Characterization of the early fiber development gene, Ligon-lintless 1 (Li1), using microarray

AbstractCotton fiber length is a key factor in determining fiber quality in the textile industry throughout the world. Understanding the molecular basis of fiber elongation would allow for improvement of fiber length. Ligon-lintless 1 (Li1) is a monogenic dominant mutation that results in short fibers. This mutant provides an excellent model system to study the molecular mechanisms of cotton fiber elongation. Microarray technology and quantitative real time PCR (qRT-PCR) were used to evaluate differentially expressed genes (DEGs) in the Ligon-lintless 1 (Li1) mutant compared to the wild-type. Although the results showed only a few differentially expressed genes at −1, 3 and 7days post anthesis (DPA); at 5 DPA, there were 1915 DEGs, including 984 up-regulated genes and 931 down-regulated genes. The critical stage for early termination of Li1 fiber elongation was 5 DPA, as there were the most differentially expressed genes in this sample. The transcription factors and other proteins identified might contribute to understanding the molecular basis of early fiber elongation. Gene ontology analysis identified some key GO terms that impact the regulation of fiber development during early elongation. These results provide some fundamental information about the TFs that might provide new insight into understanding the molecular mechanisms governing cotton fiber development

Dbh+ catecholaminergic cardiomyocytes contribute to the structure and function of the cardiac conduction system in murine heart

The heterogeneity of functional cardiomyocytes arises during heart development, which is essential to the complex and highly coordinated cardiac physiological function. Yet the biological and physiological identities and the origin of the specialized cardiomyocyte populations have not been fully comprehended. Here we report a previously unrecognised population of cardiomyocytes expressing Dbhgene encoding dopamine beta-hydroxylase in murine heart. We determined how these myocytes are distributed across the heart by utilising advanced single-cell and spatial transcriptomic analyses, genetic fate mapping and molecular imaging with computational reconstruction. We demonstrated that they form the key functional components of the cardiac conduction system by using optogenetic electrophysiology and conditional cardiomyocyte Dbh gene deletion models. We revealed their close relationship with sympathetic innervation during cardiac conduction system formation. Our study thus provides new insights into the development and heterogeneity of the mammalian cardiac conduction system by revealing a new cardiomyocyte population with potential catecholaminergic endocrine function

High-Density Linkage Map Construction and Mapping of Salt-Tolerant QTLs at Seedling Stage in Upland Cotton Using Genotyping by Sequencing (GBS)

Over 6% of agricultural land is affected by salinity. It is becoming obligatory to use saline soils, so growing salt-tolerant plants is a priority. To gain an understanding of the genetic basis of upland cotton tolerance to salinity at seedling stage, an intra-specific cross was developed from CCRI35, tolerant to salinity, as female with Nan Dan (NH), sensitive to salinity, as the male. A genetic map of 5178 SNP markers was developed from 277 F2:3 populations. The map spanned 4768.098 cM, with an average distance of 0.92 cM. A total of 66 QTLs for 10 traits related to salinity were detected in three environments (0, 110, and 150 mM salt treatment). Only 14 QTLs were consistent, accounting for 2.72% to 9.87% of phenotypic variation. Parental contributions were found to be in the ratio of 3:1, 10 QTLs from the sensitive and four QTLs from the resistant parent. Five QTLs were located in At and nine QTLs in the Dt sub-genome. Moreover, eight clusters were identified, in which 12 putative key genes were found to be related to salinity. The GBS-SNPs-based genetic map developed is the first high-density genetic map that has the potential to provide deeper insights into upland cotton salinity tolerance. The 12 key genes found in this study could be used for QTL fine mapping and cloning for further studies