Relationships among tetraploid wheat (Triticum turgidum L.) landrace populations revealed by isozyme markers and agronomic traits

Diversity and relationships among ten tetraploid wheat landrace populations, collected from different localities in the central highlands of Ethiopia, were studied using isozyme markers and agronomic traits. This type of analysis in crop species is fundamental for designing optimal germ plasm collection, management practices and for developing an index for parental selection. The populations differed in allelic frequencies. Gene-diversity estimates showed that the populations encompass an appreciable amount of variation. However, differentiation between them was low, as was also confirmed by the presence of gene flow. Much of the diversity (85%), was attributable to the within-population level. The genetic distances were mostly small with the exception of those between a few pairs of populations. Thus, the relationships discerned among the populations were more of a similarity nature which could be ascribed to sharing a common ancestral population and/or adaptation to similar climatic conditions. The pattern of genetic divergence appeared to be independent of geographic distance. Considerable divergence in the agronomic traits was observed for certain populations. Cluster analyses of the isozyme and agronomic data produced different patterns and memberships of groupings. This lack of agreement could be ascribed to the different forces of evolution acting on isozyme markers and agronomic traits since agronomic traits, are the prime target of artificial selection. The clustering based on agronomic traits resulted in grouping together populations with similar agronomic performance. The results of this study suggest that taking more samples within a locality or population would be a better approach to capture the range of variation in the landrace populations of the central highlands of Ethiopia.     

Current Efavirenz (EFV) or Ritonavir-Boosted Lopinavir (LPV/r) Use Correlates with Elevate Markers of Atherosclerosis in HIV-Infected Subjects in Addis Ababa,Ethiopia

Background

HIV patients on antiretroviral therapy have shown elevated incidence of dyslipidemia, lipodystrophy, and cardiovascular disease (CVD). Most studies, however, focus on cohorts from developed countries, with less data available for these co-morbidities in Ethiopia and sub-Saharan Africa.

Methods

Adult HIV-negative (n = 36), treatment naïve (n = 51), efavirenz (EFV)-treated (n = 91), nevirapine (NVP)-treated (n = 95), or ritonavir-boosted lopinavir (LPV/r)-treated (n=44) subjects were recruited from Black Lion Hospital in Addis Ababa, Ethiopia. Aortic pressure, augmentation pressure, and pulse wave velocity (PWV) were measured via applanation tonometry and carotid intima-media thickness (cIMT) and carotid arterial stiffness, and brachial artery flow-mediated dilation (FMD) were measured via non-invasive ultrasound. Body mass index, waist-to-hip circumference ratio (WHR), skinfold thickness, and self-reported fat redistribution were used to quantify lipodystrophy. CD4+ cell count, plasma HIV RNA levels, fasting glucose, total-, HDL-, and LDL-cholesterol, triglycerides, hsCRP, sVCAM-1, sICAM-1, leptin and complete blood count were measured.

Results

PWV and normalized cIMT were elevate and FMD impaired in EFV- and LPV/r-treated subjects compared to NVP-treated subjects; normalized cIMT was also elevated and FMD impaired in the EFV- and LPV/r-treated subjects compared to treatment-naïve subjects. cIMT was not statistically different across groups. Treated subjects exhibited elevated markers of dyslipidemia, inflammation, and lipodystrophy. PWV was associated with age, current EFV and LPV/r used, heart rate, blood pressure, triglycerides, LDL, and hsCRP, FMD with age, HIV duration, WHR, and glucose, and cIMT with age, current EFV use, skinfold thickness, and blood pressure.

Conclusions

Current EFV- or LPV/r-treatment, but not NVP-treatment, correlated with elevated markers of atherosclerosis, which may involve mechanisms distinct from traditional risk factors.     

Azole-based inhibitors of AKT/PKB for the treatment of cancer

Through a combination of screening and structure-based rational design, we have discovered a series of N¹-(5-(heterocyclyl)-thiazol-2-yl)-3-(4-trifluoromethylphenyl)-1,2-propanediamines that were developed into potent ATP competitive inhibitors of AKT. Studies of linker strand-binding adenine isosteres identified SAR trends in potency and selectivity that were consistent with binding interactions observed in structures of the inhibitors bound to AKT1 and to the counter-screening target PKA. One compound was shown to have acceptable pharmacokinetic properties and to be a potent inhibitor of AKT signaling and of in vivo xenograft tumor growth in a preclinical model of glioblastoma.     

Regulation of ISW2 by concerted action of histone H4 tail and extranucleosomal DNA

The stable contact of ISW2 with nucleosomal DNA approximately 20 bp from the dyad was shown by DNA footprinting and photoaffinity labeling using recombinant histone octamers to require the histone H4 N-terminal tail. Efficient ISW2 remodeling also required the H4 N-terminal tail, although the lack of the H4 tail can be mostly compensated for by increasing the incubation time or concentration of ISW2. Similarly, the length of extranucleosomal DNA affected the stable contact of ISW2 with this same internal nucleosomal site, with the optimal length being 70 to 85 bp. These data indicate the histone H4 tail, in concert with a favorable length of extranucleosomal DNA, recruits and properly orients ISW2 onto the nucleosome for efficient nucleosome remodeling. One consequence of this property of ISW2 is likely its previously observed nucleosome spacing activity.     

PERMANENT GENETIC RESOURCES: Twelve polymorphic microsatellite markers for the bonefish, Albula vulpes and two congeners

Twelve polymorphic microsatellite loci were isolated for the bonefish, Albula vulpes using a polymerase chain reaction‐based procedure. The number of alleles ranged from two to 23 (mean = 8.8) in 37 specimens from south Florida. Observed and expected heterozygosities ranged from 0.07 to 0.77 (mean = 0.42) and from 0.07 to 0.84 (mean = 0.48), respectively. There were no significant departures from Hardy–Weinberg equilibrium and no evidence of genotypic disequilibrium between any pair of loci. In a cross‐amplification test, all markers yielded appropriately sized alleles for specimens of the provisional Albula sp. B and 11 of the 12 loci amplified for those of Albula glossodonta.     

