Wikipedia

Mating

This article is about sexual reproduction. For the mating of mechanical components, seeEngineering fit.For the 1991 American novel, seeMating (novel).

Inbiology,matingis the pairing of either opposite-sex orhermaphroditicorganismsfor the purposes ofsexual reproduction.Fertilizationis the fusion of twogametes.[1]Copulationis the union of thesex organsof two sexually reproducing animals forinseminationand subsequentinternal fertilization.[2]Mating may also lead toexternal fertilization,as seen inamphibians,fishes and plants. For most species, mating is between two individuals of opposite sexes. However, for some hermaphroditic species, copulation is not required because the parent organism is capable of self-fertilization (autogamy); for example,banana slugs.

Blue-tailed damselflies
(Ischnura elegans) mating

The termmatingis also applied to related processes in bacteria,archaeaand viruses. Mating in these cases involves the pairing of individuals, accompanied by the pairing of theirhomologous chromosomesand then exchange of genomic information leading to formation ofrecombinantprogeny (seemating systems).

Animals

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Main article:Animal sexual behaviour
See also:Copulation (zoology)andHuman mating strategies

For animals, mating strategies includerandom mating,disassortative mating,assortative mating,or amating pool.In some birds, it includes behaviors such asnest-building andfeedingoffspring. The human practice of mating andartificially inseminating domesticated animalsis part ofanimal husbandry.

In someterrestrialarthropods,including insects representingbasal(primitive)phylogeneticclades, the male depositsspermatozoaon the substrate, sometimes stored within a special structure.Courtshipinvolves inducing the female to take up the sperm package into her genital opening without actual copulation. Courtship is often facilitated through forming groups, calledleks,in flies and many other insects. For example, maleTokunagayusurika akamusiforms swarms dancing in the air to attract females. In groups such asdragonfliesand many spiders, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female (in dragonflies, it is a set of modifiedsterniteson the second abdominal segment; in spiders, it is the malepedipalps). In advanced groups of insects, the male uses itsaedeagus,a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a "spermatophore") into the female's reproductive tract.

Other animals reproduce sexually with external fertilization, including manybasalvertebrates.Vertebrates reproduce with internal fertilization throughcloacalcopulation (in reptiles, some fish, and most birds)[3]orejaculationofsementhrough thepenisinto the female'svagina(inmammals).[4][5][3]

In domesticated animals, there are various type of mating methods being employed to mate animals like pen mating (when female is moved to the desired male into a pen) or paddock mating (where one male is let loose in the paddock with several females).

Plants and fungi

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Main articles:Mating systems § In plants,Mating in fungi,andMating of yeast

Like in animals, mating in other Eukaryotes, such as plants andfungi,denotessexual conjugation[clarify].However, in vascular plants this is mostly achieved without physical contact between mating individuals (seepollination), and in some cases, e.g., in fungi no distinguishable male or female organs exist (seeisogamy); however,mating typesin some fungal species are somewhat analogous tosexual dimorphismin animals, and determine whether or not two individual isolates can mate.Yeastsareeukaryoticmicroorganismsclassified in thekingdomFungi,with 1,500speciescurrently described.[6]In general, under high stress conditions likenutrientstarvation,haploidcells will die; under the same conditions, however,diploidcells ofSaccharomyces cerevisiaecan undergo sporulation, entering sexual reproduction (meiosis) and produce a variety of haploidspores,which can go on tomate(conjugate) and reform thediploid.[7]

Protists

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Protists are a large group of diverseeukaryoticmicroorganisms,mainlyunicellularanimals and plants, that do not formtissues.[8]The earliest eukaryotes were likely protists. Mating and sexual reproduction are widespread among extant eukaryotes including protists such asParameciumandChlamydomonas.In many eukaryotic species, mating is promoted bysex pheromonesincluding the protistBlepharisma japonicum.Based on a phylogenetic analysis, Dacks and Roger[9]proposed that facultative sex was present in the common ancestor of all eukaryotes.

