Yield stability of determinate and indeterminate dry bean cultivars

Summary Yield stability of determinate and indeterminate dry bean (Phaseolus vulgaris L.) cultivars was compared using regression of genotypic performance on environmental means. Yields of 28 dry bean cultivars differing in plant growth habit and commercial class designation were obtained from 42 Michigan performance nurseries over the 6 year period 1980 to 1985. The determinate type I large-seeded kidney and cranberry bean cultivars had below-average seed yield and large mean square deviations from regression. Lower yielding determinate small-seeded navy cultivars had low deviation mean square values, while higher yielding determinate navy cultivars had correspondingly higher mean square deviations from regression. Although seed yield of cultivars with an indeterminate growth habit was greater than determinate cultivars, prostrate type III indeterminate cultivars had deviation mean square values equivalent to those of large-seeded determinate cultivars. The erect, short vine type II indeterminate cultivars (architypes) had greater than average seed yields and minimum deviations from regression. Compared with other plant types, the architype group showed a greater yield response to more productive environments, with regression coefficient values significantly greater than unity. These results indicate that the type II growth habit offers the breeder the best opportunity of obtaining greater seed yield without incurring loss of yield stability as occurs with the type I and type III growth habits. Since the dry bean cultivars utilized in this study represent two distinct centers of domestication, the regression analysis suggests that cultivars from the predominant genetic center demonstrate more yield stability. A non-significant rank correlation coefficient between the combined and separate analyses for deviation mean square values of large-seeded cultivars implies that commercial dry bean classes should be compared separately based on center of domestication.Contributions from Michigan Bean Commission, Michigan Bean Shippers Assoc. and Michigan Agric. Exp. Sta., Michigan Agric. Exp. Sta. Journal Article No. 11986     

Cloning of genes for bacteriophage T5 stable RNAs

One EcoRI-generated fragment (440 basepairs) and two EcoRI/HindIII fragments (220 and 960 basepairs) from the deletion region of T5 phage have been inserted into the phage λ XIII and the plasmid pBR322 as vectors. Recombinant DNA molecules were studied by hybridization with in vivo ³²P-labeled T5 4–5 S RNAs on nitrocellulose filters. Two-dimensional polyacrylamide gel electrophoretic fractionation and fingerprint analysis of the RNAs eluted from the filters were carried out to identify RNAs coded by cloned fragments. For the accurate localization of the genes for these RNAs, RNA-DNA hybrids were treated with T1 and pancreatic RNAases, and the eluted RNA fragments stable against RNAase action were electrophoresed. It was shown that the EcoRI¹440 fragment contains the gene for tRNA 10 (tRNA^Asp), the EcoRI/HindIII¹220 fragment contains the gene for RNA III (107 bases) and parts of the genes for RNA I (107 bases) and tRNA 12 (tRNA^His), and the EcoRI/HindIII¹960 fragment contains only a part of the gene for tRNA 9 (tRNA^Gln). The arrangement of these genes on the physical map of T5 phage was as follows: -tRNA^Gln-tRNA^His-RNA III-RNA I-…-tRNA^Asp.     

Regulation of the ban gene containing operon of prophage P1

Summary A physical map of the ban gene of P1 and sites relevant to its regulation has been deduced from cloning of the appropriate regions of P1 wild-type and of P1 ban regulatory mutants. The cloning required the presence of P1 repressor in the cell confirming the existence of a repressible ban operon (Austin et al. 1978). Evidence for additional member(s) of that operon is presented. Of particular interest for understanding the regulation of ban are the relative positions of a binding site for the P1 repressor and of the regulatory mutations bac and crr that render ban expression constitutive. The results reveal a repressible operon-like structure of about 4 kb within the P1 EcoRI-3 fragment that comprises a c1 repressor binding site/bac additional gene(s) — crr/ban in the clockwise direction of the circular map of P1.     

Blood types of the native Americans of Oklahoma

Large numbers of Indians from Oklahoma were screened for a variety of red cell antigens. Sufficient numbers of Cherokees, Creeks, and Choctaws were studied to calculate gene frequencies. These tribes originated in the Southeastern United States and were forcibly moved to Oklahoma. The Creeks and Choctaws have not been studied previously. A small number of Cherokees remained in North Carolina, and their blood types have been reported. The blood types of the Oklahoma Cherokees are quite similar to those observed there but one important difference was discovered. The data previously reported concerning the Eastern Cherokees revealed the absence of the Dia antigen. The present study found that the Oklahoma Cherokees do have the Dia antigen, although in a lower percentage than the other southeastern tribes. The Creeks and Choctaws share a linguistic heritage as well as having similar red cell phenotypes.     

