UDP-Gal: <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine β 1–4 galactosyltransferase expressing live attenuated parasites as vaccine for visceral leishmaniasis

As compared to cutaneous leishmaniasis, vaccination against visceral leishmaniasis (VL) has received limited attention. In this study, we demonstrate for the first time that an UDP-Galactose: N-acetylglucosamine β 1–4 galactosyltransferase (GenBank Accession No. EF159943) expressing attenuated LD clonal population (A-LD) is able to confer protection against the experimental challenge with the virulent LD AG83 parasite. A-LD was also effective in established leishmania infection. The vaccinated animals showed both cell mediated (in vitro T-cell proliferation, and DTH response) and humoral responses (Th1 type). These results demonstrate the potential of the attenuated clones as an immunotherapeutic and immunoprophylactic agent against visceral leishmaniasis.     

Induction of flowering by cytokinins in a short-day plant, Lemna paucicostata

Lemna paucicostata, normally a short-day plant, can be inducedto flower under long-day conditions by providing a cytokininin a medium containing a high level of ferric citrate (5 x 10^–4M).Interestingly, when a cytokinin and EDDHA are present togetherin the medium, flowering is induced even at low levels of iron(10^–5 and 5 x 10^–5M ferric citrate). However, inthe absence of a cytokinin, flowering takes place only undershort days. (Received September 30, 1968; )     

Apomixis and Polyembryony in the Guggul Plant, Commiphora wightii

The present report is a part of our study on the reproductivebiology of a traditional Indian medicinal plant,Commiphora wightii,a source of guggul steroids. Field examination showed a predominantlylarge number of isolated and groups of female individuals. Onlyone andromonoecious and two exclusively male plants were recorded.Female plants set seed irrespective of the presence or absenceof pollen. Hand-pollination experiments and embryological studieshave confirmed the occurrence of non-pseudogamous apomixis,nucellar polyembryony and autonomous endosperm formation forthe first time in this plant, which is presently threatenedby over-exploitation. Commiphora wightii ; autonomous endosperm; guggul; medicinal plant; non-pseudogamous apomixis; nucellar polyembryony     

Fungal fruiting bodies from Lower Tertiary sediments of Sirmaur district, Himachal Pradesh, India

Fungal fruiting bodies ignored in earlier palynological investigations of the Subathu and Dagshai Formations have been studied from sediments exposed in the Dadahu Jamtah area, Sirmaur district, Himachal Pradesh. Taxa belonging to the genera Notothyrites, Asterothyrites, Parmathyrites, Phragmothyriles and Microthyriacites have been identified. These fossils are comparable with taxa reported from many Early Tertiary assemblages from different parts of the country and indicate a warm and humid climate.     

Morphology and Physiology of Lyngbya nigra with Reference to Copper Toxicity

The effect of copper sulphate on morphology and physiology of Lyngbya nigra has been studied. The growth was inhibited in all treatments (0.4 to 80.0 μM) of copper sulphate. There were no apparent morphological changes up to 0.8 μM and during the first two days of treatment even in the higher concentrations of copper sulphate. In concentrations above 0.8 μM the first symptom of toxicity was the formation of separation discs in large numbers. The trichomes contracted longitudinally and the cells became swollen and constricted at the cross walls. The cells also became yellowish due to loss of photosynthetic pigments. Finally, in 4 μM and above, vacuoles appeared in large number indicating the moribund state of the cells. Copper sulphate increased respiration at 2 μM, and optimum effect was observed in 8 μM after 96 h. Inhibition of photosynthesis was detectable in 0.8 μM, and 100% inhibition took place in 8 μM after 96 h. In higher concentrations the effect was immediate, and a conspicuous inhibition of photosynthesis could be observed within 10 min. The copper content of the alga increased with increased concentration of copper sulphate while potassium content decreased. With rise in outside concentrations of copper, there was a comparatively great increase of absorption in 2 and 4 μM, while further increases were gradually less. The observations indicate that changes in the physiological activity of the alga under treatment are closely interlinked with marked changes in morphology.     

Embryogenesis and Differentiation in Nigella sativa Leaf Callus in vitro

Embryogenesis occurred in Nigella sativa L. (Fam. Ranunculaceae) leaf callus tissue when coconut milk was replaced from the Murashige and Skoog's (MS) medium by casein hydrolysate. On MS + IAA (0.5 mg/l) + casein hydrolysate (100 and 500 mg/l) medium, tissue gained a capacity of growing embryoids for a pro-longed culture period. At a concentration of 1000 mg/l casein hydrolysate suppressed the differentiating capacity after the fifth subculture. 2.4-D and kinetin had inhibitory effects on morphogenesis. Histology of the differentiated tissue revealed that the origin of roots, shoot buds and leaves were from groups of meristematic cells whereas embryoids were initiated by the repeated division of a single cell.     

Alteration in the in vitro activity of milk leukocytes during different parity in high yielding cross-bred cows

In vitro activity of milk leukocytes (viz. neutrophils, lymphocytes and macrophages) was evaluated in forty-eight (48) clinically healthy high-yielding cross-bred cows of mid-lactation stage (100–200 days of lactation), divided into four groups namely 1st parity (n = 12), 2nd parity (n = 12), 3rd parity (n = 12) and 4th and above parity (n = 12). Milk samples were taken (250 ml/cow) were taken. Milk somatic cell counts (SCC) and differential leukocyte counts (DLC) were performed microscopically. In vitro phagocytic index (PI) of milk neutrophils and macrophages was evaluated by colorimetric nitro blue tetrazolium reductive assay. Mitogen-induced milk lymphocyte blastogenic response was measured by colorimetric MTT (tetrazolium) assay after isolation of the milk leukocytes by density gradient centrifugation. Milk SCC differed significantly (p < 0.01) between different parity. Cows of 4 and above parity showed significantly (p < 0.01) higher milk SCC compared to primiparous cows. There was no significant difference in milk DLC during different parities in high-yielding cross-bred cows. There was a significant (p < 0.01) variation in lymphocyte blastogenesis amongst parity. The highest value of lymphocyte blastogenesis was seen at 3rd parity, whereas lowest value was obtained in the cows of both 1st and 4th or above parity. PI of milk neutrophils did not differ significantly between parity. PI of milk macrophages was significantly (p < 0.01) higher in 3rd parity and lower (p < 0.01) in 1st and 4th parities. The study indicated that depressed activity of milk lymphocytes and macropages was lower and SCC was higher in the cows of 4th and above parity indicating more mammary stress and hence susceptible to udder infection and mastitis. Therefore, better care and managemental interventions should be taken around these periods.