Plant breeding: Past achievements and expectations for the future

Plant breeding improvements have been responsible for 50 percent or more of the gains in yield per unit area of major crop plants in the United States over the past 50 yr. Rates of gain attributable to genetic improvements have averaged 1% per year, have generally been linear, and show no sign of slackening. Extrapolations indicate that varieties and hybrids of the year 2000 will yield, on average, 15% more than those of 1985 Improvements in tolerance to environmental stress, in grain-to-straw ratios, and in standability, as well as maintenance of required levels of resistance to disease, insect and nematode pests, have been the major genetic causes of higher achieved yields and will continue to be the foundation for further gains in productivity and stability. Broadened genetic diversity is also an increasingly important goal to promote stability and increase productivity potentials. Proportionately large research inputs are now needed to maintain desired rates of improvement, compared to earlier years. It seems likely that contributions from biotechnology will become increasingly important in years to come if improvement rates are to be maintained.     

The NG2 proteoglycan: Past insights and future prospects

The NG2 chondroitin sulfate proteoglycan is a valuable marker for several types of incompletely-differentiated precursor cells, including oligodendrocyte progenitors in the central nervous system, developing mesenchymal cells in cartilage, muscle, and bone, and pericytes/smooth muscle cells in developing vasculature. In addition to extending our knowledge about the developmental roles of these cell types, current studies on NG2 are also providing information about the molecular mechanisms through which the proteoglycan itself influences progenitor development. This research suggests that interaction of NG2 with extracellular and intracellular ligands regulates signaling events that are important for both cell proliferation and cell migration.     

Genetic engineering of radish: current achievements and future goals

Radish is a major root crop grown in the Far East and is especially important to some low-income countries where it is consumed on a daily basis. Developments in gene technology systems have helped to accelerate the production of useful germplasms, but progress has been slow, though achieved, via in planta methods and useful traits have been introduced. In the wake of the new Millennium, future goals in terms of improving transformation efficiency and selection of new traits for generating late-flowering radish are described. Furthermore, the techniques available for incorporating pharmaceutical proteins into radish to deliver edible proteins on-site are discussed. Finally, the concerns of releasing transgenic radish to the field in terms of pollen-mediated gene transfer are also reviewed. Such a report identifies key areas of research that is required to allow the crop satisfy the need of poor impoverished countries in the Far East.     

Genetic engineering of millets: current status and future prospects

This review summarizes progress on the genetic transformation of millets and discusses the future prospects for the development of improved varieties. Only a limited number of studies have been carried out on genetic improvement of millets despite their nutritional importance in supplying minerals, calories and protein. Most genetic transformation studies of millets have been restricted to pearl millet and bahiagrass and most studies have been limited to the assessment of reporter and marker gene expression. Biolistic-mediated gene delivery has been frequently used for the transformation of millets but Agrobacterium-mediated transformation is still lagging. Improved transformation of millets, allied to relevant gene targets which may offer, for example, improved nutritional quality, resistance to abiotic and biotic stresses, and resistance to fungal infection will play important roles in millet improvement.     

Genetic transformation of wheat: current status and future prospects

Genetic transformation is a reverse genetics tool for validation of target genes and crop improvement. However, due to its low efficiency and genotype dependency, wheat is considered a recalcitrant plant for genetic transformation. During the last 20 years, various in vitro and in planta transformation methods have been reported in wheat. Until now, biolistic particle and Agrobacterium-mediated wheat transformation methods using immature embryos as explants have been the two major transformation approaches. In addition to immature embryos, other explant types, such as mature embryos, anther-derived calli, inflorescences, apical meristems, and other floral organs, have been employed; however, they need further optimization. In addition to the common marker genes, such as bar, hpt and gus, other effective markers, ALS, AtMYB12 and pmi, have been successfully used for selection of positive transgenic plants. Numerous agronomic trait genes such as biotic stress resistance or tolerance genes have been transferred into wheat plants. Future prospects, such as recipient wheat cultivars and explants, marker free issues, and transgene silencing, are discussed. The objective of this review is to summarize current successful techniques for wheat transformation and stimulate further research into long-term wheat improvement by genetic engineering approaches.     

