Molecular markers in medicinal plant biotechnology: past and present

Plant based medicines have gained popularity worldwide due to their almost negligible side effects. In India, the three traditional medicinal systems, namely homeopathy, Ayurveda and Siddha rely heavily on plants for medicinal formulations. To prevent the indiscriminate collection of these valuable medicinal plants and for their proper authentication and conservation, it is imperative to go for sustained efforts towards proper germplasm cataloguing and devising conservation strategies. For this purpose, molecular markers have a significant role, as they provide information ranging from diversity at nucleotide level (single nucleotide polymorphisms) to gene and allele frequencies (genotype information), the extent and distribution of genetic diversity, and population structure. Over the past twenty years, the molecular marker field has completely transformed the meaning of conservation genetics which has emerged from a theory-based field of population biology to a full-fledged pragmatic discipline. In this review, we have explored the transition and transformation of molecular marker technologies throughout these years.     

Molecular markers in medicinal plant biotechnology: past and present

Plant based medicines have gained popularity worldwide due to their almost negligible side effects. In India, the three traditional medicinal systems, namely homeopathy, Ayurveda and Siddha rely heavily on plants for medicinal formulations. To prevent the indiscriminate collection of these valuable medicinal plants and for their proper authentication and conservation, it is imperative to go for sustained efforts towards proper germplasm cataloguing and devising conservation strategies. For this purpose, molecular markers have a significant role, as they provide information ranging from diversity at nucleotide level (single nucleotide polymorphisms) to gene and allele frequencies (genotype information), the extent and distribution of genetic diversity, and population structure. Over the past twenty years, the molecular marker field has completely transformed the meaning of conservation genetics which has emerged from a theory-based field of population biology to a full-fledged pragmatic discipline. In this review, we have explored the transition and transformation of molecular marker technologies throughout these years.     

Isolated hepatocytes - past, present and future

The first technique for large-scale preparation of isolated hepatocytes was described in 1953 and involved perfusion of rat liver under pressure with a Ca2+-free solution containing a chelating agent. Various modifications of this technique were in use over the next ten years, until it was demonstrated that cells prepared in this manner were grossly damaged, losing most of their cytoplasmic enzymes during the preparative procedure. The successful preparation of intact isolated hepatocytes by collagenase-treatment of liver was achieved in 1967, and the widespread use of intact hepatocyte suspensions was accelerated by the development soon after of high-yield preparative techniques involving perfusion of the liver with a medium containing collagenase.The introduction of the isolated hepatocyte preparation has enabled experimental studies that otherwise would not be feasible. Important advances have been the use of cultured hepatocytes, frequently of human origin, for the investigation of the metabolism and toxicology of potential therapeutic agents. Success in this field has been achieved through the steady improvement in techniques for the maintenance in culture of differentiated hepatocytes, and in particular their cytochrome P450 complexes. Another area showing considerable promise is the employment of hepatocytes, generally from a porcine source, in temporary support systems for patients with acute liver failure. Our own studies have concentrated on the demonstration of long-range interactions between hepatocyte compartments which suggest that energy transfer between cell compartments can take place without ATP turnover.     

Polymorphisms past and present

Polymorphisms, particularly genetic variants of the red blood cell, have served as a major focus for the research of Frank B. Livingstone over the course of a long and productive career. Recent investigations confirm the value of key insights that he contributed to this area more than four decades ago. As Livingstone recognized, the same underlying evolutionary model that guides genetic studies in present populations also provides a productive framework for interpreting patterns of variation in the skeleton and dentition throughout past human evolution. Examples explored in detail here include polymorphisms in hominoid nasal bone shapes and fourth lower premolar roots. This work provides both empirical and theoretical contexts for investigating patterns of human variation over the last 6 to 8 million years.     

Charles Manning Child (1869-1954): the past, present, and future of metabolic signaling

Charles Manning Child's work focused on metabolic gradients and their influence on organismal development. Early in the 20th century, his work had considerable currency, but by the second half of the century he had become little more than a historical footnote. Yet today Child's ideas are once again topical. While there were issues of cause and effect that Child and his students were never able to address adequately, in hindsight the extent of his eclipse hardly seems warranted. In fact, the demise of Child's theories may have resulted from larger changes in the nature of biology in the early 20th century. Child frequently studied planarians, hydroids, and other animals that are capable of asexual, agametic reproduction, and his theories most clearly apply to such organisms. In contrast, Thomas Hunt Morgan, initially one of Child's competitors in studies of regeneration, later developed the field of transmission genetics based on fruit flies, which can only reproduce via gametes. Child's theories and model systems were largely casualties of the success of Morgan's mechanistic paradigm. Nevertheless, in modern biology metabolic gradients, recast in terms of redox signaling, have become central to understanding both normal and pathological development.     

Anchored cAMP signaling: onward and upward - a short history of compartmentalized cAMP signal transduction

Intracellular signal transduction pathways require a high degree of spatial and temporal resolution in order to deliver the appropriate outputs. Specific signaling mediated by the ubiquitous second messenger cAMP and its effector, the cAMP-dependent protein kinase (PKA), is governed by the spatial organization of different pathway components by A-kinase anchoring proteins (AKAPs). This review discusses the history and future of anchored cAMP signaling pathways.     

Schistosomiasis in Indonesia: past and present

Schistosomiasis is endemic in Indonesia in two isolated areas, Lindu valley and Napu valley, both located in the Province of Central Sulawesi. In 1940, a prevalence survey was initiated in Lake Lindu, which indicated a Schistosoma japonicum infection prevalence of 56% among the population of Anca, Tomado and Langko villages. Another survey was conducted in 1973 in Napu valley and very high infection prevalences of up to 72% were found among the population in Winowanga village. Since then, comprehensive studies on the epidemiology and the effects of control have been carried out in 24 endemic villages in both areas. Over the past six decades, schistosomiasis control has been implemented and the average prevalence is now much lower than before the control programme was launched. In 2006, it was 0.49% in 7 villages in Lindu valley. In Napu valley, the average infection prevalence among the population of 17 villages was 1.08% in the same year. Again in 2006, the prevalence of infection in snails ranged from 0 to 13.4% and from 0 to 9.1% in Napu and Lindu valleys, respectively. The highest prevalence among snails was found in Dodolo village. The prevalence of S. japonicum in the reservoir host Rattus spp. ranged from 0 to 20% and the highest prevalence was again found in Dodolo village. Contemporary data suggest that transmission of schistosomiasis is still ongoing in Indonesia despite regular surveillance and control activities covering the whole endemic area.     

Subtilisin‐like proteases in plant defence: the past,the present and beyond

Subtilisin‐like proteases (or subtilases) are a very diverse family of serine peptidases present in many organisms, but mostly in plants. With a broad spectrum of biological functions, ranging from protein turnover and plant development to interactions with the environment, subtilases have been gaining increasing attention with regard to their involvement in plant defence responses against the most diverse pathogens. Over the last 5 years, the number of published studies associating plant subtilases with pathogen resistance and plant immunity has increased tremendously. In addition, the observation of subtilases and serine protease inhibitors secreted by pathogens has also gained prominence. In this review, we focus on the active participation of subtilases in the interactions established by plants with the environment, highlighting their role in plant–pathogen communication.