Rabbit Anti-Human YES1 (a.a. 275-526) Polyclonal antibody

TAF4b is a cell type-specific subunit of the general transcription factor TFIID. Here, we show that TAF4b is highly expressed in embryonic stem cells (ESC) and is down-regulated upon differentiation. To examine the role of TAF4b in ESC, we applied a knockdown (KD) approach. TAF4b depletion is associated with morphological changes and reduced expression of the self-renewal marker alkaline phosphatase. In contrast, KD of TAF4, a ubiquitously expressed TAF4b paralog, retained and even stabilized ESC stemness. Retinoic acid-induced differentiation was facilitated in the absence of TAF4b but was significantly delayed by TAF4 KD. Furthermore, TAF4b supports, whereas TAF4 inhibits, ESC proliferation and cell cycle progression. We identified a subset of TAF4b target genes preferentially expressed in ESC and controlling the cell cycle. Among them are the germ cell-specific transcription factor Sohlh2 and the protein kinase Yes1, which was recently shown to regulate ESC self-renewal. Interestingly, Sohlh2 and Yes1 are also targets of the pluripotency factor Oct4, and their regulation by Oct4 is TAF4b-dependent. Consistent with that, TAF4b but not TAF4 interacts with Oct4. Our findings suggest that TAF4b cooperates with Oct4 to regulate a subset of genes in ESC, whereas TAF4 is required for later embryonic developmental stages.

Background: Modern horses represent heterogeneous populations specifically selected for appearance and performance. Genomic regions under high selective pressure show characteristic runs of homozygosity (ROH) which represent a low genetic diversity. This study aims at detecting the number and functional distribution of ROHs in different horse populations using next generation sequencing data. Methods: Next generation sequencing was performed for two Sorraia, one Dulmen Horse, one Arabian, one Saxon-Thuringian Heavy Warmblood, one Thoroughbred and four Hanoverian. After quality control reads were mapped to the reference genome EquCab2.70. ROH detection was performed using PLINK, version 1.07 for a trimmed dataset with 11,325,777 SNPs and a mean read depth of 12. Stretches with homozygous genotypes of >40 kb as well as >400 kb were defined as ROHs. SNPs within consensus ROHs were tested for neutrality. Functional classification was done for genes annotated within ROHs using PANTHER gene list analysis and functional variants were tested for their distribution among breed or non-breed groups. Results: ROH detection was performed using whole genome sequences of ten horses of six populations representing various breed types and non-breed horses. In total, an average number of 3492 ROHs were detected in windows of a minimum of 50 consecutive homozygous SNPs and an average number of 292 ROHs in windows of 500 consecutive homozygous SNPs. Functional analyses of private ROHs in each horse revealed a high frequency of genes affecting cellular, metabolic, developmental, immune system and reproduction processes. In non-breed horses, 198 ROHs in 50-SNP windows and seven ROHs in 500-SNP windows showed an enrichment of genes involved in reproduction, embryonic development, energy metabolism, muscle and cardiac development whereas all seven breed horses revealed only three common ROHs in 50-SNP windows harboring the fertility-related gene YES1. In the Hanoverian, a total of 18 private ROHs could be shown to be located in the region of genes potentially involved in neurologic control, signaling, glycogen balance and reproduction. Comparative analysis of homozygous stretches common in all ten horses displayed three ROHs which were all located in the region of KITLG, the ligand of KIT known to be involved in melanogenesis, haematopoiesis and gametogenesis. Conclusions: The results of this study give a comprehensive insight into the frequency and number of ROHs in various horses and their potential influence on population diversity and selection pressures. Comparisons of breed and non-breed horses suggest a significant artificial as well as natural selection pressure on reproduction performance in all types of horse populations.