Neural induction: New achievements and prospects

Neural induction is a triggering of neural differentiation in a portion of cells of the vertebrate embryonic ectoderm in response to signals emanating from adjacent tissues. As revealed more than ten years ago in experiments with Xenopus embryos, the major role in neural induction is played by suppression of the bone morphogenetic protein (BMP) signaling cascade in neural cell precursors. Consequently, the epidermal differentiation program is blocked and a neural program is activated in such cells by default. The so-called default model of neural induction was supported with other experimental subjects. An important role in neural induction is also played by the FGF and Wnt signaling cascades via their interactions with the BMP cascade. As new regulatory proteins involved in neural induction were identified and their properties analyzed in detail, it became possible to apply mathematical modeling to study, with the example of neural induction, the spatial self-organization of cell differentiation in the embryo as one of the main problems of developmental biology.     

Genetic nature of eastern wolves: Past, present and future

Eastern North American wolves have long been recognized as morphologically distinct from both coyotes and gray wolves. This has led to questions regarding their origins and taxonomic status. Eastern wolves are mainly viewed as: (1) a smaller subspecies of gray wolf (Canis lupus lycaon), potentially the result of historical hybridization between gray wolves (C. lupus) and red wolves (C. rufus), (2) a hybrid, the result of gray wolf (C. lupus) and coyote (C. latrans) interbreeding, or (3) a distinct species, C. lycaon, closely related to the red wolf (C. rufus). Although debate persists, recent molecular studies suggest that the eastern wolf is not a gray wolf subspecies, nor the result of gray wolf/coyote hybridization. Eastern wolves were more likely a distinct species, C. lycaon, prior to the eastward spread of coyotes in the late 1800s. However, contemporary interbreeding exits between C. lycaon to both C. lupus and C. latrans over much of its present range complicating its present taxonomic characterization. While hybridization may be reducing the taxonomic distinctiveness of C. lycaon, it should not necessarily be viewed as negative influence. Hybridization may be enhancing the adaptive potential of eastern wolves, allowing them to more effectively exploit available resources in rapidly changing environments.     

The biosynthetic pathway of FK506 and its engineering: from past achievements to future prospects

Journal of Industrial Microbiology & Biotechnology - FK506, a 23-membered macrolide produced by several Streptomyces species, is an immunosuppressant widely used to prevent the rejection of...     

The prospects of poop: a review of past achievements and future possibilities in faecal isotope analysis

What can the stable isotope values of human and animal faeces tell us? This often under-appreciated waste product is gaining recognition across a variety of disciplines. Faecal isotopes provide a means of monitoring diet, resource partitioning, landscape use, tracking nutrient inputs and cycling, and reconstructing past climate and environment. Here, we review what faeces are composed of, their temporal resolution, and how these factors may be impacted by digestive physiology and efficiency. As faeces are often used to explore diet, we clarify how isotopic offsets between diet and faeces can be calculated, as well as some differences among commonly used calculations that can lead to confusion. Generally, faecal carbon isotope (δ¹³C) values are lower than those of the diet, while faecal nitrogen isotope values (δ¹⁵N) values are higher than in the diet. However, there is considerable variability both within and among species. We explore the role of study design and how limitations stemming from a variety of factors can affect both the reliability and interpretability of faecal isotope data sets. Finally, we summarise the various ways in which faecal isotopes have been applied to date and provide some suggestions for future research. Despite remaining challenges, faecal isotope data are poised to continue to contribute meaningfully to a variety of fields.     

