Sexual system

Last updated
Barnacles have a variety of sexual systems. Tide pool Acorn barnacles, Oregon.jpg
Barnacles have a variety of sexual systems.

A sexual system is a distribution of male and female functions across organisms in a species. [1] [2] The terms reproductive system and mating system have also been used as synonyms. [3]

Contents

Sexual systems play a key role in genetic variation and reproductive success, and may also have led to the origin or extinction of certain species. [4] In flowering plants and animals, sexual reproduction involves meiosis, an adaptive process for repairing damage in the germline DNA transmitted to progeny. [5] The distinctions between different sexual systems is not always clear due to phenotypic plasticity. [2]

Interest in sexual systems goes back to Charles Darwin, who found that barnacles include some species that are androdioecious and some that are dioecious. [6]

Types of sexual systems

The life cycle of an angiosperm. Angiosperm life cycle diagram-en.svg
The life cycle of an angiosperm.

Flowering plants may have dimorphic or monomorphic sexual systems. In monomorphic sexual systems, a combination of hermaphrodite, male, and/or female flowers may be present on the same plant. Monomorphic sexual systems include monoecy, gynomonoecy, andromonoecy, and trimonoecy. In dimorphic sexual systems, individual plants within a species only produce one sort of flower, either hermaphrodite or male, or female. Dimorphic sexual systems include dioecy, gynodioecy, androdioecy, and trioecy. [7]

Male (a.k.a. staminate) flowers have a stamen but no pistil and produce only male gametes. Female (a.k.a. pistillate) flowers only have a pistil. Hermaphrodite (a.k.a. perfect, or bisexual) flowers have both a stamen and pistil. The sex of a single flower may differ from the sex of the whole organism: for example, a plant may have both staminate and pistillate flowers, making the plant as a whole a hermaphrodite. Hence although all monomorphic plants are hermaphrodites, different combinations of flower types (staminate, pistillate, or perfect) produces distinct monomorphic sexual systems. [8]

In animals, androdioecy, gynodioecy, and trioecy are referred to as mixed sexual systems; [9] where hermaphrodites coexist with single sexed individuals. [10]

List of sexual systems

Sexual systemDescription
Androdioecy males and hermaphrodites coexist in a population. [11] It is rare in both plants and animals. [12]
Andromonoecy rare sexual system in angiosperms, in which a plant has both male and hermaphroditic flowers. [13] It has been a subject of interest regarding the mechanism of sex expression. [14]
Dichogamy an individual plant produces either exclusively male or exclusively female flowers at different points in time. [15] It is thought the temporal separation of producing male and female flowers occurs to prevent self-fertilization, [16] however this is debatable as dichogamy occurs in similar frequency among species which are self-compatible and self-incompatible. [17]
Dioicy one of the main sexual systems in bryophytes. [18] In dioicy male and female sex organs are on separate gametophytes. [19]
Dioecy a species has distinct individual organisms that are either male or female, i.e., they produce only male or only female gametes, either directly (in animals) or indirectly (in plants). [20]
Gonochorism individuals are either male or female. [20]

The term "gonochorism" is usually applied to animals while "dioecy" is applied to plants. [21] Gonochorism is the most common sexual system in animals, occurring in 95% of animal species. [22]

Gynodioecy females and hermaphrodites coexist in the same population. [11]
Gynomonoecy defined as the presence of both female and hermaphrodite flowers on the same individual of a plant species. [23] It is prevalent in Asteraceae but is poorly understood. [24]
Gynodioecy-Gynomonoecya sexual system for plants when female, hermaphrodite, and gynomonoecious plants coexist in the same population. [25] : 360 
Monoicy one of the main sexual systems in bryophytes. [18] In monoicy male and female sex organs are present in the same gametophyte. [19]
Monoecy a sexual system in which male and female flowers are present on the same plant. It is common in angiosperms, [26] and occurs in 10% of all plant species. [27] [ dubious – discuss ]
Sequential hermaphroditism individuals start their adult lives as one sex, and change to the other sex at a later age. [28]
Sequential monoecya confusing sexual system, [29] in which the combination of male, female, and hermaphrodite flowers presented changes over time. [30] For example, some conifers produce exclusively either male or female cones when young, then both when older. [31] Sequential monoecy can be difficult to differentiate from dioecy. [32] Several alternative terms may be used in reference to sexual systems involving temporal changes to sex presentation of a plant species (e.g. dichogamy, sequential hermaphroditism, sex change, paradioecy, diphasy). [33]
Simultaneous hermaphroditism an individual can produce both gamete types in the same breeding season. [34] Simultaneous hermaphroditism is one of the most common sexual systems in animals (though far less common than gonochorism) and is one of the most stable. [35]
Synoecyall individuals in a population of flowering plants bear solely hermaphrodite flowers. [28]
Trioecy males, females, and hermaphrodites exist in the same population. [9] It is present in both plants and animals but is always extremely rare. [36] Trioecy occurs in about 3.6% of flowering plants. [37] Trioecy may infrequently be referred to as tridioecy. [38]
Trimonoecy (also called androgynomonoecy) is when male, female, and hermaphrodite flowers are present on the same plant. [28] [39] Triomonoecy is rare. [40]

