Opercular Activity and Temporal Organization of Surfacing Behaviour in Indian Catfishes,Clarias batrachus and Heteropneustes fossilis

Opercular and surfacing activity were observed in the Indian catfish Clarias batrachus and Heteropneustes fossilis. In the series A experiments, the opercular activity was monitored under two experimental conditions, viz., (1) surfacing allowed and (2) surfacing prevented. A statistically significant elevation of the rate of opercular activity was observed when air breathing was prevented in both species. In addition, a significant prevention effect and a time of day dependence of that were noticed in both species. In the series B experiments, temporal patterns of surfacing and air-gulping activities were examined under an artificial LD 12:12 schedule at 2-h intervals over a period of 48 h. The inter air-gulping interval in minutes between two consecutive bouts was also recorded four times each day in both species. A significant 24-h rhythm was found for the rate of surfacing activity and length of the inter air-gulping interval in both species. However, the overall activity appears to be much higher in Heteropneustes fossilis as compared to Clarias batrachus.     

Significance of the gonoduct in the classification of echiurans (Phylum Echiura)

The gonoducts of 21 species have been studies. The reliability of the gonoduct as a taxonomic tool has been assessed at different levels of the hierarchy, employing the variations in respect of the number of genital pores, and the modifications in the body of the females for lodging the males in the case of sexually dimorphic echiurans. Special reference has been made to sexually dimorphic echiurans and their position in the taxonomy of the phylum.     

Genetic markers and malaria. Observations in Gujarat, India

189 healthy controls and 175 patients suffering from malaria vivax have been investigated with regard to associations between this disease and 22 genetic polymorphisms of the blood (ABO, MN, Ss, Rh, Kell, P, Lutheran, Kidd, Duffy, Diego, Xg; ABH-Secretor; Hp, Gc, Gm, Km; aP, AK, PGM1, 6-PGD, EsD; Hb variants) Significant associations could be demonstrated only for P and Hp systems, though in accordance with other investigations it cannot be excluded that the ABO system plays also a role in this connection.     

Sequence Analysis of a Plastidial Omega-3 Desaturase Gene from Brassica juncea

A genomic clone (λg₂) encoding a plastidial omega-3 desaturase has been isolated from a genomic library of Brassica juncea cv Pusa Bold and sequenced after subcloning. A continuous stretch of 3866 by of the clone sequenced showed homology with omega-3 desaturase from other plant sources but maximum homology was with that of a plastidial omega-3 fad 7 gene. This sequence designated as Bjgfad7 includes 1381 by 5’ untranslated region, 273 by 3’ untranslated region along with an open reading frame of 1290 by interrupted by 7 introns. The 5’ untranslated region contains putative cis elements responsible for seed specificity, light responsive and stress-inducible expression besides minimal promoter elements.