Inheritance of three electrophoretically determined protein bands in potato (Solanum tuberosum L.)

Summary A modified polyacrylamide gel electrophoresis technique is employed to resolve proteins for use as biochemical gene markers in potato. Dominant, duplicate dominant and complementary gene action are three modes of inheritance that adequately explain the segregation of three respective protein bands in two generations of crossing within diploid Phureja X haploid Tuberosum families.Scientific Journal Seires Article 10,171 of the Minnesota Agricultural Experiment Station     

An interpretation of genomic balance in seed formation in interspecific hybrids of Solanum

Summary To investigate the mechanisms of seed failure in intraspecific and interspecific crosses of Solanum two diploid, S. commersonii and Group Phureja, and one tetraploid species, S. acaule, species were crossed and the seeds were analyzed for embryo and endosperm development. Many seeds of certain crosses observed seven days after pollinations were found to contain abnormal embryos and degenerating endosperms. In some cases seeds contained an embryo with no endosperm, or an endosperm with no embryo. Other interspecific crosses which were predicted to fail actually produced seeds with normally developed embryos and endosperms. To further characterize the intra- and interspecific embryos and endosperms the nuclear DNA was measured. There are several ways to explain the ploidy levels of embryos and endosperms among the crosses, the occurrence of unreduced gametes in some cases and genomic instability in other cases. The latter resulted in chromosome loss at meiotic and mitotic divisions. Genomic balance in interspecific seeds is critical to both embryo and endosperm development.Scientific Journal Series Article No. 14636 of the Minnesota Experiment Station     

Fatty acids, membrane permeability, and sugars of stored potato tubers

The relationships of potato (Solanum tuberosum L.) tuber membrane permeability and membrane lipid composition to sugar accumulation were examined. Tubers from four potato cultivars were stored for 40 weeks at 3°C and 9°C. Rates of tuber membrane electrolyte leakage, total fatty acid composition, free fatty acid composition, and sugar content were measured throughout the storage period. Storage of tubers at 3°C caused dramatic increases in total fatty acid unsaturation, membrane permeability, and sugar content compared to tubers stored at 9°C. Cultivars with higher levels of fatty acid unsaturation had lower rates of membrane electrolyte leakage and lower sugar contents. We propose that high initial levels or high induced levels of membrane lipid unsaturation mitigate increases in tuber membrane permeability during storage, thus positively influencing the processing quality of stored potato tubers.     

Distinguishing between self-incompatibility and other reproductive barriers in plants using male (MCC) and female (FCC) coefficient of crossability

Summary It is difficult to assess self-incompatibility (SI) as a phenomenon or to distinguish it from other reproductive barriers. Our objective was to demonstrate a method of separating reproductive barriers and other factors affecting SI expression. The analysis consists of four parts: (1) calculating male (MCC) and female (FCC) coefficients of crossability using seed set from a diallel crossing design; (2) determining significant male and female differences using a 11 paired Chi-square test; (3) constructing scatter diagrams of FCC versus MCC; (4) performing linear regression analysis between FCC and MCC. Diallel data from eight genera with various reproductive barriers were used to illustrate and validate the usefulness of this method. SI can be distinguished from other reproductive barriers (incongruity, inbreeding depression, post-fertilization phenomena) using 11 Chisquare and regression analysis. In addition, the incorporation of ovule counts is crucial for demarcating the SI phenomenon in species where ovule numbers vary between self- and outcross pollinations. Male and female steriles can be identified with the MCC/FCC equations and subsequently removed from further analysis.Scientific Journal Series Paper Number 16,686 of the Minnesota Agricultural Experiment StationOrder of the first two authors was statistically determined by replicated tosses (n = 10) of a penny (US currency)     

Pyrophosphorylases in Solanum tuberosum (IV. Purification,Tissue Localization,and Physicochemical Properties of UDP-Glucose Pyrophosphorylase)