Related Research Articles

<span class="mw-page-title-main">Sex</span> Trait that determines an organisms sexually reproductive function

Sex is the biological trait that determines whether a sexually reproducing organism produces male or female gametes. During sexual reproduction, a male and a female gamete fuse to form a zygote, which develops into an offspring that inherits traits from each parent. By convention, organisms that produce smaller, more mobile gametes are called male, while organisms that produce larger, non-mobile gametes are called female. An organism that produces both types of gamete is hermaphrodite.

<i>Silene</i> Genus of flowering plants

Silene is a genus of flowering plants in the family Caryophyllaceae. Containing nearly 900 species, it is the largest genus in the family. Common names include campion and catchfly. Many Silene species are widely distributed, particularly in the northern hemisphere.

<span class="mw-page-title-main">Plant reproductive morphology</span> Parts of plant enabling sexual reproduction

Plant reproductive morphology is the study of the physical form and structure of those parts of plants directly or indirectly concerned with sexual reproduction.

In biology, gonochorism is a sexual system where there are two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric.

Dioecy is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly or indirectly. Dioecious reproduction is biparental reproduction. Dioecy has costs, since only the female part of the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility.

<span class="mw-page-title-main">Sequential hermaphroditism</span> Sex change as part of the normal life cycle of a species

Sequential hermaphroditism is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodite produces eggs and sperm at different stages in life. Sequential hermaphroditism occurs in many fish, gastropods, and plants. Species that can undergo these changes do so as a normal event within their reproductive cycle, usually cued by either social structure or the achievement of a certain age or size.

<span class="mw-page-title-main">Male</span> Sex of an organism which produces sperm

Male is the sex of an organism that produces the gamete known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilisation. A male organism cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs.

Cytoplasmic male sterility is total or partial male sterility in hermaphrodite organisms, as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure to produce functional anthers, pollen, or male gametes. Such male sterility in hermaphrodite populations leads to gynodioecious populations.

Androdioecy is a reproductive system characterized by the coexistence of males and hermaphrodites. Androdioecy is rare in comparison with the other major reproductive systems: dioecy, gynodioecy and hermaphroditism. In animals, androdioecy has been considered a stepping stone in the transition from dioecy to hermaphroditism, and vice versa.

<span class="mw-page-title-main">Hermaphrodite</span> Sexually reproducing organism that produces both male and female gametes

A hermaphrodite is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.

<span class="mw-page-title-main">Gynodioecy</span> Coexistence of female and hermaphrodite within a population

Gynodioecy is a rare breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate between hermaphroditism and dioecy.

<span class="mw-page-title-main">Susanne Renner</span> German botanist

Susanne Sabine Renner is a German botanist. Until October 2020, she was a professor of biology at the Ludwig Maximilian University of Munich as well as director of the Botanische Staatssammlung München and the Botanischer Garten München-Nymphenburg. Since January 2021, she lives in Saint Louis, where she is an Honorary Professor of Biology at Washington University and a Research Associate at the Missouri Botanical Garden.

Sex determination in <i>Silene</i> Sex determination in the flower genus Silene

Silene is a flowering plant genus that has evolved a dioecious reproductive system. This is made possible through heteromorphic sex chromosomes expressed as XY. Silene recently evolved sex chromosomes 5-10 million years ago and are widely used by geneticists and biologists to study the mechanisms of sex determination since they are one of only 39 species across 14 families of angiosperm that possess sex-determining genes. Silene are studied because of their ability to produce offspring with a plethora of reproductive systems. The common inference drawn from such studies is that the sex of the offspring is determined by the Y chromosome.

