SSR 69071

High affinity, potent inhibitor of human leukocyte elastase (HLE) (IC₅₀ = 3.9 nM). Displays species-selectivity (K_i values are 0.017, 1.70, 3.01, 58 and > 100 nM?for human, mouse, rat, rabbit and porcine elastase respectively). Inhibits HLE-induced lung hemorrhage in mice (ID₅₀ = 2.8 mg/kg) and reduces infarct size in an in vivo acute model of coronary ischemia-reperfusion injury. Orally active.

Development of 44 Novel Polymorphic SSR Markers for Determination of Shiitake Mushroom (Lentinula edodes) Cultivars.[Pubmed:28338645]

Genes (Basel). 2017 Mar 24;8(4). pii: genes8040109.

The shiitake mushroom (Lentinulaedodes) is one of the most popular edible mushrooms in the world and has attracted attention for its value in medicinal and pharmacological uses. With recent advanced research and techniques, the agricultural cultivation of the shiitake mushroom has been greatly increased, especially in East Asia. Additionally, demand for the development of new cultivars with good agricultural traits has been greatly enhanced, but the development processes are complicated and more challenging than for other edible mushrooms. In this study, we developed 44 novel polymorphic simple sequence repeat (SSR) markers for the determination of shiitake mushroom cultivars based on a whole genome sequencing database of L. edodes. These markers were found to be polymorphic and reliable when screened in 23 shiitake mushroom cultivars. For the 44 SSR markers developed in this study, the major allele frequency ranged from 0.13 to 0.94; the number of genotypes and number of alleles were each 2-11; the observed and expected heterozygosity were 0.00-1.00 and 0.10-0.90, respectively; and the polymorphic information content value ranged from 0.10 to 0.89. These new markers can be used for molecular breeding, the determination of cultivars, and other applications.

An SSR-based approach incorporating a novel algorithm for identification of rare maize genotypes facilitates criteria for landrace conservation in Mexico.[Pubmed:28331579]

Ecol Evol. 2017 Feb 10;7(6):1680-1690.

As maize was domesticated in Mexico around 9,000 years ago, local farmers have selected and maintained seed stocks with particular traits and adapted to local conditions. In the present day, many of these landraces are still cultivated; however, increased urbanization and migration from rural areas implies a risk that this invaluable maize germplasm may be lost. In order to implement an efficient mechanism of conservation in situ, the diversity of these landrace populations must be estimated. Development of a method to select the minimum number of samples that would include the maximum number of alleles and identify germplasm harboring rare combinations of particular alleles will also safeguard the efficient ex-situ conservation of this germplasm. To reach this goal, a strategy based on SSR analysis and a novel algorithm to define a minimum collection and rare genotypes using landrace populations from Puebla State, Mexico, was developed as a "proof of concept" for methodology that could be extended to all maize landrace populations in Mexico and eventually to other native crops. The SSR-based strategy using bulked DNA samples allows rapid processing of large numbers of samples and can be set up in most laboratories equipped for basic molecular biology. Therefore, continuous monitoring of landrace populations locally could easily be carried out. This methodology can now be applied to support incentives for small farmers for the in situ conservation of these traditional cultivars.

Development of Gene-Based SSR Markers in Winged Bean (Psophocarpus tetragonolobus (L.) DC.) for Diversity Assessment.[Pubmed:28282950]

Genes (Basel). 2017 Mar 9;8(3). pii: genes8030100.

Winged bean (Psophocarpus tetragonolobus) is an herbaceous multipurpose legume grown in hot and humid countries as a pulse, vegetable (leaves and pods), or root tuber crop depending on local consumption preferences. In addition to its different nutrient-rich edible parts which could contribute to food and nutritional security, it is an efficient nitrogen fixer as a component of sustainable agricultural systems. Generating genetic resources and improved lines would help to accelerate the breeding improvement of this crop, as the lack of improved cultivars adapted to specific environments has been one of the limitations preventing wider use. A transcriptomic de novo assembly was constructed from four tissues: leaf, root, pod, and reproductive tissues from Malaysian accessions, comprising of 198,554 contigs with a N50 of 1462 bp. Of these, 138,958 (70.0%) could be annotated. Among 9682 genic simple sequence repeat (SSR) motifs identified (excluding monomer repeats), trinucleotide-repeats were the most abundant (4855), followed by di-nucleotide (4500) repeats. A total of 18 SSR markers targeting di- and tri-nucleotide repeats have been validated as polymorphic markers based on an initial assessment of nine genotypes originated from five countries. A cluster analysis revealed provisional clusters among this limited, yet diverse selection of germplasm. The developed assembly and validated genic SSRs in this study provide a foundation for a better understanding of the plant breeding system for the genetic improvement of winged bean.

Development and validation of EST-SSR markers for Fokienia hodginsii (Cupressaceae).[Pubmed:28337393]

Appl Plant Sci. 2017 Mar 10;5(3). pii: apps1600152.

PREMISE OF THE STUDY: Fokienia hodginsii (Cupressaceae) is a Tertiary relict evergreen conifer of the monotypic genus Fokienia. Polymorphic microsatellite markers were developed to investigate its genetic diversity and population structure. METHODS AND RESULTS: RNA transcripts of F. hodginsii were sequenced and de novo assembled into 85,818 unigenes, and 1892 simple sequence repeat (SSR) markers were detected from the unigenes. A total of 273 expressed sequence tag-SSR primer pairs were designed and tested, and 129 successfully amplified. Eleven displayed clear polymorphisms in F. hodginsii. Amplification of these polymorphic primers across three populations of F. hodginsii showed the number of alleles per locus ranged from two to seven, and the expected heterozygosity per locus varied from 0.067 to 0.847. All 11 polymorphic primers amplified in Thuja occidentalis, while 10 amplified in T. standishii, Platycladus orientalis, and Chamaecyparis obtusa. CONCLUSIONS: These microsatellite markers will be useful in exploring genetic diversity of F. hodginsii and other conifer trees.