A gut-specific chitinase gene was cloned from the mulberry longicorn beetle, Apriona germari. The A. germari chitinase (AgChi) gene spans 2894 bp and consists of five introns and six exons coding for 390 amino acid residues. AgChi possesses the chitinase family 18 active site signature and three N-glycosylation sites. Southern blot analysis of genomic DNA suggests that AgChi is a single copy gene. The AgChi cDNA was expressed as a 46-kDa polypeptide in baculovirus-infected insect Sf9 cells and the recombinant AgChi showed activity in a chitinase enzyme assay. Treatment of recombinant virus-infected Sf9 cells with tunicamycin, a specific inhibitor of N-linked glycosylation, revealed that AgChi is N-glycosylated, but the carbohydrate moieties are not essential for chitinolytic activity. Northern and Western blot analyses showed that AgChi was specifically expressed in the gut; AgChi was expressed in three gut regions, indicating that the gut is the prime site for AgChi synthesis in A. germari larvae.
A serine protease gene was cloned from the bumblebee, Bombus ignitus. The B. ignitus serine protease (BiSP) gene spans 1702 bp and consists of four introns and five exons coding for 250 amino acid residues. Southern blot analysis of genomic DNA suggested that BiSP gene is a single copy gene. The cDNA encoding BiSP was expressed as a 28-kDa polypeptide in baculovirus-infected insect cells and the recombinant BiSP showed activity in a protease enzyme assay. BiSP was specifically expressed in the midgut of B. ignitus queens, males, and workers, suggesting that the BiSP is a gut enzyme involved in the digestion of dietary proteins.
Two glutathione S-transferase (GST) cDNAs, GSTD2 and GSTS2, were cloned from the silkworm Bombyx mori. The B. mori GSTD2 (BmGSTD2) gene spans 4371 bp and consists of four introns and five exons that encode 222 amino acid residues. The deduced amino acid sequence of BmGSTD2 showed 58% protein sequence identity to the Delta-class GST of Maduca sexta. The B. mori GSTS2 (BmGSTS2) gene spans 3470 bp and consists of three introns and four exons that encode 206 amino acid residues. The deduced amino acid sequence of BmGSTS2 revealed 67%, 63%, and 61% protein sequence identities to the Sigma-class GSTs from B. mori, Platynota idaeusalis, and M. sexta, respectively. The BmGSTD2 and BmGSTS2 cDNAs were expressed as 25 kDa and 23 kDa polypeptides, respectively, in baculovirus-infected insect Sf9 cells. Northern blot and Western blot analyses showed that BmGSTD2 and BmGSTS2 were specifically expressed in three gut regions, indicating that the gut is the prime site for BmGSTD2 and BmGSTS2 synthesis in B. mori larvae.
Productivity of most improved major food crops showed stagnation in the past decades. As human population is projected to reach 9-10 billion by the end of the 21st century, agricultural productivity must be increased to ensure their demands. Photosynthetic capacity is the basic process underlying primary biological productivity in green plants and enhancing it might lead to increasing potential of the crop yields. Several approaches may improve the photosynthetic capacity, including integrated systems management, in order to close wide gaps between actual farmer’s and the optimum obtainable yield. Conventional and molecular genetic improvement to increase leaf net photosynthesis (P N) are viable approaches, which have been recently shown in few crops. Bioengineering the more efficient CC4 into C3 system is another ambitious approach that is currently being applied to the C3 rice crop. Two under-researched, yet old important crops native to the tropic Americas (i.e., the CC4 amaranths and the C3-CC4 intermediate cassava), have shown high potential P N, high productivity, high water use efficiency, and tolerance to heat and drought stresses. These physiological traits make them suitable for future agricultural systems, particularly in a globally warming climate. Work on crop canopy photosynthesis included that on flowering genes, which control formation and decline of the canopy photosynthetic activity, have contributed to the climate change research effort. The plant breeders need to select for higher P N to enhance the yield and crop tolerance to environmental stresses. The plant science instructors, and researchers, for various reasons, need to focus more on tropical species and to use the research, highlighted here, as an example of how to increase their yields., M. A. El-Sharkawy., and Obsahuje seznam literatury
In the present study changes of some blood parameters of wild female yellowfin seabream (Acanthopagrus latus) caught from Persian Gulf were assayed during reproductive cycle. Altogether, 120 female A. latus (15 each month) were captured monthly from October 2010 to May 2011 from the Mussa Creek in the north-west of Persian Gulf. Blood samples were collected from caudal vein; plasma was separated and kept at –80 °C till analysis. Total protein, glucose, cholesterol, triglyceride, electrolytes, calcium, sodium, chloride, magnesium, potassium plus hepatic enzymes, Alanine Amino Transferase (ALT) and Aspartate Amino Transferase (AST), were assayed in plasma sample. Total protein and calcium increased parallel to ovarian development and decreased after spawning time. Cholesterol and triglyceride had a peak during vitellogenesis and decreased after spawning but glucose had a peak during spawning time. Most of the electrolytes (sodium, magnesium and potassium) did not show any significant changes during the reproductive cycle in A. Latus. AST reached a peak during final
maturation of ovaries but ALT did not show any significant difference during differentsampling times.Our findings showed that biochemical parameters could be used as indicators of physiological status during differentmaturation stage in this species.