Volume 17, Issue 1
March 1992, pages 1-93
pp 1-14 March 1992
Four colonies ofRopalidia montana collected in August in the Nilgiri Hills of southern India had adult populations of 32,000-61,000. Queens represented 0·46–1·40% of the populations. All colonies contained males, but in widely varying proportions (1·47–27·00%). The large adult populations and the fact that the nests were largely filled with brood in all stages of development indicate that the colonies were in a stage of active growth in this season. In December, however, colonies have been reported to have smaller adult populations and little brood. Thus brood production appears to be seasonal in southern India.
Predation by the hornetVespa tropica was observed in 4 of 31 active colonies.Ropalidia montana adults were defenseless in the face of these depredations, which appear to continue at a low level for days or weeks on a given nest.
pp 15-27 March 1992
The study reports the relationship between hierarchy, genetic relatedness and social interaction in captive Japanese macaques. Grooming and proximity were found to be positively related to both dominance rank and degrees of relatedness. Ranks also positively correlated with threats while no relationship was observed between genetic relationships and agonistic interactions. The removal of a-male tightened the male hierarchy while the female hierarchy became relatively loose. Affiliative behaviour became more correlated with ranks than degrees of genetic relatedness. In the absence of α-male, the next dominant male avoided involvement in either agonistic or afliliative interactions with reintroduced animals and group females.
pp 29-34 March 1992
In most photoperiodic avian forms (irrespective of temperate or tropical distribution) including the baya weaver,Ploceus philippinus, seasonal reproduction comes to an end due to the development of a photoperiodically controlled photorefractory phase when birds cease to respond to the stimulatory effect of long days. In the present paper photoperiodic control of the termination of photorefractory phase has been examined by studying the effect of short-day exposure lasting 4–6 months on long-day response of birds. Results indicate that unlike in other photoperiodic birds short-day exposure of winter is not a prerequisite for the termination of photorefractory phase in the reproductive cycle of baya weaver. Artificial long days on the other hand hasten the termination of this phase. Refractory phase in baya weaver, therefore, unlike that in temperate forms, is a temporary state resulting most likely from a sequel of physiological events triggered by long days of spring/summer which temporarily mask the photostimulatory response. Spontaneous termination of photorefractoriness in birds of tropical habitats may have a selective value imparting to the reproductive cycle the necessary elasticity for adaptation to diverse ecological conditions.
pp 35-40 March 1992
A study relating to the influence of mite infestation on the longevity and fecundity of the mosquito,Mansonia uniformis was carried out in the laboratory. It was found that the mite parasitism does influence the quantity of blood ingested, survivorship and the time lag between feeding and egg-laying. However fecundity and hatching percentages were not affected.
pp 41-44 March 1992
Nectar productivity of thirteen cultivars of strawberry (Fragariq sp.) was examined in relation to the foraging activity ofApis cerana indica F. andApis mellifera L. The cultivars were found to vary in the quantity of nectar produced (0·020 to 0·735 ul/flower/day), nectar-sugar concentration (30 to 42%) and amount of sugar (0.006 to 0·2898 mg/flower/day). Consequently energy reward varied from 0·1037 to 4·851 joules/ flower/day. Foraging of bothApis cerana indicq andApis melliferq correlated with energy yields. The results suggest that cultivars with higher caloric rewards had a competitive edge over the others in attracting foraging populations of both species of the bee.
pp 45-53 March 1992
The circumsporozoite antigen of the simian malarial parasite,Plqsmodium knowlesi, consists of tandemly repeated immunodominant peptide units which may play a role in evading the immune system. To study the immunogenicity of this antigen in the absence of the immunodominant repeats, the whole of the non-repetitive region of this antigen has been expressed inEscherichia coli. The entire amino-terminal region up to the start of the repeats, and the full non-repetitive carboxyl region starting from the end of the repeats up to the termination codon, have been expressed separately, as fusion proteins with a 26 kD glutathione-S-transferase protein ofSchistosomq japonicum. A repeat-less truncated antigen has also been expressed as the same fusion protein. The amino-terminal fusion protein (GST-CSN), is a soluble protein of a molecular weight of 38 kD, which could be purified by affinity chromatography on immobilized glutathione. The carboxylterminal fusion protein (GST-CSC), is insoluble, migrates with an anomalous molecular weight of 32 kD, and binds to the affinity matrix weakly. The truncated repeat-less fusion protein (GST-CSNC) is also, an insoluble protein of molecular weight of 48 kD. Unlike the two separate domains, GST-CSNC is an extremely unstable protein inEscherichia coli.
pp 55-66 March 1992
Mini-exon derived RNA is a small nuclear RNA of trypanosomatid protozoa such asLeishmania which donates its 5′-terminal 39 nucleotides to the 5’-ends of cellular messenger RNAs by trans-splicing. We have cloned a mini-exon derived RNA gene fromLeishmania donovani and studied its organization and expression. About 200 copies of the gene per haploid genome are organized as a tandem repeat on a single chromosome. The gene is transcribed as a 95-nucleotide RNA. The first 39 nucleotides of mini-exon derived RNA is also found at the 5′-terminus of a cellular mRNA (Β-tubulin), thus confirming its identity. Sequence analysis of the gene and its flanking regions showed that while classical RNA polymerase II promoter elements such as TATA and CAAT are absent from the 5′-upstream region, intragenic sequence motifs resembling RNA polymerase III promoter elements are present. The implications of this finding for mini-exon derived RNA expression are discussed.
pp 67-85 March 1992
Immunocytochemical localization studies revealed the presence of 10·5 kDa inhibin in the prostatic epithelial cells of the human, non-human primates (Macaca radiata,Presbytis entellus, Callithrix jacchus), dog and laboratory rodents (guinea pigs, hamsters, rats and mice). The capability of the prostate gland to synthesize inhibinin vitro was shown by the incorporation of radiolabeled leucine into inhibin which was immuno-precipitated. Unlike most prostatic proteins, inhibin was found to be androgen-independent since no significant alteration in inhibin concentration in prostate occurred pre/post castration. Physicochemical and immunological characteristics of inhibin as revealed by high performance liquid chromatography and parallel dilution curve in a radioimmunoassay revealed similarities of inhibin in prostates of various species.
pp 87-93 March 1992
Abstract. The nuclear magnetic resonance imaging technique has been used to obtain images of different transverse and vertical sections in groundnut and sunflower seeds. Separate images have been obtained for oil and water components in the seeds. The spatial distribution of oil and water inside the seed has been obtained from the detailed analysis of the images. In the immature groundnut seeds obtained commercially, complementary oil and water distributions have been observed. Attempts have been made to explain these results.