New crustacean resources in the trawl fishery off Mangalore coast

Since trawling operation started during the sixties, penaeid shrimps, crabs and stomatopods formed the major part of the crustacean fishery, in trawl catches off Mangalore coast with non-penaeids and lobsters to a minor extent

DNA-induced conformational changes in RecA protein. Evidence for structural heterogeneity among nucleoprotein filaments and implications for homologous pairing

We have used circular dichroism as a probe to characterize the solution conformational changes in RecA protein upon binding to DNA. This approach revealed that RecA protein acquires significant amounts of alpha-helix upon interaction with DNA. These observations, consistent with the data from crystal structure (Story, R. M., Weber, I., and Steitz, T. (1992) Nature 355, 318-325), support the notion that some basic domains including the DNA binding motifs of RecA protein are unstructured and might contribute to the formation of alpha-helix. A comparison of nucleoprotein filaments comprised of RecA protein and a variety of DNA substrates revealed important structural heterogeneity. The most significant difference was observed with poly(dG). poly(dC) and related polymers, rich in GC sequences, which induced minimal amounts of alpha-helix in RecA protein. The magnitude of induction of alpha-helix in RecA protein, which occurred concomitant with the production of ternary complexes, was 2-fold higher with homologous than heterologous duplex DNA. Most importantly, the stimulation of ATP hydrolysis by high salt coincided with that of the induction of alpha-helix in RecA protein. These conformational differences provide a basis for thinking about the biochemical and structural transitions that RecA protein experiences during the formal steps of presynapsis, recognition, and alignment of homologous sequences

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Allergic Mastocytic Gastroenteritis and Colitis: An Unexplained Etiology in Chronic Abdominal Pain and Gastrointestinal Dysmotility

Abdominal pain, bloating, early satiety, and changes in bowel habits are common presenting symptoms in individuals with functional GI disorders. Emerging data suggests that these symptoms may be associated with mast cell excess and/or mast cell instability in the GI tract. The aim of this retrospective study was to evaluate the contribution of mast cells to the aforementioned symptoms in individuals with a history of atopic disease. A retrospective chart review of individuals seen in a university GI practice was conducted and twenty-four subjects were identified. The majority had abdominal pain, early satiety, and nocturnal awakening. 66.7% and 37.5% had a history of environmental and/or food allergy. Solid gastric emptying was increased as were the mean number of mast cells reported on biopsies from the stomach, small bowel, and colon (>37/hpf) by CD117 staining. Mean whole blood histamine levels were uniformly elevated. This study suggests that in individuals with these characteristics, consideration should be given to staining their gastrointestinal biopsies for mast cells as this may provide them with relatively non-toxic but highly targeted treatment options. Allergic gastroenteritis and colitis may represent a third type of GI mast cell disorder along with mast cell activation syndrome and mastocytic enterocolitis

Biology and exploitation of the blue swimmer crab, Portunus pelagicus (Linnaeus, 1758), from south Karnataka coast, India

Portunus pelagicus supports indigenous as well as mechanised fishery of Karnataka coast. Trawlers accounted for 98% of the landing and the highest landing was observed during 2001-2002 (403 t). The peak fishing season for crabs was during December-June. Size range observed in the fishery was 56 to 165 mm in males and 61 to 170 mm in females. The homogeneity of sex ratio (2 test) obtained for the years 1998-2005 was 1:1. Peak spawning activity occurred during February-March. Size at maturity (50%) of females was estimated at 96 mm carapace width. Growth was isometric and males were heavier than females of similar size. By von Bertalanffy's growth plot, it was estimated that males and females reach 123 and 128 mm (CW) respectively at the end of one year and reach 156 and 160 mm respectively in two years. Longevity of P. pelagicus is estimated as 3 years in both sexes. The total mortality coefficient (Z), natural mortality coefficient (M) and fishing mortality coefficient (F) values estimated for the species were 6.3, 2.2 and 4.1 respectively. The exploitation ratio (E) was 0.65 and Lc was estimated at 87.7 mm. MSY was estimated as 367 t against the present annual average yield of 333 t. From 'Thompson and Bell yield prediction analysis it is seen that any additional 10% effort from the present level will yield only less than 10% additional catch, indicating that increasing the effort will not be economical. Restricting the catch to MSY level (367 t) is suggested as a suitable management option for the sustainability of P. pelagicus fishery from the coast

Fishery and stock assessment of Portunus sanguinolentus (Herbst) from south Karnataka coast, India

The study on the exploited fishery of Portunus sanguinolentus off south Karnataka coast during 1998- 2005, revealed that it contributed to 46% of the average annual crab landing with peak in May. The carapace width (CW) varied from 61 to170 mm in males and 56 to 160 mm in females. Percentage of females in advanced maturity stage was high during January-March. Size at maturity of females was 90 mm (CW). Carapace width-weight relationship indicated that males are heavier than females and the growth is positive isometric. The longevity of the species was estimated as 2 ½ years and males and females reach 137 mm (CW) at the end of the first year and 163 mm (CW) in two years. Females reached sexual maturity in 6 months. L∞ and K were estimated as 175 mm and 1.7 year-1 respectively. The estimated total mortality coefficient (Z) was 7.15 and fishing mortality coefficient (F) 4.18. The exploitation ratio (E) was 0.58. Size at capture (L50) was 79.2 mm. Estimated total stock was 852 t standing stock was 118 t and the MSY was 544 t. An increase in fishing effort by 10 to 20 % may enhance the catch only by 3 to 4%. It is suggested that for sustaining the fishery, the fishing effort (in hours) may be reduced by 30 to 40% from the present level of exploitation

Report on the fishery of Indian Ocean Lobsterette, (Nephropsis stewarti) along Mangalore

Ever since deep-sea trawling started, Indian Ocean Lobsterette (Nephropsis stewnrti) were landed regularly at Mangalore Fisheries Harbour. They were caught from a depth of 250- 500 m. The meat of this lobster is considered as a delicacy and is procured by processing plants for export. Since the meat content is less, the price of the lobster is Rs. 20-25 Kg

Crystallographic identification of an ordered C-terminal domain and a second nucleotide-binding site in RecA: new insights into allostery

RecA protein is a crucial and central component of the homologous recombination and DNA repair machinery. Despite numerous studies on the protein, several issues concerning its action, including the allosteric regulation mechanism have remained unclear. Here we report, for the first time, a crystal structure of a complex of Mycobacterium smegmatis RecA (MsRecA) with dATP, which exhibits a fully ordered C-terminal domain, with a second dATP molecule bound to it. ATP binding is an essential step for all activities of RecA, since it triggers the formation of active nucleoprotein filaments. In the crystal filament, dATP at the first site communicates with a dATP of the second site of an adjacent subunit, through conserved residues, suggesting a new route for allosteric regulation. In addition, subtle but definite changes observed in the orientation of the nucleotide at the first site and in the positions of the segment preceding loop L2 as well as in the segment 102–105 situated between the 2 nt, all appear to be concerted and suggestive of a biological role for the second bound nucleotide

Mapping of fishery resources in trawling grounds along the Malabar-Konkan coast

Two categories of bottom trawl units are in operation along the Malabar-Konkan coast. The first category comprises of small boats (<9.75 m OAL) conducting daily trips operating trawl nets with codend mesh size of 10-20 mm and catch generally prawns, flatfishes and other finfishes