Solving parasite-related problems in cultured molluscs

A review of the economic impact of disease caused by various pathogens underlines the need for further research on molluscan pathology. In France, recent problem with Bonamia required the introduction of a strategy to limit the effect of the disease. The strategy was developed in collaboration with the authorities and the oyster farming professionals. Their own part in the definition and the settlement of measures was very important. The plan pointed out the weaknesses of the measures presently available in limiting the consequences of an epizootic. The authors recommend complementary prophylaxes which need various disciplines and illustrate the results to date. We conclude by pointing out research areas that require high priority in future work.     

Solving parasite-related problems in cultured freshwater fish

The importance of parasitoses in freshwater fish culture grows parallel with the development of fishbreeding. Especially in intensively cultured fish populations one has to reckon with outbreaks of parasitoses. Although parasite-related problems are different in cultures of salmonids, carp, tilapias, catfishes, eels and ornamental fish protozoan parasites are in general of greatest importance. Among protozoans, myxozoan parasites deserve attention as recent research on this group has brought several new results. Regarding the control of parasitic fish diseases, biological methods might be successful together with prevention and a broader scale of effective medicines.     

Solving parasite-related problems in cultured marine fish

• 1.1. Our knowledge of parasite born e diseases of cultured marine fish is restricted by the limited extent of practiced mariculture.
• 2.2. Several parasites, pathogenic to fish including capsaloid, microcotylid and diclidophoran monogeneans and caligid copepods are ubiquitous in mariculture systems in diverse species of fish and geographical regions.
• 3.3. The alga Amyloodinium ocellatum and the ciliated protozoan Cryptocaryon irritons are not as ubiquitous, but nevertheless present the most serious risk to farmed fish of most species due to their high pathogenicity, fecundity and resistance to conventional means of control.
• 4.4. Infections in maricultured fish are dominated by monoxenous parasites. Occurence of heteroxenous parasites is restricted by their requirement for additional hosts to maintain transmission.
• 5.5. Cage culture allows free exchange of infection between caged and native fishes; in inshore systems infections have to be introduced primarily from external sources.
• 6.6. Water supply does not appear to be an efficient route of entry of infection into culture systems; parasites are introduced either by wild fry or wild breeders collected into the system, or with wild fish infiltrating via water supply or drainage.
• 7.7. Adverse growth conditions are the most common circumstances in outbreak of epizooites. Over-crowding does not appear to promote primarily epizooites, its impact is indirect by contributing to the deterioration of the growth conditions.
• 8.8. Epizooites are likely to occur also in juvenile, immunologically naive fish as well as following introduction of parasites into unexperienced fish population.
• 9.9. Control has been implemented thus far through an empirical approach. Recent research is geared towards the development of methodology specifically designed to the needs of mariculture.

     

FANCJ: Solving problems in DNA replication

The FANCJ protein (also known as BACH1 and BRIP1) is a DNA helicase that is required to preserve the genetic and structural integrity of the genome in complex eukaryotes. In humans, mutations in FANCJ are associated with the chromosome instability disorder Fanconi's anemia and also with the inherited predisposition early-onset breast cancer. Here I will discuss the contribution of FANCJ to human disease, its role in maintenance of genome stability and some current thoughts on the mechanisms through which this is achieved.     

