Whole Genome Sequencing Identifies a Missense Mutation in HES7 Associated with Short Tails in Asian Domestic Cats.

Domestic cats exhibit abundant variations in tail morphology and serve as an excellent model to study the development and evolution of vertebrate tails. Cats with shortened and kinked tails were first recorded in the Malayan archipelago by Charles Darwin in 1868 and remain quite common today in Southeast and East Asia. To elucidate the genetic basis of short tails in Asian cats, we built a pedigree of 13 cats segregating at the trait with a founder from southern China and performed linkage mapping based on whole genome sequencing data from the pedigree. The short-tailed trait was mapped to a 5.6 Mb region of Chr E1, within which the substitution c. 5T > C in the somite segmentation-related gene HES7 was identified as the causal mutation resulting in a missense change (p.V2A). Validation in 245 unrelated cats confirmed the correlation between HES7-c. 5T > C and Chinese short-tailed feral cats as well as the Japanese Bobtail breed, indicating a common genetic basis of the two. In addition, some of our sampled kinked-tailed cats could not be explained by either HES7 or the Manx-related T-box, suggesting at least three independent events in the evolution of domestic cats giving rise to short-tailed traits.

The genetic basis of white tigers.

The white tiger, an elusive Bengal tiger (Panthera tigris tigris) variant with white fur and dark stripes, has fascinated humans for centuries ever since its discovery in the jungles of India. Many white tigers in captivity are inbred in order to maintain this autosomal recessive trait and consequently suffer some health problems, leading to the controversial speculation that the white tiger mutation is perhaps a genetic defect. However, the genetic basis of this phenotype remains unknown. Here, we conducted genome-wide association mapping with restriction-site-associated DNA sequencing (RAD-seq) in a pedigree of 16 captive tigers segregating at the putative white locus, followed by whole-genome sequencing (WGS) of the three parents. Validation in 130 unrelated tigers identified the causative mutation to be an amino acid change (A477V) in the transporter protein SLC45A2. Three-dimensional homology modeling suggests that the substitution may partially block the transporter channel cavity and thus affect melanogenesis. We demonstrate the feasibility of combining RAD-seq and WGS to rapidly map exotic variants in nonmodel organisms. Our results identify the basis of the longstanding white tiger mystery as the same gene underlying color variation in human, horse, and chicken and highlight its significance as part of the species' natural polymorphism that is viable in the wild.

[An experimental study of expression of angiotension converting enzyme 2 in myocardium and effect of telmisartan treatment in pressure-overloaded rats].

OBJECTIVE: To study the effect of hypertension and telmisartan treatment on the protein and gene expression of cardiac angiotensin-converting enzyme 2 (ACE2) in pressure-overloaded rats. METHODS: Coarctation of suprarenal abdominal aorta was reproduced in 8 week-old male Sprague-Dawley (SD) rats and then randomized into 4 groups, including a sham group (n=15), a suprarenal aortic coarctation group (model group, n=12), a suprarenal aortic coarctation with low-dose Telmisartan treatment group (low-dose group, 2 mgxkg(-1)xd(-1), n=11) and a suprarenal aortic coarctation with high-dose Telmisartan treatment group(high-dose group, 10 mgxkg(-1)xd(-1), n=13). Telmisartan or equivalent amount of normal saline was gavaged 24 hours before the operation and once every day afterwards for 3 weeks. At the end of 3 weeks, the concentrations of angiotensin (AngII) in plasma and myocardium were measured by radioimmunoassay. Changes in both protein quantity and gene expressions of both ACE2 and ACE were determined by Western blotting analysis and reverse transcription-polymerase chain reaction (RT-PCR) technique, respectively. RESULTS: Suprarenal abdominal aortic coarctation induced a significant increase in the plasma and myocardium AngII concentration [plasma: (495.1+/-55.6) ng/L vs. (269.2+/-39.5)ng/L, myocardium: (103.6+/-23.7) ng/g vs. (49.5+/-13.5) ng/g, both P<0.01] and expressions of gene and protein of ACE (P<0.01) and ACE2 (P<0.05). Telmisartan further increased the concentration of AngII in plasma and myocardium in a dose-dependent manner [plasma: (702.2+/-40.6) ng/L vs. (612.6+/-35.5) ng/L, myocardium (211.5+/-21.5) ng/g vs. (189.6+/-43.6) ng/g, both P<0.05], and induced a dose-dependent increase in both protein and gene expression of ACE2 (protein 1.16+/-0.06 vs. 0.79+/-0.04, gene 0.54+/-0.08 vs. 0.41+/-0.04, both P<0.05). Expression of ACE2 protein in low-dose and high-dose groups was increased by 1.0 and 1.58 folds respectively, and gene was increased by 1.3 and 1.6 folds (all P<0.05). The expression of ACE protein and gene in model group increased significantly (protein: 2.10+/-1.07 vs. 1.02+/-0.05, gene: 1.93+/-0.09 vs. 0.26+/-0.09, both P<0.01). Telmisartan had no significant effect on ACE gene and protein expressions (both P>0.05). CONCLUSION: Suprarenal abdominal aortic coarctation induced a significant increases of ACE and ACE2 gene and protein expressions. Telmisartan induces a dose-dependent increases of cardiac ACE2 gene and protein expression,which may be the mechanism of its therapeutic effects.

