湖北贝母组织培养研究 Ⅰ.湖北贝母的愈伤组织培养与形态发生

本文报道了湖北贝母在不同生长时期、不同外植体来源、不同激素浓度与组合,以及培养方法和温度对愈伤组织诱导与形态发生的影响。     

TRPP2 ion channels: Critical regulators of organ morphogenesis in health and disease

Ion channels control the membrane potential and mediate transport of ions across membranes. Archetypical physiological functions of ion channels include processes such as regulation of neuronal excitability, muscle contraction, or transepithelial ion transport. In that regard, transient receptor potential ion channel polycystin 2 (TRPP2) is remarkable, because it controls complex morphogenetic processes such as the establishment of properly shaped epithelial tubules and left-right-asymmetry of organs. The fascinating question of how an ion channel regulates morphogenesis has since captivated the attention of scientists in different disciplines. Four loosely connected key insights on different levels of biological complexity ranging from protein to whole organism have framed our understanding of TRPP2 physiology: 1) TRPP2 is a non-selective cation channel; 2) TRPP2 is part of a receptor-ion channel complex; 3) TRPP2 localizes to primary cilia; and 4) TRPP2 is required for organ morphogenesis. In this review, we will discuss the current knowledge in these key areas and highlight some of the challenges ahead.     

Lactation physiology: A ruminant animal perspective

Summary Importance of peripubertal mammary development as a foundation for subsequent mammary growth and milk production was discussed. Morphological differences in peripubertal mammary growth in rodents and ruminants were described. The relevance of tissue interactions and association with hormones and growth factors in mammary development were delineated. Data from specific studies with ruminant mammary parenchyma were outlined for comparison with rodent studies. It is concluded that the wholesale extrapolation of data from rodent studies to explain udder development is inappropriate. Lastly, recent data from experiments with culture of mammary explants from bulls is described. Pragmatically, these data suggest that responses of mammary tissue from bulls might provide a means for early selection of superior sires or provide a unique model to study tissue interactions in udder development.It has been a pleasure for me to have the opportunity to prepare this paper in honor of Dr. Stuart Patton on his 70th birthday. Dr. Patton, one of the founders of the Gordon Conference on Mammary Gland Biology, had the vision to bring together the variety of workers interested in the mammary gland and drive to foster wide ranging collaborations.     

A paradigm shift in neurobiology: peripheral nerves deliver cellular material and control development

Living beings are extremely complex. Multiple structures, especially evolutionarily young ones, develop or take their final shape during late stages of embryonic development, when the body of an embryo is large and comprised of a huge number of cells. Yet, these late structures frequently need cellular sources from other locations and, sometimes, developmental stages. During recent years it became obvious that nerves provide a perfect solution for transporting and hosting multipotent cells that are later recruited to become new cellular sources in the innervated organs. Moreover, the role of nerves and nerve-dwelling cells in morphogenesis and regeneration seems to be much broader than was previously appreciated in invertebrate and vertebrate animals. In a broader view, nerves can provide material for morphological plasticity and evolutional diversity.     

Influence of the gene brevistylis on development of the flower in Oenothera

The mutant brevistylis of Oenothera (Onagraceae) is characterized mainly by malformations of the style and by female sterility. Morphological features of the style and stigmas, such as the length of the style and the number, size, and shape of the stigmatic lobes is very variable. The abscission layer between ovary and style is missing and the placenta with ovules is protruded into the style. An interpretation of the disturbances in development observed in the br/br homozygotes is presented. The primary influence of br on development is proposed to be a general delay in meristematic growth, followed by irregularities in the timing of morphogenetic events which in turn lead to the anomalies in morphology of style and stigmas.     

Two glycosylation patterns for a single protein (exoglucanase) in Saccharomyces cerevisiae

Exoglucanases (beta-glucosidases) I and II secreted into the culture medium by Saccharomyces cerevisiae were purified from cell cultures harvested at the early exponential phase of growth in order to avoid contamination of the second by a new immunologically-related material. The amino acid composition of the purified enzymes was roughly the same. In addition, both exoglucanases exhibited an identical NH2-terminal sequence (50 residues). These results confirm our previous results about the identity of the protein moieties of both enzymes. Exoglucanase I appears to arise by elongation of one or both short oligosaccharides present in enzyme II.