Correlation between male and female reproduction in the subdioecious herb Astilbe biternata (Saxifragaceae)

2000 ◽  
Vol 87 (6) ◽  
pp. 837-844 ◽  
Author(s):  
Matthew S. Olson ◽  
Janis Antonovics
Reproduction ◽  
2018 ◽  
Author(s):  
Susana B Rulli ◽  
María Julia Cambiasso ◽  
Laura D Ratner

In mammals, the reproductive function is controlled by the hypothalamic-pituitary-gonadal axis. During development, mechanisms mediated by gonadal steroids exert an imprinting at the hypothalamic-pituitary level, by establishing sexual differences in the circuits that control male and female reproduction. In rodents, the testicular production of androgens increases drastically during the fetal/neonatal stage. This process is essential for the masculinization of the reproductive tract, genitals and brain. The conversion of androgens to estrogens in the brain is crucial for the male sexual differentiation and behavior. Conversely, feminization of the brain occurs in the absence of high levels of gonadal steroids during the perinatal period in females. Potential genetic contribution to the differentiation of brain cells through direct effects of genes located on sex chromosomes is also relevant. In this review, we will focus on the phenotypic alterations that occur on the hypothalamic-pituitary-gonadal axis of transgenic mice with persistently elevated expression of the human chorionic gonadotropin hormone (hCG). Excess of endogenously synthesized gonadal steroids due to a constant hCG stimulation is able to disrupt the developmental programming of the hypothalamic-pituitary axis in both transgenic males and females. Locally produced estrogens by the hypothalamic aromatase might play a key role in the phenotype of these mice. The “four core genotypes” mouse model demonstrated a potential influence of sex chromosome genes in brain masculinization before critical periods of sex differentiation. Thus, hormonal and genetic factors interact to regulate the local production of the neurosteroids necessary for the programming of the male and female reproductive function.


2008 ◽  
pp. 427-455
Author(s):  
Shmulik Parnes ◽  
Shaul Raviv ◽  
Amir Sagi

2019 ◽  
Vol 34 (4) ◽  
pp. 327-338 ◽  
Author(s):  
Sunil Kumar ◽  
Anupama Sharma

Abstract Background Cadmium (Cd) is a non-essential toxic heavy metal, an environmental toxicant, and toxic at a low concentration, and it has no known beneficial role in the human body. Its exposure induces various health impairments including hostile reproductive health. Objective The present review discusses the information on exposure to Cd and human reproductive health impairments including pregnancy or its outcome with respect to environmental and occupational exposure. Methods The present review provides current information on the reproductive toxic potential of Cd in humans. The data were collected using various websites and consulting books, reports, etc. We have included recent data which were published from 2000 onward in this review. Results Cd exposure affects human male reproductive organs/system and deteriorates spermatogenesis, semen quality especially sperm motility and hormonal synthesis/release. Based on experimental and human studies, it also impairs female reproduction and reproductive hormonal balance and affects menstrual cycles. Based on the literature, it might be concluded that exposure to Cd at low doses has adverse effects on both human male and female reproduction and affects pregnancy or its outcome. Further, maternal prenatal Cd exposure might have a differential effect on male and female offspring especially affecting more female offspring. Hence, efforts must be made to prevent exposure to Cd. Conclusion Cd affects both male and female reproduction, impairs hormone synthesis/regulation and deteriorates pregnancy rate or its outcome even at lower doses.


Author(s):  
Urfeya Mirza ◽  
Uiase Bin Farooq ◽  
Shahnaz Anjum

The fertility and reproductive efficiency of both male and female animals is very sensitive to climatic disturbances, particularly hyperthermia. The most evident consequences of heat stress are decreased quantity and quality of sperm production in males and compromised fertility in females. In this chapter, the effects of climate change on male and female reproduction have been separately and thoroughly elaborated. The effect of heat stress on embryo and fetal development has also been described. In the end, various approaches for mitigating the effects of heat stress on animals have been brought to light.


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