Single-cell analysis of autopsied human testes suggests that abnormalities associated with aging sperm cells might be exacerbated by elevated body mass index (BMI). The research appears May 2nd in the journal Developmental ...
May 2, 2022
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A team of Duke University Medical Center and Australian scientists has found that addictive drugs may have hijacked the same nerve cells and connections in the brain that serve a powerful, ancient instinct: the appetite for ...
Jul 11, 2011
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(Medical Xpress)—An odd and little-known feature of nerve cells may be linked to several forms of inherited intellectual disability, researchers at Washington University School of Medicine in St. Louis have learned.
Aug 30, 2013
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A new in-vitro study by University of California, Davis, researchers indicates that quaternary ammonium compounds, or "quats," used as antimicrobial agents in common household products inhibit mitochondria, the powerhouses ...
Aug 22, 2017
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RIKEN researchers have determined how a protein that transports essential amino acids across the placenta contributes to normal embryonic development in mammals.
Dec 27, 2019
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COVID-19 may negatively affect sperm quality and reduce fertility in men, according to research published in Reproduction. The study indicates that COVID-19 infection can cause increased sperm cell death, inflammation, and ...
Jan 29, 2021
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Fibrous protein clumps known as amyloids are most often associated with diseases such as Alzheimer's disease, where they form characteristic plaques in the brain.
Sep 25, 2015
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Finding the vulnerable points where HIV enters the female reproductive tract is like searching for needles in a haystack. But Northwestern Medicine scientists have solved that challenge by creating a glowing map of the very ...
Apr 27, 2016
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In 1881 a German couple – Herr and Frau B - were trying to get pregnant with no success. They consulted Dr Levy, a gynaecologist based in Munich, for help. Levy was determined to approach the problem in a scientific manner ...
Sep 10, 2014
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An injection of banked sperm-producing stem cells can restore fertility to male primates who become sterile due to cancer drug side effects, according to researchers at the University of Pittsburgh School of Medicine and ...
Nov 1, 2012
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A gamete (from Ancient Greek γαμέτης; translated gamete = wife, gametes = husband) is a cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete — called an ovum (or egg) — and a male produces the smaller tadpole-like type — called a sperm. This is an example of anisogamy or heterogamy, the condition wherein females and males produce gametes of different sizes (this is the case in humans; the human ovum is approximately 20 times larger than the human sperm cell). In contrast, isogamy is the state of gametes from both sexes being the same size and shape, and given arbitrary designators for mating type. The name gamete was introduced by the Austrian biologist Gregor Mendel. Gametes carry half the genetic information of an individual, one chromosome of each type. In humans, an ovum can carry only X chromosome (of the X and Y chromosomes), whereas a sperm can carry either an X or a Y; hence, it has been suggested that males have the control of the sex of any resulting zygote, as the genotype of the sex-determining chromosomes of a male must be XY and a female XX. In other words, due to the presence of the Y chromosome exclusively in the sperm, it is that gamete alone that can determine that an offspring will be a male.
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