Down-regulation of miR-17 family expression in response to retinoic acid induced neuronal differentiation

Whole-genome microRNA and gene expression analyses were used to monitor changes during retinoic acid induced differentiation of neuroblasts in vitro. Interestingly, the entire miR-17 family was over-represented among the down-regulated miRNA. The implications of these changes are considerable, as target gene prediction suggests that the miR-17 family is involved in the regulation of the mitogen-activated protein kinase (MAPK) signaling pathway, synaptic plasticity and other markers of neuronal differentiation. Significantly, many of the target responses predicted by changes in miRNA expression were supported by the observed changes in gene expression. As expected, markers of neuronal differentiation such as anti-apoptotic protein B-cell lymphoma 2 (BCL2), myocyte enhancer factor-2D (MEF2D) and zipper protein kinase (MAP3K12; aka ZPK/MUK/DLK) were each up-regulated in response to differentiation. The expression of these genes was also reduced in response to miR-17 and miR-20a transfection, and more specifically they were also shown to contain functional miRNA recognition elements for members of the miR-17 family by reporter gene assay. This suggests that the miR-17 family have an integral role in fine-tuning the pathways involved in the regulation of neuronal differentiation.     

Assessing water scarcity by simultaneously considering environmental flow requirements,water quantity,and water quality

Water scarcity is a widespread problem in many parts of the world. Most previous methods of water scarcity assessment only considered water quantity, and ignored water quality. In addition, the environmental flow requirement (EFR) was commonly not explicitly considered in the assessment. In this study, we developed an approach to assess water scarcity by considering both water quantity and quality, while at the same time explicitly considering EFR. We applied this quantity–quality-EFR (QQE) approach for the Huangqihai River Basin in Inner Mongolia, China. We found that to keep the river ecosystem health at a “good” level (i.e., suitable for swimming, fishing, and aquaculture), 26% of the total blue water resources should be allocated to meet the EFR. When such a “good” level is maintained, the quantity- and quality-based water scarcity indicators were 1.3 and 14.2, respectively; both were above the threshold of 1.0. The QQE water scarcity indicator thus can be expressed as 1.3(26%)|14.2, indicating that the basin was suffering from scarcity problems related to both water quantity and water quality for a given rate of EFR. The current water consumption has resulted in degradation of the basin's river ecosystems, and the EFR cannot be met in 3 months of a year. To reverse this situation, future policies should aim to reduce water use and pollution discharge, meet the EFR for maintaining healthy river ecosystems, and substantially improve pollution treatment.     

Genetic differentiation of Elysia timida (Risso, 1818) populations in the Southwest Mediterranean and Mar Menor coastal lagoon

Genetic variation at 10 enzyme loci was analysed in Elysia timida sacoglossan mollusc samples, originating from both coastal lagoon and marine sites. The observed heterozygosity ranged from 0.390 (Los Urrutias) to 0.277 (Tabarca). Marine and coastal lagoon populations were characterised by exclusive alleles.     

Microfluidic co-culture platform for investigating osteocyte-osteoclast signalling during fluid shear stress mechanostimulation

Bone cells exist in a complex environment where they are constantly exposed to numerous dynamic biochemical and mechanical stimuli. These stimuli regulate bone cells that are involved in various bone disorders, such as osteoporosis. Knowledge of how these stimuli affect bone cells have been utilised to develop various treatments, such as pharmaceuticals, hormone therapy, and exercise. To investigate the role that bone loading has on these disorders in vitro, bone cell mechanotransduction studies are typically performed using parallel plate flow chambers (PPFC). However, these chambers do not allow for dynamic cellular interactions among different cell populations to be investigated. We present a microfluidic approach that exposes different cell populations, which are located at physiologically relevant distances within adjacent channels, to different levels of fluid shear stress, and promotes cell-cell communication between the different channels. We employed this microfluidic system to assess mechanically regulated osteocyte-osteoclast communication. Osteoclast precursors (RAW264.7 cells) responded to cytokine gradients (e.g., RANKL, OPG, PGE-2) developed by both mechanically stimulated (fOCY) and unstimulated (nOCY) osteocyte-like MLO-Y4 cells simultaneously. Specifically, we observed increased osteoclast precursor cell densities and osteoclast differentiation towards nOCY. We also used this system to show an increased mechanoresponse of osteocytes when in co-culture with osteoclasts. We envision broad applicability of the presented approach for microfluidic perfusion co-culture of multiple cell types in the presence of fluid flow stimulation, and as a tool to investigate osteocyte mechanotransduction, as well as bone metastasis extravasation. This system could also be applied to any multi-cell population cross-talk studies that are typically performed using PPFCs (e.g. endothelial cells, smooth muscle cells, and fibroblasts).