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Genetics and exercise: an introduction
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Claude Bouchard, Henning Wackerhage
It is important to understand the distinction between germ cells and somatic cells. Male and female germ cells, sperm and oocyte, respectively, are termed gametes. A mature germ cell has only 22 autosomes plus one sex chromosome (i.e. 23 chromosomes in total) in its nucleus instead of the full complement of 46 chromosomes seen in somatic cells (i.e. body cells or non-germ cells). A germ cell containing 23 chromosomes is said to be “haploid”, whereas normal somatic cells contain a “diploid” set of chromosomes. When a haploid sperm and a haploid oocyte fuse, they form a diploid, fertilized oocyte, termed zygote, which is the first cell of the new organism. It has 2 × 22 autosomes plus either two X chromosomes (XX, a female) or an X and a Y (XY, a male) chromosome.
Carrier Screening for Single-Gene Disorders
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Julio Martin, Arantxa Hervas, Ana Bover, Laura Santa, Ana Cervero
In the case of gamete donors, additional input may be needed. Gamete donors are typically young individuals attending the reproductive clinic for the purpose of donating, and they may not expect to be tested for genetic disorders. Even after pre-test counseling and giving consent for testing, the possibility of being a carrier for a certain mutation may not be on potential donors' minds at all. Therefore, in the event of a positive result, the genetic counselor may have to deal with the potential donor's shock at being excluded from the donation program. In such instances, post-test genetic counseling must emphasize that, generally, there is no clinical risk for the tested individual but at the same time must indicate the clinical relevance of the information for future family planning (Figure 4.1).
Biological Effects and Significance of X-ray Exposure
Published in Robert J. Parelli, Principles of Fluoroscopic Image Intensification and Television Systems, 2020
The precursor cells of mature gametes or the mature gametes themselves are susceptible to nuclear damage/genetic mutations from ionizing radiation. Gametes that have altered genetic information can be reproduced and passed on to all of the cells of the offspring.
An overview of sex and reproductive immunity from an evolutionary/anthropological perspective
Published in Immunological Medicine, 2021
Yoshihiko Araki, Hiroshi Yoshitake, Kenji Yamatoya, Hiroshi Fujiwara
Presently, there are at least 9 million species (animals, plants and others) on Earth [1]. Most of these species reproduce via ‘gametes’ rather than clonally, as in bacteria (Figure 1). Sexual reproduction gave rise to the concept of ‘sex’. ‘Sex’ is difficult to define because of the amount of variation among organisms. However, gametes are a biologically consistent feature of sexual reproduction. Gametes are sex cells with half the number of chromosomes as somatic cells. There are two types of gametes: eggs, which are immobile and rich in cytoplasm, and other gametes (sperm), which are mobile and mostly composed of DNA (based on its function as a gamete, in the extreme, the sperm does not even need to be alive [3]). The individuals that produce these gametes are defined reproductive biologically as ‘female’ and ‘male’, respectively. More precisely, the individual that produces the ‘eggs’ is called a ‘female’ (as well as ‘male’ is defined in the same way).
Psychosocial aspects of identity-release gamete donation – perspectives of donors, recipients, and offspring
Published in Upsala Journal of Medical Sciences, 2020
Agneta Skoog Svanberg, Gunilla Sydsjö, Claudia Lampic
For identity-release gamete donors, the number of children conceived with their gametes is of particular interest, since the offspring will be able to obtain the donor’s identity and may attempt to contact the donor. However, only one study was found investigating donors’ views regarding the number of children a donor may conceive (22). About half of 235 oocyte and sperm donors 5–8 years after their donation regarded 1–10 children to be an acceptable number of offspring from one donor, with oocyte donors more often supporting an upper limit than sperm donors. Following identity-release donation, a majority of both oocyte and sperm donors would like to be informed if their donation results in pregnancy and birth (10,23). In a Swedish follow-up study of gamete donors, sperm donors reported a higher level of emotional involvement with offspring from their donation compared to oocyte donors (23). This included wanting to know how the child fares in life and feeling responsibility for the child if anything happened to his/her parents.
Purified and specific cytoplasmic pollen extract: a non-hormonal alternative for the treatment of menopausal symptoms
Published in Gynecological Endocrinology, 2020
Andrea Genazzani, Nick Panay, Tommaso Simoncini, Herman Depypere, Alfred Mueck, Christian Egarter, Nicoletta Biglia, Tomas Fait, Martin Birkhaeuser, Sven O. Skouby, Mark Brincat, Steven Goldstein, Xiangyan Ruan, Cuauhtémoc Celis-Gonzales, Santiago Palacios
Pollen (from the Greek ϖάλη [pale]: flour or dust) constitutes the male gametophyte of the flower. It is composed of minuscule ovoid grains measuring 20–55 μm in diameter that are initially contained at the end of stamens and are surrounded by a shell called an exine. The function of this pollen shell is to protect the genetic material. Well-known allergens are located on the external shell, whereas the center of the pollen contains the cytoplasm [7]. Germination occurs when the pollen is transported by wind or bees to a compatible female pistil. The male gametophyte produces a pollen tube that transfers the sperm to the egg, which contains the female gametes. Pollen has long been used for therapeutic purposes by various civilizations (e.g. Ancient Egypt and China, as far back as 200 BC). The chemical composition of pollen depends largely on the plant source and geographic origin, together with factors such as climatic conditions, soil type, and the activity and race of the bees. However, since pollen may be of unspecific origin (from unknown plants) and may be mixed with other bee products, standardization is difficult [8]. In addition, when the grain is unopened, its components can be partially assimilated because the pollen shell cannot be damaged by stomach acid [9,10]. The shell proteins are meant to be highly allergenic [9,10]. Gôsta Carlsson, a Swedish gynecologist, is considered the ‘father’ of the pollen extraction method. In the 1940s, he took an empirical approach to this field, with the hypothesis that the administration of pollen extracts could return strength and vigor to elderly patients.