Trioecy, also spelled triecy, is a sexual system characterized by the coexistence of males, females, and hermaphrodites. It has been found in both plants and animals. Like androdioecy and gynodioecy, trioecy is a mixed mating systems.

<span class="mw-page-title-main">Simultaneous hermaphroditism</span> Type of hermaphroditism

Simultaneous hermaphroditism is one of the two types of hermaphroditism, the other type being sequential hermaphroditism. In this form of hermaphroditism an individual has sex organs of both sexes and can produce both gamete types even in the same breeding season.

Andromonoecy is a breeding system of plant species in which male and hermaphrodite flowers are on the same plant. It is a monomorphic sexual system comparable with monoecy, gynomonoecy and trimonoecy. Andromonoecy is frequent among genera with zygomorphic flowers, however it is overall rare and occurs in less than 2% of plant species. Nonetheless the breeding system has gained interest among biologists in the study of sex expression.

Gynomonoecy is defined as the presence of both female and hermaphrodite flowers on the same individual of a plant species. It is prevalent in Asteraceae but is poorly understood.

<span class="mw-page-title-main">Monoecy</span> Sexual system in seed plants

Monoecy is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contrasted with dioecy where individual plants produce cones or flowers of only one sex and with bisexual or hermaphroditic plants in which male and female gametes are produced in the same flower.

Dioicy is a sexual system in non-vascular plants where archegonia and antheridia are produced on separate plants in the gametophyte phase. It is one of the two main sexual systems in bryophytes, the other being monoicy. Both dioicous and monoicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte.

Trimonoecy, also called polygamomonoecy, is when male, female, and hermaphrodite flowers are on the same plant. Trimonoecy is rare.

