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At least 19 recordsLinked to original sources
PubMed2006

The complete mitochondrial genome of Pollicipes mitella (Crustacea, Maxillopoda, Cirripedia): non-monophylies of maxillopoda and crustacea.

The whole mitochondrial genome (14,915 nt) of Pollicipes mitella (Crustacea, Maxillopoda, Cirripedia, Thoracica) was sequenced and characterized. It is the shortest of the 31 completely sequenced crustacean mitochondrial genomes, with the exception of a copepod Tigriopus japonicus (14,628 nt). It consists of the usual 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 relatively short non-coding region (294 nt). The thoracican cirripeds apart from Megabalanus volcano have the same arrangement of protein-coding genes as Limulus polypemus, but there are frequent tRNA gene translocations (at least 8). Some interesting translocation features that may be specific to the thoracican cirriped lineage are as follows: 1) trnK-trnQ lies between the control region and trnI, 2) trnA-trnE lies between trnN and trnS1, 3) trnP lies between ND4L and trnT, and 4) trnY-trnC lies between trnS2 and ND1. In P. mitella there are two trnL genes (L1 and L2) in the typical crustacean positions (ND1-L1-LrRNA and CO1-L2-CO2). The present result is compared and discussed with the other three cirriped mitochondrial genomes from one pedunculate (Pollicipes polymerus) and two sessiles (Tetraclita japonica and M. volcano) published so far. Mitochondrial protein phylogenies reconstructed by the BI and ML algorithms show that the thoracican Cirripedia is monophyletic (BPP 100/BP 100) and associated with Remipedia (BPP 98/BP 35). In addition, Oligostraca, including Ostracoda, Branchiura, and Pentastomida, is a monophyletic group (BPP 99/BP 68), and is basal to all the other examined arthropods. Remipedia + Cirripedia appears as an independent lineage within Arthropoda, apart from Thoracopoda (Malacostraca, Branchiopda, and Cephalocarida). The Thoracopoda is paraphyletic to Hexapoda. The present result suggests that the monophylies of Crustacea and Maxillopoda should be reconsidered.

Animals↗
PubMed1989

Overall study of the in vitro plasma clotting system in an invertebrate, Liocarcinus puber (Crustacea Decapoda): considerations on the structure of the Crustacea plasma fibrinogen in relation to evolution.

An overall study of the in vitro plasma coagulation system in the crab Liocarcinus puber has been carried out using various analytical methods, namely thromboelastography, spectrophotometrical examination, and a new one based on changes of the mechanical impedance of the developing clot. From the results reported here the clotting pattern in this species appears surprisingly complex for an invertebrate and unexpectedly closer to that of the vertebrates. Indirect evidences suggest that the fibrinogen polypeptide chains in this species and very likely in the other crustacean, are very different from those of the vertebrates. This would imply that crustacean and vertebrate fibrinogen would have diverged from one another in a far remote past, far beyond the individualization of the vertebrate alpha chain, that is, over 1.5 million years ago.

Animals↗
PubMed1987

Reactivity of IgE antibodies with crustacea and oyster allergens: evidence for common antigenic structures.

IgE-antibody reactivity to oysters and crustacea of sera from six oyster-sensitive, seven oyster- and crustacea-sensitive, and 12 crustacea-sensitive subjects was investigated. All six subjects with a history of only oyster sensitivity had minimal RAST reactivity (ratios 2 to 5) to extracts of raw or boiled oysters. Three of the seven oyster- and crustacea-sensitive subjects and six of the 12 crustacea-sensitive, oyster-tolerant or unexposed subjects had elevated RAST ratios to oyster (14 to 41). Generally, elevated oyster RAST correlated with skin prick test reactivity to oyster but not with total serum IgE levels. The oyster RAST values of the 19 crustacea-sensitive subjects (with or without oyster sensitivity) correlated with crustacea RAST reactivity (crab RAST, most significant; shrimp RAST, least significant). Rabbit antisera to crustacea extracts detected precipitating antigens present in extracts of raw or boiled oysters. Significant inhibition of the oyster RAST was obtained with oyster or crustacea extracts. These studies suggest that in the diagnosis of oyster sensitivity the RAST may not be useful and that oyster and crustacea contain common antigenic structures.

