Cytokinesis: ER Keeps Mid1 in the Middle (original) (raw)
Related papers
The Potential Role of Androgenesis in Cytoplasmic–Nuclear Phylogenetic Discordance
Systematic Biology, 2010
TABLE 1. Organisms demonstrated to have reproduced through androgenesis Organism Frequency a Evidence b Citation Spontaneous androgenesis Arthropods Bacillus rossius-grandii benazzii × B. benazzi 0.01 Paternity Mantovani and Scali (1992) Bacillus rossius-grandii benazzii × B. maretimi 0.18 Paternity Mantovani and Scali (1992) Bacillus rossius-grandii benazzii × B. rossius 0.13 Paternity Mantovani and Scali (1992) Drosophila melanogaster <0.001 to 0.015 Paternity Komma and Endow (1995) Vertebrates Cyprinus carpio × Ctenopharyngodon idella 0.01 Paternity Stanley (1976a, 1976b); Stanley and Jones (1976); Stanley et al. (1976) Angiosperms Brassica napus 0.21 Paternity Chen and Heneen (1989) Capsicum frutescens 10 −3 Paternity Campos and Morgan (1958) Nicotiana debneyi × N. tabacum 10 −4 to 10 −5 Paternity Horlow et al. (1993) Nicotiana debneyi-tabacum × N. tabacum 10 −5 to 10 −6 Paternity Horlow et al. (1993) Nicotiana digluta × N. tabacum 10 −3 Paternity Clausen and Lammerts (1929) Nicotiana suaveolens × N. tabacum 10 −5 Paternity Horlow et al. (1993) Nicotiana sylvestris-tabacum × N. sylvestris 0.0476 Paternity Clausen and Lammerts (1929); Kostoff (1934) Nicotiana tabacum 10 −3 to 10 −6 Paternity Burk (1962); Pelletier et al. (1987); Horlow et al. (1993) Nicotiana tabacum × N. langsdorfii Paternity Kostoff (1934) Petunia hybrida 10 −4 Paternity Singh and Cornu (1976) Poa arachnifera × P. secunda 0.053 Paternity Kindiger (2004); Kindiger and Wipff (2009) Poa arachnifera × P. pratensis 0.014 Paternity Kindiger and Wipff (2009) Poa arachnifera × P. ligularis 0.016 Paternity Kindiger and Wipff (2009) Solanum verrucosum × S. tuberosum 0.09 Paternity Abdalla and Hermsen (1972) S. verrucosum × S. phureja 0.35 Paternity Abdalla and Hermsen (1972) Tripsacum dactyloides × Zea mays 1.0 Paternity Collins and Kempton (1916) Zea mays 0.009-0.08 Paternity Goodsell (1961); Chase (1963); Kermicle (1969); Kindiger and Hamann (1993); Belicuas et al. (2007) Obligate androgenesis Arthropods Wasmania auropunctata (drones) 1.0 Paternity Fournier et al. (2005) Molluscs Corbicula australis Morphology Byrne et al. (2000) Corbicula fluminalis Morphology Korniushin (2004) Corbicula fluminea 1.0 Cytological Ishibashi et al. (2003) Corbicula leana 1.0 Cytological Komaru et al. (1998) Gymnosperms Cupressus dupreziana 1.0 Paternity Pichot et al. (2001)
When males and hermaphrodites coexist: a review of androdioecy in animals
Integrative and comparative biology, 2006
Androdioecy (populations consisting of males and hermaphrodites) is a rare mating system in plants and animals: up to 50 plants and only 36 animals have been described as being androdioecious, with most of the latter being crustaceans. To date, a thorough comparative analysis of androdioecy in animals has not been undertaken. Herein we present such an analysis. Androdioecy has only been extensively surveyed in 2 animal taxa: the nematode Caenorhabditis and the clam shrimp Eulimnadia. The other major taxon having androdioecious species is the Cirripedia (barnacles), but there are only limited studies on androdioecy in this group. In animals, androdioecy is found either in species that have morphologically and ecologically distinct sexes (that is, hermaphrodites and small, "complemental" males) that are derived from hermaphroditic ancestors (that is, the barnacles) or in species that have similarly-sized males and hermaphrodites that have been derived from dioecious ancestor...
