Identification and characterization of tsyl1, a thermosensitive chlorophyll-deficient mutant in rice (Oryza sativa).

Chloroplast development and chlorophyll biosynthesis are affected by temperature. However, the underlying molecular mechanism of this phenomenon remains elusive. Here, we isolated and characterized a thermosensitive yellow-green leaf mutant named tsyl1 (thermosensitive yellow leaf 1) from an ethylmethylsulfone (EMS)-mutagenized pool of rice. The mutant exhibits a yellow-green leaf phenotype and decreased leaf chlorophyll contents throughout development. At the mature stage of the tsyl1 mutant, the plant height, tiller number, number of spikelets per panicle and 1000 seed weight were decreased significantly compared to those of wild-type plants, but the seed setting rate and panicle length were not. The mutant phenotype was controlled by a single recessive nuclear gene on the short arm of rice chromosome 11. Map-based cloning of TSYL1, followed by a complementation experiment, showed a G base deletion at the coding region of LOC_Os11g05552, leading to the yellow-green phenotype. The TSYL1 gene encodes a signal recognition particle 54 kDa (SRP54) protein that is conserved in all organisms. The expression of tsyl1 was induced by high temperature. Furthermore, the expression of chlorophyll biosynthesis- and chloroplast development-related genes was influenced in tsyl1 at different temperatures. These results indicated that the TSYL1 gene plays a key role in chlorophyll biosynthesis and is affected by temperature at the transcriptional level.

Ultrasound biomicroscopy for the assessment of postoperative complications after congenital cataract surgery.

BACKGROUND: The aim of the present study was to investigate the role of ultrasound biomicroscopy (UBM) in the evaluation of postoperative complications in children with congenital cataracts. METHODS: A retrospective study was conducted between September 2012 and December 2016 at Guangzhou Women and Children's Medical Center. Red reflex test and high-resolution bag/balloon UBM were performed to evaluate postoperative congenital cataracts. The red reflex test results were recorded, and UBM imaging results were recorded and analyzed. Different postoperative complications were classified based on the UBM imaging features, and a second procedure was performed accordingly. The UBM images were compared with the images captured from the intraoperative videos. RESULTS: In total, we looked at 120 eyes in 96 patients (65 males and 31 females) in the present study. The age of the cohort was 3-76 months. A total of 51 eyes with poor red reflex were included. There were complications in 46 eyes after congenital cataract surgery, as detected by UBM, including posterior capsular opacification (n=29 eyes), pupil block (n=8 eyes), synechia (n=5 eyes), hyphema (n=1 eye), and abnormal intraocular lens (IOL) placement (n=3 eyes). UBM images showed specific features of postoperative complications. CONCLUSIONS: UBM is a valuable tool for the early evaluation of postoperative complications of congenital cataracts, especially for those with media opacities or when pupil dilation is not possible.

Ultrasound Biomicroscopy Detects Peters' Anomaly and Rieger's Anomaly in Infants.

AIM: Congenital corneal opacities (CCOs) are the major causes of early visual deprivation in infants. Balloon ultrasound biomicroscopy (UBM) examination is an effective method to diagnose CCO. However, whether it is suitable for children examination is still unknown. METHODS: 26 Peters' anomaly (PA) or Rieger's anomaly (RA) infants with congenital corneal opacities (CCO) (40 eyes) underwent UBM examinations to study their imaging features. RESULTS: Based on the results, they were divided into UBM Dx-Type I: Descemet's membrane (DM) and endothelium have heterogenous or discontinuous echo accompanied with corneal stroma echo-enhanced or shallow anterior chamber. Type II: Type I alteration plus abnormal strand of iris extended to the border of the posterior corneal defect or iridocorneal adhesion. Type III: Type I or II combined with the abnormal hyperechoic lens, lens luxation, or keratolenticular adhesion. Type IV: echoes of the DM and the endothelium are continuous, corneal stroma echo is enhanced, and an abnormal strand of peripheral iris extends to the prominent Schwalbe line, accompanied by iris stroma or pupil heteromorphism and a shallow or flat anterior chamber. CONCLUSION: UBM not only could accurately evaluate the anterior segment abnormalities in CCO infants but also would be a step forward for the management of PA- and RA-associated CCO.

Image features of lens opacity in pediatric cataracts using ultrasound biomicroscopy.

PURPOSE: To study lens opacity in pediatric cataract images captured using ultrasound biomicroscopy (UBM). METHODS: The medical records of patients operated on from September 2012 to October 2013 were reviewed retrospectively. Prior to surgery, patients were placed in the supine position under sedation with oral chloral hydrate for UBM imaging. Lens morphology was evaluated by UBM examination with a 50 MHz probe that was equipped with a water bag instead of the standard plastic shell. UBM images were compared to images captured from intraoperative videos. RESULTS: UBM examination was performed in 50 patients (including 10 infants) aged 2 months to 6 years. The UBM ecographic images showed features specific to pediatric cataract lenses. These features were used to define 2 types of anterior capsule of the lens, 4 types of cortex and nucleus of the lens, 3 types of posterior capsule of the lens, and membranous cataracts. CONCLUSIONS: Capsule morphology and the cortex density of pediatric cataracts could be evaluated before surgery using UBM imaging. Adoption of this technique could provide useful preoperative information to surgeons.