References

Footnotes

  1. ↑ Encyclopedia of Animal Behavior. Vol. 4. Academic Press. 2019-01-21. p. 584. ISBN   978-0-12-813252-4.
  2. 1 2 Leonard 2019, p. 1.
  3. ↑ Cardoso, João Custódio Fernandes; Viana, Matheus Lacerda; Matias, Raphael; Furtado, Marco Túlio; Caetano, Ana Paula de Souza; Consolaro, Hélder; Brito, Vinícius Lourenço Garcia de (Jul–Sep 2018). "Towards a unified terminology for angiosperm reproductive systems". Acta Botanica Brasilica. 32 (3): 329–348. doi: 10.1590/0102-33062018abb0124 . ISSN   0102-3306. S2CID   91470660.
  4. ↑ Goldberg EE, Otto SP, Vamosi JC, Mayrose I, Sabath N, Ming R, Ashman TL (April 2017). "Macroevolutionary synthesis of flowering plant sexual systems". Evolution; International Journal of Organic Evolution. 71 (4): 898–912. doi:10.1111/evo.13181. PMID   28085192. S2CID   19562183.
  5. ↑ Bernstein H, Byerly HC, Hopf FA, Michod RE (September 1985). "Genetic damage, mutation, and the evolution of sex". Science. 229 (4719). New York, N.Y.: 1277–81. Bibcode:1985Sci...229.1277B. doi:10.1126/science.3898363. PMID 3898363.
  6. ↑ Yusa Y, Yoshikawa M, Kitaura J, Kawane M, Ozaki Y, Yamato S, Høeg JT (March 2012). "Adaptive evolution of sexual systems in pedunculate barnacles". Proceedings. Biological Sciences. 279 (1730): 959–66. doi:10.1098/rspb.2011.1554. PMC   3259936 . PMID   21881138.
  7. ↑ Torices R, Méndez M, Gómez JM (April 2011). "Where do monomorphic sexual systems fit in the evolution of dioecy? Insights from the largest family of angiosperms". The New Phytologist. 190 (1): 234–248. Bibcode:2011NewPh.190..234T. doi: 10.1111/j.1469-8137.2010.03609.x . PMID   21219336.
  8. ↑ Jabbour, Florian; Espinosa, Felipe; Dejonghe, Quentin; Le Péchon, Timothée (2022-01-07). "Development and Evolution of Unisexual Flowers: A Review". Plants. 11 (2): 155. doi: 10.3390/plants11020155 . ISSN   2223-7747. PMC   8780417 . PMID   35050043.
  9. 1 2 Oyarzún PA, Nuñez JJ, Toro JE, Gardner J (2020). "Trioecy in the Marine Mussel Semimytilus algosus (Mollusca, Bivalvia): Stable Sex Ratios Across 22 Degrees of a Latitudinal Gradient". Frontiers in Marine Science. 7. doi: 10.3389/fmars.2020.00348 . ISSN   2296-7745.
  10. ↑ Leonard J, Cordoba-Aguilar A (2010-07-19). The Evolution of Primary Sexual Characters in Animals. Oxford University Press, USA. pp. 29–30. ISBN   978-0-19-532555-3.
  11. 1 2 Fusco G, Minelli A (2019-10-10). The Biology of Reproduction. Cambridge University Press. pp. 132–133. ISBN   978-1-108-49985-9.
  12. ↑ Pontarotti P (2011-07-20). Evolutionary Biology – Concepts, Biodiversity, Macroevolution and Genome Evolution. Springer Science & Business Media. p. 36. ISBN   978-3-642-20763-1.
  13. ↑ Casimiro-Soriguer R, Herrera J, Talavera S (March 2013). "Andromonoecy in an Old World Papilionoid legume, Erophaca baetica". Plant Biology. 15 (2): 353–9. Bibcode:2013PlBio..15..353C. doi:10.1111/j.1438-8677.2012.00648.x. PMID   22823201.
  14. ↑ Pugnaire F, Valladares F (2007-06-20). Functional Plant Ecology. CRC Press. p. 524. ISBN   978-1-4200-0762-6.
  15. ↑ Lloyd, David G.; Webb, C. J. (1986-07-01). "The avoidance of interference between the presentation of pollen and stigmas in angiosperms I. Dichogamy". New Zealand Journal of Botany. 24 (1): 135–162. Bibcode:1986NZJB...24..135L. doi:10.1080/0028825X.1986.10409725. ISSN   0028-825X.
  16. ↑ Renner, Susanne S. (2014-10-01). "The relative and absolute frequencies of angiosperm sexual systems: Dioecy, monoecy, gynodioecy, and an updated online database". American Journal of Botany. 101 (10): 1588–1596. doi: 10.3732/ajb.1400196 . PMID   25326608.
  17. ↑ Bertin, Robert I. (1993-05-01). "Incidence of Monoecy and Dichogamy in Relation to Self-Fertilization in Angiosperms". American Journal of Botany. 80 (5): 557–560. doi:10.1002/j.1537-2197.1993.tb13840.x. PMID   30139145.
  18. 1 2 Ramawat KG, Merillon JM, Shivanna KR (2016-04-19). Reproductive Biology of Plants. CRC Press. p. 62. ISBN   978-1-4822-0133-8.
  19. 1 2 Villarreal JC, Renner SS (November 2013). "Correlates of monoicy and dioicy in hornworts, the apparent sister group to vascular plants". BMC Evolutionary Biology. 13 (1): 239. Bibcode:2013BMCEE..13..239V. doi: 10.1186/1471-2148-13-239 . PMC   4228369 . PMID   24180692.