Acetylcholine as sensory transmitter in crustacea

Summary In an attempt to learn more about the so-called map component in pigeon navigation, nine series of tests comprising 34 test releases were performed at a release site, 89 miles NNE of Ithaca, New York, where Cornell pigeons regularly depart nonrandomly but with a large clockwise deviation from the true home direction. The tests included releases of: (1) experienced pigeons new to the site, under sun; (2) pigeons with previous experience at the site, under sun; (3) experienced pigeons new to the site, under total overcast; (4) pigeons with previous experience at the site, under total overcast; (5) first-flight youngsters, under sun; (6) directionally trained pigeons; (7) pigeons from two other Ithaca-area lofts; (8) pigeons from two more distant lofts; (9) Bank Swallows from an Ithaca colony; (10) clock-shifted pigeons; (11) radio- and airplane-tracked pigeons.The results of these tests indicate that the directional bias of the Cornell pigeons is, in general, not dependent on weather conditions or on the previous experience of the birds. Moreover, a similar bias is shown by both pigeons from other Ithacaarea lofts and Bank Swallows from Ithaca. And a similar bias from their respective home directions is shown by birds from other areas. Clock-shifted pigeons departing more directly toward home have poorer homing success than controls. It is concluded that some environmental factor basic to the avian homing process is rotated clockwise at this release site, that biologically the birds are not making an error but are probably reading correctly a distorted map.I thank Irene Brown and Timothy Larkin for their aid in all phases of this project; Donald Windsor for help in two releases; Charles Walcott and Martin Michener for aid in airplane tracking; J. Downhower for collaboration in the radio tracking and swallow releases; Andre Gobert, Howard French, A. E. Newton, and Ludwig Karl for permitting me to use their pigeons, George Yerdon, Forest Ranger, and Andy Misura, District Ranger, New York State Department of Environmental Conservation, for their cooperation in making the facilities of the Castor Hill Fire Tower available to us; Monica Howland for preparing the drawings; and Bertha Blaker for typing. Research supported in part by NSF Grants GB-13046X and GB-35199X, and in part by Federal Hatch funds.     

Muscle receptor organs in some decapod crustacea

The presence of muscle receptor organs was determined in the abdomen of ten species of decapod Crustacea. These were Pandalus danae, Paracrangon echinata, Crago franciscorum, Eualus sp. (tribe Caridea) belonging to the Natantia, and Munida quadrispina (tribe Galatheidea), Upogebia pugettensis, Callianassa gigas (tribe Thalassinidea), Paragus aleuticus, P. alaskensis, P. kennerlyi (tribe Paguridea) belonging to the Reptantia. Responses of the sensory neurons were obtained by flexion of the joints of isolated abdomens, and in some cases by stretching the organs themselves or by the use of acetylcholine. All species yielded slowly-adapting responses and some gave also fast-adapting responses. Anatomical examination was used to confirm the existence of the organs in a number of species. In one species of true crab, Cancer magister (tribe Brachygnatha), no evidence was obtained, either physiologically or anatomically, for the presence of muscle receptor organs. The known distribution of muscle receptor organs in higher Crustacea is tabulated and the possible widespread occurrence of such organs in the Crustacea as a whole is discussed.     

Haemolymph magnesium levels in some oceanic crustacea

• 1.1. Data are presented for the haemolymph magnesium levels of a number of amphipod and decapod species from oceanic mid-waters of the northern South Atlantic.
• 2.2. The values are compared with neritic brachyuran haemolymph magnesium levels.
• 3.3. No obvious correlation was apparent between the presumed general activity levels of the oceanic Crustacea and their haemolymph magnesium concentrations; non migrating forms had not dissimilar concentrations to those species known to undertake substantial daily vertical migration.

     

Solving satisfiability problems using a novel microarray-based DNA computer

An algorithm based on a modified sticker model accompanied with an advanced MEMS-based microarray technology is demonstrated to solve SAT problem, which has long served as a benchmark in DNA computing. Unlike conventional DNA computing algorithms needing an initial data pool to cover correct and incorrect answers and further executing a series of separation procedures to destroy the unwanted ones, we built solutions in parts to satisfy one clause in one step, and eventually solve the entire Boolean formula through steps. No time-consuming sample preparation procedures and delicate sample applying equipment were required for the computing process. Moreover, experimental results show the bound DNA sequences can sustain the chemical solutions during computing processes such that the proposed method shall be useful in dealing with large-scale problems.     

SNP-detecting DNA technologies: Solving problems of applied biochemistry

The heterozygosity of CANP3, ACTN3, and GHR genes in specialized collections was studied using state-of-the-art DNA technologies for DNA analysis. A new dinucleotide deletion (AC) at the beginning of exon 21 was identified in five individuals with a heterozygous CANP3 gene. Analysis of polymorphism (1747 C T) of the ACTN3 gene demonstrated a positive association of allele C with high muscular performance. Real-time PCR assay of SNP1630 (A C) in the GHR gene suggested a putative negative association of allele C of this SNP with high muscular performance.__________Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 3, 2005, pp. 303–307.Original Russian Text Copyright © 2005 by Krakhmaleva, Shishkin, Shakhovskaya, Stolyarova, Plugov, Knyazev, Khomenkov, Shevelev, Chernov.