, body weight, haemoglobin, haematocrit and total plasma albumin declined, while total white blood cells and proportion of lymphocytes to granular leucocytes rose. This indicated that this period was one of change in condition for this species. Compared to adult females, adult males were larger and heavier, had higher values of haematocrit and lymphocytes, and lower values of granular leucocytes, free steroids, CBGBd and albumin bound corticosteroid. There was considerable between-year variability in condition of individuals and both sexes differed significantly in September 1981 and 1982 in their weight, haematocrit, total white blood cells, granular leucocytes, MCBC and testosterone. Individuals at disparate localities at the Mitchell Plateau showed similar seasonal physiological and physical responses, except for one grid where they were heavier.


1990 ◽  
Vol 68 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Morten Ryg ◽  
Thomas G. Smith ◽  
Nils Are Øritsland

Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) from the Svalbard Islands are described. The blubber content of adult females decreased from a high of about 50% at the beginning of the pupping season in March–April to a low of 31% during moulting in June. In adult males, the blubber content decreased from 41% in March to 29% in June. By estimating an individual seal's body mass by 1 April from its standard body length, we calculated an average daily loss of body mass of 160 g/day in adult females and 100 g/day in adult males from the start of lactation to the middle of moulting. The blubber content of sexually immature seals was less in June and July than in April, but the seasonal changes were smaller than in adult seals. We found no evidence of significant changes in core mass in adult seals, and suggest that the seasonal body mass changes are mostly due to changes in body fat content.


Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 222-234 ◽  
Author(s):  
Gary R. Hepp

AbstractBehavioural dominance was studied in captive American black ducks (Anas rubripes) during October-December 1984. Eighty ducks were marked individually, and groups of 10 ducks consisting of 5 adults (3 males and 2 females) and 5 juveniles (3 males and 2 females) were assigned to each of 8 experimental pens. Ducks in 4 pens received an ad libitum diet, and ducks in the other 4 pens were given a restricted diet. Dominance structure within pens was linear. Adults were dominant to young, and body mass had no influence on dominance rank. The effect of sex on dominance rank was age-specific. Adult males were dominant to adult females and to young black ducks of both sexes; however, dominance rank of young males did not differ from adult or young females. Paired adults were dominant to unpaired adults and to young individuals that were either paired or unpaired. Paired young black ducks were similar in dominance rank to unpaired adults and unpaired young indicating that pairing did not make these individuals more dominant. Ducks on the restricted diet gained less body mass than ducks on the ad libitum diet (HEPP, 1986), but dominant and subordinate black ducks within treatment groups experienced similar changes in body mass during the early winter. Dominant black ducks interacted more frequently and were more likely to form pair bonds than subordinates, thus higher energy costs of dominant individuals may explain the poor relationship between physical condition and dominance rank. There was a significant positive association between the dominance ranks of pair members.


2008 ◽  
pp. 745-752
Author(s):  
AV Sirotkin ◽  
P Chrenek ◽  
K Darlak ◽  
F Valenzuela ◽  
Z Kuklova

In the present in vitro experiments we examined FSH- and ghrelin-induced changes in ovarian hormone secretion by transgenic rabbits. Fragments of ovaries isolated from adult transgenic (carrying mammary gland-specific mWAP-hFVIII gene) and non-transgenic rabbits from the same litter were cultured with and without FSH or ghrelin (both at 0, 1, 10 or 100 ng/ml medium). The secretion of progesterone (P4), estradiol (E2) and insulin-like growth factor I (IGF-I) was assessed by RIA. It was observed that ovaries isolated from transgenic rabbits secreted much less P4, E2 and IGF-I than the ovaries of nontransgenic animals. In control animals FSH reduced E2 (at doses 1-100 ng/ml medium) and IGF-I (at 1-100 ng/ml), but not P4 secretion, whereas ghrelin promoted P4 (at 1 ng/ml) and IGF-I (at 100 ng/ml), but not E2 output. In transgenic animals, the effects were reversed: FSH had a stimulatory effect on E2 (at 100 ng/ml) and ghrelin had an inhibitory effect on P4 (at 10 ng/ml). No differences in the pattern of influence of FSH on P4 and IGF-I and of ghrelin on E2 and IGF-I were found between control and transgenic animals. The present observations suggest that 1) both FSH and ghrelin are involved in rabbit ovarian hormone secretion, 2) transgenesis in rabbits is associated with a reduction in ovarian secretory activity, and 3) transgenesis can affect the response of ovarian cells to hormonal regulators.


