Sexual system

Last updated

A sexual system is a pattern of sex allocation [1] or a distribution of male and female function across organisms in a species. [2] Terms like reproductive system and mating system have also been used as synonyms. [3]

Contents

The distinction between sexual systems is not always clear due to phenotypic plasticity. [1] Sexual systems are viewed as a key factor for genetic variation and reproductive success, and may have also led to the origin or extinction of certain species. [4]

Interests in sexual systems go back to Darwin, who found that barnacles contain species that are androdioecious and some that are dioecious. [5]

Types of sexual systems

In angiosperms there are monomorphic sexual systems where a species has combination of hermaphrodite, male, and/or female flowers on the same plant. Monomorphic sexual systems include monoecy, gynomonoecy, andromonoecy, and trimonoecy. There are also dimorphic sexual systems where individual plants within a species only produce one sort of flower — hermaphrodite, male, or female. Dimorphic sexual systems include dioecy, gynodioecy, androdioecy, and trioecy. [6] Mixed sexual systems are where hermaphrodites coexist with single sexed individuals. [7] This includes androdioecy, gynodioecy, and trioecy. [8]

What determines whether a flower is male, female, or hermaphroditic is the presence of a stamen — which contains male gametes — and/or pistil — which contains female gametes. Male (a.k.a. staminate) flowers only have a stamen. 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. [9]

(See Plant reproductive morphology for further details on plant sexual systems.)

List of sexual systems

Sexual systemDescription
Androdioecy males and hermaphrodites coexist in a population. [10] It is rare in both plants and animals. [11]
Andromonoecy rare sexual system in angiosperms, in which a plant has both male and hermaphroditic flowers. [12] It has been a subject of interest regarding the mechanism of sex expression. [13]
Dichogamy an individual plant produces either exclusively male or exclusively female flowers at different points in time. [14] It is thought the temporal separation of producing male and female flowers occurs to prevent self-fertilization, [15] however this is debatable as dichogamy occurs in similar frequency among species which are self-compatible and self-incompatible. [16]
Dioicy one of the two main sexual systems in bryophytes. [17] In dioicy male and female sex organs are on separate gametophytes. [18]
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). [19]
Gonochorism individuals are either male or female. [19]

The term "gonochorism" is usually applied to animals while "dioecy" is applied to plants. [20] Gonochorism is the most common sexual system in animals, occurring in 95% of animal species. [21]

Gynodioecy females and hermaphrodites coexist in the same population. [10]
Gynomonoecy defined as the presence of both female and hermaphrodite flowers on the same individual of a plant species. [22] It is prevalent in Asteraceae but is poorly understood. [23]
Gynodioecy-Gynomonoecya sexual system for plants when female, hermaphrodite, and gynomonoecious plants coexist in the same population. [24] : 360 
Monoicy one of the two main sexual systems in bryophytes. [17] In monoicy male and female sex organs are present in the same gametophyte. [18]
Monoecy a sexual system in which male and female flowers are present on the same plant. It is common in angiosperms, [25] and occurs in 10% of all plant species. [26] [ dubious – discuss ]
Sequential hermaphroditism individuals start their adult lives as one sex, and change to the other sex at a later age. [27]
Sequential monoecya confusing sexual system, [28] in which the combination of male, female, and hermaphrodite flowers presented changes over time. [29] For example, some conifers produce exclusively either male or female cones when young, then both when older. [30] Sequential monoecy can be difficult to differentiate from dioecy. [31] 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). [32]
Simultaneous hermaphroditism an individual can produce both gamete types in the same breeding season. [33] 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. [34]
Synoecyall individuals in a population of flowering plants bear solely hermaphrodite flowers. [27]
Trioecy males, females, and hermaphrodites exist in the same population. [8] It is present in both plants and animals but is always extremely rare. [35] Trioecy occurs in about 3.6% of flowering plants. [36] Trioecy may infrequently be referred to as tridioecy. [37]
Trimonoecy (also called androgynomonoecy) is when male, female, and hermaphrodite flowers are present on the same plant. [27] [38] Triomonoecy is rare. [39]

Related Research Articles

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

Sex is the trait that determines whether a sexually reproducing organism produces male or female gametes. A male organism produces small mobile gametes, while a female organism produces larger, non-mobile gametes. An organism that produces both types of gamete is called a hermaphrodite. 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.

