Skin colour: A window into human phenotypic evolution and environmental adaptation.

As modern humans ventured out of Africa and dispersed around the world, they faced novel environmental challenges that led to geographic adaptations including skin colour. Over the long history of human evolution, skin colour has changed dramatically, showing tremendous diversity across different geographical regions, for example, the majority of individuals from the expansive lands of Africa have darker skin, whereas the majority of people from Eurasia exhibit lighter skin. What adaptations did lighter skin confer upon modern humans as they migrated from Africa to Eurasia? What genetic mechanisms underlie the diversity of skin colour observed in different populations? In recent years, scientists have gradually gained a deeper understanding of the interactions between pigmentation gene and skin colour through population-based genomic studies of different groups around the world, particularly in East Asia and Africa. In this review, we summarize our current understanding of 26 skin colour-related pigmentation genes and 48 SNPs that influence skin colour. Important pigmentation genes across three major populations are described in detail: MFSD12, SLC24A5, PDPK1 and DDB1/CYB561A3/TMEM138 influence skin colour in African populations; OCA2, KITLG, SLC24A2, GNPAT and PAH are key to the evolution of skin pigmentation in East Asian populations; and SLC24A5, SLC45A2, TYR, TYRP1, ASIP, MC1R and IRF4 significantly contribute to the lightening of skin colour in European populations. We summarized recent findings in genomic studies of skin colour in populations that implicate diverse geographic environments, local adaptation among populations, gene flow and multi-gene interactions as factors influencing skin colour diversity.

Weakened tanning ability is an important mechanism for evolutionary skin lightening in East Asians.

The evolution of light-skin pigmentation among Eurasians is considered as an adaptation to the high-latitude environments. East Asians are ideal populations for studying skin color evolution because of the complex environment of East Asia. Here, we report a strong selection signal for the pigmentation gene phenylalanine hydroxylase (PAH) in light-skinned Han Chinese individuals. The intron mutation rs10778203 in PAH is enriched in East Asians and is significantly associated with skin color of the back of the hand in Han Chinese males (P < 0.05). In vitro luciferase and transcription factor binding assays show that the ancestral allele of rs10778203 could bind to SMAD2 and has a significant enhancer activity for PAH. However, the derived T allele (the major allele in East Asians) of rs10778203 decreases the binding activity of transcription factors and enhancer activity. Meanwhile, the derived T allele of rs10778203 shows a weaker ultraviolet radiation response in A375 cells and zebrafish embryos. Furthermore, rs10778203 decreases melanin production in transgenic zebrafish embryos after ultraviolet B (UVB) treatment. Collectively, PAH is a potential pigmentation gene that regulates skin tanning ability. Natural selection has enriched the adaptive allele, resulting in weakened tanning ability in East Asians, suggesting a unique genetic mechanism for evolutionary skin lightening in East Asians.

Room-Temperature Gate-Tunable Nonreciprocal Charge Transport in Lattice-Matched InSb/CdTe Heterostructures.

Symmetry manipulation can be used to effectively tailor the physical order in solid-state systems. With the breaking of both the inversion and time-reversal symmetries, nonreciprocal magneto-transport may arise in nonmagnetic systems to enrich spin-orbit effects. Here, the observation of unidirectional magnetoresistance (UMR) in lattice-matched InSb/CdTe films is investigated up to room temperature. Benefiting from the strong built-in electric field of 0.13 V nm-1 in the heterojunction region, the resulting Rashba-type spin-orbit coupling and quantum confinement result in a distinct sinusoidal UMR signal with a nonreciprocal coefficient that is 1-2 orders of magnitude larger than most non-centrosymmetric materials at 298 K. Moreover, this heterostructure configuration enables highly efficient gate tuning of the rectification response, wherein the UMR amplitude is enhanced by 40%. The results of this study advocate the use of narrow-bandgap semiconductor-based hybrid systems with robust spin textures as suitable platforms for the pursuit of controllable chiral spin-orbit applications.

Higher expression of mRNA and protein of insulin-like growth factor binding protein-3 in old rat penile tissues: implications for erectile dysfunction.

INTRODUCTION: Previous studies have confirmed the gene transfer of insulin-like growth factor-1 (IGF-1) and the IGF-1 protein can improve the erectile function in aging rats. IGF binding protein (BP)-3 can regulates the availability of IGF-I. The higher expression of IGFBP-3 may play an important role in erectile dysfunction (ED). AIM: The study aimed to investigate the mRNA and protein expression of IGFBP-3 in young and old rat penile tissues and assess the alteration of the penile structure and the NO-guanosine 3',5'-cyclic-monophosphate (cGMP) signaling pathways-related marker in ED associated with aging. MAIN OUTCOME MEASURES: The main outcome measures for this study were the expression of IGFBP-3, morphological changes, NO-cGMP signaling pathways-related marker, erectile responses were determined. METHODS: Traditional reverse transcriptase polymerase chain reaction (RT-PCR) and real-time PCR were performed to examine the mRNA expression of the IGFBP-3. The Western blot was used to confirm the protein expression. Immunohistochemistry was also performed to identify the cellular localization of the encoded protein. The percentage of smooth muscle in corpus cavernosum tissue, the activity of nitric oxide synthase (NOS), and concentration of cGMP in penile tissue were also analyzed. RESULTS: The expression levels of IGFBP-3 of mRNA and protein were greatly increased in aging rats compared with young control rats, which is confirmed by traditional RT-PCR, real-time PCR, and Western blot (P < 0.01, respectively). Increased IGFBP-3 protein was localized to the epithelium of the urethra, penile endothelium, and smooth muscle in the corpus cavernosum. Significant depletion of the smooth muscle density relative to the connective tissue was also observed in the penis of the aged rats, and the lower activity of NOS and lower concentration of cGMP was also demonstrated accompanied with a significant reduction in the intracavernous pressure. CONCLUSIONS: Our data suggest that the increased mRNA and protein expression of IGFBP-3 in old rats may play a role in ED.

