Cohesin Removal along the Chromosome Arms during the First Meiotic Division Depends on a NEK1-PP1γ-WAPL Axis in the Mouse

SummaryMammalian NIMA-like kinase-1 (NEK1) is a dual-specificity kinase highly expressed in mouse germ cells during prophase I of meiosis. Loss of NEK1 induces retention of cohesin on chromosomes at meiotic prophase I. Timely deposition and removal of cohesin is essential for accurate chromosome segregation. Two processes regulate cohesin removal: a non-proteolytic mechanism involving WAPL, sororin, and PDS5B and direct cleavage by separase. Here, we demonstrate a role for NEK1 in the regulation of WAPL loading during meiotic prophase I, via an interaction between NEK1 and PDS5B. This regulation of WAPL by NEK1-PDS5B is mediated by protein phosphatase 1 gamma (PP1γ), which both interacts with and is a phosphotarget of NEK1. Taken together, our results reveal that NEK1 phosphorylates PP1γ, leading to the dephosphorylation of WAPL, which, in turn, results in its retention on chromosome cores to promote loss of cohesion at the end of prophase I in mammals

Transitions In Spectral Statistics

We present long range statistical properties of a recently introduced unitary random matrix ensemble, whose short range correlations were found to describe a transition from Wigner to Poisson type as a function of a single parameter.Comment: 12 pp. late

Summation Formulas for the product of the q-Kummer Functions from Eq(2)E_q(2)

Using the representation of E_q(2) on the non-commutative space zz^*-qz^*z=\sigma; q0 summation formulas for the product of two, three and four q-Kummer functions are derived.Comment: Latex, 8 page

Functional Social Support Moderates Stress on Depression in Individuals with CID during the COVID-19 Pandemic: A Two-Wave Study.

Depression is a common psychological experience for those living with a chronic illness and disease (CID). Social support (SS) can influence psychological health by regulating emotional functioning. The functional domain of SS refers to supportive exchange, including the emotional and instrumental functions. Public health measures during the COVID-19 pandemic include social distancing and isolation, which have impacted functional aspects of SS. The health risks of being isolated are comparable to the risks linked to obesity, blood pressure, and cigarette smoking. PURPOSE: To investigate the moderating effect of functional SS on the stress-depression relationship on individuals with CID during the COVID-19 pandemic. METHODS: Two waves of data were collected from a US sample: Apr. ’20: N = 321; Jun. ’20: N = 238. Participants completed the Patient Health Questionnaire–9 (depression symptoms), the Medical Outcomes Study–Social Support Survey–8 (perceived social support), and the Perceived Stress Scale–10 (perceived stress). For each wave of data, social support was entered as a moderator of the stress-depression relationship via multiple regression. RESULTS: The moderation models were estimated separately by wave. In the first wave, there was a negative but nonsignificant moderating effect (b = -0.19, p = .10) of social support on the stress-depression relationship (R2 = 51). In the second wave, the moderating relationship of social support doubled in magnitude (b = -0.30, p = .03, R2 = .57). During the COVID pandemic, functional social support weakened the association between stress and depression. CONCLUSION: Given the increased risk for social isolation and negative social exchange among people with CID during the COVID-19 pandemic, practitioners in rehabilitation psychology need to be informed about the potential implications of a lack of SS for the psychological health of the CID clients they work with. Drawing from the stress-buffering model and Lazarus et al.’s stress and coping theory (Lazarus, 1966; Lazarus & Folkman, 1984), our findings indicate that increased levels of perceived support can reduce the effects of stress on depression during the pandemic by contributing to fewer negative appraisals. Interventions targeting the particular functions of emotional (e.g., opportunities for emotional expression and venting) and instrumental (e.g., material aid) support could have immediate implications for facilitating rehabilitation outcomes (e.g., quality of life, interpersonal functioning, psychiatric symptomatology) during this public health crisis

Strong asymptotics for Jacobi polynomials with varying nonstandard parameters

Strong asymptotics on the whole complex plane of a sequence of monic Jacobi polynomials $P_n^{(\alpha_n, \beta_n)}$ is studied, assuming that $$\lim_{n\to\infty} \frac{\alpha_n}{n}=A, \qquad \lim_{n\to\infty} \frac{\beta _n}{n}=B,$$ with $A$ and $B$ satisfying $A > -1$, $B>-1$, $A+B < -1$. The asymptotic analysis is based on the non-Hermitian orthogonality of these polynomials, and uses the Deift/Zhou steepest descent analysis for matrix Riemann-Hilbert problems. As a corollary, asymptotic zero behavior is derived. We show that in a generic case the zeros distribute on the set of critical trajectories $\Gamma$ of a certain quadratic differential according to the equilibrium measure on $\Gamma$ in an external field. However, when either $\alpha_n$, $\beta_n$ or $\alpha_n+\beta_n$ are geometrically close to $\Z$, part of the zeros accumulate along a different trajectory of the same quadratic differential.Comment: 31 pages, 12 figures. Some references added. To appear in Journal D'Analyse Mathematiqu

Coherent radiation from neutral molecules moving above a grating

We predict and study the quantum-electrodynamical effect of parametric self-induced excitation of a molecule moving above the dielectric or conducting medium with periodic grating. In this case the radiation reaction force modulates the molecular transition frequency which results in a parametric instability of dipole oscillations even from the level of quantum or thermal fluctuations. The present mechanism of instability of electrically neutral molecules is different from that of the well-known Smith-Purcell and transition radiation in which a moving charge and its oscillating image create an oscillating dipole. We show that parametrically excited molecular bunches can produce an easily detectable coherent radiation flux of up to a microwatt.Comment: 4 page

A BAC pooling strategy combined with PCR-based screenings in a large, highly repetitive genome enables integration of the maize genetic and physical maps

BACKGROUND: Molecular markers serve three important functions in physical map assembly. First, they provide anchor points to genetic maps facilitating functional genomic studies. Second, they reduce the overlap required for BAC contig assembly from 80 to 50 percent. Finally, they validate assemblies based solely on BAC fingerprints. We employed a six-dimensional BAC pooling strategy in combination with a high-throughput PCR-based screening method to anchor the maize genetic and physical maps. RESULTS: A total of 110,592 maize BAC clones (~ 6x haploid genome equivalents) were pooled into six different matrices, each containing 48 pools of BAC DNA. The quality of the BAC DNA pools and their utility for identifying BACs containing target genomic sequences was tested using 254 PCR-based STS markers. Five types of PCR-based STS markers were screened to assess potential uses for the BAC pools. An average of 4.68 BAC clones were identified per marker analyzed. These results were integrated with BAC fingerprint data generated by the Arizona Genomics Institute (AGI) and the Arizona Genomics Computational Laboratory (AGCoL) to assemble the BAC contigs using the FingerPrinted Contigs (FPC) software and contribute to the construction and anchoring of the physical map. A total of 234 markers (92.5%) anchored BAC contigs to their genetic map positions. The results can be viewed on the integrated map of maize [1,2]. CONCLUSION: This BAC pooling strategy is a rapid, cost effective method for genome assembly and anchoring. The requirement for six replicate positive amplifications makes this a robust method for use in large genomes with high amounts of repetitive DNA such as maize. This strategy can be used to physically map duplicate loci, provide order information for loci in a small genetic interval or with no genetic recombination, and loci with conflicting hybridization-based information