Adolescent↗
PubMed1985

Hypersensitivity reactions to ingested crustacea: clinical evaluation and diagnostic studies in shrimp-sensitive individuals.

Adverse reactions to ingested crustacea are common and may be life-threatening. We studied 14 individuals with histories of such reactions to shrimp by immediate skin tests and RAST with extracts of shrimp, crab, crayfish, and lobster. Nine of these subjects (8/8 atopics and 1/6 nonatopics) had positive immediate skin tests (wheal greater than or equal to 2 mm) and RAST (ratios greater than 3.0) to shrimp. Their skin tests and RAST ratios to the other crustacea were also frequently positive even, in several cases, in the absence of prior exposure. In contrast, only 1/10 volunteers with no history of intolerance to crustacea had a weak positive skin test to raw shrimp. These studies suggest that both skin tests and RAST are useful in the confirmation of hypersensitivity to shrimp in atopic individuals and that cross-reactivity among crustacea may exist.

Adult↗
PubMed2003

Na(+)+K(+)-ATPase in gills of aquatic crustacea.

The sodium pump, or Na(+)+K(+)-ATPase, provides at least part of the driving force for transepithelial movement of monovalent ions across the gills and other transporting tissues in many aquatic animals including the Crustacea. The crustacean Na(+)+K(+)-ATPase, like that in all animal cells, is composed of a catalytic alpha-subunit and an accompanying beta-subunit. The amino acid sequence of the crustacean alpha-subunit is 71-74% identical to vertebrate alpha-subunit sequences. In brachyuran Crustacea, the Na(+)+K(+)-ATPase is more highly expressed in posterior gills compared with anterior and is found predominantly in mitochondria-rich cells that are morphologically and biochemically specialized to mediate NaCl uptake from the medium. When the external salinity is lowered from that of normal seawater, producing conditions in which many euryhaline Crustacea hyperosmo regulate their hemolymph, both the enzymatic activity of the Na(+)+K(+)-ATPase and the gene expression of the alpha-subunit are increased in these tissues. Although the precise regulatory mechanism is not known, evidence suggests that crustacean hyperglycemic hormone may be responsible for the induction of Na(+)+K(+)-ATPase activity. Whether it also plays a role in activation of gene transcription is not known. A comparison of a range of aquatic Crustacea suggests that the level of Na(+)+K(+)-ATPase function in transporting tissues may be correlated with their ability to invade estuarine habitats.

Amino Acid Sequence↗
PubMed2001

Neurogenesis in the developing visual system of the branchiopod crustacean Triops longicaudatus (LeConte, 1846): corresponding patterns of compound-eye formation in Crustacea and Insecta?

In the discussion on arthropod phylogeny, the structural evolution of compound eyes and optic ganglia in Crustacea and Insecta is an important topic. On the one hand, many morphological features as well as developmental aspects of the visual system in Insecta and Crustacea correspond in so much detail that eye design in these two groups is likely to have a common euarthropodan ancestor. On the other hand, however, some authors advocate a convergent evolution of the crustacean and insect visual system founding their arguments on differences in the arrangement of the visual neuropils and the fibre connections between Malacostraca and Entomostraca (the "entomostracan enigma"). Therefore, information about cellular aspects of visual system formation in entomostracan Crustacea is likely to enliven this debate, but is not yet available. To fill this gap, we examined the proliferation of neuronal stem cells in the developing visual system of the tadpole shrimp Triops longicaudatus (LeConte, 1846) (Entomostraca, Branchiopoda, Phyllopoda, Calmanostraca, Notostraca) by in vivo incorporation of the proliferation marker bromodeoxyuridine and subsequent immunohistochemical detection. Our results indicate that in the developing visual system of T. longicaudatus, three band-shaped zones containing neuronal stem cells are present corresponding to the proliferation zones found in Malacostraca. We therefore conclude that the ontogenetic mechanisms of visual-system formation are evolutionarily conserved (homologous) in Branchiopoda, Malacostraca, and Insecta.

