Monopterus Albus Zuiew Research Articles

THE STUDY OF RICE EEL FARMING (MONOPTERUS ALBUS) IN THE RECIRCULATION SYSTEM

The study of rice eel farming (Monopterus albus Zuiew, 1793) in the recirculation system is to find out a suitable model for rice eel growth and contribute to responding to climate change. The average length and weight of the rice eels were 22.28 ± 0.21 cm/inds and 14.65 ± 0.48 g/inds, respectively. The experiment was conducted with two treatments: the control treatment and the recirculation treatment; each of them was repeated 3 times in 180 days. Rice eel was fed with 80% fresh trash fish and 20% pelleted pellets with 30% protein. The results showed that the environmental factors such as temperature, pH, N-NH3-, N-NO2- and alkalinity were in suitable range for rice eel growth during the experiment. The survival rate was not different between the two treatments. Weight growth rate in the recirculation system (97.70 ± 9.04 g/inds) was higher than the control (80.67 ± 0.16 g/inds) (p<0,05). Feed conversion ratio (FCR) in two treatments was not different with 2.49 ± 0.05% and 2.41 ± 0.22%. The amount of water was added in recirculation system (3.12 m3/tank) during 180 days only 1/10 compared with thecontrol (32.8 m3/tank). These results showed that the recirculation system was perfectly suited for the growth and development of rice eel.

Karyological characterization and identification of four repetitive element groups (the 18S - 28S rRNA gene, telomeric sequences, microsatellite repeat motifs, Rex retroelements) of the Asian swamp eel (Monopterus albus).

Among teleost fishes, Asian swamp eel (Monopterus albus Zuiew, 1793) possesses the lowest chromosome number, 2n = 24. To characterize the chromosome constitution and investigate the genome organization of repetitive sequences in M. albus, karyotyping and chromosome mapping were performed with the 18S – 28S rRNA gene, telomeric repeats, microsatellite repeat motifs, and Rex retroelements. The 18S – 28S rRNA genes were observed to the pericentromeric region of chromosome 4 at the same position with large propidium iodide and C-positive bands, suggesting that the molecular structure of the pericentromeric regions of chromosome 4 has evolved in a concerted manner with amplification of the 18S – 28S rRNA genes. (TTAGGG)n sequences were found at the telomeric ends of all chromosomes. Eight of 19 microsatellite repeat motifs were dispersedly mapped on different chromosomes suggesting the independent amplification of microsatellite repeat motifs in M. albus. Monopterus albus Rex1 (MALRex1) was observed at interstitial sites of all chromosomes and in the pericentromeric regions of most chromosomes whereas MALRex3 was scattered and localized to all chromosomes and MALRex6 to several chromosomes. This suggests that these retroelements were independently amplified or lost in M. albus. Among MALRexs (MALRex1, MALRex3, and MALRex6), MALRex6 showed higher interspecific sequence divergences from other teleost species in comparison. This suggests that the divergence of Rex6 sequences of M. albus might have occurred a relatively long time ago.

Lasers fractionnés : la maîtrise des paramètres

The aspartic protease pepsin is less specific than other endoproteinases. Because aspartic proteases like pepsin are active at low pH, they are utilized in hydrogen deuterium exchange mass spectrometry (HDX MS) experiments for digestion under hydrogen exchange quench conditions. We investigated the reproducibility, both qualitatively and quantitatively, of online and offline pepsin digestion to understand the compliment of reproducible pepsin fragments that can be expected during a typical pepsin digestion. The collection of reproducible peptides was identified from > 30 replicate digestions of the same protein and it was found that the number of reproducible peptides produced during pepsin digestion becomes constant above 5–6 replicate digestions. We also investigated a new aspartic protease from the stomach of the rice field eel (Monopterus albus Zuiew) and compared digestion efficiency and specificity to porcine pepsin and aspergillopepsin. Unique cleavage specificity was found for rice field eel pepsin at arginine, asparagine, and glycine. Different peptides produced by the various proteases can enhance protein sequence coverage and improve the spatial resolution of HDX MS data. This article is part of a Special Issue entitled: Mass spectrometry in structural biology.