Male-biased hermaphrodites in a gynodioecious shrub, Daphne jezoensis
Gynodioecy, a state where female and hermaphrodite plants coexist in populations, has been widely proposed an intermediate stage in the evolutionary pathway from hermaphroditism to dioecy. In the gynodioecy–dioecy pathway, hermaphrodites may gain most of their fitness through male function once females invade populations. To test this prediction, comprehensive studies on sex ratio variation across populations and reproductive characteristics of hermaphrodite and female phenotypes are necessary. This study examined the variation in sex ratio, sex expression, flower and fruit production and sexual dimorphism of morphological traits in a gynodioecious shrub, Daphne jezoensis, over multiple populations and years. Population sex ratio (her-maphrodite:female) was close to 1:1 or slightly hermaphrodite-biased. Sex type of individual plants was largely fixed, but 15% of plants changed their sex during a 6-year census. Hermaphrodite plants produced larger flowers and invested 2.5 times more resources in flower production than female plants, but they exhibited remarkably low fruit set (proportion of flowers setting fruits). Female plants produced six times more fruits than hermaphrodite plants. Low fruiting ability of hermaphrodite plants was retained even when hand-pollination was performed. Fruit production of female plants was restricted by pollen limitation under natural conditions, irrespective of high potential fecundity, and this minimised the difference in resources allocated to reproduction between the sexes. Negative effects of previous flower and fruit production on current reproduction were not apparent in both sexes. This study suggests that gynodioecy in this species is functionally close to a dioecious mating system: smaller flower production with larger fruiting ability in female plants, and larger flower production with little fruiting ability in hermaphrodite plants.
Sex inheritance in gynodioecious species: a polygenic view
Proceedings. Biological sciences / The Royal Society, 2005
Gynodioecy is defined as the coexistence of two different sexual morphs in a population: females and hermaphrodites. This breeding system is found among many different families of angiosperms and is usually under nucleo-cytoplasmic inheritance, with maternally inherited genes causing male sterility and nuclear factors restoring male fertility. Numerous theoretical models have investigated the conditions for the stable coexistence of females and hermaphrodites. To date, all models rest on the assumption that restoration of a given male sterile genotype is controlled by a single Mendelian factor. Here, we review data bearing on the genetic determinism of sex inheritance in three gynodiecious plant species. We suggest that restoration of male fertility is probably best viewed as a quantitative trait controlled by many loci. We develop a threshold model that accommodates an underlying polygenic trait, which is resolved at the phenotypic level in discrete sexual morphs. We use this model...
Ecology and Evolution, 2016
Negative reproductive interactions are likely to be strongest between close relatives and may be important in limiting local coexistence. In plants, interspecific pollen flow is common between co-occurring close relatives and may serve as the key mechanism of reproductive interference. Agamic complexes, systems in which some populations reproduce through asexual seeds (apomixis), while others reproduce sexually, provide an opportunity to examine effects of reproductive interference in limiting coexistence. Apomictic populations experience little or no reproductive interference, because apomictic ovules cannot receive pollen from nearby sexuals. Oppositely, apomicts produce some viable pollen and can exert reproductive interference on sexuals by siring hybrids. In the Crepis agamic complex, sexuals co-occur less often with other members of the complex, but apomicts appear to freely co-occur with one another. We identified a mixed population and conducted a crossing experiment between sexual diploid C. atribarba and apomictic polyploid C. barbigera using pollen from sexual diploids and apomictic polyploids. Seed set was high for all treatments, and as predicted, diploid-diploid crosses produced all diploid offspring. Diploid-polyploid crosses, however, produced mainly polyploidy offspring, suggesting that non-diploid hybrids can be formed when the two taxa meet. Furthermore, a small proportion of seeds produced in open-pollinated flowers was also polyploid, indicating that polyploid hybrids are produced under natural conditions. Our results provide evidence for asymmetric reproductive interference, with pollen from polyploid apomicts contributing to reduce the recruitment of sexual diploids in subsequent generations. Existing models suggest that these mixed sexual-asexual populations are likely to be transient, eventually leading to eradication of sexual individuals from the population.
