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Androdioecious
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. Androdioecy is sometimes referred to as a mixed breeding system with trioecy and gynodioecy. It is a dimorphic sexual system in plants alongside gynodioecy and dioecy. Evolution of androdioecy The fitness requirements for androdioecy to arise and sustain itself are theoretically so improbable that it was long considered that such systems do not exist. Particularly, males and hermaphrodites have to have the same fitness, in other words the same number of offspring, in order to be maintained. However, males only have offspring by fertilizing eggs or ovules of hermaphrodites, while hermaphrodites have offspring both through fertilizing eggs or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caenorhabditis Tropicalis
''Caenorhabditis tropicalis'' is a species of ''Caenorhabditis'' nematodes, belonging to the ''Elegans'' super-group and ''Elegans'' group within the genus. It is a close relative of ''C. wallacei.'' ''C. tropicalis'' is collected frequently in tropical South America, Caribbean islands, and various islands in the Indian and Pacific Oceans from rotting fruit, flowers and stems. ''C. tropicalis'' was referred to as “''C.'' sp. 11” prior to 2014. Anatomy The mean body lengths of adult hermaphroditic and adult male ''C. tropicalis'' were calculated as 1378.63µm and 992.85µm, respectively, making ''C. tropicalis'' males and hermaphrodites on average larger than other hermaphroditic species like ''C. elegans'' and ''C. briggsae''. Spicule shape The spicules of ''C. tropicalis'' males consist of a long, slender, pointed, and simple morphology, which is a common feature among Caenorhabditis species outside of the Elegans super-group (with the exception of ''C. japonica'' and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual System
A sexual system is a pattern of sex allocation or a distribution of male and female function across organisms in a species. Terms like reproductive system and mating system have also been used as synonyms. The distinction between sexual systems is not always clear due to phenotypic plasticity. 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. Interests in sexual systems go back to Charles Darwin, Darwin, who found that barnacles contain species that are Androdioecy, androdioecious and some that are Dioecy, dioecious. Types of sexual systems In plants there are monomorphic sexual systems where a species has hermaphrodite, male and/or female flowers on the same plant. Monomorphic sexual systems include Monoecious (botany), monoecy, gynomonoecy, andromonoecy and trimonoecy. There are also dimorphic sexual systems like dioecy, gynodioecy and androdioecy. Mixed sexual syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Allocation
Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones (ova, often called egg cells). Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent. Males and females of a species may have physical similarities (sexual monomorphism) or differences (sexual dimorphism) that reflect various reproductive pressures on the respective sexes. Mate choice and sexual selection can accelerate the evolution of physical differences between the sexes. The terms ''male'' and ''female'' typically do not apply in sexually undifferentiated species in which the individuals are isomorphic (look the same) and the gametes are isogamous (indistinguishable in size and shape), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabditis Rainai
''Rhabditis'' is a genus of nematodes in the family Rhabditidae. ; Names brought to synonymy: ''Rhabditis (Caenorhabditis)'' Osche, 1952 is a synonym for ''Caenorhabditis'' Dougherty, 1955 Species *''Rhabditis aberrans'' *''Rhabditis marina'' *''Rhabditis maxima'' *''Rhabditis necromena'' *''Rhabditis sylvatica'' *''Rhabditis terricola ''Rhabditis'' is a genus of nematodes in the family Rhabditidae. ; Names brought to synonymy: ''Rhabditis (Caenorhabditis)'' Osche, 1952 is a synonym for ''Caenorhabditis'' Dougherty, 1955 Species *''Rhabditis aberrans'' *''Rhabditis marina ...'' References External links * Rhabditidae Rhabditida genera {{Rhabditida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscheius Guentheri
''Oscheius'' is a genus of nematode. '' O. tipulae'' is a satellite developmental genetic model organism used to study vulva formation. In phylogenetic studies, based on the analysis of sequences of three nuclear genes, ''Oscheius'' groups with ''Caenorhabditis'' species and the ''Diploscapter'', ''Protorhabditis'' and ''Prodontorhabditis ''Prodontorhabditis'' is a genus of nematodes belonging to the family Rhabditidae. The species of this genus are found in Europe and Central America. Species: *''Prodontorhabditis anthobia ''Prodontorhabditis'' is a genus of nematodes belongi ...'' 'Protorhabditis' group, all included in the 'Eurhabditis' group of Rhabditidae genera.The phylogenetic relationships of Caenorhabditis and other rhabditids. Karin Kiontke and David H. A. Fitch, Wormbook, 2005, References External links Rhabditidae Rhabditida genera Model organisms {{Rhabditida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscheius Tipulae
''Oscheius tipulae'' is a species of nematodes, described in association of the leatherjacket, the larva of ''Tipula paludosa''. ''O. tipulae'' is a satellite developmental genetic model organism used to study vulva formation.Polymorphism and evolution of vulval precursor cell lineages within two nematode genera, Caenorhabditis and Oscheius. M Delattre, MA Félix - Current Biology, 2001 It is an androdioecious 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 bee ... species characterized by the coexistence of males and hermaphrodites. References External links Rhabditidae Nematodes described in 1971 Animal models {{Rhabditida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscheius Dolchura