1998 ◽  
Vol 20 (2) ◽  
pp. 311
Author(s):  
S.A. Munks ◽  
H.M. Otley ◽  
J. Jackson ◽  
M. Hindell

Studies into the ecology of the platypus have concentrated on populations inhabiting !otic waters on mainland Australia. This paper presents preliminary results of a study into the feeding ecology and energetics of the platypus in a subalpine lake in Tasmania. During the autumn, winter and early spring months 29 individual platypuses were captured (13 adult females, 13 adult males and 3 juveniles). Of these, 46% of the adult males, 31% of the adult females and one of the juveniles were recaptured between one and eight times. Catch per unit effort was similar for the 1800-2400hrs, 0600-1200hrs and 1200-1800hrs time periods (0.158, 0.161 and 0.156, respectively). However catch per unit effort was low (0.057) between 2400hr and 0600hrs. There was no significant difference in the mean body mass of adult males and females between autumn, winter and early spring, however the condition of the females, indicated by the tail fat index, decreased in early spring. The overall mean body mass for adult males and adult females caught during the autumn/winter and early spring months was 2293.21g ± 300 (1920-2740g) and 1375.22g ± 147 (1150-1580g), respectively. This supports the observation that platypuses in Tasmania are larger than those occurring in mainland water bodies. The timing of juvenile captures suggests that matings occur at Lake Lea between mid September through to January. This indicates that the breeding season may be later in Tasmania than on the mainland. The contents of cheek pouches were collected from individuals caught during the autumn, winter and early spring months for identification of food items. Food items identified so far include Trichoptera, Gastropod molluscs, Ephemeroptera nymphs, Coleoptera larvae and Diptera, with Trichoptera forming the dominant food item. Measurements of the daily energy expenditure of six adults were attempted during late winter and early spring using the doubly labelled water technique.


1994 ◽  
Vol 72 (3) ◽  
pp. 465-469 ◽  
Author(s):  
F. Palomares

Home-range size has been found to be related to body mass of some animals both across species and within species when the spatial strategies of the sexes differ. I studied home-range size in a polygynous carnivore, the Egyptian mongoose (Herpestes ichneumon), and compared observed home-range size with predictions based on body mass. First, I tested whether mongooses actually exhibited site fidelity (for daily and multiday periods). Mongooses always showed site fidelity for a multiday home range, but in only 59% of the cases for daily home range. Adult males exhibited less daily site fidelity than did adult females or young. Multiday home-range size was similar among age–sex classes, but males had significantly more core areas than females or young. Multiday home-range size was positively correlated with body mass for adult males (r2 = 0.98, P = 0.0122) and negatively correlated with body mass of adult females (r2 = 0.40, P = 0.0374). Differences in these relationships and daily site fidelity between adult males and females suggest that the spatial strategies of male and female Egyptian mongooses are different, with the larger females defending the areas richer in resources and the larger males having more access to females.


The Auk ◽  
2002 ◽  
Vol 119 (4) ◽  
pp. 996-1009
Author(s):  
Joel A. Schmutz ◽  
Karen K. Laing

Abstract Broods of geese spend time feeding according to availability and quality of food plants, subject to inherent foraging and digestive constraints. We studied behavioral patterns of broods of Emperor Geese (Chen canagica) on the Yukon–Kuskokwim Delta, Alaska, and examined how feeding and alert behavior varied in relation to habitat and goose density. During 1994–1996, time spent feeding by Emperor Goose goslings and adult females was positively related to multispecies goose densities near observation blinds, and not to just Emperor Goose density. Similarly, body mass of Emperor Goose goslings was more strongly related (negatively) to multispecies goose densities than intraspecific densities. A grazing experiment in 1995 indicated that most above ground primary production by Carex subspathacea, a preferred food plant, was consumed by grazing geese. Those results demonstrate that interspecific competition for food occurred, with greatest support for goslings whose behavioral repertoire is limited primarily to feeding, digesting, and resting. Although the more abundant Cackling Canada Geese (Branta canadensis minima) differed from Emperor Geese in their preferred use of habitats during brooding rearing (Schmutz 2001), the two species occurred in equal abundance in habitats preferred by Emperor Goose broods. Thus, Cackling Canada Geese were a numerically significant competitor with Emperor Geese. Comparing these results to an earlier study, time spent feeding by goslings, adult females, and adult males were greater during 1993–1996 than during 1985–1986. During the interval between those studies, densities of Cackling Canada Geese increased two to three times whereas Emperor Goose numbers remained approximately stable, which implies that interspecific competition affected foraging behavior over a long time period. These density-dependent changes in foraging behavior and body mass indicate that interspecific competition affects nutrient acquisition and gosling growth, which has a demonstrated effect (Schmutz 1993) on juvenile survival of Emperor Geese. Management of Emperor Geese should consider interspecific relations and densities of all goose species occurring on the Yukon–Kuskokwim Delta, Alaska.


