Pollen morphology of Sorghum Moench – Sections Eu-sorghum and Para-sorghum

Pollen morphological studies have been carried out by SEM on 23 species of Sorghum (Gramineae) in order to resolve the exine surface patterns in sections Eu-sorghum (subsection Arundinacea-series Spontanea and Sativa and subsection Halepensia), and Para-sorghum. Basically, two exine ornamentation types have been observed viz. granular and insular. In section Eu-sorghum, series Spontanea and Sativa (of subsection Arundinacea) are heterogeneous having both types of exine pattern. In the same section, subsection Halepensia is characterised by having only a granular exine. Section Para-sorghum shows a marked pollen morphological similarity with subsection Halepensia of section Eu-sorghum. Snowden's concept that the two series Spontanea and Sativa are closely related and that the cultivated Sorghum (series Sativa) might have evolved from the wild Sorghum (series Spontanea), is supported by the present observations.     

Computational identification of miRNAs,their targets and functions in three‐spined stickleback (Gasterosteus aculeatus)

An intriguing question in biology is how the evolution of gene regulation is shaped by natural selection in natural populations. Among the many known regulatory mechanisms, regulation of gene expression by microRNAs (miRNAs) is of critical importance. However, our understanding of their evolution in natural populations is limited. Studying the role of miRNAs in three‐spined stickleback, an important natural model for speciation research, may provide new insights into adaptive polymorphisms. However, lack of annotation of miRNA genes in its genome is a bottleneck. To fill this research gap, we used the genome of three‐spined stickleback to predict miRNAs and their targets. We predicted 1486 mature miRNAs using the homology‐based miRNA prediction approach. We then performed functional annotation and enrichment analysis of these targets, which identified over‐represented motifs. Further, a database resource (GAmiRdb) has been developed for dynamically searching miRNAs and their targets exclusively in three‐spined stickleback. Finally, the database was used in two case studies focusing on freshwater adaptation in natural populations. In the first study, we found 44 genomic regions overlapping with predicted miRNA targets. In the second study, we identified two SNPs altering the MRE seed site of sperm‐specific glyceraldehyde‐3‐phosphate gene. These findings highlight the importance of the GAmiRdb knowledge base in understanding adaptive evolution.     

Utilization of oligosaccharides by three imperfect fungi

Summary The utilization of oligosaccharides (maltose, sucrose, lactose and raffinose) by three imperfect fungi viz.Alternaria tenuis Auct.,Colletotrichum capsici (Syd.)Butler &Bisby andColletotrichum gloeosporioides Penz. isolated from diseased leaves of tomato,Scindapsus pictus andPolyscias balfuriana respectively, was studied chromatographically. Except for lactose, all the sugars were utilizzed through a hydrolytic pathway and almost all proved to be a suitable source of carbon for the growth of fungi. Along with the utilization of sucrose, a simultaneous synthesis of an oligosaccharide was also observed in case of two species ofColletotrichum. C. gloeosporioides, however, also synthesized an oligosaccharide, maltotriose if it is grown in the medium containing maltose. During the utilization of raffinose, melibiose and fructose were detectted in the culture medium ofA. tenuis. Melibiose was further broken down into glucose and galactose by the two species ofColletotrichum.All the sugars were consumed from the media within 15 days except for lactose which persisted in the media even after 15 days.     

Microspheres based on mannosylated lysine-co-sodium alginate for macrophage-specific delivery of isoniazid

The present investigation reports coupling of ?- and α-amino groups of lysine (LS) with mannose (m-LS) and sodium alginate (SA), respectively, to reduce its toxicity. Prepared conjugate, m-LS-co-SA, was characterized through infra-red spectroscopy and differential scanning calorimetry. Cell viability studies were undertaken to assess the safety profile of the prepared conjugate. Microspheres, based on the conjugate, were prepared using spray drying technique and studied for targeting of isoniazid to alveolar macrophages (AMs). Pharmacokinetic studies of the optimized formulation batch were performed in Charles Foster rats.Infra-red spectral data of the synthesized conjugate were in agreement to the presumptive sequence of the conjugation process. Dispersibility, thermal stability and safety of the conjugate were conducive to its biomedical application. Microspheres, formulated from the conjugate, were of uniform size and offered satisfactory drug loading efficiency and in vitro release characteristics. X-ray diffraction studies established that drug was entrapped within the microspheres rather than being adsorbed on to the surface. Pharmacokinetic studies revealed that the conjugate could be a potential vehicle towards both active targeting of isoniazid to AMs and controlling its release rate.