Genetic basis of stony coral biomineralization: History,trends and future prospects

Despite their simple body plan, stony corals (order Scleractinia, phylum Cnidaria) can produce massive and complex exoskeletal structures in shallow, tropical and subtropical regions of Earth’s oceans. The species-specific macromorphologies of their aragonite skeletons suggest a highly coordinated biomineralization process that is rooted in their genomes, and which has persisted across major climatic shifts over the past 400 + million years. The mechanisms by which stony corals produce their skeletons has been the subject of interest for at least the last 160 years, and the pace of understanding the process has increased dramatically in the past decade since the sequencing of the first coral genome in 2011. In this review, we detail what is known to date about the genetic basis of the stony coral biomineralization process, with a focus on advances in the last several years as well as ways that physical and chemical tools can be combined with genetics, and then propose next steps forward for the coming decade.     

Some coccidial parasites of the lizard Amphisbaena alba (Reptilia: Amphisbaenia: Amphisbaenidae)

Five parasites are described in the lizard Amphisbaena alba (Amphisbaenidae) from the state of Par , North Brazil. Mature oocysts of Choleoeimeria amphisbaenae n. sp., are passed already mature in the faeces. They are ellipsoidal-cylindrical, average 33.7 x 22.8 m and are devoid of micropyle, oocyst residuum or polar body. The colourless wall is smooth and of 2 layers. The 4 dizoic sporocysts have no Stieda body and average 13 x 9.3 m. Endogenous stages develop in the epithelial cells of the gall-bladder in the manner described for the genus and may cause extensive tissue damage. Sporulation of Isospora capanemaensis n. sp., is completed 3 days after the oocysts are voided in the faeces. They average 14.8 x 14.5 m and have no micropyle, oocyst residuum or polar body. The 2 tetrazoic sporocysts are pear-shaped, average 8.6 x 6.6 and have an inconspicuous Stieda body. Endogenous development is in the epithelial cells of the ileum, and heavy infections cause considerable tissue destruction. Multisporocystic oocysts passed in the faeces of one A. alba possibly originated from an invertebrate host ingested by the lizard. A globidium-like cyst in the digestive tract of A. alba measured 105 x 85 m and contained many hundreds of merozoites. A stained kidney smear of the same lizard revealed the presence of an unidentified parasite producing multinucleate cyst-like stages.     

Vertebrate palaeohistology: Past and future

Vertebrate palaeohistology has been considered for a long time as a modest subdivision of Palaeontology. Starting in the 1930s and 1940s, comparative bone tissue histology and palaeohistology progressively demonstrated the multiple correlations between bone tissue distribution and numerous biological variables, such as ontogenetic origin, growth, size, shape, biomechanics, physiology, and ecology. During the last three decades, Palaeohistology has focussed on deciphering the numerous, complex causes explaining the patterns and processes of Vertebrate evolution. Palaeohistology is a powerful tool, in connection with Biology, for the reconstruction of fossil Vertebrates as living organisms.     

Economic botany: Past and future

Economic botany, like botany, had its origin with the herbalists. Its development was encouraged by various European rulers during the Age of Exploration and Discovery in the 16th century. Recent developments in the United States include A. F. Hill’s textbook, Economic Botany, in 1937 the founding of the journal Economic Botany by E. H. Fulling in 1947 and the formation of the Society for Economic Botany in 1959 Some of the breakthroughs in the development of agriculture, beginning with its origin some 10,000 yr ago, are given. It is concluded that we now need another significant breakthrough to feed the world’s population adequately in the year 2000 Some look to genetic engineering to provide such a breakthrough.     

Population biology of parasites: current status and prospects

The present state of parasite population biology is reviewed with special reference to parasites of fish. Mathematical models have provided a coherent body of theory which is supported by many laboratory investigations. There is nevertheless some disagreement between predictions based on this theory and data obtained from investigations of natural parasite populations. It is suggested that this is partly due to the oversimplifications and limitations of the models, and partly to the unsystematic approach of many field investigations and the resulting shortage of data of the right sort. In freshwater habitats disagreement may also be due to the rapid and extensive changes that are taking place in the habitats themselves as a direct consequence of human activities. Future developments should involve models becoming more realistic, and field investigations being conducted in a more systematic and analytical manner in order to obtain quantitative measurements of the essential population parameters.