Sterility (physiology)

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Sterility is the physiological inability to effect sexual reproduction in a living thing, members of whose kind have been produced sexually. Sterility has a wide range of causes. It may be an inherited trait, as in the mule; or it may be acquired from the environment, for example through physical injury or disease, or by exposure to radiation.

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Sterility is the inability to produce a biological child, while infertility is the inability to conceive after a certain period. [1] Sterility is rarely discussed in clinical literature and is often used synonymously with infertility. Infertility affects about 12-15% of couples globally. [2] Still, the prevalence of sterility remains unknown. Sterility can be divided into three subtypes natural, clinical, and hardship. [1] Natural sterility is the couple's physiological inability to conceive a child naturally. Clinical sterility is natural sterility for which treatment of the patient will not result in conception. Hardship sterility is the inability to take advantage of available treatments due to extraneous factors such as economic, psychological, or physical factors. Clinical sterility is a subtype of natural sterility, and Hardship sterility is a subtype of Clinical sterility.

Mechanisms of sterility

Hybrid sterility can be caused by different closely related species breeding and producing offspring. These animals are usually sterile due to the different numbers of chromosomes between the two parents. The imbalance results in offspring that is viable but not fertile, as is the case with the mule.

Sterility can also be caused by selective breeding, where a selected trait is closely linked to genes involved in sex determination or fertility. For example, goats breed to be polled (hornless). This results in a high number of intersex individuals among the offspring, which are typically sterile. [3]

Sterility can also be caused by chromosomal differences within an individual. These individuals tend to be known as genetic mosaics. Loss of part of a chromosome can also cause sterility due to nondisjunction.

XX male syndrome is another cause of sterility, wherein the sexual determining factor on the Y chromosome (SRY) is transferred to the X chromosome due to an unequal crossing over. This gene triggers the development of testes, causing the individual to be phenotypically male but genotypically female.

Economic uses of sterility

Economic uses of sterility include:

See also

Related Research Articles

<span class="mw-page-title-main">Hybrid (biology)</span> Offspring of cross-species reproduction

In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, species or genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera. Hybrids are not always intermediates between their parents, but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are.

Reproductive technology encompasses all current and anticipated uses of technology in human and animal reproduction, including assisted reproductive technology (ART), contraception and others. It is also termed Assisted Reproductive Technology, where it entails an array of appliances and procedures that enable the realization of safe, improved and healthier reproduction. While this is not true of all people, for an array of married couples, the ability to have children is vital. But through the technology, infertile couples have been provided with options that would allow them to conceive children.

Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species. It is the normal state of a human child or other young offspring, because they have not undergone puberty, which is the body's start of reproductive capacity.

<span class="mw-page-title-main">Haldane's rule</span> Observation in evolutionary biology

Haldane's rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J. B. S. Haldane, that states that if — in a species hybrid — only one sex is inviable or sterile, that sex is more likely to be the heterogametic sex. The heterogametic sex is the one with two different sex chromosomes; in therian mammals, for example, this is the male.

<span class="mw-page-title-main">Reproductive success</span> Passing of genes on to the next generation in a way that they too can pass on those genes

Reproductive success is an individual's production of offspring per breeding event or lifetime. This is not limited by the number of offspring produced by one individual, but also the reproductive success of these offspring themselves.

<span class="mw-page-title-main">Azoospermia</span> Medical condition of a man whose semen contains no sperm

Azoospermia is the medical condition of a man whose semen contains no sperm. It is associated with male infertility, but many forms are amenable to medical treatment. In humans, azoospermia affects about 1% of the male population and may be seen in up to 20% of male infertility situations in Canada.

Male infertility refers to a sexually mature male's inability to impregnate a fertile female. In humans it accounts for 40–50% of infertility. It affects approximately 7% of all men. Male infertility is commonly due to deficiencies in the semen, and semen quality is used as a surrogate measure of male fecundity. More recently, advance sperm analyses that examine intracellular sperm components are being developed.

A chemosterilant is a chemical compound that causes reproductive sterility in an organism. Chemosterilants are particularly useful in controlling the population of species that are known to cause disease, such as insects, or species that are, in general, economically damaging. The sterility induced by chemosterilants can have temporary or permanent effects. Chemosterilants can be used to target one or both sexes, and it prevents the organism from advancing to be sexually functional. They may be used to control pest populations by sterilizing males. The need for chemosterilants is a direct consequence of the limitations of insecticides. Insecticides are most effective in regions in which there is high vector density in conjunction with endemic transmission, and this may not always be the case. Additionally, the insects themselves will develop a resistance to the insecticide either on the target protein level or through avoidance of the insecticide in what is called a behavioral resistance. If an insect that has been treated with a chemosterilant mates with a fertile insect, no offspring will be produced. The intention is to keep the percent of sterile insects within a population constant, such that with each generation, there will be fewer offspring.

<span class="mw-page-title-main">Female infertility</span> Diminished or absent ability of a female to achieve conception

Female infertility refers to infertility in women. It affects an estimated 48 million women, with the highest prevalence of infertility affecting women in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Infertility is caused by many sources, including nutrition, diseases, and other malformations of the uterus. Infertility affects women from around the world, and the cultural and social stigma surrounding it varies.