Peratrial closure of atrial septal defects without cardiopulmonary bypass.

The objective of this study was to introduce a new technique for occlusion of an atrial septal defect without cardiopulmonary bypass, using a modified Amplatzer device. Between October 2004 and November 2005, 96 secundum atrial septal defects in 83 patients were occluded by this method. A 3-cm incision in the right 4(th) intercostal space and a minithoracotomy were performed. Via this incision, the right atrium was exposed and the septal closure device was deployed under transesophageal echocardiographic guidance. The sizes of the defects ranged from 10 to 39 mm. The mean device size was 34.1 +/- 9 mm (12-46 mm). There was no operative mortality and no major morbidity on follow-up of 3-15 months. This new minimally invasive method of secundum atrial septal defect closure is safe and cosmetically superior to conventional surgery. Avoidance of cardiopulmonary bypass can reduce recovery time and complications. The indications are more extensive than percutaneous transcatheter closure, and the results are encouraging.

[Study on up-regulation of the expression of angiotensin-converting enzyme-2 in human umbilical vein endothelial cells by telmisartan].

OBJECTIVE: To investigate the effect of telmisartan on the protein and gene expression of angiotensin-converting enzyme-2 (ACE2) in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with various concentrations of telmisartan (10(-7), 10(-6) and 10(-5) mol/L) for 24 hours. In a time-control experiment, HUVECs were treated with telmisartan at the final concentration of 10(-6) mol/L for 6, 12 and 24 hours, respectively. In another experiment, HUVECs were treated with PD123319 (10(-6) mol/L) only or combined with same final concentration of telmisartan for 12 hours, respectively. Changes in both protein and gene expression of ACE2 were determined with Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) technique, respectively. RESULTS: Telmisartan induced a concentration and time dependent increase in both protein and gene expression of ACE2 (P<0.05 or P<0.01). Compared with control group, treatment of HUVECs with telmisartan at the concentration of 10(-7), 10(-6) and 10(-5) mol/L stimulated 1.5-, 2.7- and 4.6-fold increase in the ACE2 protein expression, as well as 1.2-, 2.3- and 4.5-fold increase in its gene expression, respectively. After treatment of HUVECs with telmisartan for 6, 12, and 24 hours at the concentration of 10(-6) mol/L, the ACE2 protein expression increased 1.6-, 2.7- and 4.2-fold, and its gene expression increased 1.3-, 2.3- and 4.0-fold, respectively. Compared with control and telmisartan groups, PD123319 had no effect on both protein and gene expression of ACE2 (P>0.05). CONCLUSION: Telmisartan up-regulates the protein and gene expression of ACE2 in HUVECs in a concentration and time dependent manner. This effect may be mediated via its specific pathway.

