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Larval Tissues (larval + tissue)
Selected AbstractsMethane-derived carbon flows through methane-oxidizing bacteria to higher trophic levels in aquatic systemsENVIRONMENTAL MICROBIOLOGY, Issue 5 2007Peter Deines Summary Recent investigations have shown that biogenic methane can be a carbon source for macro invertebrates in freshwater food webs. Stable carbon isotopic signatures, used to infer an organism's food source, indicated that methane can play a major role in the nutrition of chironomid larvae. However, the pathway of methane-derived carbon into invertebrate biomass is still not confirmed. It has been proposed that chironomid larvae ingest methane-oxidizing bacteria (MOB), but this has not been experimentally demonstrated to date. Using 13C-labelled methane we could show for the first time that chironomid larvae assimilate methane-derived carbon through MOB. Chironomid larval biomass was significantly 13C-enriched after dwelling for 10 days in lake sediment enriched with labelled methane. Moreover, phospholipid fatty acids diagnostic for MOB were detected in larval tissue and were significantly 13C-enriched, which encompasses the 13C-uptake predicted for a methane-based nutrition. Additionally, chironomid larvae fed on sediment and water-column derived MOB biomass. [source] Use of Cyclop-eeze as a substitute for Artemia nauplii in larval rearing of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879)AQUACULTURE NUTRITION, Issue 2 2007C. MOHANAKUMARAN NAIR Abstract Four feeding experiments, replacing 25% (T1), 50% (T2), 75% (T3) and 100% (T4), by dry weight, of the live feed Artemia nauplii for Cyclop-eeze, a new larval feed that was claimed to contain the highest known levels of astaxanthin and omega-3 polyunsaturated fatty acids, were compared against a control that was fed with Artemia and egg custard alone, to the larvae of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879). Analysis of different production characteristics of the larvae revealed that the highest survival up to postlarvae (PL) stage was obtained for T2 in which 50% of the Artemia nauplii were replaced by Cyclop-eeze [freeze-dried (FD) deep frozen (DF)], and the highest astaxanthin content of the larval tissue obtained in T4 in which the larvae were fed 100% Cyclop-eeze, although the survival rate was the lowest in this treatment. The costs of different treatments were also compared. The Artemia consumption million,1 larvae was the highest in control (11490 g), followed by T1 (8240 g), T2 (4990 g), T3 (3730 g) and T4, which completely replaced Artemia from stage 5 onwards (1830 g). The highest consumption of Cyclop-eeze million,1 larvae was in T4 (1670 and 10 880 g), followed by T3 (850 and 5560 g), T2 (410 and 2690 g) and T1 (230 and 1490 g) of FD and DF, respectively. The astaxanthin contents of the late-stage larvae fed under the four treatments were 24.90, 27.40, 28.60 and 35.60 ,g g,1 tissue for T1, T2, T3 and T4, respectively, while that of the control was 23.70 ,g g,1. The lowest cost of live feeds million,1 PL was obtained for T2 (US$ 428.60), followed by T1 (US$ 490.46), control (US$ 529.07) and T3 (US$ 583.26), while it was the highest for T4 (US$ 890.93). The results indicated that Cyclop-eeze could economically replace Artemia nauplii at 50% level that could significantly improve the survival and carotenoid composition of the larvae of M. rosenbergii. [source] CELLULAR LOCALIZATION AND EXPRESSION OF pygo DURING DROSOPHILA DEVELOPMENTINSECT SCIENCE, Issue 2 2003LIN Xin-da Abstract Wg/Wnt signaling is a key signaling pathway in Drosophila. Many genes involved in Wingless(wg) signal transduction pathway downstream of Wg, or it s vertebrate Wg homologue Wnt, have been identified. Transduction of the Wg signal downstream of Wg is mediated by nuclear TCF/LEF-1, through association with Armadillo (Arm),-catenin. Pygopus (pygo) is a new identified component in this pathway. Cellular localization experiment showed that pygo was expressed specifically in the nucleus. The expression profile of pygo in embryos was examined using in situ hybridization. Although pygo expressed ubiquitously in the embryos, it expressed at relatively high level in pre-blastoderm embryos which indicate a high degree of maternally provided message, followed by a low level of ubiquitous zygotic expression. This continues into larval tissues (including wing disc, eye disc and leg disc), where pygo appears to be expressed at low level. Comparison of pygo expression levels, in the wing disc, eye disc and leg disc, showed pygo expression level in the wing disc pouch and leg disc were relative higher. [source] Hormonal and nutritional regulation of insect fat body development and functionARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2009Ying Liu Abstract The insect fat body is an organ analogue to vertebrate adipose tissue and liver and functions as a major organ for nutrient storage and energy metabolism. Similar to other larval organs, fat body undergoes a developmental "remodeling" process during the period of insect metamorphosis, with the massive destruction of obsolete larval tissues by programmed cell death and the simultaneous growth and differentiation of adult tissues from small clusters of progenitor cells. Genetic ablation of Drosophila fat body cells during larval-pupal transition results in lethality at the late pupal stage and changes sizes of other larval organs indicating that fat body is the center for pupal development and adult formation. Fat body development and function are largely regulated by several hormonal (i.e. insulin and ecdysteroids) and nutritional signals, including oncogenes and tumor suppressors in these pathways. Combining silkworm physiology with fruitfly genetics might provide a valuable system to understand the mystery of hormonal regulation of insect fat body development and function. © 2009 Wiley Periodicals, Inc. [source] Comparative analysis of two biliproteins, BP1 and BP2, from haemolymph of cabbage white butterfly, Pieris rapaeARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2006Chi Won Choi Abstract Two blue-pigment binding proteins, BP1 and BP2, are present in larval and pupal haemolymph of cabbage white butterfly, Pieris rapae, and fluctuate in expression during development. Both BP1 and BP2 are found in pupal haemolymph in varying proportions as well as in adult haemolymph, while only small amounts of BP2 are found in larval haemolymph. BPs are separated by 75% ammonium sulfate, and then purified effectively by ion exchange column chromatography and preparative gel electrophoresis. It was shown that BP1 and BP2 have molecular masses of 20,244 and 19,878 Da, and isoelectric points of 7.0 and 6.8, respectively. Considering their amino acid compositions and N-terminal amino acid sequences, the two proteins are almost identical except the first N-terminal amino acid. The first amino acid of BP1 is asparagine, whereas the initial residue of BP2 is aspartic acid. Anti-BP1 cross-reacts with BP2, indicating that they have immunological homogeneity. Western blotting analyses revealed that only BP1 was present in the larval tissues such as fat body, integument, muscle, and hindgut. However, BP1 was not found in midgut, Malphigian tubules, and silk gland. BP1 was also present in the protein bodies, and both cuticle and hemocoel sides of larval epidermis cells by the transmission electron microscopic observation. The information in this report will facilitate studies on the molecular biology and biological significance of insect BPs. Arch. Insect Biochem. Physiol. 61:220,230, 2006. © 2006 Wiley-Liss, Inc. [source] | ||||||||||