Inconstant males' and the maintenance of labile sex expression in subdioecious plants
The New phytologist, 2007
Here, we evaluate the role of pollen limitation and selfing in the maintenance of labile sex expression in subdioecious plant species. • We used a literature survey to explore which factors correlated with a significant occurrence of hermaphrodites in dioecious species. We developed models to explore the selective maintenance of labile sex expression. The models had similar ecological assumptions but differed in the genetic basis of sex lability.
Siring Success and Paternal Effects in Heterodichogamous Acer opalus
Annals of Botany, 2008
† Background and Aims Heterodichogamy (a dimorphic breeding system comprising protandrous and protogynous individuals) is a potential starting point in the evolution of dioecy from hermaphroditism. In the genus Acer, previous work suggests that dioecy evolved from heterodichogamy through an initial spread of unisexual males. Here, the question is asked as to whether the different morphs in Acer opalus, a species in which males co-exist with heterodichogamous hermaphrodites, differ in various components of male in fitness. † Methods Several components of male fertility were analysed. Pollination rates in the male phase were recorded across one flowering period. Pollen viability was compared among morphs through hand pollinations both with pollen from a single sexual morph and also simulating a situation of pollen competition; in the latter experiment, paternity was assessed with microsatellite markers. It was also determined whether effects of genetic relatedness between pollen donors and recipients could influence the siring success. Finally, paternal effects occurring beyond the fertilization process were tested for by measuring the height reached by seedlings with different sires over three consecutive growing seasons. † Key Results The males and protandrous morphs had higher pollination rates than the protogynous morph, and the seedlings they sired grew taller. No differences in male fertility were found between males and protandrous individuals. Departures from random mating due to effects of genetic relatedness among sires and pollen recipients were also ruled out. † Conclusions Males and protandrous individuals are probably better sires than protogynous individuals, as shown by the higher pollination rates and the differential growth of the seedlings sired by these morphs. In contrast, the fertility of males was not higher than the male fertility of the protandrous morph. While the appearance of males in sexually specialized heterodichogamous populations is possible, even in the absence of a fitness advantage, it is not clear that males can be maintained at an evolutionary equilibrium with two classes of heterodichogamous hermaphrodites.
Male sterility in plants: occurrence, determinism, significance and use
Comptes Rendus De L Academie Des Sciences Serie Iii-sciences De La Vie-life Sciences, 2001
Most of higher plant species are hermaphroditic and male-sterility is often considered as an accident of development. In fact among the multiple possible causes of male-sterility, the most frequently met in nature is cytoplasmic male-sterility (cms) which is a maternally inherited trait playing an active role in the evolution of gynodioecious species. Recent molecular studies have shown that this trait is determined by additional genes created in plant mitochondrial genomes due to their high recombinogenic activity. The physiological mechanisms by which the products of these genes interfere with the formation of male gametophytes are still the subject of intense research. © 2001 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS cytoplasmic male-sterility / mitochondria / gynodioecy / F1 hybrids Résumé -Stérilité mâle chez les plantes : présence, déterminisme, signification et utilisation. La plupart des espèces de plantes supérieures sont hermaphrodites et la stérilité mâle est souvent considérée comme une anomalie du développement. En fait, parmi les multiples causes possibles de stérilité mâle, la plus fréquemment rencontrée dans la nature est la stérilité mâle cytoplasmique (smc) qui est un caractère à hérédité maternelle jouant un rôle actif dans l'évolution des espèces. Les études moléculaires récentes ont montré que ce caractère est déterminé par des gènes supplémentaires créés au sein du génome mitochondrial grâce à sa très forte activité recombinogène. Les mécanismes physiologiques par lesquels ces gènes interfèrent avec le développement des gamétophytes mâles sont encore l'objet d'une recherche intense. © 2001 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS stérilité mâle cytoplasmique / mitochondrie / gynodïoecie / hybrides F1