How does the female body recognize that it is pregnant?
It seems to be a relatively simple question: How does a female of a species recognize early on that she is pregnant? In humans, the embryo produces hormones soon after conception that triggers physiological changes that allow the mother to maintain pregnancy. In ruminants, the embryo secretes large quantities of a protein. But the horse is a mystery. Colorado State University researchers are studying equine physiology to determine how a mare recognizes an embryo in an effort to find new ways to prevent embryonic loss. In mares, a high number of embryos are lost in the first 18 days of pregnancy. Understanding the intricacies of embryo recognition and loss in horses may help scientists and doctors better understand these issues in other species, including humans.
Common environmental pollutants may affect reproduction, sexual function
Recent research shows that exposure to common environmental pollutants, including byproducts of chemicals used to disinfect drinking water, may have serious consequences for the male reproductive system by impairing sperm quality and sexual function. Exposures to pollutants that mimic hormones are top suspects, and research at Colorado State University is looking into the cause-and-effect association. Laboratory tests show exposure to certain chemicals during fetal development and adolescence cause failure of testes to descend (called cryptorchidism, the incidence of this condition is on the rise globally) and disrupt sperm production and sexual function as adults. The compounds studied include some pesticides, a variety of common industrial pollutants and water disinfection byproducts. Researchers found that developmental exposures to some of these chemicals cause cryptorchidism, abnormal differentiation of germ cells and decline in sperm quality, and sexual dysfunction and impotence. Colorado State researchers also found similar defects spontaneously occurring in domesticated horses and wild deer, providing evidence of the widespread impact of environmental contaminants. The research shows that some so-called innocuous chemicals may harm the developing male reproductive system and can cause lasting effects in a number of species.
Sex differentiation between males and females
In birthing rooms around the world, the first words of the doctor are often "It's a boy!" or "It's a girl!" But in the US alone for one out of approximately every 4,200 births, the sex of a child is not clear cut. Sometimes, a child may display features of both sexes, or a phenomenon known as sex reversal can occur when the child may display genitalia of one sex but genetically be of the opposite sex when chromosomes are evaluated. How females and males develop is first a matter of genetics, and then environmental and hormonal factors " many of which scientists still don't understand. Colorado State University scientists are beginning to understand more about what determines sex differentiation between male and female, and what happens when things go wrong.
Pre-determining the sex of offspring
Technology developed at Colorado State University allows scientists and doctors to pre-determine the sex of offspring " in animals and humans. Mothers can be impregnated with sperm that is sorted by the sex it will create " male or female. A practice taking on popularity in some agricultural fields, sperm sexing can now be done with 80 to 90 percent accuracy in humans and the service is available at a few locations. The practice can be important in disease prevention; for example, if parents carry sex-linked genetic disease genes that will impact male offspring, the technology will allow them to have females who are free of the disease through in vitro fertilization or artificial insemination.
How aging affects reproduction and offspring
How much does a mother's age affect her pregnancy and the health of her offspring? Researchers at Colorado State know that changes in aging female horses, or mares, are comparable to the changes in older women " and the impact of age on lost pregnancies and healthy babies are also strikingly similar. In general, women over 30 and mares in their teens see a rapid decline in fertility as the quality of their eggs declines and the follicle undergoes changes. As a result, lost pregnancies are more common and offspring may not be as healthy. For example, children born from older women may be more likely to have chromosomal defects, and the foals of an older mare may not have the athletic potential of offspring from a younger mare. By finding ways to help aging mares have healthy foals, university researchers hope to also uncover secrets that will aid women as well.
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