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Capsaspora
''Capsaspora'' is a monotypic genus containing the single species ''Capsaspora owczarzaki. C. owczarzaki'' is a single-celled eukaryote that occupies a key phylogenetic position in our understanding of the origin of animal multicellularity, as one of the closest unicellular relatives to animals. It is, together with ''Ministeria vibrans'', a member of the Filasterea clade (see “Taxonomy” below). This amoeboid protist has been pivotal to unravel the nature of the unicellular ancestor of animals, which has been proved to be much more complex than previously thought. Description ''C. owczarzaki'' was originally described as an amoeba-like “symbiont” of the fresh-water snail ''Biomphalaria glabrata''. The amoebae were obtained from the haemolymph of snails originally sampled in Puerto Rico. ''C. owczarzaki''’s life cycle comprises 3 different stages with three different cell types, which was reported only recently. Under culture conditions, ''C. owczarzaki’''s filopodial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filasterea
Filasterea is a proposed basal Filozoan clade that includes ''Ministeria'' and ''Capsaspora''. It is a sister clade to the Choanozoa in which the Choanoflagellatea and Animals appeared. Originally proposed by Shalchian-Tabrizi et al. in 2008, based on a phylogenomic analysis with dozens of genes. Filasterea was found to be the sister-group to the clade composed of Metazoa and Choanoflagellata within the Opisthokonta, a finding that has been further corroborated with additional, more taxon-rich, phylogenetic analyses. Etymology From Latin ''filum'' meaning "thread" and Greek ''aster'' meaning "star", it indicates the main morphological features shared by all their integrants: small, rounded amoeboids with a mononucleated cellular body, covered in long and radiating cell protrusions known as filopodia. These filopodia may be involved in substrate adhesion and capture of prey. Applications There are currently cultures from two filasterean species: ''Capsaspora owczarzaki'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomphalaria Glabrata
''Biomphalaria glabrata'' is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. ''Biomphalaria glabrata'' is an intermediate snail host for the trematode ''Schistosoma mansoni'', which is one of the main schistosomes that infect humans. This snail is a medically important pest, because of transferring the disease intestinal schistosomiasis, the most widespread of all types of schistosomiasis. The parasite ''Schistosoma mansoni'' (which these snails and other ''Biomphalaria'' snails carry) infects about 83.31 million people worldwide. ''Biomphalaria glabrata''/''Schistosoma mansoni'' provides a useful model system for investigating the intimate interactions between host and parasite. There is a great deal of information available about this snail, because it has been, and continues to be, under intensive study by many malacologists, parasitologists and other researchers, on account of its medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holozoa
Holozoa is a group of organisms that includes animals and their closest single-celled relatives, but excludes fungi. ''Holozoa'' is also an old name for the tunicate genus ''Distaplia''.'' Because Holozoa is a clade including all organisms more closely related to animals than to fungi, some authors prefer it to recognizing paraphyletic groups that mostly consists of Holozoa minus animals. Perhaps the best-known holozoans, apart from animals, are the choanoflagellates, which strongly resemble the collar cells of sponges, and so were theorized to be related to sponges even in the 19th century. ''Proterospongia'' is an example of a colonial choanoflagellate that may shed light on the origin of sponges. The affinities of the other single-celled holozoans only began to be recognized in the 1990s. The sub-classification Ichthyosporea or Mesomycetozoea contains a number of mostly parasitic species. The amoeboid genera ''Ministeria'' and ''Capsaspora'' may be united in a group call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filozoa
The Filozoa are a monophyletic grouping within the Opisthokonta. They include animals and their nearest unicellular relatives (those organisms which are more closely related to animals than to fungi or Mesomycetozoa). Three groups are currently assigned to the clade Filozoa: * Group Filasterea - recently erected to house the genera ''Ministeria'' and ''Capsaspora'' * Group Choanoflagellatea - collared flagellates * Kingdom Animalia - the animals proper Etymology From Latin ''filum'' meaning "thread" and Greek ''zōion'' meaning "animal". Phylogeny A phylogenetic tree of Filozoa and its most closely related clades: Characteristics The ancestral opisthokont cell is assumed to have possessed slender filose (thread-like) projections or 'tentacles'. In some opisthokonts (Mesomycetozoa and ''Corallochytrium'') these were lost. They are retained in Filozoa, where they are simple and non-tapering, with a rigid core of actin bundles (contrasting with the flexible, tapering and br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose Cell (biology), cells have a cell nucleus, nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the Three-domain system, three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard (archaea), Asgard archaea. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass (ecology), biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Tree
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote Genera
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Eukar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode Lifecycle Stages
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions. The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc. The hatchling is called a ''miracidium,'' a free-swimming, ciliated larva. Miracidia will then grow and develop within the intermediate host into a sac-like structure known as a sporocyst or into rediae, either of which may give rise to free-swimming, motile cercariae larvae. The cercariae then could either infect a vertebrate host or a second intermediate host. Adult metacercariae or mesocercariae, depending on the individual trematode's life cycle, will then infect the vertebrate host or be rejected and excreted thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody stool, or blood in the urine. Those who have been infected for a long time may experience liver damage, kidney failure, infertility, or bladder cancer. In children, it may cause poor growth and learning difficulty. The disease is spread by contact with fresh water contaminated with the parasites. These parasites are released from infected freshwater snails. The disease is especially common among children in developing countries, as they are more likely to play in contaminated water. Other high-risk groups include farmers, fishermen, and people using unclean water during daily living. It belongs to the group of helminth infections. Diagnosis is by finding eggs of the parasite in a person's urine or stool. It can also be confirmed by fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schistosoma Mansoni
A paired couple of ''Schistosoma mansoni''. ''Schistosoma mansoni'' is a water-borne parasite of humans, and belongs to the group of blood flukes (''Schistosoma''). The adult lives in the blood vessels ( mesenteric veins) near the human intestine. It causes intestinal schistosomiasis (similar to '' S. japonicum'', '' S. mekongi'', ''S. guineensis'', and '' S. intercalatum''). Clinical symptoms are caused by the eggs. As the leading cause of schistosomiasis in the world, it is the most prevalent parasite in humans. It is classified as a neglected tropical disease. As of 2021, the World Health Organization reports that 236.6 million people have schistosomiasis and most of it is due to ''S. mansoni''. It is found in Africa, the Middle East, the Caribbean, Brazil, Venezuela and Suriname. Unlike other flukes (trematodes) in which sexes are not separate ( monoecious), schistosomes are unique in that adults are divided into males and females, thus, gonochoric. However, a permanent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digenea
Digenea (Gr. ''Dis'' – double, ''Genos'' – race) is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms (known as ''flukes'') with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date. Morphology Key features Characteristic features of the Digenea include a syncytial tegument; that is, a tegument where the junctions between cells are broken down and a single continuous cytoplasm surrounds the entire animal. A similar tegument is found in other members of the Neodermata; a group of platyhelminths comprising the Digenea, Aspidogastrea, Monogenea and Cestoda. Digeneans possess a vermifo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrins
Integrins are transmembrane receptors that facilitate cell-cell and cell-extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. The presence of integrins allows rapid and flexible responses to events at the cell surface (''e.g''. signal platelets to initiate an interaction with coagulation factors). Several types of integrins exist, and one cell generally has multiple different types on its surface. Integrins are found in all animals while integrin-like receptors are found in plant cells. Integrins work alongside other proteins such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins and syndecans, to mediate cell–cell and cell–matrix interaction. Ligands for integrins include fibronectin, vitronectin, collagen and laminin. Structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
