Generation of ESTs for Flowering Gene Discovery and SSR Marker Development in Upland Cotton

BACKGROUND: Upland cotton, Gossypium hirsutum L., is one of the world's most important economic crops. In the absence of the entire genomic sequence, a large number of expressed sequence tag (EST) resources of upland cotton have been generated and used in several studies. However, information about the flower development of this species is rare. METHODOLOGY/PRINCIPAL FINDINGS: To clarify the molecular mechanism of flower development in upland cotton, 22,915 high-quality ESTs were generated and assembled into 14,373 unique sequences consisting of 4,563 contigs and 9,810 singletons from a normalized and full-length cDNA library constructed from pooled RNA isolated from shoot apexes, squares, and flowers. Comparative analysis indicated that 5,352 unique sequences had no high-degree matches to the cotton public database. Functional annotation showed that several upland cotton homologs with flowering-related genes were identified in our library. The majority of these genes were specifically expressed in flowering-related tissues. Three GhSEP (G. hirsutum L. SEPALLATA) genes determining floral organ development were cloned, and quantitative real-time PCR (qRT-PCR) revealed that these genes were expressed preferentially in squares or flowers. Furthermore, 670 new putative microsatellites with flanking sequences sufficient for primer design were identified from the 645 unigenes. Twenty-five EST-simple sequence repeats were randomly selected for validation and transferability testing in 17 Gossypium species. Of these, 23 were identified as true-to-type simple sequence repeat loci and were highly transferable among Gossypium species. CONCLUSIONS/SIGNIFICANCE: A high-quality, normalized, full-length cDNA library with a total of 14,373 unique ESTs was generated to provide sequence information for gene discovery and marker development related to upland cotton flower development. These EST resources form a valuable foundation for gene expression profiling analysis, functional analysis of newly discovered genes, genetic linkage, and quantitative trait loci analysis

[In Press] The influence of running shoes on familiarization time for treadmill running biomechanics evaluation

This study investigated treadmill familiarisation time in different shoe conditions by comparing lower limb consecutive kinematics waveforms using a trend symmetry method to calculate trend symmetry index, range amplitude ratio and range offset. Eighteen young adults (26.6 ± 3.3 years, 7 females) completed three 10-minute running trials at their preferred running speed (2.30 ± 0.17 m/s) on a treadmill with three shoe conditions (i.e., usual, minimalist and maximalist shoes) in a random order. Sagittal lower limb kinematic data were recorded using inertial measurement units. The results showed that sagittal-plane kinematic waveforms in the hip, knee and ankle remained consistent (trend symmetry > 0.95) without extreme excursions (range amplitude ratio ≈ 1) over 10 minutes within each testing shoe condition. Significant time × shoe interaction effect was observed in range offset (i.e., absolute differences in the average degree of kinematic waveforms between consecutive minutes) at ankle (p = 0.029, ŋp2 = 0.096) and knee (p = 0.002, ŋp2 = 0.126). Post-hoc analysis suggested that running with novel shoes required a shorter time to achieve stable lower limb kinematics (2 to 3 minutes) compared with usual shoes (7 minutes). In conclusion, young healthy adults need up to 3 and 7 minutes to familiarise to the treadmill when running at their preferred speed with their novel and usual running shoes