Influence of age,weaning, season and body weight on the levels of progesterone,oestradiol-17β and luteinizing hormone in growing buffalo heifers (Bubalus bubalis)

The influence of age, weaning, season of the year and body weight on the peripheral levels of progesterone, oestradiol-17β and luteinizing hormone (LH) were studied during neonatal, perinatal and peripubertal periods in buffalo heifers. The buffalo heifers exhibited oestrus only after 30 months of age and had higher levels of LH and oestradiol-17β and a lower level of progesterone on the day of oestrus. The progesterone concentration was affected significantly (P < 0.01) by different seasons, by weaning (P < 0.05) and varied between pubertal and neonatal periods (P < 0.01), whereas the oestradiol-17β level was affected significantly (P < 0.01) by weaning and varied at different seasons and with body weight. However, the LH concentration was greater during the neonatal period than the pre- and peripubertal periods and changed significantly (P < 0.01) between groups of ages and body weights. The results suggest that increases in the levels of oestradiol-17β and progesterone after 30 months of age are probably indicative of the onset of puberty in buffalo heifers. However, a further increase in oestradiol-17β, LH, and a decrease in progesterone are essential for oestrus and cyclicity to be exhibited in buffalo heifers.     

Development of sporeless/low sporing strains of Pleurotus through mutation

Summary The sporophores of Pleurotus are gymnocarpous and continuously release spores in the atmosphere causing respiratory allergies like hay fever and farmer’s lung disease among workers. The allergy is caused by the antigens present on the walls of the spores. Apart from this, during commercial production, these spores settle on the fruit bodies, germinate and form a velvety film which gives an unpleasant appearance to the mushrooms. The spores emitted may include new genotypes likely to attack wood or trees. Spore allergy is one of the most important limiting factors for the large scale cultivation of this species. Different approaches are being adopted at IIHR for the production of commercial sporeless/low-sporing strains of Pleurotus to alleviate the spore allergy problem. Attempts were made during the present investigation to produce sporeless or low-sporing mutants through u.v. mutation. Mutation of the mycelium did not yield the desired results. Mutation of the spores of Pleurotus sajor-caju yielded an extremely low-sporing mutant after 75 min exposure. The character has been found to be stable for more than 10 generations of subculturing.     

Quantitative structure activity relationship studies on 3-triazines using van der Waal volume and molecular connectivity index

QSAR studies have been performed on the homologues of 3-triazines, using molecular connectivity index and van der Waal volume as structural parameters. The regression analysis has shown good correlation between antitumour activity and the two structural parameters.     

Induction of mutation in the cyanobacteriumAnabaena doliolum: A strain-specific property

Mutations with respect to the sporulating character in the cyanobacteriumAnabaena doliolum (AdS and AdB strains) were induced after treatment with acriflavin, acridine organge 9-aminoacridine, N-methyl-N′-nitro-N-nitrosoguanidine, ethyl methanesulfonate, hydroxylamine, nitrous acid, low pH (pH 4.2) and elevated temperature (65±1 °C). Exposure to higher temperature was most effective in inducing nonsporulating mutants in both strains. Uptake of acridine dyes, inactivation and mutability with respect to sporulation of two strains of cyanobacteriumA. doliolum revealed that the mutagen uptake could be directly correlated with the frequency of induced mutations but that survival and mutability are independent strain-specific properties.     

Certain observations on Scytonema stuposum (Kuetz.) Born. (Cyanophyta,Nostocales)

Some interesting cultural observations on Scytonema stuposum (Kuetz.) Born., were recorded. It was observed that frequently one or more terminal cells of a branch get cut off but they still remain attached over the sheath of the mother filament. Even in this condition such structures continue their growth and may become a multicellular body. Later, such a structure gets detached from the mother filament and serve as a hormogonium.     

Molecular modeling to predict the structural and biological effects of mutations in a highly conserved histone mRNA loop sequence.

The 3'-end of histone mRNAs contains a highly conserved sequence motif which is believed to form a 6 base pair stem and a 4 base loop. These sequences are involved in both the efficiency of 3'-end formation and stability of the mature histone mRNA. We have modeled four stem basepairs and the loop portion of this structure using the wildtype sequences and several mutant sequences. A structure for the wildtype stem-loop is proposed that is based on energy minimization using a representative wildtype sequence and comparison with structures obtained using naturally occurring mutations which do not alter loop function. A wildtype structure is proposed in which the top basepair of the stem is broken, forming a six base loop. Mutant sequences with altered bases in the loop and in the stem were also modeled. The effect of these mutations on the proposed wildtype structure is discussed and possible biological consequences considered.     

NMR study of the molecular and electronic structure of the heme cavity of Aplysia metmyoglobin. Resonance assignments based on isotope labeling and proton nuclear Overhauser effect measurements

The 1H NMR characteristics of the high-spin metmyoglobin from the mollusc Aplysia limacina have been investigated and compared with those of the myoglobin (Mb) from sperm whale. Aplysia metMb exhibits a normal acid----alkaline transition with pK approximately 7.8. In the acidic form, the heme methyl and meso proton resonances have been assigned by 1H NMR using samples reconstituted with selectively deuterated hemins and in the latter case by 2H NMR as well. On the basis of the methyl peak intensities and shift pattern, heme rotational disorder could be established in Aplysia Mb; approximately 20% of the protein exhibits a reversed heme orientation compared to that found in single crystals. Three meso proton resonances have been detected in the upfield region between -16 and -35 ppm, showing that the chemical shift of such protons can serve as a diagnostic probe for a pentacoordinated active site in hemoproteins, as previously shown to be the case in model compounds. The temperature dependence of the chemical shift of the meso proton signals deviates strongly from the T-1 Curie behavior, reflecting the presence of a thermally accessible Kramers doublet with significant S = 3/2 character. Nuclear Overhauser effect, NOE, measurements on Aplysia metMb have provided the assignment of individual heme alpha-propionate resonances and were used to infer spatial proximity among heme side chains. The hyperfine shift values for assigned resonances, the NOE connectivities, and the NOE magnitudes were combined to reach a qualitative picture of the rotational mobility and the orientation of the vinyl and propionate side chains of Aplysia metMb relative to sperm whale MbH2O.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence for intracellular formation of angiotensins: coexistence of renin and angiotensin-converting enzyme in Leydig cells of rat testis

Leydig cells were purified from rat testes by discontinuous metrizamide density gradient and were shown to contain renin (EC 3.4.99.1), angiotensin-converting enzyme (dipeptidyl carboxypeptidase, (EC 3.4.15.1), and the peptide hormone angiotensins I, II and III as determined by the combined HPLC and radioimmunoassay. In germinal cells only angiotensin II (AII) was found at a significant level. These findings provide evidence for intracellular formation of AII in testicular cells and demonstrate that an intracellular renin-angiotensin system exists in normal non-transformed cells.     

Isolation of sodium chloride-tolerant callus line of Cicer arietinum L. cv. BG-203

A NaCl-tolerant callus line of Cicer arietinum has been isolated, as a spontaneous variant, on agar-solidified MS-medium supplemented with 100 mM NaCl. The growth of this line, in the presence of 100 mM NaCl, was comparable to that of the NaCl-sensitive callus line growing in the absence of NaCl. Regarding relative tolerance of the two callus lines towards NaCl (0 to 200 mM), the tolerant line performed poorly in the absence of NaCl and exhibited optimal growth at 50 mM NaCl. The tolerance persisted even after three passages of 4-wk each, tested so far, away from the selective agent.