Animals↗
PubMed1987

Crawfish and lobster allergens: identification and structural similarities with other crustacea.

Antigenic and allergenic components in crawfish and lobster extracts were studied using crossed immunoelectrophoretic techniques. Crossed immunoelectrophoresis with rabbit antisera revealed 23 antigens in crawfish and 17 antigens in lobster extracts. Both extracts exhibited structural similarities in antigens mutually and with other crustacea in cross-line immunoelectrophoresis. Crossed radioimmunoelectrophoresis (CRIE) demonstrated 6 crawfish and 4 lobster allergens when individual or pooled sera from radioallergosorbent test (RAST)-positive crustacea-sensitive subjects were used. Since radiostaining was also observed with sera from RAST-negative nonsensitive subjects, specificity of IgE binding was tested using CRIE-inhibition. Preincubation of RAST-positive sera with crawfish or lobster extract decreased radiostaining in CRIE, while no changes occurred when using control sera. These results confirmed the presence of IgE-mediated mechanisms in seafood allergy and demonstrated a number of shared antigenic determinants among crustacea allergens.

Allergens↗
PubMed2006

vasa-related genes and their expression in stem cells of colonial parasitic rhizocephalan barnacle Polyascus polygenea (Arthropoda: Crustacea: Cirripedia: Rhizocephala).

vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea: Cirripedia: Rhizocephala), and the parasitic isopodan Athelgis takanoshimensis (Crustacea: Isopoda). The colonial Polyascus polygenea, a parasite of the coastal crabs Hemigrapsus sanguineus and Hemigrapsus longitarsis was used as a model object for further detailed investigations. Phylogenetic analysis suggested that PpVLG and CpVLG are closely related to vasa-like genes of other Arthropoda. The rest of the studied genes form their own separate branch on the phylogenetic tree and have a common ancestry with the p68 and PL10 subfamilies. We suppose this group may be a new subfamily of the DEAD-box RNA helicases that is specific for parasitic Crustacea. We found PpVLG and PpDRH1 expression products in stem cells from stolons and buds of internae, during asexual reproduction of colonial P. polygenea, and in germ cells from sexually reproducing externae, including male spermatogenic cells and female oogenic cells.

Amino Acid Sequence↗
PubMed1991

Distribution of cholecystokinin-like immunoreactivity within the stomatogastric nervous systems of four species of decapod crustacea.

The distribution of cholecystokinin-like immunoreactivity was studied in the stomatogastric nervous systems, pericardial organs, and haemolymph of four species of decapod crustacea, by using immunocytochemical and radioimmunoassay techniques. Whereas cholecystokinin-like immunoreactivity was found within the stomatogastric nervous systems of all four species, its distribution in each is unique. Two species (Panulirus interruptus and Homarus americanus) have cholecystokinin-like immunoreactivity within fibers and neuropil of the stomatogastric ganglion (STG); two other species (Cancer antenarius and Procambarus clarkii) do not. Further, the cholecystokinin-like immunoreactivity within the STGs of Panulirus and Homarus arise from distinct structures; from a projection of anterior ganglia in Panulirus, and from somata within the posterior motor nerves in Homarus. The staining in the other ganglia of the stomatogastric nervous system also shows some interspecies variability, although it appears to be more highly conserved than staining within the STG. These differences in staining were confirmed by measuring the amount of CCK-like peptide present in tissue extracts of ganglia by radioimmunoassay. In contrast to the variable staining within the STG, all four species have cholecystokinin-like immunoreactivity within the neurosecretory pericardial organs and thoracic segmental nerves. This cholecystokinin-like immunoreactivity is contained within fibers and within varicosities that coat the surface of these structures. The location of this staining and the presence of detectible levels of CCK-like peptide in the haemolymph suggests that CCK-like peptides in decapod crustacea may be utilized as neurohormones.

Animals↗
PubMed2000

Chaotic or periodic variation? Looking at Crustacea hearts.

