Blood glucose in marine penaeid prawns: I. Neuroendocrine regulation in Parapenaeopsis hardwickii (Miers). (Crustacea,Decapoda, Penaeidae)

In the present investigation on femaleP. hardwickii, the blood glucose level in bilateral eyestalk extirpated, reinjected with ES extract as well as normal prawns, administered with ES, different concentrations of BR and ThG extracts, was estimated quantitatively after fifteen minutes and two hours. During all treatments there was an immediate hike in blood glucose level after fifteen minutes but after 24 hr. of eyestalk ablation the level does not differ significantly (P > 0.05) from controls. There was a significant (P < 0.01) enhancement in blood glucose level in the cauterized eyestalkless and normal prawns injected with ES extract after 2 hr. There was a considerable (93% level of confidence) decrease in blood glucose level of normal prawns after injecting higher concentrations of BR and ThG extracts. There was an obvious change in blood glucose level due to the endocrine hormones injected from other prawns of the related family. ES extracts ofP. stylifera produced a significant (P < 0.01) increase, whereas higher concentration of BR and ThG extracts caused considerable (92% level of confidence) decrease in blood glucose level after injecting in cauterized eyestalkless prawns. The extracts of the same endocrine centres fromMetapenaeus monocerus did not induce any significant (P > 0.05) alteration in blood glucose quantity ofP. hardwickii. Hence from the above findings it may be inferred that, the hormones produced by eyestalks (X organ-Sinus gland Complex) posses a hyperglycemic factor, whereas hormones released from BR and ThG might be having a property to cause hypoglycemia (?).     

Molecular and immunological characterization of Mycobacterium avium 65 kDa heat shock protein (Hsp65)

The heat shock protein Hsp65 has been characterized previously in several mycobacterial species. This is the first report of the complete sequence of the coding region of the Mycobacterium avium homologue. The sequence was highly homologous to the Hsp65 of other mycobacterial species, as well as being related closely to the murine and human homologues. Recombinant Hsp65 (rHsp65) was expressed in Escherichia coli to high levels and the recombinant protein tested for its immunogenicity in a murine model of M. avium infection. Although mice infected with M. avium produced antibodies that reacted with rHsp65, they showed low proliferative T-cell responses and no cytokine production in response to the same antigen. However, immunization with rHsp65 in the adjuvant dimethydioctadecylammonium bromide (DDA), induced T cells that responded to native Hsp65 with proliferation and IFN-gamma production, indicating that the recombinant and native forms of the protein were antigenically similar. Therefore, the findings indicate that Hsp65 is not a dominant T-cell antigen during M. avium infection.     

Evaluation of genetic and phenotypic consistency of <Emphasis Type="Italic">Bacillus coagulans</Emphasis> MTCC 5856: a commercial probiotic strain

Commercial probiotics preparation containing Bacillus coagulans have been sold in the market for several decades. Due to its high intra-species genomic diversity, it is very likely that B. coagulans strain may alter in different ways over multiple years of production. Therefore, the present study focuses to evaluate the genetic consistency and probiotic potential of B. coagulans MTCC 5856. Phenotypic and genotypic techniques including biochemical profiling, 16S rRNA sequencing, GTG 5″, BOX PCR fingerprinting, and Multi-Locus-Sequence typing (MLST) were carried out to evaluate the identity and consistency of the B. coagulans MTCC 5856. Further, in vitro probiotic potential, safety and stability at ambient temperature conditions of B. coagulans MTCC 5856 were evaluated. All the samples were identified as B. coagulans by biochemical profiling and 16S rRNA sequencing. GTG 5″, BOX PCR fingerprints and MLST studies revealed that the same strain was present over 3 years of commercial production. B. coagulans MTCC 5856 showed resistance to gastric acid, bile salt and exhibited antimicrobial activity in in-vitro studies. Additionally, B. coagulans MTCC 5856 was found to be non-mutagenic, non-cytotoxic, negative for enterotoxin genes and stable at ambient temperature (25 ± 2 °C) for 36 months. The data of the study verified that the same strain of B. coagulans MTCC 5856 was present in commercial preparation over multiple years of production.     

