Detection of an exon 53 polymorphism in the dystrophin gene

We utilized a heteroduplex method to screen for small mutations in Duchenne muscular dystrophy patients who did not have deletions or duplications. A dystrophin exon 53 heteroduplex band was identified in 14.4% of the affected patients. Direct sequencing of the amplified product from DNA producing the heteroduplex revealed the presence of a polymorphism in the coding region. The codon for asparagine was converted from AAT to AAC.     

Comprehensive Analysis of the 16p11.2 Deletion and Null Cntnap2 Mouse Models of Autism Spectrum Disorder

Autism spectrum disorder comprises several neurodevelopmental conditions presenting symptoms in social communication and restricted, repetitive behaviors. A major roadblock for drug development for autism is the lack of robust behavioral signatures predictive of clinical efficacy. To address this issue, we further characterized, in a uniform and rigorous way, mouse models of autism that are of interest because of their construct validity and wide availability to the scientific community. We implemented a broad behavioral battery that included but was not restricted to core autism domains, with the goal of identifying robust, reliable phenotypes amenable for further testing. Here we describe comprehensive findings from two known mouse models of autism, obtained at different developmental stages, using a systematic behavioral test battery combining standard tests as well as novel, quantitative, computer-vision based systems. The first mouse model recapitulates a deletion in human chromosome 16p11.2, found in 1% of individuals with autism. The second mouse model harbors homozygous null mutations in Cntnap2, associated with autism and Pitt-Hopkins-like syndrome. Consistent with previous results, 16p11.2 heterozygous null mice, also known as Del(7Slx1b-Sept1)4Aam weighed less than wild type littermates displayed hyperactivity and no social deficits. Cntnap2 homozygous null mice were also hyperactive, froze less during testing, showed a mild gait phenotype and deficits in the three-chamber social preference test, although less robust than previously published. In the open field test with exposure to urine of an estrous female, however, the Cntnap2 null mice showed reduced vocalizations. In addition, Cntnap2 null mice performed slightly better in a cognitive procedural learning test. Although finding and replicating robust behavioral phenotypes in animal models is a challenging task, such functional readouts remain important in the development of therapeutics and we anticipate both our positive and negative findings will be utilized as a resource for the broader scientific community.     

Family Physicians' Barriers to Cancer Screening in Extremely Obese Patients

Extremely obese women are less likely than nonobese women to receive breast and cervical cancer screening examinations. Reasons for this disparity are unclear and may stem from patient and/or physician barriers. This sequential mixed‐methods study used individual in‐depth interviews of 15 family physicians followed by a mail survey of 255 family physicians (53% response rate) to understand the barriers they faced in performing cancer screening examinations in extremely obese women. Barriers fell into three main areas: (i) difficulty doing pelvic and breast exams; (ii) inadequate equipment; and (iii) challenges overcoming patient barriers and refusal. This led some physicians to avoid performing breast and pelvic examinations on extremely obese women. Having more knowledge about specific examination techniques was associated with less difficulty in palpating lumps on breast and pelvic examinations (P < 0.005). Physicians perceived that embarrassment, aversion to undressing, and avoidance of discussions related to their weight were the most frequent barriers extremely obese women had with getting physical examinations. Educating and/or motivating patients and addressing fears were strategies used most frequently when patients refused mammograms or Pap smears. Interventions focusing on physician barriers, such as educating them on specific examination techniques, obtaining adequate equipment and supplies, and providing resources to assist physicians in dealing with patient barriers and refusal, may be fruitful in increasing cancer screening rates in extremely obese patients. Future research studies testing the effectiveness of these strategies are needed to improve cancer outcomes in this high‐risk population.     

Mzm1 Influences a Labile Pool of Mitochondrial Zinc Important for Respiratory Function

Zinc is essential for function of mitochondria as a cofactor for several matrix zinc metalloproteins. We demonstrate that a labile cationic zinc component of low molecular mass exists in the yeast mitochondrial matrix. This zinc pool is homeostatically regulated in response to the cellular zinc status. This pool of zinc is functionally important because matrix targeting of a cytosolic zinc-binding protein reduces the level of labile zinc and interferes with mitochondrial respiratory function. We identified a series of proteins that modulate the matrix zinc pool, one of which is a novel conserved mitochondrial protein designated Mzm1. Mutant mzm1Δ cells have reduced total and labile mitochondrial zinc, and these cells are hypersensitive to perturbations of the labile pool. In addition, mzm1Δ cells have a destabilized cytochrome c reductase (Complex III) without any effects on Complexes IV or V. Thus, we have established that a link exists between Complex III integrity and the labile mitochondrial zinc pool.     

The ability of females to predict male status via urinary odors

In an earlier study, estrous female hamsters were found to prefer the urinary odors of dominant males. This study investigated whether estrous females would exhibit preferential responding to randomly chosen, socially naive males before dominance testing occurred. Estrous females were indeed found to exhibit such preferences. Such discriminative abilities are discussed with reference to adaptive mating strategies for females.     

Use of time-lapse microscopy to visualize rapid movement of the replication origin region of the chromosome during the cell cycle in Bacillus subtilis

We describe the use of time-lapse fluorescence microscopy to visualize the movement of the DNA replication origin and terminus regions on the Bacillus subtilis chromosome during the course of the cell cycle. The origin and terminus regions were tagged with a cassette of tandem lac operator repeats and visualized through the use of a fusion of the green fluorescent protein to the LacI repressor. We have discovered that origin regions abruptly move apart towards the cell poles during a brief interval of the cell cycle. This movement was also seen in the absence of cell wall growth and in the absence of the product of the parB homologue spo0J . The origin regions moved apart an average distance of 1.4 μm in an 11 min period of abrupt movement, representing an average velocity of 0.17 μm min⁻¹. and reaching a maximum velocity of greater than 0.27 μm min⁻¹. The terminus region also exhibited a striking pattern of movement but not as far or a rapid as the origin region. These results provide evidence for a mitotic-like motor that is responsible for segregation of the origin regions of the chromosomes.     

The contributions of Indigenous Peoples and local communities to ecological restoration

Indigenous Peoples and local communities (IPLC) are affected by global environmental change because they directly rely on their immediate environment for meeting basic livelihood needs. Therefore, safeguarding and restoring ecosystem resilience is critical to support their well‐being. Based on examples from the literature, we illustrate how IPLC participate in restoration activities maintaining traditional practices, restoring land degraded by outsiders, and joining outside groups seeking to restore ecosystems. Our review also provides examples of how Indigenous and Local Knowledge can be incorporated in the planning, execution, and monitoring of restoration activities. However, not all restoration initiatives engaging IPLC are beneficial or successful, and the factors that lead to success are not fully known. While local involvement in restoration projects is often mentioned as an element of success, this is primarily associated to projects that actively involve IPLC in codesigning restoration activities affecting their territories, ensure both short‐term direct benefits to IPLC and long‐term support of the maintenance of restored areas, and recognize IPLC local traditions and customary institutions. Based on these examples, we argue that IPLC should be a more important focus in any post‐2020 CBD agenda on restoration.