Hair follicle development and related gene and protein expression of skins in Rex rabbits during the first 8 weeks of life

Objective We aimed to observe hair follicle (HF) development in the dorsal skin and elucidate the expression patterns of genes and proteins related to skin and HF development in Rex rabbits from birth to 8 weeks of age. Methods Whole-skin samples were obtained from the backs of Rex rabbits at 0, 2, 4, 6, and 8 weeks of age, the morphological development of primary and secondary HFs was observed, and the gene transcript levels of insulin-like growth factor-I (IGF-I), epidermal growth factor (EGF), bone morphogenetic protein 2 (BMP2), transforming growth factor β-1, 2, and 3 (TGFβ-1, TGFβ-2, and TGFβ-3) were examined using quantitative real-time polymerase chain reaction (PCR). Additionally, Wnt family member 10b (Wnt10b) and β-Catenin gene and protein expression were examined by quantitative real-time PCR and western blot, respectively. Results The results showed significant changes in the differentiation of primary and secondary HFs in Rex rabbits during their first 8 weeks of life. The IGF-I, EGF, TGFβ-2, and TGFβ-3 transcript levels in the rabbits were significantly lower at 2 weeks of age than at birth and gradually increased thereafter, while the BMP2 and TGFβ-1 transcript levels at 2 weeks of age were significantly higher than those at birth and gradually decreased thereafter. β-Catenin gene expression was also significantly affected by age, while the Wnt10b transcript level was not. However, the Wnt10b and β-catenin protein expression levels were the lowest at 2 and 4 weeks of age. Conclusion Our data showed that a series of changes in HFs in dorsal skin occurred during the first 8 weeks. Many genes, such as IGF-I, EGF, BMP2, TGFβ-1, TGFβ-2, TGFβ-3, and β-Catenin, participated in this process, and the related proteins Wnt10b and β-Catenin in skin were also affected by age

A genome-wide association study of coat color in Chinese Rex rabbits

Coat color is an important phenotypic characteristic of the domestic rabbit (Oryctolagus cuniculus) and has specific economic importance in the Rex rabbit industry. Coat color varies considerably among different populations of rabbits, and several causal genes for this variation have been thoroughly studied. Nevertheless, the candidate genes affecting coat color variation in Chinese Rex rabbits remained to be investigated. In this study, we collected blood samples from 250 Chinese Rex rabbits with six different coat colors. We performed genome sequencing using a restriction site-associated DNA sequencing approach. A total of 91,546 single nucleotide polymorphisms (SNPs), evenly distributed among 21 autosomes, were identified. Genome-wide association studies (GWAS) were performed using a mixed linear model, in which the individual polygenic effect was fitted as a random effect. We detected a total of 24 significant SNPs that were located within a genomic region on chromosome 4 (OCU4). After re-fitting the most significant SNP (OCU4:13,434,448, p = 1.31e-12) as a covariate, another near-significant SNP (OCU4:11,344,946, p = 7.03e-07) was still present. Hence, we conclude that the 2.1-Mb genomic region located between these two significant SNPs is significantly associated with coat color in Chinese Rex rabbits. The well-studied coat-color-associated agouti signaling protein (ASIP) gene is located within this region. Furthermore, low genetic differentiation was also observed among the six coat color varieties. In conclusion, our results confirmed that ASIP is a putative causal gene affecting coat color variation in Chinese Rex rabbits

Targeted RNA N6‐Methyladenosine Demethylation Controls Cell Fate Transition in Human Pluripotent Stem Cells

Abstract Deficiency of the N6‐methyladenosine (m6A) methyltransferase complex results in global reduction of m6A abundance and defective cell development in embryonic stem cells (ESCs). However, it's unclear whether regional m6A methylation affects cell fate decisions due to the inability to modulate individual m6A modification in ESCs with precise temporal control. Here, a targeted RNA m6A erasure (TRME) system is developed to achieve site‐specific demethylation of RNAs in human ESCs (hESCs). TRME, in which a stably transfected, doxycycline‐inducible dCas13a is fused to the catalytic domain of ALKBH5, can precisely and reversibly demethylate the targeted m6A site of mRNA and increase mRNA stability with limited off‐target effects. It is further demonstrated that temporal m6A erasure on a single site of SOX2 is sufficient to control the differentiation of hESCs. This study provides a versatile toolbox to reveal the function of individual m6A modification in hESCs, enabling cell fate control studies at the epitranscriptional level

Light- and Electric-Field-Controlled Wetting Behavior in Nanochannels for Regulating Nanoconfined Mass Transport

Water wetting behavior in nanoconfined environments plays an important role in mass transport and signal transmission of organisms. It is valuable and challenging to investigate how water behaves in such a nanometer-scale with external stimuli, in particular with electric field and light. Unfortunately, the mechanism of hydrophobic reaction inside the nanospaces is still obscure and lacks experimental support for the current electric-field- or photoresponsive nanochannels which suffer from fragility or monofunctionality. Here, we design functionalized hydrophobic nanopores to regulate ion transport by light and electric field using azobenzene-derivatives-modified polymer nanochannels. With these addressable features, we can control the pore surface wetting behavior to switch the nanochannels between nonconducting and conducting states. Furthermore, we found these hydrophobic nanochannels are rough with a contact angle of 67.3°, making them extremely different from the familiar ones with a smooth pore surface and larger contact angles (>90°). These findings point to new opportunities for studying and manipulating water behavior in nanoconfined environments