Recent Progress of Inverted Perovskite Solar Cells with a Modified PEDOT:PSS Hole Transport Layer.

Organic-inorganic hybrid perovskite solar cells (PSCs) has achieved the power conversion efficiency (PCE) of 25.2% in the last 10 years, and the PCE of inverted PSCs has reached >22%. The rapid enhancement has partly benefited from the employment of suitable hole transport layers. Especially, poly(3,4-ethenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is one of the most widely used polymer hole transport materials in inverted PSCs, because of its high optical transparency in the visible region and low-temperature processing condition. However, the PCE and stability of PSCs based on pristine PEDOT:PSS are far from satisfactory, which are ascribed to low fitness between PEDOT:PSS and perovskite materials, in terms of work function, conductivity, film growth, and hydrophobicity. This paper summaries recent progress regarding to modifying/remedy the drawbacks of PEDOT:PSS to improve the PCE and stability. The systematically understanding of the mechanism of modified PEDOT:PSS and various characteristic methods are summarized here. This Review has the potential to guide the development of PSCs based on commercial PEDOT:PSS.

[Restriction landmark genomic scanning for screening aberrant CpG methylations in prostate cancer].

OBJECTIVE: To screen methylations of CpG islands in prostate cancer using restriction landmark genomic scanning (RLGS). METHODS: The DNA was extracted from homogeneous cells captured by laser capture microdissection in 20 prostate cancer and 18 benign prostatic hyperplasia (BPH) tissues for scanning the CpG islands using RLGS. The methylation status of each CpG island was compared between the cancer and BPH samples to screen the genes involved in prostate cancer development. The screened genes were uploaded to DAVID database for GO analysis, and the genes with the most significant methylation were analyzed by pyrosequencing. RESULTS AND CONCLUSION: Among all the tested CpG islands, 10245 (37.2%) in prostate cancer and 8658 (30.3%) in BPH samples were found to be abnormally methylated, and >60% of the methylated CpG islands were in the promoter region. Compared with BPH samples, the prostate cancer samples showed differential methyation in 735 CpG islands, including 458 hepermethyated and 256 hypomethelated ones. Seven genes (DPYS, P16, APC, GSTP1, TMEM122, RARB, and ARHGAP20) in prostate cancer were identified to have distinct methylations. Bioinformatics analysis suggested that these genes were associated with several biomolecular and biological processes, and among them DPYS gene was involved in 13 GO anotated biologic functions, development of 50 diseases and 47 protein interactions. Pyrosequencing of 7 sites of the CPG island in DPYS gene showed a methylation frequency of 32.7%, suggesting the importance of DPYS gene in the carcinogenesis and progression of prostate cancer.

[Clinical efficacy of transperitoneal verus retroperitoneal laparoscopic partial nephrectomy for renal tumors with R. E. N. A. L score over 7].

OBJECTIVE: To compare the safety, feasibility and efficacy of transperitoneal and retroperitoneal laparoscopic partial nephrectomy (LPN) in the treatment of renal tumors with R. E. N. A. L score more than 7. METHODS: The clinical data were collected from 62 patients undergoing transperitoneal LPN (32 cases) and retroperitoneal LPN (30 cases) for a complex renal mass (R.E.N.A.L. score≥7) between January 2012 and March 2014. The surgical and early postoperative outcomes and complications were analyzed to evaluate the efficacy of the treatments. The mean operative time, estimated blood loss, warm ischemia time, surgical complications, blood transfusion rate, tolerating regular diet time, postoperative hospital stay and surgical margin were compared between the two groups. RESULTS: The operations were completed successfully in all cases except for 1 case in transperitoneal group and 3 in retroperitoneal group that required conversion to open surgery. No significant differences were found in age, body mass index, ASA score, Charlson comorbidity index, tumor size or R.E.N.A.L. nephrometry score (P>0.05), nor in estimated blood loss, warm ischemia time, intraoperative complication, blood transfusion rate or surgical margin between the two groups (P>0.05, respectively). The transperitoneal LPN group had a shorter mean operative time than retroperitoneal LPN group (210.4∓59.2 vs 252∓58.3 min, P<0.05) but showed longer tolerating regular diet time (47∓10 h vs 23∓6 h, P<0.05) and postoperative hospital stay time (8.4∓1.9 days vs 6.5∓1.6 days, P<0.05). CONCLUSION: Both transperitoneal LPN and retroperitoneal LPN are safe, feasible and effective for surgical management of complex localized tumors, but the transperitoneal procedure offers larger operative space with better exposure; the retroperitoneal procedure better promotes postoperative recovery of the patients.