The enzyme UDP-glucose pyrophosphorylase (UGPase) from potato (Solanum tuberosum L. cv Norchip) tubers was purified 177-fold to near homogeneity and to a specific activity of 1099 international units/mg of protein. The molecular mass of the purified enzyme was 53 kD as determined by SDS-PAGE and gel filtration. Immunological and activity assays detected UGPase at similar levels in potato stems, stolons, and tubers. Leaves and roots contained lower levels of UGPase activity and protein. Lineweaver-Burk plots for substrates inorganic pyrophosphate and UDP-glucose were linear in the pyrophosphorolytic direction, yielding Km values of 0.13 and 0.14 mM, respectively. However, Lineweaver-Burk plots for the substrates glucose-1-P and UTP were biphasic in nature when UGPase was assayed in the direction of UDP-glucose synthesis. At physiological substrate concentrations (i.e. from 0.05-0.20 mM), Km values of 0.08 mM (glucose-1-P) and 0.12mM (UTP) were obtained. When substrate concentrations increased above 0.20 mM, Km values increased to 0.68 mM (glucose-1-P) and 0.53 mM (UTP). These kinetic patterns of potato UGPase suggest a "negative cooperative effect" (A. Conway, D.E. Koshland, Jr. [1968] Biochemistry 7: 4011-4022) with respect to the substrates glucose-1-P and UTP. The biphasic substrate saturation curves were similar to the kinetics of the dimeric form of UGPase purified from Salmonella typhimurium (T. Nakae [1971] J Biol Chem 246: 4404-4411). The in vivo significance of the enzyme's "negative cooperativity" in the direction of UDP-glucose synthesis and potato sweetening is discussed.     

Superoxide Dismutase, Catalase, and alpha-Tocopherol Content of Stored Potato Tubers

Activated oxygen or oxygen free radical mediated damage to plants has been established or implicated in many plant stress situations. The extent of activated oxygen damage to potato (Solanum tuberosum L.) tubers during low temperature storage and long-term storage is not known. Quantitation of oxygen free radical mediated damage in plant tissues is difficult. However, it is comparatively easy to quantitate endogenous antioxidants, which detoxify potentially damaging forms of activated oxygen. Three tuber antioxidants, superoxide dismutase, catalase, and α-tocopherol were assayed from four potato cultivars stored at 3°C and 9°C for 40 weeks. Tubers stored at 3°C demonstrated increased superoxide dismutase activities (up to 72%) compared to tubers stored at 9°C. Time dependent increases in the levels of superoxide dismutase, catalase, and α-tocopherol occurred during the course of the 40 week storage. The possible relationship between these increases in antioxidants and the rate of activated oxygen production in the tubers is discussed.     

Disc-electrophoresis of proteins and enzymes from styles,pollen and pollen tubes of self-incompatible cultivars ofLilium longiflorum

Summary Lilium longiflorum possesses several advantages for investigating the nature of self-incompatibility. The large hollow styles permit analyses of proteins and enzymes from pollen tubes removed from the styles after selfing or crossing along with their corresponding styles, as well as from pollen grains and from styles of unpollinated flowers. Biochemical methods have been developed for protein extractions and subsequent analyses by disc electrophoresis. These techniques have been used to demonstrate changing protein and esterase patterns in pollen and styles from four cultivars. No apparent association between the self-incompatibility reaction and proteins which migrate at pH 8.3 in 71/2% acryamide gel was noted. These analyses included soluble proteins, esterases, peroxidases and several dehydrogenases.