A simple relationship between the burst length of the trigger neurons of the Crustacea cardiac ganglion and the length of the heartbeat, is shown to lead to chaotic heart rate. Interestingly, the same type of relationship is also capable of generating complex periodic deviations from steady heart rhythm. Real Crustacea hearts are not likely to follow strictly either suite. The general procedure of analysis, however, is applicable to various biological rhythms, and explains how variation around the mean value can occasionally show up as intricate patterns which repeat themselves with accuracy.

Animals↗
PubMed1976

Conservation of repeated DNA base sequences in Crustacea: a molecular approach to decapod phylogeny.

Analysis of data obtained from molecular hybridization of 3H-labeled repetitious DNA has been utilized to reconstruct the broad outlines of phylogenetic relationships among decapod Crustacea. This molecular reconstruction agrees reasonably well with the paleontological record, and with other schemes obtained by comparative morphological and serological approaches. Preliminary evidence is in line with the hypothesis that continuous addition of new repeated sequence families to the genome over long periods of time may in part account for the correlation observed between percent repetitious DNA hybridized and divergence time. It is tentatively concluded that a core of DNA base sequence homology has been highly conserved throughout the evolution of the Crustacea. Demonstration of inter-species sequence homology has important implications to models which relegate a genetic regulatory function to repeated DNAs.

Animals↗
PubMed2005

Biochemical and molecular characterisation of hemocyanin from the amphipod Gammarus roeseli: complex pattern of hemocyanin subunit evolution in Crustacea.

Hemocyanin is a copper-containing respiratory protein that is widespread within the arthropod phylum. Among the Crustacea, hemocyanins are apparently restricted to the Malacostraca. While well-studied in Decapoda, no hemocyanin sequence has been known from the 'lower' Malacostraca. The hemocyanin of the amphipod Gammarus roeseli is a hexamer that consists of at least five distinct subunits. The complete cDNA sequence of one subunit and a tentative partial sequence of another subunit have been determined. The complete G. roeseli hemocyanin subunit comprises 2,150 bp, which translates in a protein of 672 amino acids with a molecular mass of 76.3 kDa. Phylogenetic analyses show that, in contrast to previous assumptions, the amphipod hemocyanins do not belong to the alpha-type of crustacean hemocyanin subunits. Rather, amphipod hemocyanins split from the clade leading to alpha and gamma-subunits most likely at the time of separation of peracarid and eucarid Crustacea about 300 million years ago. Molecular clock analyses further suggest that the divergence of beta-type subunits and other crustacean hemocyanins occurred around 315 million years ago (MYA) in the malacostracan stemline, while alpha- and gamma-type subunits separated 258 MYA, and pseudohemocyanins and gamma-subunits 210 million years ago.

Amino Acid Sequence↗
PubMed1980

Ultrastructural observation of oogenesis in the crustacea amphipoda Orchestia gammarellus (Pallas).

The oogenesis of the Crustacea Amphipoda Orchestia gammarellus can be divided in five stages taking into consideration both the oocyte ultrastructure and the physiology of the ovary. The primary oogonium (12 micron in diameter) is lodged within the germinative zone: after division, the daughter cell (or secondary oogonium) leaves this area and enters meiotic prophase. Stage I is represented by the oocyte with visible chromosomes (12-18 micron in diameter) the cytoplasmic ultrastructure of which is comparable to that of the oogonium. Stage II or previtellogenesis is characterized by a considerable growth of the oocyte (18-80 micron in diameter) which becomes enriched in ribosomes and vesicles of the rough endoplasmic reticulum; the oocyte does not yet contain any vitelline reserve (proteinaceous and lipid). Stage III or primary vitellogenesis (80-160 micron in diameter) is typified by the synthetic activity of the rough endoplasmic reticulum, corresponding to an endogenous accumulation of proteinaceous yolk. Stage IV or secondary vitellogenesis (160-800 micron in diameter) only appears during the period of reproduction; by means of endocytosis the oocyte accumulates yolk spheres in addition to lipid droplets, the origin of which is uncertain; towards the end of vitellogenesis, cortical granules become a feature that is noted for the first time in Crustacea. The last stage or maturation (800 micron in diameter) starts right before or immediately after the exuviation of the female and ends with fertilization.