Hormonal control of egg-laying in the marine pulmonate,Onchidium verruculatum

Extirpation of the pleurovisceral ganglia (PV) blocked egg-laying whereas reimplantation of PV or injection of a PV homogenate into PV-less animals restored the egg-laying capacity of the marine pulomonate, O. verruculatum. Injection of PV homogenate induced egg-laying in intact, mature individuals within 15–45 minutes. Boiling of the homogenate for 15 minutes did not abolish its egg-laying efficacy. However, after incubation with trypsin, a PV homogenate lost its potency. Homogenates of PV from colchicinized animals could not induce egg-laying in intact Onchidium. Similarly, colchicinized animals did not respond to a PV ectract from intact Onchidium. It is hypothesized that egg-laying in O. verruculatum is under the control of a heat-stable, trypsin sensitive hormone secreted by the PV ganglia.     

Role of eyestalk hormone in the carbohydrate metabolism of a marine penaeid prawn,Parapenaeopsis hardwickii (MIERS) (Crustacea,Decapoda, Penaeidae)

Data furnished here concern with the role of eyestalk hormone in the regulation of carbohydrate metabolism in Parapenaeopsis hardwickii. Bilateral eyestalk ablation has brought about a significant (P < 0.01) fall and rise in the glycogen content in the midgut gland and abdominal muscle respectively. Although eyestalk ablation resulted in a significant (P < 0.01) depletion of fat in midgut gland, n0 significant (P > 0.05) change was observed in the abdominal muscle. Eyestalk extract administration in eyestalk-less prawns has significantly (P < 0.05) restored the glycogen and fat metabolites in the midgut gland. There was an obvious change in the glycogen content of the midgut gland and abdominal muscle of normal prawns when injected with eyestalk extracts from prawns in different molting stages. Eyestalk extract from intermolt prawns caused a significant (P < 0.05) decrease and increase in the glycogen quantity in the midgut gland and abdominal muscle respectively. Eyestalk extract from premolt and postmolt prawns has, although not significantly (P > 0.05), decreased and increased the utilization of glycogen respectively in the midgut gland. The physiological significance of these findings are discussed briefly.Paper forms part IV of the series

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Effect of thermal stress on the neurosecretory cells of the freshwater prawn,macrobrachium kistnensis (Tiwari)

The brain and thoracic ganglion neurosecretory cells of the freshwater prawn, M. kistnensis displayed characteristic changes following 24 hr exposure to warm (31.0° ± 0.5°C) and cold (13.0° ±0.5°C) stress. A and B cells from the brain showed significant elevation in their nuclear diameters after warm and cold stress. Warm stress depressed whereas cold stress enhanced the neurosecretory material intensity of A cells. However, the intensity of B cells neurosecretory material remained unaltered following both treatments. On the contrary nuclear diameters of both A and B neurosecretory cell significantly decreased and an increment in neurosecretory material intensity was revealed in the thoracic ganglion of both warm and cold stressed prawns.     

Effects of some extrinsic factors on the respiratory metabolism of the freshwater leech,poecilobdella viridis (blanchard): desiccation and temperature

The influence of desiccation and temperature on the respiratory metabolism of P. viridis have been investigated. There was a significant (p < 0.05) downfall in the respiratory rates as the period of desiccation increased, but for after 18 hours where it was enhanced significantly. The respiration augmented significantly (p < 0.03) when the temperature of the medium increased. Q₁₀ was significantly high at 32–28°C and was low between 35 and 32°C and 20–10°C Functional significance of these changes to the leeches in combating environmental hazards is briefly discussed.     

Seasonal variations in biochemical constituents of the clam,Paphia laterisulca

1. The total protein, fat and glycogen contents were estimated from the edible clam, P. laterisulca. Seasonal variations in these constituents along with the water content were studied.
2. The gonad index in P. laterisulca was found to increase during the ripe condition and in winter (December–January) and decrease on spawning.
3. A relatively high water content was obtained during monsoon (June to September). This might be due to the loss of salts and gain of water in low salinities.
4. Protein content varied with the reproductive cycle of the clam. The level reached its peak in the mature stage and declined on spawning. Immature clams showed less protein content than gravid ones.
5. Lipid content started to increase as the gametogenesis commenced, reached its peak in fully mature condition (August) and sharply declined due to the shedding of gametes during spawning.
6. Glycogen content was high during the period of active gameto-genesis (May–June). A sharp decrease took place when the clams were fully ripe (July). The glycogen might have been utilized in the formation of active ripe gametes.
7. After starvation for twelve days, total protein and fat contents remained constant, while glycogen content decreased by 66.82%. The water content increased by 4.67%.
8. Seasonal variation in the organic constituents are discussed in relation to the reproductive cycle of the clam.