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Zusammenfassung Blüten vonLilium longiflorum bieten mehrere Vorteile bei Untersuchungen über die Natur der Selbstinkompatibilität: Die großen, hohlen Griffel lassen Protein- und Enzymanalysen sowhl von aus den Griffeln isolierten Pollen-Schläuchen nach Selbstung oder Fremdung zu, als auch von Pollen-Körnern und von bestäubten und unbestäubten Griffeln. Zur Extraktion von Proteinen und ihrer anschließenden Analyse mittels Disk-Elektrophorese wurden von uns biochemische Methoden entwickelt, die zur Demonstration von Veränderungen der Protein- und Esterase-Muster in Pollen und Griffeln von vier Klonen (cultivars) angewendet wurden. Dabei konnte kein offensichtlicher Zusammenhang zwischen der Selbstinkompatibilitätsreaktion und den bei pH 8.3 in 71/2% Acrylamid-Gel wandernden Proteinen festgestellt werden. Die Analysen erstreckten sich auf lösliche Proteine, Esterasen, Peroxydasen und eigige Dehydrogenasen.

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Paper No. 1212 from the Laboratory of Genetics, University of Wisconsin. Supported in part by a grant from National Science Foundation.

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SD was a predoctoral trainee from National Institute of Health GM-398.     

Focus: Health Equity: The Social Value of Implementing the Ten Steps to Successful Breastfeeding in an Indonesian Hospital: A Case Study

Background: Despite the known importance of breastfeeding for women’s and children’s health, global exclusive prevalence among infants under 6 months old is estimated at only 41%. In 2018, Indonesia had a lower exclusive breastfeeding rate of 37% at 6 months postpartum; ranging from 20% to 56%, showing unequal breastfeeding support throughout the country. The World Health Organization (WHO) launched the Ten Steps to Successful Breastfeeding (Ten Steps) in 1989, later embedded in UNICEF’s Baby-Friendly Hospital Initiative (BFHI) program in 1991. The BFHI aims to encourage maternity facilities worldwide to ensure adequate education and support for breastfeeding mothers by adhering to the Ten Steps and complying with the International Code of Marketing of Breastmilk Substitutes. An Indonesian survey in 2011 found that less than one in 10 government hospitals implemented the Ten Steps. It has been common for Indonesian health services to collaborate with infant formula companies. While no Indonesian hospitals are currently BFHI-accredited, the WHO/UNICEF Ten Steps (updated in 2018) have been adopted in Indonesia’s national regulation of maternity facilities since 2012. Internationally, implementation of the Ten Steps individually and as a package has been associated with benefits to breastfeeding rates and maternal and infant health. However, to date, few studies have examined the impact of implementing the Ten Steps in economic terms. This study aims to measure the economic benefit of Ten Steps implementation in an Indonesian hospital. Methods: The study was conducted in January 2020 in Airlangga University Hospital, Surabaya, Indonesia, which has implemented the Ten Steps since it was established in 2012. To understand and generate evidence on the social value of the Ten Steps, we conducted a “Social Return on Investment (SROI)” study of implementing the Ten Steps in this maternity facility. To estimate the costs relating to the Ten Steps we interviewed the financial and nursing managers, a senior pediatrician, and senior midwife due to their detailed understanding of the implementation of the Ten Steps in the hospital. The interview was guided by a questionnaire which we developed based on the 2018 WHO/UNICEF Ten Steps to Successful Breastfeeding. The analysis was supported with peer-reviewed literature on the benefits of Ten Steps breastfeeding outcomes. Results: The total per annum value of investment (cost) required to implement Ten Steps in Airlangga University Hospital was US$ 972,303. The estimate yearly benefit was US$ 22,642,661. The social return on the investment in implementing Ten Steps in this facility was calculated to be US$ 49 (sensitivity analysis: US$ 18-65). Thus, for every US$ 1 invested in Ten Steps implementation by Airlangga Hospital could be expected to generate approximately US$ 49 of benefit. Conclusions: Investment in the Ten Steps implementation in this Surabaya maternity facility produced a social value 49 times greater than the cost of investment. This provides novel evidence of breastfeeding as a public health tool, demonstrating the value of the investment, in terms of social impact for mothers, babies, families, communities, and countries. Breastfeeding has the potential to help address inequity throughout the lifetime by providing the equal best start to all infants regardless of their background. Indonesia’s initial moves towards implementing the WHO/UNICEF Ten Steps can be strengthened by integrating all elements into the national regulation and health care system.