<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 only 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. In particular, 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. In some species of fish, sequential hermaphroditism is much more common than simultaneous hermaphroditism.

<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 fertilization. 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.

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 of different sexes, either male or female but not both, are gonochoric, which is the opposite of hermaphroditic.

<span class="mw-page-title-main">Female</span> Sex of an organism that produces ova

An organism's sex is female if it produces the ovum, the type of gamete that fuses with the male gamete during sexual reproduction.

<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.

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, tridioecy or subdioecy, is a sexual system characterized by the coexistence of males, females, and hermaphrodites. It has been found in both plants and animals. Trioecy, androdioecy and gynodioecy may be described as mixed mating systems.

<span class="mw-page-title-main">Simultaneous hermaphroditism</span> One of the two types 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.

Dioicy is a sexual system where archegonia and antheridia are produced on separate gametophytes. 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.

Thor manningi is a species of crustacean. The common name for this species is the Manning grass shrimp. On average the life span in this species is 4 to 5 months. The species uses drag powered swimming to move from place to place.

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

References

  1. 1 2 Leonard JL (2019-05-21). Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems. Springer. p. 1. ISBN   978-3-319-94139-4.
  2. ↑ Encyclopedia of Animal Behavior. Vol. 4. Academic Press. 2019-01-21. p. 584. ISBN   978-0-12-813252-4.
  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. ↑ 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.
  6. ↑ 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. doi: 10.1111/j.1469-8137.2010.03609.x . PMID   21219336.
  7. ↑ 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.
  8. 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.
  9. ↑ 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.
  10. 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.
  11. ↑ 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.
  12. ↑ Casimiro-Soriguer R, Herrera J, Talavera S (March 2013). "Andromonoecy in an Old World Papilionoid legume, Erophaca baetica". Plant Biology. 15 (2): 353–9. doi:10.1111/j.1438-8677.2012.00648.x. PMID   22823201.
  13. ↑ Pugnaire F, Valladares F (2007-06-20). Functional Plant Ecology. CRC Press. p. 524. ISBN   978-1-4200-0762-6.
  14. ↑ 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. doi:10.1080/0028825X.1986.10409725. ISSN   0028-825X.
  15. ↑ 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.
  16. ↑ 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.
  17. 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.
  18. 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. doi: 10.1186/1471-2148-13-239 . PMC   4228369 . PMID   24180692.
  19. 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.
  20. ↑ Encyclopedia of Evolutionary Biology. Vol. 2. Academic Press. 2016-04-14. p. 212. ISBN   978-0-12-800426-5.
  21. ↑ 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.
  22. ↑ 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.
  23. ↑ Martínez-Gómez P (2019-07-11). Plant Genetics and Molecular Breeding. MDPI. p. 442. ISBN   978-3-03921-175-3.
  24. ↑ Lüttge, Ulrich; Cánovas, Francisco M.; Matyssek, Rainer (2016-05-27). Progress in Botany 77. Springer. ISBN   978-3-319-25688-7.
  25. ↑ 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.
  26. ↑ Willmer P (2011-07-05). Pollination and Floral Ecology. Princeton University Press. p. 85. ISBN   978-1-4008-3894-3.
  27. 1 2 3 Beentje, Henk (2016). The Kew Plant Glossary (second ed.). Richmond, Surrey: Royal Botanic Gardens, Kew. ISBN   978-1-84246-604-9.
  28. ↑ Putz, Francis E.; Mooney, Harold A. (1991). The Biology of Vines. Cambridge University Press. p. 411. ISBN   978-0-521-39250-1.
  29. ↑ 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.
  30. ↑ 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. doi:10.1007/BF03030628. ISSN   1867-0725.
  31. ↑ 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)
  32. ↑ 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.
  33. ↑ Leonard, Janet L. (2019-05-21). Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems. Springer. p. 14. ISBN   978-3-319-94139-4.
  34. ↑ 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.
  35. ↑ Leonard JL (2019-05-21). Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems. Springer. p. 23. ISBN   978-3-319-94139-4.
  36. ↑ 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.
  37. ↑ 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.
  38. ↑ 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.
  39. ↑ 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. doi:10.1007/s00606-011-0494-3. ISSN   1615-6110. S2CID   13226982.
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.