Animals↗
PubMed2002

Polycyclic aromatic hydrocarbons in sediments, mussels and crustacea around a former gasworks site in Shoreham-by-Sea, UK.

Concentrations of polycyclic aromatic hydrocarbons have been determined in sediments, mussels and crustacea in the vicinity of a former gasworks site by Shoreham Harbour, UK. Very high concentrations of PAH were found in the substrate, an ash-like material deposited on the former gasworks site, which exhibited a profile consistent with the major source of contamination being coal or coke tar produced during the period of gas production at the site. Elevated PAH concentrations were also found in mussels both from the beach below the former gasworks site, and from sites further to the east in Portslade and Hove. The significance of these concentrations were assessed using an approach which involved the calculation of benzo[a]pyrene equivalent conoentrations (BaPEs), summing concentrations of individual PAH on the basis of their comparative potency as carcinogens. BaPE ranged from values of, or close to, zero for crustacea, to 336 microg kg(-1) wet weight in mussels from Southwick Beach. The contaminated mussels are not exploited commercially but may be taken by casual gatherers, and notices have been posted to warn potential consumers.

Animals↗
PubMed1998

Cytochromes P450 in crustacea.

Since the last review of this topic, further insight has been gained into the presence and functions of cytochrome P450 proteins in the hepatopancreas and other organs of aquatic crustacean species, although progress has been slow relative to the advances in other species. Recent studies with several lobster, shrimp, crab and crayfish species suggest that cytochromes P450 in the 2 and 3 families are the most abundant forms in hepatopancreas microsomes. Substrates normally metabolized by CYP2 and CYP3 family members are monooxygenated more rapidly by crustacea than substrates normally metabolized by CYP1 family enzymes, e.g. erythromycin, testosterone and aminopyrine are much more rapidly monooxygenated than ethoxyresorufin. Some progress has been made in cloning and sequencing crustacean P450 forms. CYP2L1 and CYP2L2 cDNA sequences have been cloned from spiny lobster hepatopancreas libraries, and there was evidence for at least two more cytochromes P450 in spiny lobster hepatopancreas. An area of continued interest, but of no consensus or general findings, relates to the presence and inducibility of CYP1 family members in crustacea. Some studies indicate weak induction of total cytochrome P450 and increased turnover of substrates normally associated with CYP1, while others show no effect of the classic inducers that act at the Ah receptor in vertebrates. A few studies of the roles of cytochromes P450 in the biosynthesis and degradation of steroids, including ecdysteroids, have been published. Further studies are needed to understand the regulation and normal function of the crustacean cytochromes P450.

Animals↗
PubMed1975

[Biological cycles in the egg-layering by aquatic cave-dwelling crustacea].

In the populations of aquatic troglobitic Crustacea, breeding females are found all year round, with an annual peak. Data about their biological cycle suggest four phases of reproduction per year. Synchronisation of egg-laying (for the fraction of females actually reproducing) seems to happen for several species of Crustacea both in nature and at the laboratory. The onset of reproduction is sharpest either late winter or mid-spring, and its amplitude decreases along the annual cycle. The existence of a seasonal trigger is probable.

Animals↗
PubMed2004

Organization of the mitochondrial genome of Antarctic krill Euphausia superba (Crustacea: Malacostraca).

We determined the nearly complete DNA sequence of the mitochondrial genome of Antarctic krill Euphausia superba (Crustacea: Malacostraca), one of the most ecologically and commercially important zooplankters in Antarctic waters. All of the genome sequences were purified by gene amplification using long polymerase chain reaction (PCR), and the products were subsequently used as templates for either direct sequencing using a primer-walking strategy or nested PCR with crustacea-versatile primers. Although we were unable to determine a portion of the genome owing to technical difficulties, the sequenced position, 14,606 bp long, contained all of the 13 protein-coding genes, 19 of the 22 transfer RNA genes, and the large subunit as well as a portion of the small subunit ribosomal RNA genes. Gene rearrangement was observed for 3 transfer RNA genes (tRNACys, tRNATyr, and tRNATrp) and the 2 leucine tRNA genes.

Amino Acid Sequence↗