Development of 15 polymorphic microsatellite markers in the Atlantic tarpon (Megalops atlanticus) for capture-recapture studies

Fifteen polymorphic microsatellite DNA loci for Atlantic tarpon, Megalops atlanticus, were isolated by using PIMA, a polymerase chain reaction‐based technique. The number of alleles at each locus ranged from two to 24 (mean = 7.7) in 65 specimens from Tampa Bay, Florida. Observed and expected heterozygosities ranged from 0.27 to 0.92 (mean = 0.60) and from 0.28 to 0.95 (mean = 0.62), respectively. Genotypes at one locus deviated significantly from Hardy–Weinberg equilibrium. In exact tests for genotypic disequilibrium, there was no evidence of associations between any pair of loci. Overall, loci were well resolved and highly polymorphic, confirming their suitability for DNA fingerprinting applications and other genetic studies.     

Ten di- and trinucleotide microsatellite loci in the Caribbean spiny lobster, Panulirus argus, for studies of regional population connectivity

We describe 10 microsatellite loci for Panulirus argus (Caribbean spiny lobster). The number of alleles at each locus ranged from four to 39 (mean = 21.8) in 89 juvenile specimens collected at two different times at a recruitment site in south Florida. Levels of expected and observed heterozygosities ranged from 0.48 to 0.96 (mean = 0.83) and from 0.32 to 0.98 (mean = 0.71), respectively. Significant departures from Hardy–Weinberg equilibrium were observed at two loci. There was no evidence of genotypic disequilibrium for any pair of loci. Overall, the loci were well resolved, highly polymorphic and independently segregating, confirming their utility for population genetic studies.     

Tool-assisted predation on a squirrel by a female chimpanzee in the Mahale Mountains,Tanzania

A 12-year-old female chimpanzee (Pan troglodytes schweinfurthii) of M-Group in the Mahale Mountains National Park, Tanzania was seen to rouse, capture, and eat a squirrel hiding in the narrow hole of a tree. The kill was aided by the use of a sturdy tool modified from a branch of the same tree. This appears to be the first reported case for chimpanzees, or any other nonhuman primate, of tool-use that directly led to the capture of a mammalian prey species. This behavior is discussed in relation to possible factors contributing to the occurrence of tool-use in small mammal predation especially by females to exploit a low competition meat source.     

Topography of the ISW2-nucleosome complex: insights into nucleosome spacing and chromatin remodeling

Linker DNA was found to be critical for the specific docking of ISW2 with nucleosomes as shown by mapping the physical contacts of ISW2 with nucleosomes at base-pair resolution. Hydroxyl radical footprinting revealed that ISW2 not only extensively interacts with the linker DNA, but also approaches the nucleosome from the side perpendicular to the axis of the DNA superhelix and contacts two disparate sites on the nucleosomal DNA from opposite sides of the superhelix. The topography of the ISW2-nucleosome was further delineated by finding which of the ISW2 subunits are proximal to specific sites within the linker and nucleosomal DNA regions by site-directed DNA photoaffinity labeling. Although ISW2 was shown to contact approximately 63 bp of linker DNA, a minimum of 20 bp of linker DNA was required for stable binding of ISW2 to nucleosomes. The remaining approximately 43 bp of flanking linker DNA promoted more efficient binding under competitive binding conditions and was functionally important for enhanced sliding of nucleosomes when ISW2 was significantly limiting.     

A single 24 h recall overestimates exclusive breastfeeding practices among infants aged less than six months in rural Ethiopia

Background

Exclusive breastfeeding (EBF) to six months is one of the World Health Organization’s (WHOs) infant and young child feeding (IYCF) core indicators. Single 24 h recall method is currently in use to measure exclusive breastfeeding practice among children of age less than six months. This approach overestimates the prevalence of EBF, especially among small population groups. This justifies the need to look for alternative measurement techniques to have a valid estimate regardless of population characteristics.

Method

The study involved 422 infants of age less than six months, living in Gurage zone, Southern Ethiopia. The study was conducted from January to February 2016. Child feeding practices were measured for seven consecutive days using 24 h recall method. Recall since birth, was used to measure breastfeeding practices from birth to the day of data collection. Data on EBF obtained by using single 24 h recall were compared with seven days repeated 24 h recall method. McNemar’s test was done to assess if a significant difference existed in rates of EBF between measurement methods.

Result

The mean age of infants in months was 3 (SD ?1.43). Exclusive breastfeeding prevalence was highest (76.7%; 95% CI 72.6, 80.8) when EBF was estimated using single 24 h recall. The prevalence of EBF based on seven repeated 24 h recall was 53.2% (95% CI: 48.3, 58.0). The estimated prevalence of EBF since birth based on retrospective data (recall since birth) was 50.2% (95% CI 45.4, 55.1). Compared to the EBF estimates obtained from seven repeated 24 h recall, single 24 h recall overestimated EBF magnitude by 23 percentage points (95% CI 19.2, 27.8). As the number of days of 24 h recall increased, a significant decrease in overestimation of EBF was observed.

Conclusion

A significant overestimation was observed when single 24 h recall was used to estimate prevalence of EBF compared to seven days of 24 h recall. By increasing the observation days we can significantly decrease the degree of overestimation. Recall since birth presented estimates of EBF that is close to seven repeated 24 h recall. This suggests that a week recall could be an alternative indicator to single 24 h recall.