Sports ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 30
Author(s):  
Jenny M. Mahoney ◽  
Brett R. Baughman ◽  
Ailish C. Sheard ◽  
Brandon J. Sawyer

The aim of the present study was to assess the validity of verification phase (VP) testing and a 3 min all-out test to determine critical power (CP) in males with obesity. Nine young adult males with a body mass index (BMI) ≥ 30 kg·m−2 completed a cycle ergometer ramp-style VO2max test, four randomized VP tests at 80, 90, 100, and 105% of maximum wattage attained during the ramp test, and a 3 min all-out test. There was a significant main effect for VO2max across all five tests (p = 0.049). Individually, 8 of 9 participants attained a higher VO2max (L/min) during a VP test compared to the ramp test. A trend (p = 0.06) was observed for VO2max during the 90% VP test (3.61 ± 0.54 L/min) when compared to the ramp test (3.37 ± 0.39 L/min). A significantly higher VO2max (p = 0.016) was found in the VP tests that occurred below 130% of CP wattage (N = 15, VO2max = 3.76 ± 0.52 L/min) compared to those that were above (N = 21, VO2max = 3.36 ± 0.41 L/min). Our findings suggest submaximal VP tests at 90% may elicit the highest VO2max in males with obesity and there may be merit in using % of CP wattage to determine optimal VP intensity.


2021 ◽  
Author(s):  
Kenta Uchida ◽  
Rachel Ng ◽  
Samuel A Vydro ◽  
Jennifer E Smith ◽  
Daniel T Blumstein

Abstract The benefits of dominance may not come without costs, particularly for males. For example, the “immunocompetence handicap hypothesis” states that males with enhanced mating success allocate resources to enhance reproductive output at a cost to their current health, whereas the “resource quality hypothesis” predicts that high-ranking males may benefit from increased reproduction and good health. While the predictions from each have been well tested in captive animals and in a variety of highly social primates, fewer studies have been carried out in free-living, facultatively social animals. Using adult male yellow-bellied marmots (Marmota flaviventer), we evaluated predictions of these hypotheses by examining the relationship between social rank and two health indicators–fecal corticosterone metabolite (FCM) levels, and neutrophil/lymphocyte (N/L) ratios–after accounting for variation explained by age, body mass, and seasonality. We found that higher-ranking males tended to have a lower N/L ratio (reflecting good health) than lower-ranking individuals, whereas FCM levels were not significantly related to rank. In addition, heavier male marmots had lower N/L ratios, while body mass was not associated with FCM levels. We also found that older adult males had lower FCM levels (reflecting less physiological stress) but higher N/L ratios than younger adults. Finally, we found that FCM levels decreased as the active season progressed and FCM levels were associated with the time of the day. Overall, our results suggest that socially-dominant male marmots enjoyed better, not worse health in terms of lower N/L ratios.


Zootaxa ◽  
2011 ◽  
Vol 2983 (1) ◽  
pp. 39 ◽  
Author(s):  
IVAN L. F. MAGALHÃES ◽  
ADALBERTO J. SANTOS

In this paper, M. yanomami n. sp., from Brazilian Amazonia, Chaetacis bandeirante n. sp., from Central Brazil, and the males of M. gaujoni Simon, 1897 and M. ruschii (Mello-Leitão, 1945) n. comb. , respectively from Ecuador and Brazil, are described and illustrated for the first time. An ontogenetic series of the last development stages of both sexes of Micrathena excavata (C. L. Koch, 1836) is illustrated and briefly described. Adult females are larger and have longer legs and larger abdomens than adult males. Probably females undergo at least one additional moult before adulthood, compared to males. Micrathena ornata Mello-Leitão, 1932 is considered a junior synonym of M. plana (C. L. Koch, 1836), and M. mastonota Mello-Leitão 1940 is synonymized with M. horrida (Taczanowski, 1873). Acrosoma ruschii Mello-Leitão, 1945 is revalidated, transferred to Micrathena and considered a senior synonym of M. cicuta Gonzaga & Santos, 2004. Chaetacis necopinata (Chickering, 1960) is recorded for Brazil for the first time. Chaetacis incisa (Walckenaer, 1841) is considered a nomen dubium.


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