Accessing the reproducibility and specificity of pepsin and other aspartic proteases

The aspartic protease pepsin is less specific than other endoproteinases. Because aspartic proteases like pepsin are active at low pH, they are utilized in hydrogen deuterium exchange mass spectrometry (HDX MS) experiments for digestion under hydrogen exchange quench conditions. We investigated the reproducibility, both qualitatively and quantitatively, of online and offline pepsin digestion to understand the compliment of reproducible pepsin fragments that can be expected during a typical pepsin digestion. The collection of reproducible peptides was identified from >30 replicate digestions of the same protein and it was found that the number of reproducible peptides produced during pepsin digestion becomes constant above 5–6 replicate digestions. We also investigated a new aspartic protease from the stomach of the rice field eel (Monopterus albus Zuiew) and compared digestion efficiency and specificity to porcine pepsin and aspergillopepsin. Unique cleavage specificity was found for rice field eel pepsin at arginine, asparagine, and glycine. Different peptides produced by the various proteases can enhance protein sequence coverage and improve the spatial resolution of HDX MS data. This article is part of a Special Issue entitled: Mass spectrometry in structural biology.

Induksi Pematangan Gonad dengan Ovaprim-C: untuk Penyediaan Benih Belut Sawah (Monopterus albus) Berkelanjutan

Rice eel ( Monopterus albus Zuiew), have economical value is high in Banyumas, national to international markets, but rarely is grown intensively, the seed is still dependent on the catch. Reproduction of swamp eel unlike other fish species in the presence of phase teleostei intersex / hermafroditus and in nature only spawn once a year. This study will seek to accelerate the scale seed production with natural canvas with several techniques triggers lust and sex organ maturation eels based preparedness aspects of reproductive anatomy, hormones estradiol and testosterone profiles and the intrinsic need for hormonal regulation and the mechanism for the reproductive cycle of the eel rice. In the first year aims to determine (1) the profile of estradiol and testosterone hormonal parent during the natural reproductive cycle, (2) histologic gonadogenesis (development of the testes and ovaries) eel rice during the natural reproductive cycle was evaluated by measuring fecundity. Results: In the control group, body weight gradually decreased during the study. Unlike the control group, the treatment groups were observed every two weeks showed an increase in body weight; Results of the study, in the control group (A 0 ), the value of female eels GSI average of the first two weeks until the fourth two weeks is 0.67 % and 1.78%. While the treatment group A1 was 1.42% - 4.28% (DM-1 s / d DM-4), for the treatment A2 GSI average value is 2.52% - 7.05%; fecundity eggs increased during induction period; calibration titer two types of hormones in the first two weeks to the fourth two weeks showed improvement when compared with the control group; histological profile of rice eel gonad after induction of ovaprim-C show that up to the fourth two weeks, gonad has reached late-stage yolk globule (advanced primary oocyte), even the most mature oocyte has reached the stage: in male eels up to the fourth two weeks has reached the stage of spermatozoa

Purification and characterization of pepsinogens and pepsins from the stomach of rice field eel (Monopterus albus Zuiew)

Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish rice field eel (Monopterus albus Zuiew) by ammonium sulfate fractionation and chromatographies on DEAE-Sephacel, Sephacryl S-200 HR. The molecular masses of the three purified PGs were all estimated as 36 kDa using SDS-PAGE. Two-dimensional gel electrophoresis (2D-PAGE) showed that pI values of the three PGs were 5.1, 4.8, and 4.6, respectively. All the PGs converted into corresponding pepsins quickly at pH 2.0, and their activities could be specifically inhibited by aspartic proteinase inhibitor pepstatin A. Optimum pH and temperature of the enzymes for hydrolyzing hemoglobin were 3.0-3.5 and 40-45 °C. The K (m) values of them were 1.2 × 10⁻⁴ M, 8.7 × 10⁻⁵ M, and 6.9 × 10⁻⁵ M, respectively. The turnover numbers (k(cat)) of them were 23.2, 24.0, and 42.6 s⁻¹. Purified pepsins were effective in the degradation of fish muscular proteins, suggesting their digestive functions physiologically.

