High impact information on Platyhelminths

• Serotonin receptors are present in several species of parasitic flatworms and appear to participate in the regulation of motility and carbohydrate metabolism [1].
• Pax-6 homologs have been isolated from a wide variety of organisms ranging from flatworms to humans [2].
• Using the polymerase chain reaction with degenerate primers corresponding to conserved sequences within the ETS DNA-binding domain, we have detected ets genes in a range of lower metazoans, including sponges, ctenophores, anemones, flatworms and nematodes, and in several higher invertebrate metazoans [3].
• In general, most flatworms contain very little histamine (HA) and their nervous systems often lack, or contain very few, histaminergic elements [4].
• The finding of Pax-6 from flatworms to humans suggests that eyeless is a universal master control gene and that the various types of eyes in the various animal phyla may have evolved from a single prototype [5].

Biological context of Platyhelminths

• Heterogeneity of ouabain binding sites in Schistosoma mansoni. First evidence for the presence of two (Na+ + K+)-ATPase isoforms in platyhelminths [6].
• We have analyzed the embryonic development of the temnocephalid flatworms Craspedella pedum and Diceratocephala boschmai, using a combination of fuchsin-labeled whole-mount preparation, histology, and transmission electron microscopy [7].
• Homologs of mammalian CLCA genes were detected in the genomes of a vast array of multicellular animals: lower vertebrates, tunicates, insects, crustaceans, echinoderms, and flatworms [8].

Anatomical context of Platyhelminths

• In addition to comparable similarities with presumed photoreceptors in other platyhelminths, the photoreceptive function of the ciliary lamellate bodies and light-refracting bodies was tested using tritiated thymidine ([3H]T) vitamin-A autoradiography [9].
• Other departures from the universal code, all in nonplant mitochondria, are CUN (leucine) for threonine (in yeasts), AAA (lysine) for asparagine (in platyhelminths and echinoderms), UAA (stop) for tyrosine (in planaria), and AGR (arginine) for serine (in several animal orders) and for stop (in vertebrates) [10].

Associations of Platyhelminths with chemical compounds

• Despite this, no reports of GABA in flatworms have to date been published [11].
• The tRNAs that transferred serine lacked a DHU arm, as is also observed in a number of parasitic platyhelminths and metazoans [12].
• Neuropeptides, biogenic amines and acetylcholine are expressed abundantly within the nervous systems of parasitic flatworms, and are particularly evident in the innervation of the musculature [13].
• Neutral lipids of these flatworms contained sterols, sterol esters, triacylglycerols and free fatty acids [14].
• Parasitic and free-living flatworms differed in phospholipid composition: the turbellarian did not contain phosphatidylserine, and the trematodes had practically no sphingomyelin or lysophosphatidyl choline [14].

Gene context of Platyhelminths

• However, already in the earliest protostomian invertebrates, such as flatworms and annelids, somatostatin and PP immunoreactive nerve fibres were found [15].
• Of particular interest to parasitologists is the fact that selected neuropeptide families are common to metazoan pest species (nematodes, platyhelminths and arthropods) and fulfil specific roles in the modulation of muscle function in each of the three phyla [16].
• There is no evidence for cytochrome P450 in adult helminths (nematodes and platyhelminths) based on P450 content and mono-oxygenase activity with classical substrates, although low activities may be present in free-living larval stages [17].
• Many of these classes, including Antennapedia, engrailed and paired, are strongly conserved in higher multicellular animals, but have not previously been found in platyhelminths, the flatworms which represent the most primitive bilateral metazoans [18].
• Neuropeptide F is the most abundant neuropeptide in parasitic flatworms and is analogous to vertebrate neuropeptide Y [19].

Analytical, diagnostic and therapeutic context of Platyhelminths

• We used the polymerase chain reaction (PCR) to detect Hox/HOM-class homeobox genes from species representing two classes of flatworms [20].

References