  20. 1 2 King RC, Stansfield WD, Mulligan PK (2007). "Gonochorism". A Dictionary of Genetics. Oxford University Press. doi:10.1093/acref/9780195307610.001.0001. ISBN   978-0-19-530761-0 . Retrieved 2021-07-28.
  21. ↑ Encyclopedia of Evolutionary Biology. Vol. 2. Academic Press. 2016-04-14. p. 212. ISBN   978-0-12-800426-5.
  22. ↑ Leonard JL (October 2013). "Williams' paradox and the role of phenotypic plasticity in sexual systems". Integrative and Comparative Biology. 53 (4): 671–88. doi: 10.1093/icb/ict088 . PMID   23970358.
  23. ↑ Allaby M (2006). "Gynomonoecious". A Dictionary of Plant Sciences. Oxford University Press. doi:10.1093/acref/9780198608912.001.0001. ISBN   978-0-19-860891-2.
  24. ↑ Martínez-Gómez P (2019-07-11). Plant Genetics and Molecular Breeding. MDPI. p. 442. ISBN   978-3-03921-175-3.
  25. ↑ Lüttge, Ulrich; Cánovas, Francisco M.; Matyssek, Rainer (2016-05-27). Progress in Botany 77. Springer. ISBN   978-3-319-25688-7.
  26. ↑ Bahadur B, Sujatha M, Carels N (2012-12-14). Jatropha, Challenges for a New Energy Crop: Volume 2: Genetic Improvement and Biotechnology. Springer Science & Business Media. pp. 27–28. ISBN   978-1-4614-4915-7.
  27. ↑ Willmer P (2011-07-05). Pollination and Floral Ecology. Princeton University Press. p. 85. ISBN   978-1-4008-3894-3.
  28. 1 2 3 Beentje, Henk (2016). The Kew Plant Glossary (second ed.). Richmond, Surrey: Royal Botanic Gardens, Kew. ISBN   978-1-84246-604-9.
  29. ↑ Putz, Francis E.; Mooney, Harold A. (1991). The Biology of Vines. Cambridge University Press. p. 411. ISBN   978-0-521-39250-1.
  30. ↑ Flores-Rentería, Lluvia; Molina-Freaner, Francisco; Whipple, Amy V.; Gehring, Catherine A.; Domínguez, C. A. (2013-03-01). "Sexual stability in the nearly dioecious Pinus johannis (Pinaceae)". American Journal of Botany. 100 (3): 602–612. doi:10.3732/ajb.1200068. ISSN   0002-9122. PMID   23445824.
  31. ↑ Kang, Hyesoon (2007-04-01). "Changes in gender expression in korean populations ofPinus densiflora over a five-year period". Journal of Plant Biology. 50 (2): 181–189. Bibcode:2007JPBio..50..181K. doi:10.1007/BF03030628. ISSN   1867-0725. S2CID   19890328.
  32. ↑ Greenwood, Paul J.; Greenwood, Greenwood, Paul John; Harvey, Paul H.; Harvey, Reader in Biology Department of Zoology Paul H.; Slatkin, Montgomery; Slatkin, Professor of Integrative Biology Montgomery; Cambridge, University of (1985-07-11). Evolution: Essays in Honour of John Maynard Smith. CUP Archive. p. 240. ISBN   978-0-521-25734-3.{{cite book}}: CS1 maint: multiple names: authors list (link)
  33. ↑ Windsor, Jon and Lesley Lovett-Doust Professor of Biology the University of (1988-07-07). Plant Reproductive Ecology : Patterns and Strategies: Patterns and Strategies. Oxford University Press, USA. ISBN   978-0-19-802192-6.
  34. ↑ Leonard 2019, p. 14.
  35. ↑ Leonard J, Cordoba-Aguilar A (2010-07-19). The Evolution of Primary Sexual Characters in Animals. Oxford University Press, USA. p. 20. ISBN   978-0-19-532555-3.
  36. ↑ Leonard 2019, p. 23.
  37. ↑ Albert B, Morand-Prieur MÉ, Brachet S, Gouyon PH, Frascaria-Lacoste N, Raquin C (October 2013). "Sex expression and reproductive biology in a tree species, Fraxinus excelsior L". Comptes Rendus Biologies. 336 (10): 479–85. doi:10.1016/j.crvi.2013.08.004. PMID   24246889.
  38. ↑ Heikrujam, Monika; Sharma, Kuldeep; Prasad, Manoj; Agrawal, Veena (2015-01-01). "Review on different mechanisms of sex determination and sex-linked molecular markers in dioecious crops: a current update". Euphytica. 201 (2): 161–194. doi:10.1007/s10681-014-1293-z. ISSN   1573-5060. S2CID   254468003.
  39. ↑ Atwell BJ, Kriedemann PE, Turnbull CG (1999). Plants in Action: Adaptation in Nature, Performance in Cultivation. Macmillan Education AU. p. 244. ISBN   978-0-7329-4439-1.
  40. ↑ Cardoso-Gustavson P, Demarco D, Carmello-Guerreiro SM (2011-08-06). "Evidence of trimonoecy in Phyllanthaceae: Phyllanthus acidus". Plant Systematics and Evolution. 296 (3): 283–286. Bibcode:2011PSyEv.296..283C. doi:10.1007/s00606-011-0494-3. ISSN   1615-6110. S2CID   13226982.

Bibliography

Leonard, Janet (2019-05-21), Transitions Between Sexual Systems: Understanding the Mechanisms Of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems, Springer Publishing, ISBN   978-3-319-94139-4

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.