Melatonin is Involved in Sex Change of the Ricefield Eel, Monopterus albus Zuiew

The ricefield eel (Monopterus albus Zuiew), a burrowing eel-like synbranchoid teleost, undergoes a natural sex change from female to male during its life history. Since the teleost pineal gland and its melatoninergic output have been suggested as regulators in seasonal reproduction and sexual maturation in many fish species, it is reasonable to postulate that melatonin may play important roles in the ricefield eel’s sex-change process. This hypothesis was tested by examining secretional characteristics and reproductive effects of melatonin in the ricefield eel. Results indicate that serum melatonin (mainly secreted from the pineal complex, retinae and gastrointestinal tract) is involved in sex change of this species. It seems that, within a reproductive cycle, relatively lower mid-night serum melatonin (MNSM) levels are necessary for natural spawning, but relatively higher MNSM levels after spawning permit initiation of the sex-change process. A putative model is presented to clarify the involvement of melatonin in natural sex change of the ricefield eel, although the precise mechanisms are still under further investigation.

Ag-staining pattern, FISH and ISH with rDNA probes in the rice field eel (Monopterus albus Zuiew) chromosomes.

The present paper reports the Results of rice field eel (Monopterus albus Zuiew) chromosomal analysis by Ag-staining techniques, FISH and ISH with 18S rDNA. Both the Ag-NORs and the hybridization signals were observed on the pericentromeric region of chromosome pairs 3 and 7. The Ag-NORs and the hybridization signals on homologous chromosomes 3 and 7 were corresponding to each other. And rDNA genes were mapped to bivalents 3q12-q24 and 7q14-q26. No heteromorphic sex chromosome pair was identified. The Results obtained were discussed with respect to the feature of Ag-NORs and the position of rDNA genes on chromosome pairs 3 and 7.

Sex Chromosomal Homologies between Human and Fish Karyotypes Revealed by Chromosome Painting

Human sex chromosome-specific probes were hybridized to metaphase spreads of three fish species, Monopterus albus Zuiew, Danio rerioandMastacembelus aculeatusBasilewsky, to reveal evolutionary conservation of sex chromosomal segments between distantly related species of vertebrates. The human X chromosomal paint disclosed 4, 8, and 6 conserved syntenic segments in the karyotypes of the three fish species respectively, which were scattered in several pairs of homologous chromosomes. But no conserved segment was identified in our experiments when the human Y chromosomal probes were used. The evolution of the X chromosome of vertebrates is discussed.

Development of specific chromosomal DNA pool for rice field eel and their application to gene mapping

The chromosomes 1, 3, 5, 6, 7, 10 and 12 of rice field eel (Monopterus albus Zuiew) have been microdissected successfully from meiosis I diakinesis spreads by using glass microneedle under an inverted microscope. And the DOP-PCR products of the single chromosome dotted on the nylon membrane as “specific chromosomal DNA pool”, have been hybridized with 6 probes to map these genes. The mapping results show that Zfa has been mapped to chromosome 1, rDNA to chromosomes 3 and 7, both Gh and Pdegy to chromosome 10, Hsl to chromosome 5 and Hox genes have been detected on chromosomes 1, 3, 6 and 10 meantime. It has initiatively been suggested that chromosome 10 of rice field eel might possess the commom conserved synteny to that on chromosome 17 of human, chromosome 11 of mouse, chromosome 12 of pig and chromosome 19 of bovine. And so chromosome 3 of rice field eel might also contain the commom conserved synteny to that on chromosome 2 of zebrafish. Our study is an attempt to establish a new and feasible method to advance the study of gene mapping and chromosome evolution in fish, and also to provide a new idea to distinguish each chromosome on the base of molecular markers for fish.

“The lampbrush-like chromosome” on pachytene bivalents of rice-field eels (Monopterus albus Zuiew)

IN our previous studies, we have used in situ nick translation techniques for analysis of DNaseⅠ sensitivity and restriction enzymes in situ cleavage on pachytene bivalents of rice-field eels ( Monopterus albus Zuiew). A characteristic construction of bivalents——"the lampbrush-likechromosome", which has not been reported yet, was detected in some pachytene bivalents...