QTL mapping of morphological characteristics that correlated to drought tolerance in St. Augustinegrass.

St. Augustinegrass is a warm-season grass species widely utilized as turf in the southeastern U.S. It shows significant variation in plant growth and morphological characteristics, some of which are potentially associated with drought tolerance. However, the genetic basis of these variations is not well understood. Detecting quantitative trait loci (QTL) associated with morphological traits will provide a foundation for the application of genetic and molecular breeding in St. Augustinegrass. In this study, we report QTL associated with morphological traits, including leaf blade width (LW), leaf blade length (LL), canopy density (CD), and shoot growth orientation (SGO) in a St. Augustinegrass 'Raleigh' x 'Seville' mapping population containing 115 F1 hybrids. Phenotypic data were collected from one greenhouse and two field trials. Single and joint trial analyses were performed, finding significant phenotypic variance among the hybrids for all traits. Interval mapping (IM) and multiple QTL method (MQM) analysis detected seven QTL for CD, four for LL, five for LW, and two for SGO, which were distributed on linkage groups RLG1, RLG9, SLG3, SLG7, SLG8 and SLG9. In addition, three genomic regions where QTL colocalized were identified on Raleigh LG1 and Seville LG3. One genomic region on Seville LG3 overlapped with two previously reported drought-related QTL for leaf relative water content (RWC) and percent green cover (GC). Several candidate genes related to plant development and drought stress response were identified within QTL intervals. The QTL identified in this study represent a first step in identifying genes controlling morphological traits that might accelerate progress in selection of St. Augustinegrass lines with lower water usage.

Longitud cervical en la predicción de parto prematuro espontáneo y resultados perinatales en población de gemelos (dobles) en Hospital Provincial, Chile / Cervix measurement in spontaneous labor prediction and perinatal results in twins from a provincial hospital, Chile

RESUMEN Diversas publicaciones han demostrado que el acortamiento cervical es un elemento predictor de parto prematuro en embarazo gemelar. Los objetivos del presente trabajo fueron comparar los resultados perinatales de gestantes con longitud cervical (LC), entre las 20-24 semanas, ≤ 25mm y aquellas con LC > 25mm; y evaluar la capacidad predictiva para parto prematuro ≤ 32 semanas. Estudio analítico observacional, retrospectivo de cohorte, se recogieron los datos de las gestantes con embarazo gemelar doble, atendidas en el servicio de Obstetricia y Ginecología Hospital Las Higueras Talcahuano, durante los años 2010 al 2018; quienes se les había realizado al menos una evaluación cervical entre las 20 y 24 semanas; recolectando desde base de datos y ficha clínica sus datos perinatales. Se obtuvo los datos de 186 pacientes, la edad promedio de las pacientes fue 29 años, longitud cervical promedio fue 40,8 mm, parto promedio fue a las 35,6 semanas. El 71% de las gestantes fue gemelar Bicorial-Biamniótico y 29% Monocorial-Biamniótico. El 3,2% de los casos (n=6) tuvo longitud cervical ≤ 25mm en el segundo trimestre. En el grupo con longitud cervical ≤ 25 mm la EG al parto fue 30,7 semanas, con peso promedio de 1.555 gramos y una talla de 41,1 cm; mientras que estos mismos valores en el grupo con cérvix > 25 mm fueron 35,8 semanas, 2,527 gramos y 45,8 cm. La longitud cervical en relación a parto ≤ 32 semanas tuvo una sensibilidad de un 27,8%; especificidad de un 99,4%; VPP de 83,3% y un VPN de 92,8%. CONCLUSIÓN: Nuestros resultados muestran que la longitud cervical logra tener una gran especificidad, VPP y VPN en relación del parto prematuro ≤ 32 semanas, pero con una sensibilidad limitada. Pudiendo ser un buen método para identificar al embarazo gemelar en riesgo de parto prematuro ≤ 32 semanas.

ABSTRACT Several publications have shown that cervical shortening is a predictive element of premature delivery in twin pregnancy. The objectives of the present study were to compare the perinatal results of pregnant women with cervical length, between 20-24 weeks, ≤ 25mm and those with> 25mm; and evaluate the predictive capacity for premature delivery ≤ 32 weeks. An observational, cohort, retrospective, analytical study collected the data of pregnant women with double twin pregnancy treated at the Obstetrics and Gynecology Service Hospital Las Higueras Talcahuano during the years 2010 to 2018; who had at least one cervical measurement between 20 and 24 weeks of pregnancy; collecting perinatal data from database and clinical record. Data were obtained from 186 patients, the average age of the patients was 29 years, average cervical measurement was 40.8 mm, average delivery was 35.6 weeks. The 71% of pregnant women were twin BcBa and 29% McBa. The 3.2% (n = 6) had cervical measurement ≤ 25mm in the second trimester. In the group with cervical length ≤ 25 mm, the GA at delivery was 30.7 weeks, with an average weight of 1555 grams and a height of 41.1 cm; while these same values in the group with cervix > 25 mm were 35.8 weeks, 2527 grams and 45.8 cm. Cervical measurement in relation to childbirth ≤ 32 weeks had a sensitivity of 27.8%; specificity of 99.4%; PPV of 83.3% and a NPV of 92.8%. CONCLUSION: Our results show that cervical length has great specificity, PPV and NPV in relation to premature labor ≤ 32 weeks, but with limited sensitivity. It can be a good method to identify the twin pregnancy at risk of preterm birth ≤ 32 weeks.

Viral expression of ALS-linked ubiquilin-2 mutants causes inclusion pathology and behavioral deficits in mice.

BACKGROUND: UBQLN2 mutations have recently been associated with familial forms of amyotrophic lateral sclerosis (ALS) and ALS-dementia. UBQLN2 encodes for ubiquilin-2, a member of the ubiquitin-like protein family which facilitates delivery of ubiquitinated proteins to the proteasome for degradation. To study the potential role of ubiquilin-2 in ALS, we used recombinant adeno-associated viral (rAAV) vectors to express UBQLN2 and three of the identified ALS-linked mutants (P497H, P497S, and P506T) in primary neuroglial cultures and in developing neonatal mouse brains. RESULTS: In primary cultures rAAV2/8-mediated expression of UBQLN2 mutants resulted in inclusion bodies and insoluble aggregates. Intracerebroventricular injection of FVB mice at post-natal day 0 with rAAV2/8 expressing wild type or mutant UBQLN2 resulted in widespread, sustained expression of ubiquilin-2 in brain. In contrast to wild type, mutant UBQLN2 expression induced significant pathology with large neuronal, cytoplasmic inclusions and ubiquilin-2-positive aggregates in surrounding neuropil. Ubiquilin-2 inclusions co-localized with ubiquitin, p62/SQSTM, optineurin, and occasionally TDP-43, but were negative for α-synuclein, neurofilament, tau, and FUS. Mutant UBLQN2 expression also resulted in Thioflavin-S-positive inclusions/aggregates. Mice expressing mutant forms of UBQLN2 variably developed a motor phenotype at 3-4 months, including nonspecific clasping and rotarod deficits. CONCLUSIONS: These findings demonstrate that UBQLN2 mutants (P497H, P497S, and P506T) induce proteinopathy and cause behavioral deficits, supporting a "toxic" gain-of-function, which may contribute to ALS pathology. These data establish also that our rAAV model can be used to rapidly assess the pathological consequences of various UBQLN2 mutations and provides an agile system to further interrogate the molecular mechanisms of ubiquilins in neurodegeneration.