A seedless fruit is a fruit developed to possess no mature seeds. Since eating seedless fruits is generally easier and more convenient, they are considered commercially valuable.

<span class="mw-page-title-main">Sheep–goat hybrid</span> Offspring of a sheep and a goat

A sheep–goat hybrid is the offspring of a sheep and a goat. While sheep and goats are similar and can be mated, they belong to different genera in the subfamily Caprinae of the family Bovidae. Sheep belong to the genus Ovis and have 54 chromosomes, while goats belong to the genus Capra and have 60 chromosomes. The offspring of a sheep–goat pairing is generally stillborn. Despite widespread shared pasturing of goats and sheep, hybrids are very rare, demonstrating the genetic distance between the two species. They are not to be confused with sheep–goat chimera, which are artificially created by combining the embryos of a goat and a sheep.

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The concept of a biological species as a group of organisms capable of interbreeding to produce viable offspring dates back to at least the 18th century, although it is often associated today with Ernst Mayr. Species of the fruit-fly Drosophila are one of the most commonly used organisms in evolutionary research, and have been used to test many theories related to the evolution of species. The genus Drosophila comprises numerous species that have varying degrees of premating and postmating isolation between them. These species are useful for testing hypotheses of the reproductive mechanisms underlying speciation.

Inherited sterility in insects is induced by substerilizing doses of ionizing radiation. When partially sterile males mate with wild females, the radiation-induced deleterious effects are inherited by the F1 generation. As a result, egg hatch is reduced and the resulting offspring are both highly sterile and predominately male. Compared with the high radiation required to achieve full sterility in Lepidoptera, the lower dose of radiation used to induce F1 sterility increases the quality and competitiveness of the released insects as measured by improved dispersal after release, increased mating ability, and superior sperm competition.

<span class="mw-page-title-main">Evolution of eusociality</span> Origins of cooperative brood care

Eusociality evolved repeatedly in different orders of animals, notably termites and the Hymenoptera. This 'true sociality' in animals, in which sterile individuals work to further the reproductive success of others, is found in termites, ambrosia beetles, gall-dwelling aphids, thrips, marine sponge-dwelling shrimp, naked mole-rats, and many genera in the insect order Hymenoptera. The fact that eusociality has evolved so often in the Hymenoptera, but remains rare throughout the rest of the animal kingdom, has made its evolution a topic of debate among evolutionary biologists. Eusocial organisms at first appear to behave in stark contrast with simple interpretations of Darwinian evolution: passing on one's genes to the next generation, or fitness, is a central idea in evolutionary biology.

<span class="mw-page-title-main">Fertility testing</span>

Fertility testing is the process by which fertility is assessed, both generally and also to find the "fertile window" in the menstrual cycle. General health affects fertility, and STI testing is an important related field.

Equid hybrids, also called hybrid equines, are created from the crossing of members from the horse family such as a horse, donkey and zebra.

Caenorhabditis nigoni is a male-female species in the Elegans group of the genus Caenorhabditis, first identified and described as "Caenorhabditis species 9" or "C. sp. 9" before being renamed as "C. nigoni". The specific epithet is a tribute to Victor Nigon who first studied Caenorhabditis elegans in the laboratory with Ellsworth Dougherty in the 1940s. Isolates come from the Democratic Republic of the Congo and Kerala, India.

Hybrid incompatibility is a phenomenon in plants and animals, wherein offspring produced by the mating of two different species or populations have reduced viability and/or are less able to reproduce. Examples of hybrids include mules and ligers from the animal world, and subspecies of the Asian rice crop Oryza sativa from the plant world. Multiple models have been developed to explain this phenomenon. Recent research suggests that the source of this incompatibility is largely genetic, as combinations of genes and alleles prove lethal to the hybrid organism. Incompatibility is not solely influenced by genetics, however, and can be affected by environmental factors such as temperature. The genetic underpinnings of hybrid incompatibility may provide insight into factors responsible for evolutionary divergence between species.

References

  1. 1 2 Royfman R, Shah TA, Sindhwani P, Nadiminty N, Avidor-Reiss T (2020). "Sterility, an Overlooked Health Condition". Women. 1 (1): 29–45. doi: 10.3390/women1010003 . ISSN   2673-4184.
  2. Pandruvada S, Royfman R, Shah TA, Sindhwani P, Dupree JM, Schon S, Avidor-Reiss T (February 2021). "Lack of trusted diagnostic tools for undetermined male infertility". Journal of Assisted Reproduction and Genetics. 38 (2): 265–276. doi:10.1007/s10815-020-02037-5. PMC   7884538 . PMID   33389378.
  3. "Domestic goat". Read facts about... Archived from the original on 29 November 2014. Retrieved 30 May 2014.
  4. Kozik EU, Nowakowska M, Staniaszek M, Dyki B, Stepowska A, Nowicki M (December 2013). "More than meets the eye: A multi-year expressivity analysis of tomato sterility in ps and ps-2 lines" (PDF). Australian Journal of Crop Science. 7 (13): 2154–2161.