However, to many biologists it seemed unlikely until recently, that mating and sex could be a primordial and fundamental characteristic of eukaryotes. A principal reason for this view was that mating and sex appeared to be lacking in certainpathogenicprotists whose ancestors branched off early from the eukaryotic family tree. However, several of these protists are now known to be capable of, or to recently have had, the capability formeiosisand hence mating. To cite one example, the common intestinal parasiteGiardia intestinaliswas once considered to be a descendant of a protist lineage that predated the emergence of meiosis and sex. However,G. intestinaliswas recently found to have a core set of genes that function in meiosis and that are widely present among sexual eukaryotes.[10]These results suggested thatG. intestinalisis capable of meiosis and thus mating and sexual reproduction. Furthermore, direct evidence for meiotic recombination, indicative of mating and sexual reproduction, was also found inG. intestinalis.[11]Other protists for which evidence of mating and sexual reproduction has recently been described are parasitic protozoa of the genusLeishmania,[12]Trichomonas vaginalis,[13]andacanthamoeba.[14]

Protists generally reproduce asexually under favorable environmental conditions, but tend to reproduce sexually under stressful conditions, such as starvation or heat shock.[15]

See also

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References

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  1. ^The Free Dictionary."'Fertilization' – definition of ".Farlex, Inc.Archivedfrom the original on 28 May 2022.Retrieved25 January2014.
  2. ^Naguib, Marc (19 April 2020).Advances in the Study of Behavior.Academic Press.ISBN978-0-12-820726-0.
  3. ^abLibbie Henrietta Hyman (15 September 1992).Hyman's Comparative Vertebrate Anatomy.University of Chicago Press.ISBN978-0-226-87013-7.Archivedfrom the original on 1 August 2023.Retrieved21 November2016.
  4. ^Birkhead, Tim R.; Møller, Anders Pape (12 August 1998).Sperm Competition and Sexual Selection.Elsevier.ISBN978-0-08-054159-4.
  5. ^Dixson, Alan F. (3 June 2021).Mammalian Sexuality: The Act of Mating and the Evolution of Reproduction.Cambridge University Press.ISBN978-1-108-69949-5.
  6. ^"What are yeasts?".Yeast Virtual Library.13 September 2009. Archived fromthe originalon 26 February 2009.Retrieved28 November2009.
  7. ^Neiman, A.M. (2005)."Ascospore formation in the yeast Saccharomyces cerevisiae".Microbiology and Molecular Biology Reviews.69(4): 565–584.doi:10.1128/MMBR.69.4.565-584.2005.PMC1306807.PMID16339736.
  8. ^Javaux EJ, Knoll AH, Walter MR (2001). "Morphological and ecological complexity in early eukaryotic ecosystems".Nature.412(6842): 66–9.Bibcode:2001Natur.412...66J.doi:10.1038/35083562.PMID11452306.S2CID205018792.
  9. ^Dacks J, Roger AJ (1999). "The first sexual lineage and the relevance of facultative sex".J. Mol. Evol.48(6): 779–83.Bibcode:1999JMolE..48..779D.doi:10.1007/pl00013156.PMID10229582.S2CID9441768.
  10. ^Ramesh MA, Malik SB, Logsdon JM (2005)."A phylogenomic inventory of meiotic genes; evidence for sex in Giardia and an early eukaryotic origin of meiosis".Curr. Biol.15(2): 185–91.Bibcode:2005CBio...15..185R.doi:10.1016/j.cub.2005.01.003.PMID15668177.S2CID17013247.
  11. ^Cooper MA, Adam RD, Worobey M, Sterling CR (2007)."Population genetics provides evidence for recombination in Giardia".Curr. Biol.17(22): 1984–8.Bibcode:2007CBio...17.1984C.doi:10.1016/j.cub.2007.10.020.PMID17980591.S2CID15991722.
  12. ^Akopyants NS, Kimblin N, Secundino N, Patrick R, Peters N, Lawyer P, Dobson DE, Beverley SM, Sacks DL (2009)."Demonstration of genetic exchange during cyclical development of Leishmania in the sand fly vector".Science.324(5924): 265–8.Bibcode:2009Sci...324..265A.doi:10.1126/science.1169464.PMC2729066.PMID19359589.
  13. ^Malik SB, Pightling AW, Stefaniak LM, Schurko AM, Logsdon JM (2008)."An expanded inventory of conserved meiotic genes provides evidence for sex in Trichomonas vaginalis".PLOS ONE.3(8): e2879.Bibcode:2008PLoSO...3.2879M.doi:10.1371/journal.pone.0002879.PMC2488364.PMID18663385.
  14. ^Khan NA, Siddiqui R (2015)."Is there evidence of sexual reproduction (meiosis) in Acanthamoeba?".Pathog Glob Health.109(4): 193–5.doi:10.1179/2047773215Y.0000000009.PMC4530557.PMID25800982.
  15. ^Fowler, Samantha; Roush, Rebecca; Wise, James (2013). "Chapter 13: Diversity of Microbes, Fungi, and Protists".Concepts of Biology.OpenStax. Archived fromthe originalon 19 April 2021.Retrieved13 November2020.
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