In vivo distribution of c-myc antisense oligodeoxynucleotides local delivered by gelatin-coated platinum-iridium stents in rabbits and its effect on apoptosis.

BACKGROUND: Post-stenting restenosis is a significant clinical problem, involving vascular smooth muscle cells (VSMCs) proliferation and apoptosis. It is reported that c-myc antisense oligodeoxynucleotides (ASODNs) local delivered by catheter can inhibit VSMCs proliferation. This study was designed to assess tissue distribution of c-myc ASODN local delivered using gelatin-coated platinum-iridium (Pt-Ir) stents, and its effect on apoptosis of VSMCs. METHODS: Gelatin-coated Pt-Ir stents that had absorbed caroboxyfluorescein-5-succimidyl ester (FAM) labeled c-myc ASODNs (550 microg per stent) were implanted into the right carotid arteries of 6 rabbits. Tissue samples were obtained at 45 minutes, 2 hours, and 6 hours. Tissue distribution of c-myc ASODNs was assessed by fluorescence microscopy. In addition, 32 rabbits were randomly divided into two groups. Rabbits in the control group (n = 16) were implanted with gelatin-coated Pt-Ir stents, and those in the treatment group (n = 16) were implanted with gelatin-coated stents that had absorbed c-myc ASODNs. 7, 14, 30, or 90 days (n = 4, respectively, for each group) after the stenting procedure, the stented segments were harvested, and histopathological examinations were performed to calculate neointimal area and mean neointimal thickness. The expression of c-myc was assessed using in situ hybridization (ISH) and immunohistochemical methods. Apoptotic VSMCs were detected using terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM). RESULTS: According to fluorescence microscopic results, FAM-labeled c-myc ASODNs were concentrated in the target vessel media at the 45 minutes time point, and then dispersed to the adventitia. Morphometric analysis showed that neointimal area and mean neointimal thickness increased continuously up to 90 days after stent implantation, but that total neointimal area and mean neointimal thickness were less in the treatment group than in the control group at all time points (P < 0.0001). At day 7 and day 14 after stenting, there were no detectable apoptotic cells in either group. However, apoptotic cells were present in the neointima 30 and 90 days after stenting, and the number of apoptotic cells was less at 30 days than at 90 days. Meanwhile, c-myc ASODNs appeared to induce apoptosis in more cells in the treatment group than that in the control group. Typical apoptotic VSMCs were observable under TEM. The expression of c-myc was positive in the control group and negative or weakly positive in the c-myc ASODN treatment group, according to both ISH and immunohistochemical examination. CONCLUSION: Gelatin-coated Pt-Ir stent mediated local delivery of c-myc ASODNs is feasible. The localization of c-myc ASODN is primarily in the target vessel walls. c-myc ASODNs can inhibit VSMCs proliferation and induce its apoptosis after local delivery in vivo.

Prognostic value of exercise in combination with 24-hour ambulatory blood pressure monitoring in elderly hypertensive patients.

OBJECTIVE: To investigate the prognostic value of exercise combined with 24-hour ambulatory blood pressure monitoring (ABPM) in the elderly hypertensive patients. METHODS: Forty-five patients over 60 years old were asked to perform submaximal exercise with controlled symptoms according to modified Bruce protocol to detect exercise-induced hypertension, followed by ABPM. RESULTS: The blood pressure of all the patients was within normal range, but the exercise induced the peak blood pressure reached 211.98+/-9.37 mmHg/101.50+/-12.86 mmHg. Fourteen patients with exercise-induced hypertension conformed to the diagnosis of hypertension according to ABPM, who had significantly higher measurements in ABPM than the normotensive patients (P<0.001). CONCLUSION Exercise test combined with ABPM may help identify hypertension in early stage in elderly patients.