scholarly journals Long-term effects of litter sex ratio on female reproduction in two iteroparous mammals

2014 ◽  
Vol 28 (4) ◽  
pp. 954-962 ◽  
Author(s):  
Raquel Monclús ◽  
Dietrich von Holst ◽  
Daniel T. Blumstein ◽  
Heiko G. Rödel
2011 ◽  
Vol 2011 (1) ◽  
Author(s):  
Susanne Lund Kristensen ◽  
Cecilia Høst Ramlau-Hansen ◽  
Erik Ernst ◽  
Sjurdur Frodi Olsen ◽  
Jens Peter Bonde ◽  
...  

Author(s):  
Thanet Khomphet ◽  
Theera Eksomtramage ◽  
Jakarat Anothai ◽  
Pilalak Popet

Background: Intercropping is wildly practiced in oil palm plantation in Thailand for a long time. However, there are few studies connected to oil palm intercropping. This study evaluated the effects of perennial intercrops on the agronomic and yield traits of oil palm.Methods: The observation used a completely randomized design with eight treatments including oil palm monocropping, oil palm intercropped with Intsia palembanica, Hopea odorata, Swietenia macrophylla, Ternstroemia wallichiana, Azardirachta excelsa, Magnolia champaca and Mesua ferrea. The height and stem perimeter of intercrops were recorded as were the plant height and diameter, number of male and female inflorescences and sex ratio of the oil palms. Those parameters were observed in October 2019, February and June 2020.Result: Oil palm intercropped with A. excelsa produced the highest number of female inflorescences and oil palm intercropped with M. champaca produced the highest sex ratio in October 2019 and February 2020, however, the differences of those parameters were not found in June 2020. There were no significant differences in the diameter, height, the number of male inflorescences throughout the observation. Among the 7 intercrops, M. champaca and A. excelsa produced the highest growth rate of plant height and stem perimeter, respectively. In conclusion, oil palm can be intercropped with perennial plants. However, more research is needed to determine the long-term effects of intercropping in oil palm.


2013 ◽  
Vol 25 (1) ◽  
pp. 38 ◽  
Author(s):  
R. Laguna-Barraza ◽  
P. Bermejo-Álvarez ◽  
P. Ramos-Ibeas ◽  
C. de Frutos ◽  
A. P. López-Cardona ◽  
...  

Preimplantation developmental plasticity has evolved in order to offer the best chances of survival under changing environments. Conversely, environmental conditions experienced in early life can dramatically influence neonatal and adult biology, which may result in detrimental long-term effects. Several studies have shown that small size at birth, which is associated with a greater risk of metabolic syndrome, is largely determined before the formation of the blastocysts because 70%–80% of variation in bodyweight at birth has neither a genetic nor environmental component. In addition, it has been reported that adult bodyweight is programmed by energy-dependent process during the pronuclear stage in the mouse. Although the early embryo has a high developmental plasticity and adapts and survives to adverse environmental conditions, this adaptation may have adverse consequences and there is strong evidence that in vitro culture can be a risk factor for abnormal fetal outcomes in animals systems, with growing data suggesting that a similar link may be apparent for humans. In this context, male and female preimplantation embryos display sex-specific transcriptional and epigenetic regulation, which, in the case of bovine blastocysts, expands to one-third of the transcripts detected through microarray analysis. This sex-specific bias may convert the otherwise buffered stochastic variability in developmental networks in a sex-determined response to the environmental hazard. It has been widely reported that environment can affect preimplantation development in a sex-specific manner, resulting in either a short-term sex ratio adjustment or in long-term sex-specific effects on adult health. The present article reviews current knowledge about the natural phenotypic variation caused by epigenetic mechanisms and the mechanisms modulating sex-specific changes in phenotype during early embryo development resulting in sex ratio adjustments or detrimental sex-specific consequences for adult health. Understanding the natural embryo sexual dimorphism for programming trajectories will help understand the early mechanisms of response to environmental insults.


2013 ◽  
Vol 28 (12) ◽  
pp. 3337-3348 ◽  
Author(s):  
S. L. Kristensen ◽  
C. H. Ramlau-Hansen ◽  
E. Ernst ◽  
S. F. Olsen ◽  
J. P. Bonde ◽  
...  

Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.


Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.


2012 ◽  
Vol 43 (3) ◽  
pp. 42
Author(s):  
MITCHEL L. ZOLER
Keyword(s):  

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