''Oscheius'' is a genus of nematode. '' O. tipulae'' is a satellite developmental genetic model organism used to study vulva formation. In phylogenetic studies, based on the analysis of sequences of three nuclear genes, ''Oscheius'' groups with ''Caenorhabditis'' species and the ''Diploscapter'', ''Protorhabditis'' and ''Prodontorhabditis ''Prodontorhabditis'' is a genus of nematodes belonging to the family Rhabditidae. The species of this genus are found in Europe and Central America. Species: *''Prodontorhabditis anthobia ''Prodontorhabditis'' is a genus of nematodes belongi ...'' 'Protorhabditis' group, all included in the 'Eurhabditis' group of Rhabditidae genera.The phylogenetic relationships of Caenorhabditis and other rhabditids. Karin Kiontke and David H. A. Fitch, Wormbook, 2005, References External links Rhabditidae Rhabditida genera Model organisms {{Rhabditida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscheius Myriophila
''Oscheius'' is a genus of nematode. '' O. tipulae'' is a satellite developmental genetic model organism used to study vulva formation. In phylogenetic studies, based on the analysis of sequences of three nuclear genes, ''Oscheius'' groups with ''Caenorhabditis'' species and the ''Diploscapter'', ''Protorhabditis'' and ''Prodontorhabditis ''Prodontorhabditis'' is a genus of nematodes belonging to the family Rhabditidae. The species of this genus are found in Europe and Central America. Species: *''Prodontorhabditis anthobia ''Prodontorhabditis'' is a genus of nematodes belongi ...'' 'Protorhabditis' group, all included in the 'Eurhabditis' group of Rhabditidae genera.The phylogenetic relationships of Caenorhabditis and other rhabditids. Karin Kiontke and David H. A. Fitch, Wormbook, 2005, References External links Rhabditidae Rhabditida genera Model organisms {{Rhabditida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caenorhabditis Briggsae
''Caenorhabditis briggsae'' is a small nematode, closely related to ''Caenorhabditis elegans''. The differences between the two species are subtle. The male tail in ''C. briggsae'' has a slightly different morphology from ''C. elegans''. Other differences include changes in vulval precursor competence and the placement of the excretory duct opening. ''C. briggsae'' is frequently used to study the differences between it and the more intimately understood ''C. elegans'', especially at the DNA and protein sequence level. Several mutant strains of ''C. briggsae'' have also been isolated that facilitate genetic analysis of this organism. ''C. briggsae'', like ''C. elegans'', is a hermaphrodite. The genome sequence for ''C. briggsae'' was determined in 2003. History ''C. briggsae'' was initially discovered by Margaret Briggs in 1944. The first individuals were isolated from a pile of leaves found on the Palo Alto campus of Stanford University. Briggs, who was studying for her MS, ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabditida
Rhabditida is an order of free-living, zooparasitic, and phytoparasitic microbivorous nematodes living in soil. The Cephalobidae, Panagrolaimidae, Steinernematidae, and Strongyloididae seem to be closer to the Tylenchia, regardless of whether these are merged with the Rhabditia or not.Tree of Life Web Project (2002b)Nematoda Version of 2002-JAN-01. Retrieved 2008-NOV-02. Families Rhabditida * Myolaimina **''Incertae sedis'' *** Myolaimoidea ****Myolaimidae *Rhabditina ** Bunonematomorpha *** Bunonematoidea ****Bunonematidae ** Diplogasteromorpha *** Cylindrocorporoidea ****Cylindrocorporidae *** Diplogasteroidea **** Cephalobiidae ****Diplogasteridae ****Diplogasteroididae ** Rhabditomorpha *** Mesorhabditoidea ****Peloderidae *** Rhabditoidea ****Rhabditidae * Spirurina ** Ascaridomorpha *** Ascaridoidea **** Acanthocheilidae ****Anisakidae ****Ascarididae ****Heterocheilidae **** Raphidascarididae *** Cosmocercoidea ****Atractidae ****Kathlaniidae *** Seuratoidea **** Cuc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabditidae
The Rhabditidae are a family of nematodes which includes the model organism '' Caenorhabditis elegans''. Genera ''Bursilla'' *''Bursilla monhysteria'' (Butschli, 1873) ''Caenorhabditis'' *''Caenorhabditis brenneri'' Sudhaus & Kiontke, 2007 *''Caenorhabditis briggsae'' *''Caenorhabditis dolichura'' *'' Caenorhabditis elegans'' Maupas, 1900 *''Caenorhabditis rara'' ''Diploscapter'' Genus ''Diploscapter'' *''Diploscapter bicornis'' *''Diploscapter coronata'' (Cobb, 1893) *''Diploscapter lycostoma'' *''Diploscapter pachys'' ''Halicephalobus'' *''Halicephalobus gingivalis'' (Stefanski, 1954) Andrássy, 1984 *''Halicephalobus mephisto'' Borgonie, García-Moyano, Litthauer, Bert, Bester, van Heerden, Möller, Erasmus & Onstott, 2011 *'' Halicephalobus similigaster'' (Andrássy, 1952) ''Macramphis'' *'' Macramphis stercorarius'' ''Mesorhabditis'' *''Mesorhabditis acris'' *''Mesorhabditis irregularis'' *''Mesorhabditis oschei'' *''Mesorhabditis spiculigera'' ''Neorha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broad range of environments. Less formally, they are categorized as Helminths, but are taxonomically classified along with Arthropod, arthropods, Tardigrade, tardigrades and other moulting animalia, animals in the clade Ecdysozoa, and unlike platyhelminthe, flatworms, have tubular digestion, digestive systems with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species described to date vary by author and may change rapidly over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
